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median arcuate ligament syndrome opinion peripheral aneurysm techniques

Nonoperative management of median arcuate ligament syndrome (MALS)

The patient is a young woman who presented with classic symptoms and findings of median arcuate ligament syndrome (MALS). She avoided food because eating triggered severe pain in her upper abdomen. Over a year, this resulted in 15 pounds of weight loss. As a result, she no longer had the energy to work or exercise. She had an extensive gastrointestinal workup including blood work (LFT’s, amylase, cholesterol panel), abdominal CT scan, and upper endoscopy which were normal except for the finding of narrowing of the celiac axis due to compression by the median arcuate ligament. Examination was notable for upper abdominal pain exacerbated by pressure and seated, hunched-over posture. Unfortunately, due to her health insurance, surgery was not covered and she did not want any. So I recommended she try the following. 

  1. Eat standing up with good posture, shoulder back, back arched, taking deep breaths and holding once food passes
  2. Practice upward facing dog yoga pose (figure) 5 reps daily with deep inhalation breath holds. If this is difficult, do this standing up. 
  3. Improve the posture during seated work, never hunch over and pressed forward with “shrimp back,” periodically take a deep breath and hold with excellent posture. 
Upward facing dog yoga pose -shoulders square, outward collar bone tension, with deep inhalation breath holds

Over the past several years, I’ve noted that most patients respond to this, even in acute MALS pain situations (yes, there is acute MALS like slipped discs, for another post). That patient came back a few weeks later reporting that she was able to eat more food, more frequently. She also acknowledged compliance with the exercise and postural adjustments at work. A month later she reported regaining her lost weight and only mild pain with sitting in a car for a long time. She was still eating standing up, and she was grateful for having been treated without surgery.

From reference below, a mechanism for celiac plexus compression, injury, fibrosis, and development of neuropathy

We have postulated that MALS is a nerve compression syndrome of the celiac plexus by the median arcuate ligament (reference). There are two consequences to MALS, neither of which is mesenteric ischemia. The first is this compression of the celiac plexus with injury resulting in inflammation and fibrosis, resulting in further compression and a neuropathy of the celiac plexus. This neuropathy triggers aberrant pain sensations in response to eating. The other consequence is remodeling and injury due to arterial compression. The celiac axis can develop post-stenotic dilatation, growing large enough to be considered aneurysmal. The compression can damage the intima resulting in dissection. The artery can be injured and a pseudoaneurysm can develop. Finally, the aneurysmal segments may develop thrombosis and be the source of thromboembolism, usually to the spleen. Even when the celiac axis clots off, unless there has been resectional surgery such as a Whipple or splenectomy, the stomach gets enough collateral flow that ischemia is rare when celiac axis occlusion occurs. So similarly to  thoracic outlet syndrome (TOS), there is a neurogenic MALS and an arterial MALS. 

The first line of therapy in neurogenic TOS is physical therapy. With symptomatic MALS, I wondered if there could be physical therapy as well. This young woman and others I have managed nonoperatively suggests good response in some,  and partial response in most to exercises and maneuvers designed to address the compression.

Currently, in lieu of celiac plexus block, I have patients treat their MALS nonoperatively using the above protocol  for 2-4 weeks, typically while they undergo further workup to rule out more common gastrointestinal etiologies of their abdominal pain, and many have been able to improve their circumstances with these measures alone. This patient chose not to have operation as she was able to live symptom free and regain lost weight with these recommendations alone. 

Addendum

I received a comment from Ms. Suzanne Peek, president of the National MALS Foundation, who correctly pointed out not everyone presents in this way. I agree each patient undergoes a unique journey that is often marked by diagnostic delays because this is a rare condition. As I stated, not every patient responds to this regimen and after work up typically will undergo surgery to which in our published results 85% have a positive response to when diagnosed with MALS. Is certainly an area of further study to see if more people can respond to this non-operative approach. Our previous protocol which we instituted after the publication of our report was to use celiac plexus blockade as a diagnostic study and occasionally permanent blockade as therapy for those with prohibitive operative risk. A positive response to this regimen may signal a positive response to surgical celiac plexus ablation.

Reference

Weber JM, Boules M, Fong K, Abraham B, Bena J, El-Hayek K, Kroh M, Park WM. Median Arcuate Ligament Syndrome Is Not a Vascular Disease. Ann Vasc Surg. 2016 Jan;30:22-7. doi: 10.1016/j.avsg.2015.07.013. Epub 2015 Sep 10. PMID: 26365109.

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AAA Commentary common iliac artery aneurysm complications CTA EVAR innovation ruptured AAA techniques training

Lifelong surveillance after EVAR -is it worth it?

About ten years ago, I had a patient who came to see me for moderate carotid disease. While his carotid disease was asymptomatic, he also had metastatic colon cancer. With colectomy, cryoablation of liver mets, and chemotherapy, he was in remission. Every 6 to twelve months he had some kind of CT scan with contrast. His renal function was poor and this was blamed on his chemotherapy. While it had nothing to do with this patient, I thought to myself, “Having an aortic stent graft was a lot like having metastatic cancer in remission.” After a stent graft, the patient is forever tied to the health care system. Without surveillance, there may be an endoleak, sac expansion, rupture, and even death. Patients and vascular surgeons can make choices that lengthen life, improve its quality, and avoid the complications of disease. But what if a treatment becomes a condition and a burden on healthcare resources and the patient’s finances?

Fool me once…

Type Ib Endoleak Causing re-Rupture of a previous r-AAA after no surveillance

Take this patient who had previously ruptured his AAA and undergone EVAR. Several years out from his rupture, he ruptured again from a type Ib endoleak due to aneurysmal degeneration of his right common iliac artery. Per his family, he never followed up. Perhaps he assumed he was cured of his disease? Repairing this was tricky, primarily because I hopped up and down, thinking, “I could cure this!” An open revision with a bifurcated graft would eliminate the need for EVAR surveillance, avoid abdominal compartment syndrome, and the physiologic consequences of a large retroperitoneal hematoma. But who wants a laparotomy? Not this patient, who was hypovolemic shock, and whose family chose the minimally invasive option that everyone assumes is better.

Not a clamp

I took him to the hybrid operating room, balloon occluding to stabilize his blood pressure, embolizing the normal internal iliac artery and extending the stent graft into the external iliac artery.

Completion -there is an Amplatzer plug in the right internal iliac artery

This patient stabilized and had abdominal tightness due to his large hematoma which did not need evacuation. After a stay lengthened by concern for abdominal compartment syndrome, moderate pain, fevers, and bilirubinemia (due to the hematoma), he was discharged and never showed up for followup. None of the phone numbers work. Without followup, EVAR is a menace. We will keep trying.

Regrets, I’ve Had a Few…

The great feature of EVAR is that the complications up-front at the time of surgery are wonderfully low. This patient pictured above here presented in middle age with a rupture into the retroperitoneum. He was unconscious and had hemorrhagic shock.

The decision to perform EVAR was made late in the transfer because I did not have the images from the transferring hospital (another subject for another blog post) so I set up for both open repair and EVAR. En route to the OR, I scanned, slowly, through the CT images sent via CD-ROM, and my internal discussion went something like this.

He’s a 50-something smoker in shock with a contained rupture of a 8cm infrarenal AAA with a good neck. Let’s take care of this in 30 minutes with a percutaneous endovascular aneurysm repair (p-EVAR).”

He’s a 50-something smoker in shock with a contained rupture with a good neck -let’s take care of this in 90 minutes with a tube graft, open aortic repair (OAR).”

With p-EVAR, he’s going to have just two groin punctures and much lower complication rate, shorter length of stay, similar to lower mortality. Look -his blood pressure is 75mmHg systolic!

That hypotension is permissive to minimize bleeding. With OAR, he’ll avoid abdominal hypertension and complications of a giant hematoma. Because he’s young, he’ll avoid lifelong surveillance. If anyone can clamp this AAA, it’s me...”

Pride cometh before the fall. Get this man off the table and figure out the logistics later. p-EVAR. You open him up, he’ll exsanguinate and expire before you get the clamp on.

I sighed, looked up at the gathered team, and announced, “p-EVAR.” The percutaneous EVAR is something I’ve been doing since 2004, long before it was a big deal, and we were done under an hour. His blood pressure stabilized, but general surgery was consulted for his abdominal compartment syndrome. With sedation, fluids and time, his urine out put recovered but his belly remained distended and his bladder pressures which were never seriously elevated, trended down.

It was made known to me that the patient had very limited insurance making followup surveillance challenging. Due to his coverage, he had to have his imaging done at designated hospitals, so I wrote a detailed note -basically the timings of his followup CT scan, and asked that the reports should be sent to me. I ordered a CTA prior to discharge which showed a type II endoleak adjacent to the graft and connected to both lumbar and inferior mesenteric arteries (first image above). After some thinking, I took the patient for an aortogram, accessed the IMA via the SMA and coiled into his AAA sac and the IMA.

It was only a few weeks ago one of my colleagues across town contacted me that the patient had been admitted with abdominal pain, a CT showing a type II endoleak from his lumbars, but a smaller AAA sac than his pre-repair size of 8.5cm. The patient is seeking to repatriate, and I doubt he would be able to get adequate followup in his home country without paying in cash. Happy that the patient survived his rupture, I still have persistent regrets at not getting him through an open repair, which I am sure he would have done fine with… Or maybe not.

Je Ne Regret Rien…

Recently I admitted a patient, in his 70’s, with a symptomatic 6.5cm infrarenal AAA with bilateral common iliac artery aneurysms, the right being 25mm, the left over 30mm. Because of the pandemic, he was stuck here, seeking to repatriate. Over ten years before, he had a segment of descending thoracic aorta repaired for a traumatic tear -probably one of the last before the wide adoption of thoracic stent grafts which work great by the way.

Cardiac risk evaluation revealed an ejection fraction of 35% with reversible ischemia on nuclear stress test. CTA of the coronaries revealed triple vessel coronary artery disease corroborated by catheterization. Off-pump CABG was planned which would eliminate the effects of cardiopulmonary bypass.

Preparations were made for EVAR with IBE of the left iliac aneurysm as a contingency, but there was no question that if the patient recovered well from his CABG, he would undergo open repair. This was because bell-bottoming or IBE must have regular coordinated surveillance which was not going to be easy with the patient leaving for another country in the middle of a pandemic. It is difficult to get followup to happen in normal circumstances (see above cases). I expressed my opinion to the patient and family and we agreed to see how the patient responded to off-pump CABG.

He underwent off-pump CABG with three vessels revascularized. He was extubated POD#1 and mobilized. By POD #4, he was on a regular patient floor, being co-managed by hospital medicine who takes care of all of our patients. The patient expressed readiness for the next operation. His kidney function remained normal. He was transfused 2 units of PRBC to bring his hematocrit to 30%. He was taken off Plavix, but kept on aspirin. On POD#6, he was taken back to the operating room for open aortic bypass. This would not have been possible without close coordination of cardiology, cardiac surgery, and vascular surgery. Choosing off-pump CABG was a critical element in being able to proceed with open aortic surgery.

Right branch taken to iliac bifurcation, separate bypasses sent to left internal and external iliac bypasses.

I do several things to decrease the physiologic impact of the operation. First is keeping all the viscera retracted under the skin. This simple move has the effect of decreasing the rate of intestinal paralysis and amount of fluid shifts that occur postop, akin to going retroperitoneal. This decreases the space you potentially have if you use standard clamps, but I use the Cherry Supraceliac clamp (image), DeBakey Sidewinder (transverse), or just a Satinsky clamp oriented transversely. This minimizes the occupation of volume over the anastomosis which always happens with standard aortic cross clamps. The anastomosis is easier without the clamp taking up valuable space.

Cherry Supraceliac Aortic Clamp

The iliacs are always clamped with Wylie Hypogastric clamps, again, with the principle of eliminating clamp overhang. Suturing is done with 4-0 Prolene on SH needles -this is plenty (link). The proximal anastomosis wants to bleed, and sewing to a fully cut ring of aorta ensures good posterior bites but also allows for sliding a band of graft down over the anastomosis (Dan Clair calls this a gusset) which works well at creating a hemostatic proximal anastomosis rapidly-trust me, getting this done well is the key step of the operation. Before closing, I infiltrate the rectus sheath and preperitoneum bilaterally with local anesthesia -lidocaine 1% with epinephrine 1:1 with bupivicaine 0.5%. The skin is closed with absorbable dermal sutures because staples create as many problems as they solve. The patient had cell salvage through the case and no extra units of transfused blood.

The patient was extubated that night and started on clear liquid diet. The next day his lines were removed and he was moved to the floor and started on regular diet when he expressed hunger. On POD#2, he was pacing floor, asking when he could be discharged.

Sternotomy and Laparotomy POD#2, walking the floor

As he was eating, walking, talking, breathing, evacuating bowel and urine, and pain free (well controlled), I saw no reason to keep him beyond POD #3 AAA/#9 CABG. I have kept in touch with him and his family and he is doing well and has given permission for this posting.

Satisfaction

This final case has confirmed several of my beliefs. First, calling something high risk can drive one to make bad choices and in fact endanger patients. This last patient would qualify as high risk on any international criteria, and you would not be wrong in quoting upwards of 30% major morbidity and mortality for cardiac revascularization and AAA repair, but you would also be tying your hands from offering the best solution for this man who fortunately was able to undergo two prodigious operations. He will not require much in the way of followup. Coronary revascularization with arterial conduit and open aortic grafting frees him from the need for close followup and reassures us that his repair is durable.

Second, calling something advanced and minimally invasive gives one cachet in the marketplace but forgoes careful discussion and consideration of what is being abandoned. The first two patients survived their ruptures but now face the consequences of having stent grafts. It is a shame when podium speakers at international symposia declare surgery to represent failure because this affects training by encouraging abandonment of hard to acquire skills. It seeps into patient perceptions and expectations. I hope that a balanced approach prevails. You have to be capable of both open and endovascular approaches to be able to offer the best treatment for a particular patient.

Finally, these old operations are cost efficient and there is a lot of room to improve these procedures with new perspectives, techniques, and data. I don’t operate the same way I trained, and it is only through continued application of operations that improvements can come about. As budgets tighten and economies are stressed, cost efficacy will rein in much of the interest and demand in new stuff unless it adds value. That said, I am grateful to our stent graft representatives who have worked to get us bell bottoms and IBE’s for when they will be needed. These grafts will be used when the time is right.

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iliocaval venous ivc ivc filter techniques ultrasound Venous venous intervention vte

Leave Nothing Behind -IVC filter edition

Why There is a Literature on Filter Removal

A long time ago, there was the IVC clip which survives today as a vestigial CPT code. Then in the 1980’s, the Greenfield filter was introduced and changed the management of thromboembolism (reference). The explosive adoption of endovascular technology in the late nineties and early 2000’s drove the growth in implantation of newer generations of IVC filters that were designed to be retrievable. The people requesting the filters -the physicians, surgeons, and even patients looking to stop taking anticoagulation, were basing their decision on common sense –“sometimes, people are vulnerable to pulmonary embolism and are at risk of hemorrhage with anticoagulation, so an IVC filter makes sense.” There was frankly a data gap -a breach into which multiple companies jumped in with their own flavor of filter. Many interventionists saw no need to be selective -these were easy to place, and easy to remove, and if they stayed in there was the excellent long term results of the Greenfield filter to cite, and their referring docs asked for it. There was also the high revenue density (revenue/time) that gave filters a gravitational pull. There were several problems with this endo-enthusiasm (like in so many other cases). In the absence of data and with the aggressive marketing, too many filters went in for weak indications. We now know that most of these filters do not behave like the Greenfield, which itself is not completely innocent. Unless followup is part of a process, many patients neglected to have their filters removed. And finally, the data caught up and failed several filters which are no longer on the market and the indication for these filters is now quite narrow.

In 2009, I was asked to consult on a young man who was hospitalized for upper GI bleeding. The EGD revealed the tines of an IVC filter poking through (the jpg is somewhere I swear). The prior year, he had been in a bad car accident and had a filter placed but never had it removed. The filter had migrated out of the IVC into the duodenum and into the spine and aorta. I removed it operatively, and that was the beginning of a series of cases, about 1-2 annually in my general vascular practice, of filters that had eroded through the IVC and was causing symptoms of bleeding or pain. The pain typically was associated with a tine touching on or eroding into the spine. Biomechanically, the IVC is a collapsible tube and all the viscera on top of it weighs about as much as an equivalent sack of uncooked chitterlings when recumbent and grinds on the filter and any sharp parts. Imagine unbending a paperclip (figure) and putting it in the belly. Over time, that clip will poke a hole in something. Why would we not expect an IVC filter to behave otherwise?

An Iliocaval Thrombosis Below a TrapEase Filter

The patient is a younger man who over a decade ago had a TrapEase permanent IVC filter placed when he had a pulmonary embolism while having multiorgan failure. He was on coumadin briefly, but in the 17 years since filter placement, never had another venous thromboembolic event, but did develop venous insufficiency and varicose veins that were successfully treated. Several days prior to admission, he had been working out and developed back pain. After trying to sleep it off, he woke with severely swollen and painful legs. On admission, he was found to have no lower extremity DVTs, but had slow flow suggesting central occlusion. An abdominal x-ray showed the TrapEase filter (image below).

CT scanning and MRV showed the occlusion of the patient’s iliac veins and erosion of the struts of the filter outside the IVC (axial images below).  

On heparin infusion and bedrest, his swelling improved and we had a chance to go over our treatment options. They included

  1. Catheter directed thrombolysis
  2. Angiojet thrombectomy
  3. Large sheath thrombectomy (link)

with one of the following

  1. Surgical resection of filter
  2. Endovascular retrieval of filter
  3. Balloon venoplasty and stent exclusion of the filter (link)

Catheter directed thrombolysis of such a large volume of clot in the absence of a good flow channel usually necessitates multiple days of thrombolysis with return for venography and adjustment, with a small but not zero chance of fatal or disabling hemorrhage. It is expensive -multiple ICU days, return trips to the OR angiosuite. Angiojet thrombectomy is useful for clearing smaller vessels and grafts but due to the pulsing of the jet, it has a good chance at creating pulmonary emboli if the filter’s occlusion is not complete. Plus it is expensive and limited by the volume of fluid necessary to create the suction. Large sheath thrombectomy has worked for me in the past (link), but I worry about leaving behind thrombus that would embolize when the filter is removed or pushed aside.

Endovascular removal of the filter is always an option -I have removed a Greenfield filter over two decades in. I have never been able to remove an OptEase or TrapEase filter -there is nothing easy about these. I have a picture somewhere sent to me by a trainee who was consulted on a patient whose IVC was transected during the attempt to remove one of these endovascularly. That said, both my partners Houssam Younes here in Cleveland Clinic Abu Dhabi and Christopher Smolock at Cleveland Clinic Main Campus suggested trying with a two-team approach with a 16F sheath and wire from above and a 12F sheath and wire from below. That would be contingent on being able to clear the thrombus adequately.

Surgery to remove the filter is something I am comfortable with. It sometimes is the only option (link). Several times a year, I scrub in with urologists and oncologic surgeons to remove tumor from the retroperitoneum or IVC and the exposure is straightforward. When I only need control of the IVC, I make a transverse incision slightly above the umbilicus and mobilize the retroperitoneum leaving the kidney down to expose the IVC. For the IVC and iliacs, a midline laparotomy with a Cattell maneuver allows for broad control. Surgical thrombectomy would be great if the thrombus was all fresh, but challenging if there were differing amounts of fresh and chronic occlusion. The CT scan, showing the iliac veins and IVC to be swole with clot, suggesting most of it was fresh. Neither CT nor MRV could tell me if the IVC below the renal confluence was occluded. I had to be certain.

I went over these issues in detail with the patient and we agreed to proceed with diagnostic venography to check out the clot. The verbiage of clot, tofu, and cheese (link) worked well in communicating the information needed to achieve our goal of getting the filter out and the IVC and iliac veins cleared of thrombus. I sent a hypercoagulability study (even on heparin, the genetic component is useful information) which returned negative.

The diagnostic venogram is much more than just the pictures. For me, so much information is transmitted from the tip of a Glidewire as it passes through an obstruction or clot. Venography (image below) showed the thrombus but more importantly, the wire passed effortlessly in either side, got caught up in the bottom of the filter, but I was able to get through and the 5cm of IVC below the renal confluence turned out to be patent. The wire looped easily on both sides to the full extant of the dilated vein suggesting no chronic component.

I recommended surgery in our hybrid angiography suite. It would avoid multiple days of thrombolysis and its attendant risks. It would avoid subtotal clearance of thrombus. It would avoid failed filter retrieval and bailing out by stenting the filter (link), something acceptable in an older higher risk patient but not in an active young man. It would avoid surgery after several days of failed thrombolysis. The ability to perform venography and sonography with a clamp on the IVC ensured the ability to fully clear clot. And we had cell saver. After laying out my thoughts and concerns, the patient agreed.

The patient was opened via a generous midline laparotomy. I recruited the assistance of my friend Waleed Hassen, master urologic surgeon here at CCAD, in exposing the IVC. The vessel loop in the picture (below) is around the ureter. Green arrows on the right image show the anterior struts (there are three posterior struts). I had just assisted Waleed recently in removing a metastatic testicular tumor off the IVC, aorta, and mesenteric arteries through the same exposure.

The surprising finding was the anterior hooks of the TrapEase filter had penetrated the serosa of the overlying duodenum. While not perforating, it eventually would have, as the struts had eroded through the wall of the IVC and were outside the adventitial. After heparinizing the patient, the cava was clamped above the filter and I opened the cava lontitudinally along the anterior most strut. I got the sternal wirecutters and removed the anterior three struts along with their hooks. There were large draining lumbar veins which were acting as collaterals that were ligated. The filter was removed internally in pieces leaving the posterior three struts behind as they were outside the IVC lumen. The lower cone can be seen with tissue ingrowth and chronic thrombus. It was dangerous and bloody behind the IVC and I chose to leave these struts behind as they would no longer be pressing into the spine with the filter mostly out. (image below).

The initial thrombectomy was done manually by massaging the vein from either side and up the cava -the thrombus (image below) in the basin on the left expelled as a unit with a spout of blood. Thrombectomy with a #5 Fogarty proved ineffective in the large vessel, and I resorted to using a Foley catheter, directing it left and right, with removal of some more thrombus.

Duplex demonstrated clearance of thrombus from the right iliac vein but adherent thrombus on the left. I placed an 18F sheath into the left femoral vein over a wire I had directed up and over into the right iliac system and advanced the sheath while suctioning -this collapsed the vein and allowed the sheath to scrape the walls of the vein, retrieving the final clot material in the right basin. Duplex confirmed the absence of clot in the left iliac vein. The venotomy was then closed primarily and a completion venogram was performed (below).

The patient recovered and was sent home after a duplex confirmed patency of his leg and iliac veins and IVC. He will be on 3 months of a NOAC for provoked DVT.

Discussion:

Most of these filters can be retrieved with endovascular techniques. The principle is of gaining control of the top of the cone and collapsing it like an umbrella. For the Cordis TrapEase and OptEase filters, both cones have to be collapsed, and the struts which will have grown into the walls of the IVC have to be be stripped away from the IVC. I had attempted removal of an OptEase with control from above when I was in Ohio, but like in this case, the filter had tissue ingrowth on the lower cone making looping and control of the filter difficult as the hook was encased. While I was able to collapse the filter into a 16F sheath supported through an 18F sheath, it was clear the IVC was invaginating into the sheath and with enough force, I would tear the IVC. It is not the worst thing, perforating the IVC, as it is a low pressure system, and a small perforation is tolerated, but a large one needs operative repair. This can be avoided with surgical removal of the filter.

Performing this in the hybrid suite allowed for complete clearance of thrombus. That said, the thrombus in the internal iliac veins likely did not come out, nor did I seek to clear them. Rather, I will rely on systemic anticoagulation to do this for me.

I use duplex sonography intraoperatively liberally during my procedures. During EVAR, transabdominal ultrasound is sufficient in ruling out or specifying endoleaks. During complex kidney transplantation which I sometimes participate in, duplex is a critical tool for evaluating flow. In this case, images showing a cleared vein (will post, currently stuck in portable ultrasound memory) assured me that I could open the clamps with confidence that pulmonary embolism could be avoided. Gratifyingly, the patient had immediate reduction of leg swelling and can be expected to avoid problems as nothing (such as stents) was left behind in the vena cava lumen.

References

  1. J-P Galanaud, J-P LarocheM Righini. J Thromb Haemost 2013;11(3):402-11. doi: 10.1111/jth.12127.
Categories
bypass CTA EVAR open aneurysm surgery taaa tbad techniques TEVAR thoracabdominal aortic aneurysm type b aortic dissection

Debranch First! or Why Haven’t We Done This All Along for Thoracoabdominal Aortic Aneurysms?

figure 1

Context

Despite all the advances in endovascular repair of thoracoabdominal aortic aneurysms, no data shows their superiority in the mid to long term compared to open repair. That is why branched stent graft programs occur hand-in-hand with robust open surgical programs, to offer durable open solutions to younger healthier patients while mitigating risk in older sicker patients by going with a branched or fenestrated device. Despite these advances, clamp time and visceral ischemia persists as a challenge to safe performance of open thoracoabdominal aortic surgery. Even a straightforward group IV requires the surgeon to be swift. Time on an thoracic aortic clamp results in visceral ischemia with a predictable response of coagulopathy, acidosis, systemic inflammation, and renal insufficiency. Adding cardiopulmonary bypass mitigates some things (distal ischemia, normothermia, hypertension) but brings on other complexities (cannulation, circuitry, coagulopathy). Sewing to a Carrel patch allows one to perform one large anastomosis rather than four individual ones, gaining speed and time, but compromises by leaving aneurysmal tissue which could progress to a troublesome patch aneurysm. TAAA is a condition that demands referral to high volume centers. It is in high volume centers that these apex predator surgical conditions can be subdued. It is in these centers that branched/fenestrated stent graft programs can offer treatment for patients high risk for open repair. It is in these centers that patients can avoid compromises such as snorkels and chimneys. Unfortunately, these centers are long air flights away and the means of the patients may not match the desires. Out here in Abu Dhabi, half a world away from Cleveland, Rochester, Houston, Boston, Chapel Hill, New York, and Seattle, and over six hours from major centers in Europe, we usually have to find our own way. Thankfully, we have the resources in experienced staff and abundant materiel.

During my time at the main campus of Cleveland Clinic, I came to appreciate the hospital as a highly evolved tool for healing, but for open repair of TAAA, it still falls on the operating surgeon and the choices made that shaped the outcome. In this most invasive of operations, simplicity and efficiency translating to speed offers the only consistent path to success. My partner, Dr. Houssam Younes, who trained in Houston, mentioned that Dr. Joseph Coselli, has clamp times approaching 30 minutes for group II TAAA -an almost inhuman speed achieved by doing these cases every day. For this reason, stent grafts are popular because repair of aortic aneurysms can be achieved by more practitioners in widely distributed settings. Because of the marketing of all things minimally being better, patients come asking for endovascular.

Case

The patient is a fifty-something smoker who had a prior type B aortic dissection nearly a decade past who presented with substernal chest pain radiating to the back. He was found on CTA (figure below) to have a 6.5cm extant V TAAA starting above the diaphragm and ending at the level of the renal arteries.

figure 1

Closer inspection revealed it to be aneurysmal degeneration of the aorta at a large false lumen fenestration. The aneurysm had grown eccentrically into the patient’s right chest and retroperitoneum. The remaining dissection above to the left subclavian artery and to the aortic bifurcation was chronic and thrombosed. His pain waxed and waned with hypertension which initially had to be controlled with parenteral agents. His cardiac workup revealed normal ejection fraction and valve function, and no critical coronary artery disease on coronary CTA. Pulmonary consultation deemed him a low pulmonary risk for major surgery. I offered him open repair, and initially the patient balked, asking for an endovascular repair, but I carefully walked him through the concepts, principles, and data guiding my recommendation. Yes, in a rupture, I have stented and followed with visceral debranching (link) and we have placed multiple snorkels in a very high risk octogenarian with a rupture, but who would offer endovascular repair to an otherwise good risk 50 year old?

The operation was initially planned in the standard way with cell salvage, plan for clamping in the transition point where the descending thoracic aorta took a rightward turn. The sequence of operation was for proximal anastomosis, right renal anastomosis, cooling the left kidney, celiac axis (CA), superior mesenteric artery (SMA), left kidney, and finally distal anastomosis with reimplantation of any prominent intercostal vessels. Preop imaging suggested the one at the T12 level was large. CT surgery was asked to be available for cardiopulmonary bypass via left atrium and femoral vein. Cardiac anesthesia and I had a discussion about intraoperative monitoring and management. Plans were made for CSF drainage -despite recent papers suggesting as much harm as benefit from these drains, I still feel critical time is lost if the patient is ventilated for a prolonged period postop and motor evoked potential monitoring is not available. The culture of CCAD mirrors that of Cleveland Clinic’s main campus in Ohio, and collaboration is ingrained. It was also serendipitous that one of the clinical associates, Dr. Niranjan Hiremath, had a particular interest and training in aortic surgery and suggested something amazing.

The Game is Changed

Dr. Hiremath trained in both vascular surgery and cardiothoracic surgery in Melbourne under Dr. Matalanis. Drs. Matalanis and Ch’ng published a series of 5 patients done with a separate branched bypass to the visceral vessels fed from the cardiopulmonary bypass circuit (reference). A separate aortic bypass was then performed and this truncal visceral graft was anastomosed to the main aortic graft. It was a visceral branch application of what is commonly done for the aortic arch great vessels. It was clear to me that this concept eliminated the need for desperate speed, and minimized clamp time to the 5-15 minutes required for each visceral branch anastomosis. A game changer.

My process for incorporating new concepts to an operation requires comfort and familiarity. The familiarity with this modification had everything to do with my extensive use of shunts during peripheral bypass surgery. Placing the shunt into one of the renal branches of a 4 branch Coselli graft turns this graft into a live blood vessel. By fixing the proximal and distal ends of the graft in the correct orientation and position relative to the branches, each of the visceral branches could be anastomosed to the graft one at a time while the patient’s aorta remained unclamped. This is best described with the sketches I put together for the preop huddle (gif and figure below).

figure 2 animated

Figure 2

Even though I have done many of these operations, because of the smaller population at risk, thoracoabdominal aortic aneurysms are a relatively low frequency disease and no assumptions can be made. The fact was, it took very little convincing for me to understand this concept as a game changer, but I took the liberty of modifying it for the particular situation of the patient. Every operation is ultimately another quantum of experience for the people involved to take away priceless information for the next one which will always be unique. We must take these as opportunities for improvement. For once in a long time, I felt this would be a big improvement.

Day of Surgery

Our operations always start with a huddle, but this one was different because of the numbers of people involved. There were the cardiac anesthesiologists, some of the best I have ever worked with in my career led by Dr. Dominique Prudhomme. The cardiac surgeons, Dr. Tareq Aleneiti and Hiremath, who planted this idea, along with the perfusion team, cardiovascular nursing team, and my partner Dr. Younes walked through the steps of the operation with me, with bailout points and plans B and C (CPB with hypothermia and circulatory arrest as a last resort for any unforeseen uncontrollable bleeding). I felt like I was the ringleader in a heist movie, only in this case, rather than jewels, we were grabbing something actually priceless (figure 3).

figure 3

The patient was placed in the right lateral decubitus position across the table break in the golf backswing position with pelvis relatively flat to the shoulders which were upright. The incision extended from the top of the sixth rib into the abdomen. This dissection is really two -the thoracotomy and separation of the peritoneum from the retroperitoneum linked by the takedown of the diaphragm and cutting of the costal margin. It is a tactile portion of the operation -only the hands really understand when to pull down and separate the two layers. The celiac and SMA are entangled in myenteric plexus which had to be cut to exposure sewable lengths of both. The left renal artery was also tricky in that the prior inflammation of the dissection resulted in stickiness of the tissues. It goes quickly and we have this exposure (figure 4).

Figure 4

Heparinized

The patient is heparinized with a goal ACT around 250. Not enough for CPB, but good enough for rock and roll. The cardiac surgeons placed a cannula within a double ring of advential sutures, cinched with Rummel tourniquets and secured with an 0 silk tie -a maneuver I did many times myself during my cardiac rotations in residency. This was placed on a Y connector, one branch going to the CPB pump in case of a need to go to plan C, and the other to a tubing connector inserted into the right renal artery branch of the Coselli graft -a slight modification of the original plan (figure 5).

figure 5

The other branches were simply clamped and the aortic ends of the graft were rolled up with a straight Kelly and secondarily clamped with aortic clamps -this gave weight to the ends letting them be positioned in a way that kept the branches oriented properly. There is need for precision and prediction as everything rotates back 45-90 degrees and the viscera sit on the grafts and the anastomoses. That is why keeping some length is crucial -this length accommodates this rotation. The Coselli graft is opened to systemic pressure by releasing the shunt. The proximal and distal ends of the main graft are twisted and double clamped to position the graft branches in the correct radial and z-axis orientation.

The aortic and branch exposure with takedown of the diaphragm is a standard exposure. One technical difference for this procedure is the need to expose about 2cm of the CA and SMA. Typically, only enough to clamp the vessel is necessary in standard surgery as these vessels are prepared with aortic buttons or anastomosed as an island patch. These vessels are surrounded by myenteric nerve plexus which feels like fascia or scar tissue but can be divide. Use of a hook cautery typically used in laparoscopic surgery along with a Ligasure speeds dissection.

These arteries, starting with the left renal artery, are ligated at the origin and divided for end to end anastomoses to the Coselli graft branches. As these arteries are only briefly clamped for the anastomosis while the remainder are getting flow from the aorta or the shunted Coselli graft, visceral ischemia is minimized. I still chilled the kidneys with manual injections of cold Ringer’s Lactate via large syringes and Stoney injector tips. The final product is shown on figure 6.

figure 6

The operation no longer felt like a sprint. The atmosphere was lively and relaxed -something that does not happen in these cases even at closing as exhausted residents or fellows focus on stitching together all the separated layers of the patient’s chest and abdomen. I played a soundtrack of classic Bollywood tracks, alternating between mellow and lively.

What was striking was the absence of the need for blood transfusion -about a liter and half ended up in the cell saver, and the patient received 2 units of plasma, out of tradition. The patient had a minimal brief plasma lactate elevation which did not persist. He was closed with a chest tube and brought to the cardiac intensive care unit, stable, not on pressors. He was extubated that night, and moved all of his limbs to command. The chest tube was removed on POD#2, and he left the unit to recuperate on the floor. Amazingly, his serum creatinine did not rise significantly. Prior to clamping he received the usual cocktail of mannitol but it was likely unnecessary. Most of these patients, even with revascularizing first after the proximal aortic anastomosis in the fastest of hands, there is at least 30 minutes of ischemia manifest postoperatively as a rise in the creatinine with recovery in most. This rise was brief and transient (graph).

GRAPH

In the visceral circulation, the ischemia in the normal open repair is manifest postoperatively as systemic inflammation requiring pressors, persistent lactic acidosis, and coagulopathy, which at best is transient but at worst, fatal. This patient had no significant shift in any of these parameters. He had his CSF drain removed POD#2 after clamping for 24 hours, and was discharged home POD#11, having to recover from right chest atelectasis and a blood patch placed for persistent headache. CTA prior to discharge showed a good result. The left renal graft had been on stretch but was rendered redundant on repositioning of the viscera. No stenoses were noted.

figure 7

Aftermath

Of course we are writing this case up, but case reports by their form cannot be overly enthusiastic whereas on my personal blog I can be excited. The normal course of postoperative recovery, the ebb and flow taught in surgical critical care books, is a result of ischemia, blood loss and replacement, fluid resuscitation, and cardiopulmonary support. Add to that cardiopulmonary bypass and you get an additional hurdle for the patient to recover from. This technique of shunting reminds me most of the temporary axillofemoral bypass. When I was a fellow at Mayo, I assisted Audra Noel in taking an elderly patient with a 25% ejection fraction through open aortic surgery with nearly miraculous recovery largely by avoiding the factors that trigger the ebb and flow. This technique is easier but mandates a strong normal segment of thoracic aorta to serve as inflow, otherwise an axillary artery will need to be cannulated.

Spinal cord protection is made easier with this technique by avoiding the massive fluid shifts, the pressors, and the acidosis in a typical thoracoabdominal aortic aneurysm repair. The blood pressure and cardiac output were never seriously perturbed. Several large intercostals and lumbar arteries were encountered and they backbled so avidly, after the short operation that I really felt there was no need to revascularize them. The spinal drain was kept open only for a day, and kept another day clamped to ensure that it would not be needed before removing it.

If you accept that spinal cord ischemia is multifactorial, we had avoided those factors. The absence of massive blood loss, negligible pressor use, no fluid shifts, minimal ischemia, no significant acidosis, no prolonged OR and clamp times, no blood transfusions, and the presence of avid back bleeding suggesting strong collateralization, compelled me to end the operation without revascularizing these intercostal vessels.

The patient recuperated for an ten days after his operation but was walking from postoperative day #1. He had atelectasis due to mucus plugging in his right lung base and was treated for aspiration, but clinically did not have a pneumonia and his atelectasis cleared with chest physiotherapy and nebulizers and was discharged home. Gratefully, he has given us permission to discuss and study his case.

There is no success in these cases without a team, and we are blessed with talented caregivers. This technique greatly reduces the physiologic impact of this surgery on the patient, reducing the injury to the equivalent of a broad sword cut from chest to abdomen that missed all the vital organs and vessels. In the right hands, this concept will broaden the appeal of open repair of these challenging aneurysms.

Reference

Matalanis G, Ch’ng SL. Semin Thoracic Surg 31:8:708-12.

Categories
acute mesenteric ischemia chronic mesenteric ischemia complications CTA hybrid technique imaging techniques Technology visceral malperfusion

Abdominal Stroke Alert!

It is a rare day that passes without the announcement of a stroke alert at CCAD. A reflex arc of activity is initiated, as time becomes the critical metric of success. Patients with strokes have a limited window of time to reverse the effects of the arterial occlusion, and the whole hospital is organized around getting the patient into the angiographic suite to open up blood vessels. If you watch it happen, it is the pinnacle of modern medicine, to achieve what only a decade ago was deemed unachievable. It was built around a foundation laid by cardiologists for heart attacks -the STEMI alert. The teams practice like racing pit crews with a stopwatch to get a patient from the emergency room, to CT scan, to angio suite. A long time ago, as a young surgeon, I had to work hard to get institutional support of ruptured AAA and cold legs. Vascular surgery has traditionally struggled to get recognition for its patients, their diseases, and its work, which is nothing less than the most important safety net for any large general multi-specialty hospital, critical infrastructure like oxygen plumbing and backup generators. As I transition to that weird designation of mid-career surgeon (please don’t call me a senior surgeon), I have also appreciated that Steve Jobs aphorism about good artists copying, great artists stealing. It’s only stealing if you don’t give credit. Here is what I borrowed from the neurologists.

Acute mesenteric ischemia is an abdominal stroke. Use it in your conversations with other people as you speed your patients way into the angio suite. The reflex arc is in there. For the emergency department, the operating room, and all the physicians, acute mesenteric ischemia sounds like tummy trouble, but abdominal stroke brings sudden clarity to conversations like:

“Well, you’re in line behind a gallbladder and a cystoscopy. Is the patient NPO?”

Me: “It’s an abdominal stroke. We literally only have a few hours before the patient dies…”

“I’ll bring the backup team in!”

The patient is a middle aged man with risk factors of NIDDM and prior history of DVT who developed severe mid-abdominal pain at 5pm. He came to the ED at around 11pm and had a general surgery consultation who ordered a CT Angiogram showing SMA occlusion (pictured below).

Acute Mesenteric Ischemia case presentation

Acute Mesenteric Ischemia case presentation (1)
Heparin was started, and at 11:30, vascular surgery was consulted. The patient had a soft, doughy texture to his abdomen, but great pain with palpation -classic pain out of proportion to the exam. Determining the patient to have acute mesenteric ischemia from a thromboembolism, I took the patient to our hybrid angiographic OR suite with the plan for arteriography, possible open thrombectomy, and exploratory laparotomy.
Arteriography from femoral access showed an occlusion of the SMA beyond the middle colic artery, a typical pattern for an embolism that occurs when embolism lodges distally and propogates proximally (image below).

Acute Mesenteric Ischemia case presentation (2)
I got Glidewire access into the ileocolic terminus of the SMA, exchanged for a Rosen wire, over which I placed an 8F sheath into the proximal SMA. This was a rather large sheath meant to catch thrombus as I suctioned it out with a 6F Penumbra catheter. This is another technique I borrowed from the neurointerventionalists. Whenever a stroke alert is going on, curiosity drives me to peak in and see what marvelous gadget or gewgaw they are using, and I was impressed by how efficiently the neurointerventionalists were able to get to the smallest thrombus in the furthest branch vessels. I was prepped for open thrombectomy, consented for bypass if necessary, but having experience in suctioning clot through single catheters and sheaths, I thought the simple design of the Penumbra and its efficacy in the cerebral system could easily translate into the mesenteric.The problem with open thrombectomy is the inability to see if you have cleared thrombus from all the branches unless you do an arteriogram after you’ve completed your procedure. This may be a significant contributor to the 20-30% bowel resection rate that occurs on second look laparotomy in my old paper and in the literature since its publication.

The Penumbra was effective in removing much of the fresh thrombus, but I was also cognizant of the fact that pulling out the catheter will draw clot into the 8F sheath that did not make it into the catheter. I placed a wire, and removed the sheath to expel much of the bulky thrombus (picture below).

Acute Mesenteric Ischemia case presentation (3)

The completion angiogram (below) doesn’t show the intermediate angiograms showing thrombus that embolized to other arteries as I manipulated the catheters and thrombectomized -I was able to successfully retrieve these with selective catheterization, another neurointerventional series of maneuvers that I have successfully borrowed.

Acute Mesenteric Ischemia case presentation (4)
After being satisfied with the completion, I removed the sheaths and explored the abdomen finding this segment of infarcted small bowel (next image).

Acute Mesenteric Ischemia case presentation (6)
There was no question in my mind that there would be some dead bowel based on the time course described by the patient. Despite my excitement about calling for GIA staplers -I am general surgery boarded- I called in the general surgeons for their help in resecting and anastomosing this segment of bowel. They would be the ones taking the patient back for any second look laparotomy, although in this patient, I determined that there would likely be no need. After the anastomosis was completed, I did a Wood’s Lamp examination (pictured), which is accomplished with a black light after giving the patient an ampule or two of Fluorescein.

Acute Mesenteric Ischemia case presentation (7)
The bowel had a splotchy fluorescence pattern which is typical of ischemia-reperfusion. This is where you have to ask the anesthesiologist and any critical care specialist who follows -no pressors please! Edema won’t kill an anastomosis as badly as ischemia will, and the gut is as sensitive to norepinephrine as are the toes. Workup in the hospital including echocardiography and CTA of the entire aorta failed to reveal a proximal source or cardiac shunts or thrombus. The patient recovered and has recently followed up, eating well, and tolerating his anticoagulation which he will be on for life.
I sent out the pictures to my neurointerventional friends with some glee, but also with the purpose of informing them that in the case that the vascular surgeons become incapacitated or quarantined due to the COVID-19 pandemic, their skills would be recruited in the care of an abdominal stroke -a blood vessel is a blood vessel.
Acute mesenteric ischemia should be the first thing on everyone’s differential of sudden onset abdominal pain because of its time dependence, yet it does not have the same resonance to the unfamiliar as abdominal stroke. Survival is dismal when too much time and intestinal death has occurred. When associated with the stroke alert concept, it translates into processes already in place throughout the hospital and it becomes natural for everyone to appreciate the urgency of treating abdominal stroke. This is the system adopted by Roussel et al. in France, where they have regionalized care of intestinal stroke. They report mortality rate of 6.9%, which is in a selected population, but significantly lower than the traditionally reported 30-60% mortality.

I am still an advocate of an open approach, especially when angiographic resources are unavailable, and every trainee needs to be able to describe the exposure of the SMA, and management of acute mesenteric ischemia. Hopefully, everyone will appreciate the urgency of all the various ischemic conditions manifest in the peripheral circulation, but rebranding them as a stroke (leg stroke, hand stroke, intestinal stroke…) is helpful. Finally, there is no survival with dead bowel -it must be found through exploration and resected.

Reference:

Roussel A, Castel Y, et al. Revascularization of acute mesenteric ischemia after creation of a dedicated multidisciplinary center. 2015 Nov;62(5):1251-6. doi: 10.1016/j.jvs.2015.06.204.

Categories
acute limb ischemia humor limb salvage techniques training

Of Clot, Tofu, and Cheese

The process of clotting is something vascular surgeons take for granted, but patients may have a hard time understanding what a clot is because in most people’s experience, it is rare for someone to see enough blood to form clot. How many patients or even health care providers have seen a tube or a basin of blood clot? So how do we describe clot to patients? I think the solution lies in food.

Most people who know me will say that I propose food as the answer for most things but hear me out. In describing clot, food is particularly salient. Clot is protein made insoluble, and there are many foods that have similar properties. Tofu, jello, and cheese and their making can give context where the word “clot” cannot.

All are made by taking a solution of protein and allowing them to form clumps that cause them to fall out of solution. It may require an acid, as in the case of tofu and cheese, but mere time and cooling may be sufficient as in the case of jello. And like these, clot may take on a soft crumbly quality when it is fresh clot, to a tenacious formed clump when given enough time. The difference is like silken or soft tofu and firm tofu. Or fresh ricotta cheese before it has time to set in its mold and the firmer cheese you get after weeks of curing.
With enough time, you get a hard substance that you can slice with a knife, like a dry cheddar or Parmesan. That is how I think of clot. It can be soft and formless like early jello before it is ready to eat. Or it can be hard and formed like mature dry cheese. The softer it is, the easier it is to dissolve or suck out via gadget or catheter, but there is a time factor to this softness -thing of your jello setting and hardening in your fridge. The harder the thrombus is, the less likely it is you can remove it with catheters and more likely you will have success with an operation as in the first picture. The harder stuff in fact crumbles well like a parmesan cheese and is harder to remove.

Burrata, handmade in Calabria is similar to the kind of semi-mature clot that deforms well but is tenacious and difficult to break up and remove except in one piece.

There are several things to draw from this with regard to devices designed to retrieve clot. Clot can occlude catheters as much as they can occlude arteries. Clot retrieval depends on net output of fresh clot that deforms well and flows well but fails in the hardened brittle clot that is well organized and adherent. Retrieving these crusty dried clot matter may be impossible for a device that depends on clot deformability or a maximum particle size, and these clots are the ones that are more partial to crumbling and embolizing. All devices must accept the fact that the unclogging is done in a flowing circulatory system where items swept downstream have the consequence of killing tissues whose arteries are blocked by emboli. There is always embolism with minimally invasive approaches. These devices make sense for hard to access circuits like the brain, but make far less sense in circuits like the extremities where surgical control is relatively low risk and results in reversal of blood flow -like in TCAR. Each of these devices can cost several thousand dollars. The fact is, operations can be faster and safer because embolism can be controlled and a wider range of clots, and larger amounts of it, can be removed at a lower cost. The first picture shows the results of a popliteal cut down and tibial thrombectomy where inflow was first restored in the below knee popliteal artery, and clot retrieved from each of the three tibial vessels (misleadingly, the tibial thrombus is all lined up), and a simultaneous 4 compartment fasciotomy performed, all under 90 minutes with no use of contrast. Unfortunately, open thrombectomy is a bit of a lost art in that many of the maneuvers and steps required to revascularize a limb successfully with no preoperative imaging requires experience. A younger patient with an arrthymia related embolism and normal soft arteries is approached far differently from an older person with atherosclerosis and diabetes, where open thrombectomy is better suited for the first, and catheter based approaches better for the latter.

Diagnostic and Therapeutic

The open surgical exploration of the extremity arteries is fast becoming a lost art along with the physical examination. In the setting of acute limb ischemia, the first decision in my mind is: was this an embolism? The presence of arrrhythmias, cardiac shunts, and aneurysms may suggest this, the next question is did this patient have a prodrome of limb ischemia related symptoms and history of atherosclerosis. The fact is, you have about 4-6 hours to return blood flow before irreversible neuromuscular damage sets in, maybe less if important collaterals are lost. Choice of procedure then devolves to choices about the most expedient methods for returning blood flow to the extremity, and between endovascular procedures and open surgery, it is rarely possible to manage significant clot burden with endovascular methods without adding the burden of procedural time. These considerations are balanced by patient risk. If the patient cannot tolerate general anesthesia, it is still possible to operate under local anesthesia. Otherwise, one is faced with choices like stenting across clot or common femoral artery. The algorithm is simple -ensure inflow, thrombectomize outflow, check for backbleeding, restore flow, check flow, repeat as necessary downstream. Fasciotomy as needed and close the skin if you can.

Endovascular options deal with the basic physics of trying to pull clot of varying consistency through a small lumen over a long length while not pushing emboli. The needs are simple -a low profile, cheap, over the wire solution for evacuating clot without embolizing nor injuring the patient on a 100cm and 150cm length catheter. Cost wise, open surgery always beats any endovascular option if wound complications of open surgical exposure are avoided. Both methods can’t cover themselves if open fasciotomy wounds keep the patient in the hospital for weeks. The fact is, we already have this magic system in the catheters that we already have on the wall, albeit, they don’t work particularly well if you are dealing with Parmesan, but none of the systems do. I recently declotted a graft fistula with just 6F sheaths, a regular #3 Fogarty ballon, 6mg of tissue plasminogen activator, and was able to salvage the blood and return to the patient.

Conclusion

Vascular surgeons should have as many words for clot as Eskimos purportedly do for snow. There is no one solution to a problem, but all the tools must be available to the vascular surgeon. Ironically, only the simplest are needed most of the time.

Categories
skunk works techniques Technology Uncategorized

Distraction free writing used to be the norm with technology

IMG_0645

Distraction Free Writing: Portable, Disconnected, AA Battery Powered

Distraction free writing has been a buzzword. It used to be the norm with computers by their limitations and design to focus you on writing. Today, technology is increasingly put in front of you to entertain and distract. The problem for students and writers is that your computer and phone are gateways to music, video, and communication in ways that were only dreams twenty years ago. The key elements of distraction free writing are a decent keyboard, extended battery life, simple interfaces, lack of connectivity, and   absence of party line operators. Each of these elements formed the core of our computers back in the 1980’s, when computers were rarely networked, they were all monochrome, and your words were all that you saw. This desire is driving the market for distraction free writing software and hardware, but you can find ways to create your own portable distraction free writing tools without dropping a fortune. And distraction-free writing is also intrusion-free -something to consider in today’s shifting privacy boundaries. At the end, the best distraction free options may be in reconsidering decades old devices that may be picked up cheaply used or at greatly reduced prices for new. Most current devices are made to last about a thousand recharges, and struggle with purposeful obsolescence. You may find that there are many fine older options that will suit your writing needs while greatly increasing your productivity while avoiding costs.

Consider the keyboards we had back in 1985. They were all mechanical spring keyboards which made a nice click sound. Writing was a tactile pleasure. This was in contrast to the membrane based keys seen on games and toys, and mistakes like the PCjr. You see them today as controls for microwave ovens. The moving keys send a message of accomplishment to your brain. Despite this, flat keyboards with no physical component  are still being thrown up to see if they would stick. The smartphone keyboard on the first iPhone killed the physical ones on Blackberry and the Treo’s after all. Manufacturers are still experimenting with flat keyboards such as on the latest Yoga Book’s e-ink keyboard, and the upcoming Microsoft Surface Duo devices.

IMG_0649
flat screen based keys like on the latest Yoga Book takes some getting used to

These software and touch display based keyboards rely on spelling correction and ultimately constant connectivity to minimize error. The push for ultra-portability means dispensing with the original mechanical keyboard which was descended from electric typewriters like the IBM Selectric. This resulted in the terribly mushy, mass produced keyboards introduced in the 1990’s, getting ever worse. The high point of this design viewpoint was introduced in the 2015 MacBook and recently retired in the 2019 Macbook Pro when Apple realized everyone hated typing on superflat keys meant to accommodate flatness over functionality. There is a welcome movement back to reasonable keyboards. I would even claim that the persistent life and value of the Thinkpad line is the focus on the keyboard that remains preserved after IBM sold it to Lenovo. The new-old keyboard on the 2019 MacBook Pro 16’s are a concession to the realization that typing is a core function of these machines.

There is a push back as writers, office workers, and gamers have created a market for mechanical keyboards. These are usually Bluetooth connected devices, and typically paired to tablets for writing. Unfortunately, separate keyboards connected to tablets are not as portable as a laptop.

QWERKYwriter is a retro mechanical keyboard for tablets but try taking that onto an airplane

I would argue that laptops are not as portable as they could be. The Freewrite (link) was designed with writers in mind as an update to electric typewriters with cloudbased file management and an e-ink display with days of battery life on a single charge. I almost bought one but the small display and the relatively bulky size kept me from springing. I have ordered a Freewrite Traveler (link) which is their mini-laptop version, but since I ordered one last spring, it has remained vaporware with its delivery date pushed back from summer 2019 to spring 2020.

Battery life is a sore point for me. Laptops are now expected to be wonderful if they exceed 8 hours of battery life, but I remember that the original portable computers like the Radio Shack 100 series could go days on AA batteries. Writing appliances were introduced in the 80’s including electric typewriters with single line LCD displays and single file memory which would allow you to compose and edit. I had such a device from Japan in high school that had a four line LCD display, built in thermoelectric (fax paper) printer, and battery life that went several days on 4 AA batteries.

By using computers and smartphones, which function as portable televisions and multi-function, shopping kiosks which use Watts of power, the trade off is battery life and constantly worrying about plugging in for a recharge. We forgot the days of battery life and are happy with 8 hours. The battery power bar is terribly distracting for me and I tend to stop working to find an outlet to recharge when it inevitably drops and when my productivity is nearly always highest. If I’m traveling, this means carrying the power brick, another injury to this one who remembers AA battery powered writing tools.

In 2017, the Samsung Galaxy Note 7 was famously recalled after spontaneously combusting and were banned from airplanes. All Lithium batteries must now be hand carried. Just recently, I was told while checking in that Apple Macbooks could not be turned on during flight because of heating issues. This is a consequence of the greatly increased energy densities of Lithium cells and their chemical volatility. AA batteries and their nickel metal hydride (NiMH) rechargeable variants suffer from no such problem.

Even with great battery life, you have to remember most of that power, and therefore bulk and weight of the Lithium batteries is devoted to painting vivid colors on the screen, communicating via radio signal to the world, and keeping dozens of apps updated on your activities, and not to writing.

The Lithium battery which can power a car because of its energy density is overkill if all you want is to write. The modern computer operating systems, Windows, MacOS, iOS, and Android, are all over-powered for the simple act of preserving words. Consider the lowly text file to a modern Word file. The text file for a novel might take kilobytes of memory, but the same Office Word file is measured in megabytes -thousands of times bigger. Try emailing a fully formatted Word file through your corporate firewalls if it exceeds your company’s limits on attachment file sizes. The size and complexity of information that is exchanged burns power. Compare that to the notes you might write onto paper. The few microcalories used to power your neurons and move pencil on paper, the motor and optics circuitry processing the information at a speed suitable for your ape brain.

My friend and early mentor, Professor David Tilson, refused to relinquish his DOS based word processor even well into the Windows era. And I understood. The monochrome and monotype letters forced you to look at the words and not the style of the words. While I admire Steve Jobs, and his introduction of fonts to our everyday lives, the ability to shape the look of your writing intrudes on its composition. Monochrome does not mean monotonous, and modern distraction-free software efforts like IA Writer embrace simplicity. The emergence of dark mode is another effort at rolling back the clock. When you enable it for your iPhone, it reaffirms the utility and critical need for focus and simplicity. Do you need millions of colors or just letters on a simple background? While you can change the color setting of your laptop screen or your writing software, the ultimate in monochrome experience is an e-ink display.

The e-ink display is what you see on Amazon Kindles. Originally meant for low power usage, high contrast functions like in store signs, e-Ink is currently used for e-Readers, although there is a niche market for e-ink based displays and tablets which do offer the low power hi contrast display perfect for a focused writing work station – you can find them on Amazon and eBay. Unfortunately, because these e-Ink tablets are run typically on Android, there is no escaping the internet on these, and because they do so, their battery lives are not that much different from standard tablets. What the we need is for Amazon to gift the writers of the world with Bluetooth or wired keyboard functionality to their Kindles and offer a text writer that can be synced to their cloud..

What the we need is for Amazon to gift the writers of the world with bluetooth or wired keyboard functionality to their Kindles and offer a text writer that can be synced to their cloud.

The constant need for connectivity drives software and hardware inefficiency. Writing requires intimacy and privacy. Just as you cannot write while engaged in a shouting match with someone, you cannot write with notifications of arriving messages, pictures, and videos. I cannot write while watching a movie or listening to certain music, but all of these distractions are baked into the function of modern computers and smartphones. This uses up battery life. The devices are in a race to maximize the battery and screen size at the cost of purpose and meaning aside from commerce.

Party line operators were a feature of the early telephone systems. Your locality was serviced by an operator that routed your calls and inevitably your conversations were open to intrusion both intentional and unintentional. When all your work is kept on a cloud server, it really is no different. And it isn’t that hackers that may take all your work. My generation grew up with the Cold War, and its dark tales of thought crimes and writers imprisoned for samizdat -ideas forbidden by a state entity. In a time when your social media is a subject for governmental and not just consumer interest, returning to off line options is something to consider seriously. The meaning of party line operators is in this context wholly changed.

The one feature of cloud based options is the convenience of accessing it across all of your devices. But are you really going to be writing on your iPhone, then on your desktop, then on your laptop, then from an airport kiosk? Your file can be lost during the sync process or changed to a competing version from another computer you were working on. And goodbye work if you get hacked or if your cloud service shuts you down or out. While you write, you have to keep a local version and back up to a nonvolatile storage option.

Not connecting to the internet saves you battery life. It also frees you from taking deep YouTube dives into funny cat videos or answering emails or Facebook posts. The stillness you need to just write is difficult to achieve with a modern laptop, tablet or smartphone. It can be attained with these older devices which people in the know still value decades after they left their boxes. I suggest these options if you are thinking of trying a focused writing appliance (a typewriter!).

Option 1: King Jim Pomera DM100  (link) is best described as a writing appliance designed in Japan adapted for the English speaking market. It is a sleek thin portable that allows one to type words unencumbered by internet. The files on it can be transferred to another computer by Bluetooth, and to smart phones by QR code which is cool. It runs for days on AA batteries, and has a backlit monochrome LCD screen. It is priced on th high end at 392.61, but receives the best rating on Amazon which to me is a 4.5. I never come across 5 star reviews that aren’t fake. One reviewers comment that the keyboard is cramped and takes getting used to. It can be used as a Bluetooth keyboard and stand for iOS devices.

Option 2: Neo 2 Alphasmart Word Processor with Full Size Keyboard,, Calculator

The Alphasmart Neo2 (link) was the last of a line of writing appliances put out by a pair of former Apple engineers who wanted to provide affordable word processing options on a full mechanical keyboard. The Neo2 is the most available and apparently the most usable, allowing one to type out hundreds of pages and transfer to a computer via USB connection. The screen is an LCD screen like on a calculator. The killer feature on this device is nearly forever battery life on AA cells. It has a rabid following of professional writers who appreciate the pared down experience for productive writing. It achieves that perfect 4.5 star rating. This is for a device discontinued in 2007 and sells for about 40-50USD in used condition. Reviewers rave about turning it on and instantly being able to type without bootup, and avoiding distraction by email, notifications, social media etc.

Option 3: Psion Series 5MX

The Psion Series 5MX represented the apex of portable computer design in the late 1990s. It was a computer made from the ground up from circuits, hardware, operating system, and apps by British engineers and it was a thing of beauty. Made in the late 1990’s, this device’s killer features, long battery life via AA cells, ultraportabiity, and lack of easy internet access puts it in a separate class. Not everyone like the keyboard, but I have long been able to type on it without difficulty with average to large sized hands. I had one during residency in the 1990’s and it followed me into fellowship. Before EHR, I composed full consultation notes and H&Ps on it and filed them on my password protected CF drive for later retrieval and update for frequent flyer patients. I picked up a pair of these for about 90USD from the Netherlands, but the going priced varies from about 70 to 200USD for a used one in good condition. New ones pop up but they go for nearly their original price -they are that good. I suspect I got a deal because they were Ericsson MC218, a Swedish licensed clone.

It has a compact flash drive, and with the save as text file function in the built-in word processor which works fast and reliably, it is possible to back up to a nonvolatile memory (the CF drive) and transfer to a regular computer. The one caveat is that the maximum size of CF drive it will see seems to be 128mB -that is megabytes which is hard to find. In certain older industrial machinery, instructions are uploaded via CF cards of these size, and so these cards are available on Amazon. Or look in a drawer for an old unused CF card.

I wrote this post on the Psion, and never once looked at emails, social media, or Youtube.

IMG_0651
I wrote this post on the Psion, and never once looked at emails, social media, or Youtube.

Categories
acute limb ischemia aortoiliac occlusive disease (AIOD) innovation limb salvage PAD skunk works techniques ultrasound

The shunt as temporary bypass -a modest proposal

The rise of cardiopulmonary bypass life support has also given a rise to the need to keep large, obstructive cannulas in femoral arteries. ECMO cannulas are often kept in for days, and it is not uncommon to discover limb ischemia and infarction relatively late. This can be avoided by placing a distal perfusion cannula to shunt blood to the leg early in the ECMO process. The ECMO cannulas have a convenient side port to send a little flow to a 6F sheath placed in the femoral or popliteal artery. This is an established technique (reference 1, sketch below), and it works despite the modest flows achieved because it does not take much to keep the leg alive. These patients are not walking, nor are they need to heal leg wounds, so just enough blood flow means something just a little more than what they get when the common femoral artery is completely occluded by the life support cannulas. What is fascinating to me is that these shunts can pptentially help to save limbs when used as temporary extracorporeal bypasses when definitive vascular surgical care is not immediately available.

brachial to femoral shunt sketch

 

When I was a medical student, I took on a research project after my first year where I had a Langendorff preparation of a rat heart (below).

langendorff prep in MRI
an isolated, perfused, beating rat heart placed in a superconducting magnet for NMR spectra acquisition 

My project was to take a rat heart and keep it alive, beating, and even working, through a perfusion apparatus and place this inside a superconductive magnet to obtain Phosphorus nuclear magnetic resonance spectra -intracellular metabolism data including concentration of ATP, intracellular pH, and ATP/ADP ratio. While the project was successful -I am quite proud to have been the only person at Columbia to have successfully acquired NMR-S data with living beating heart, I moved on to other interests and took away this concept: with oxygenated, glucose enriched, isoosmolar fluid perfused at arterial pressure, any organ can be kept alive, possibly indefinitely, including a brain which only recently others have found possible (reference 2) in reputable scientific circles, but the the Nature publishing Yalies were scooped by the Simpsons decades ago (below), and maybe Mary Shelley centuries before,

simpsons head

This is the simple idea. Revascularization is keeping the target vascular bed alive by delivering oxygenated blood. With a shunt, it could be little, it could be a lot, but it certainly is better than zero, and even a little can buy you time.

The breakthrough that I had was several years ago, a patient arrived from another hospital with an Impella pump which did not have a side port like an ECMO cannula. It is a large catheter that augments cardiac output and in the patient that I was asked to see this patient as their leg was cold and pulseless. Their cardiac output was very poor, and they were sustaining an augmented systolic pressure in the 90’s. There was no way to get this patient to the operating room for a revascularization of any sort. It did strike me that the patient had the misfortune of having catastrophic heart failure in the absence of significant athersclerosis and had normal brachial arteries. After discussing the ramifications with the ICU and family, I placed a brachial artery 5F cannula, and connected it to a 5F sheath I placed in the superficial femoral artery below the occlusive common femoral sheath (figure below). A doppler on the tubing connecting the two cannulas confirmed flow and the patient’s left hand maintained a pulsatile oximetry waveform. The leg pinked up and eventually there was a signal in the foot. This managed to perfuse the leg which did better than the patient who succumbed to multiorgan failure from heart failure. The leg did great.

Which leads me to these thoughts. Most hospitals are good at diagnosing large vessel occlusion via CTA. Most hospitals have doctors who can place arterial lines with ultrasound guidance. In the instance of aortoiliac occlusion or femoral occlusion from thromboemboliem, time is a critical limiting factor to limb salvage. Many hospitals do not have vascular surgeons. Many hospitals transfer these patients with a heparin drip but in the ischemic condition. Transfer arrangements may take hours. Why not ameliorate this situation by having an appropriate physician -an anesthesiologist, an intensivist, an EM physician, place an ultrasound guided radial or brachial arterial line, connect to arterial line tubing to a dorsalis pedis arterial line. Tape it all down on the patient after confirming flow (crude sketch below). This would be better than the three extra hours of ischemia the patient gets hit with on transfer. No one would transport a donor kidney without adequate perfusion and protection, but dying legs get transferred all the time with established warm ischemia. If done well, it might turn an emergency procedure into an urgent, semi-elective one. Have the vascular surgeon video conference in to confirm the absence of blood flow and appropriateness of temporary shunting.

radial to dp shunt
radial artery to dorsalis pedis artery shunt

If we are to live in  a world with less vascular surgeons, then the radius of survival has to be extended with use of technology and simple ideas such as this. Comments are welcome.

Reference
1. Foltan M, Philipp A, Göbölös L, Holzamer A,
Schneckenpointner R, Lehle K, Kornilov I, Schmid C, Lunz D. Quantitative assessment of peripheral limb perfusion using a modified distal arterial cannula in venoarterial ECMO settings. Perfusion. 2019 Mar 13:267659118816934. doi: 10.1177/0267659118816934.

2. Vrselja, Z., Daniele, S. G., Silbereis, J., Talpo, F., Morozov, Y. M., Sousa, A. M. Mario, S., Mihovil, P., Navjot, K., Zhuan, Z. W., Liu, Z., Alkawadri, R., Sinusas, A. J., Latham, S.R., Waxman, S. G., & Sestan, N. (2019). Restoration of brain circulation and cellular functions hours post-mortem. Nature, 568(7752), 336–343.

Categories
AAA EVAR hybrid technique mycotic aneurysm ruptured AAA skunk works techniques training

The Hands of a Surgeon

My partner, Lee Kirksey, Vice-Chair of Vascular Surgery, just got a paper on-line (link) about the curiously increasing volume of open surgical repairs we were experiencing from 2010-2014 at the Cleveland campus of the Cleveland Clinic. When I joined in 2012, my impressions at that time were mostly the paucity of straightforward EVAR cases that I had seen in private practice, and the high prevalence of stent graft explantation, infected aortic grafts, and open aortic aneurysm repairs (OAR) for juxtarenal and thoracoabdominal aortic aneurysms for nominally high risk patients. My TAAA muscles had atrophied during my years out of fellowship and I eagerly took the opportunity to recruit the help of my partners and scrub in on these cases with Pat O’Hara, Jean Kang, Dan Clair, Ezequiel Parodi, and Lee Kirksey. It is without any shame that I sought out not just extra expert hands, but interrogated these experts for different ideas and approaches, and absorbed feedback. At the time, I was ten years removed from graduation, a full-fledged vascular surgeon who thought he could do any operation put before him. I cannot imagine the thoughts churning through the head of a recent graduate faced with the choice of taking on an open aortic operation with only 5 cases under their belt, referring the case on to the regional tertiary center, or trying to McGyver an endovascular solution. I contributed probably about 35-50 cases to this paper, but the outcomes were a collective effort. Even today, I will run cases by Sean Lyden, Christopher Smolock, or Lee, if only for the company and gossip.

“We explain this distribution of cases as a function of several factors: a unique, broad regional quaternary referral practice whereby patients with complex aneurysmal disease are referred to our institution; an institutional practice evolution resulting from a critical analysis and understanding of EVAR failure modes that lead to explantation, thus generating a different perspective in the EVAR vs open decision-making process; a parallel high-risk IDE fenestrated graft study; a historical willingness to accept all physician and self-directed patient referrals (ie, a willingness to manage more complex cases); and a published expertise in the area of EVAR device explantation with an annually growing volume of commercial device removals” -from El-Arousy et al.

Reading through that paper, I have come to the conclusion that the increasing open aortic volumes at the Cleveland campus has as much to do with the ongoing retirement of experienced surgeons regionally as it does with the ability to attract these cases. Loss of these surgeons has a cascade effect like losing a species in an ecosystem. The operating rooms forget where the OMNI retractor is because nobody asks for it anymore. The ICU’s are no longer familiar with the ebb and flow of the postoperative open aortic operation. The floors lose institutional memory of the care of these vascular patients as the stent grafts and interventions go home within 48 hours, sometimes the same day.

If you were a vascular surgeon born before 1970, your approach to the scenario of the ruptured abdominal aortic aneurysm may differ substantially from that of surgeons born after the Carter administration. Most of my cohort, Gen-X and older, feel comfortable applying some betadine, opening the belly and placing a clamp. Those younger than us have told me they feel more comfortable putting up a large balloon and deploying a stent graft. In this generation, it is normal to call a general surgeon to decompress the abdominal compartment syndrome and manage the abdominal vacuum dressing. For our generation, the giant industrial robot arms and 80 inch monitors creates a barrier to the problem at hand, and gathering all the extra staff after hours and on weekends requires the logistical skills of a wedding planner.

We prefer an operating table, a willing anesthesiologist, a cooler full of O-neg blood, Prolene and a graft, strong suction, and an extra set of hands. The data suggests either method is equivalent in outcome, but I would argue that depending on the circumstance, there is an optimal method for that patient and you have to have the ability to do either open or endovascular or some hybrid combination. Unfortunately, it is clear that open vascular surgery is year over year diminishing, and and it might not be so great when we start rupturing our aneurysms.

The open approach is preferred because we got good at it by doing a lot of these cases. Your hands -it becomes natural to change the course of the disease and the fate of the patient with your hands. One of the things you lose with a wire based approach is the tactile feedback from the organ that you are treating. Yes, there is a subtle feedback from the flexible tip of a Glidewire, but that’s missing the point. The thing that is rarely considered with open surgery is the tactile aspects of operating.

Your fingers are your point of care ultrasound. As an intern, one of my earliest tasks was reaching in through a 2cm incision with my index finger, feeling for what I would describe as a rotten shrimp, and delivering it out by hooking my distal phalanx around its base. Adhesions were rubbed like money between finger and thumb to judge if you could bovie through it. If you felt a sliding sensation, it was mucosa to mucosa and you looked for another spot to cut. Into my fellowship which could be called the triple-redo, no-one else wants to do-, difficult vascular operations fellowship, the pulse or the plaque felt under the finger would guide me to carve away scar tissue from blood vessel, visualizing the feedback from the fingers. In a rupture, with the belly under a dark mire of blood, there is no seeing, only feeling. Your hands reach into the lesser sac or transverse mesocolon and strangle the aorta -your fingers while clamping, feel and avoid the caudate lobe, the NG tube in the esophagus, and split the crura of the diaphragm like a pick pocket. Once the pulse returns as anesthesia refills the tank, you scratch free the aorta with your thumb and forefinger, then slide the jaws of the aortic cross clamp over your fingers and against the spine and clamp. This takes about 60 to 90 seconds (link).

When a patient is bleeding out, this is the way to control the bleeding. In practice, no amount of rehearsing for getting a patient into a endovascular suite, getting airway and access, swinging in the industrial robot arm, and getting everyone into lead aprons, sending up wire, placing a 12F sheath and an aortic occlusion balloon, will be satisfactorily smoothly and efficiently as a STEMI or STROKE alert. The rAAA is for most hospitals, unless you are in Seattle, a once in a while occurence. Many more people can find a scalpel and an aortic clamp than they can find a 32 inch aortic balloon, a stiff exchange length wire, and a 12F sheath.

When a patient presents with a slowly bleeding, contained rupture, there is time to assemble the teams required for an endovascular repair, and for opening and decompressing the abdomen, for anesthesia to get IV’s, central lines, arterial lines, and order crossmatched blood. One has the time to get and review CT scans and choose grafts. One can even do things backwards, debranching after securing the leak (link) with a stent graft. The luxury of time should signal to you that the endovascular option is the preferable route, as all the advantages of minimally invasive repair are possible. Rural hospitals sending patients two hours by ambulance or arranging for a helicopter -this is the great filter through which those likely to survive make it into the endovascular suite. These patients do great with EVAR, because everything moves more or less like a routine elective EVAR.

The setting up the operating room for tackling rAAA is quite simple. Keep everything nearby. Nothing should ever be stored out of sight, retrievable only by arcane codes whispered in the ears of people down in the basement or across the street. Amazon gives itself a day to get that gadget to you, but the rupturing patient does not have the time to have a 28mm stent graft ordered by looking up a Lawson number, finding the materials person in the faraway room to find it, running it over a city block. The stuff has to be next to the OR. Every scenario is unique, and the best planning is assuming no one person knows where everything is but everything is close at hand -major vascular sets, retractors, C-arm, cell saver, stent grafts, open grafts, balloons, cardiopulmonary bypass -every gewgaw is few steps away. The inventory is what you see, because if you can’t grab it, it does not help the hemorrhaging patient.

If you are a vascular surgeon born after 1980, it is likely that you may have trained in a 0-5 residency and all the old people harumphing about the old ways seem biased. Rather than being rational about their awful upbringing, the old people seem to suffer from Stockholm Syndrome, turning from victims of a harsh and brutal system inherited from the original, Halsted, a cocaine addict, to willing collaborators now mooning about the good old days of every other day call and 120 hour work weeks.

There might be a growing suspicion about advocating for open surgery when fewer people can perform it. One of the truisms of surgery is if only one surgeon claims to be able to do a rare operation with great results when everyone else abandons it, like venous valve surgery or robot assisted mastectomies, it can mean that surgeon might be uniquely talented or shamelessly selling something. It is a shame that open vascular surgery is devolving into that category of arcana, like the Jedi. I have no doubt that the last open vascular surgeon will be a reclusive, bitter, wild eyed hermit like Luke Skywalker was in episode VIII, if we let it get that far.

Bald eagles were saved from extinction. The methods of species reclamation may be what is needed to save open vascular surgery. Financial metabolism drives behavior, and there must be recognition of the time and dedication required to perform good open vascular surgery in the form of increased RVUs and reimbursement. The surgeons retiring in their mid 60’s with straight backs and steady hands need to be incentivized to stay around and coach the next generation in the ways of the Jedi. Call it the master surgeon designation. Every 0-5 graduate needs to focus on getting 100 leg bypasses, 50 carotid emdarterectomy, and 25 open aortas within the first five years of practice with a master surgeon if they did not get this experience during training. Like dead Jedi, it would help even if they were just virtually present, shimmering on Facetime in their (bath)robes to go over planning and approaches, but being physically present and reimbursed for it would make the most sense.

There is always self service in any human activity. One mildly prominent vascular surgeon that I have come across is famous for saying he did not have a vascular fellowship because he did not want to train his competition. It is easy for the fifty somethings to sit and proffer their open skills and profit from its scarcity but it goes against decency to not pass on this collective body of hard won knowledge and skills. There must be stewardship of this great thing we do, this honorable and treasured endowment.

Of the concrete ways we are trying is creating a network of advanced open surgery capable surgeons regionally organized by Martin Maresch, capitalizing on social media and electronic communications. Here at CCAD we are in the organizing phase of a vascular residency, and I very fortunate to have Houssam Younes join us as he shares my interest in surgical education and open vascular surgery. We are contemplating a non-accredited fellowship. We have general surgery residents coming through our service as well as medical students.

One of my mentors told me, “I can train a monkey to do cardiac surgery,” as he was training me to do cardiac surgery. And he was right. The final comment I have is you have to demystify surgery, take away the Instagram perfection, the romance, and list in practical terms the toolkit of maneuvers that form the component parts of all operations and propagate it. Let us not kid ourselves. The technical skills of surgery can be taught to anyone. The Mayo brothers were performing surgery as teenagers before medical school. The knowledge and experience and judgement -that varies as much as people vary and we have a curriculum for that, but the physical acts of surgery need to be taught starting at the medical school level. Standardized drills and exercises need to be created so that proficiency can be metered.

“The individual per trainee OAR volume did not decrease during this period. In the training program, the use of “component separation” (separation of each
operation into discrete, instructionable steps that facilitates trainee mastery) is integral to instruction of open aortic aneurysm repair techniques and permits the
trainee to master all of the technical exposure and repair skills necessary to address and to manage both straightforward and complex aneurysm anatomy. Component
separation is essential to maximize trainee experience across all levels” –from reference 1

Here is my list of things a trainee must accomplish by the time they graduate from a vascular residency or fellowship.
1. Tying knots with gloves on with 6-0 Prolene inside a pickle jar without lifting or moving a 12 ounce lead fishing weight to which the suture is being tied, fast, one handed, two handed, left and right handed.
2. Holding forceps, needle holders, and clamps
3. Correct operation of the OMNI retractor, Weitlander retractor, Balfour retractor, Thompson retractor
4. Incise skin through dermis through correct depth and length with both #15 and #10 blade
5. Open the abdomen through midline and flank incisions and close these incisions
6. Harvest saphenous vein
7. Vascular anastomosis on a table, inside a pickle jar, inside a short Pringle’s can
8. Dissection of adhesions and scar tissue around blood vessels and organs
9. Dissect and expose the common femoral artery via vertical and oblique incisions and close these incisions
10. Dissect and expose the carotid bifurcation, left and right side, and close these incisions
11. Dissect and expose the tibial vessels in various parts of the leg and foot
12. Dissect out the brachial artery at the elbow
13. Dissect out the axillary artery and vein below the clavicle
14. Dissect out the axillary artery and vein from the axilla
15. Dissect out the subclavian artery, vein, and brachial plexus above the clavicle
16. Dissect out the arm veins
17. Dissect out the iliac artery via a lower quadrant pelvic retroperitoneal exposure
18. Dissect out the abdominal aorta via midline laparotomy
19. Dissect out the abdominal aorta via retroperitoneal approach
20. Dissect out the thoracoabdominal aorta via a thoracoabdominal exposure
21. Dissect out the popliteal artery via suprageniculate, infrageniculate incisions and prone position
22. Dissect out the inferior vena cava
23. Dissect out the iliac veins
24. Harvest deep femoral vein
25. Temporal artery biopsy
26. Endarterectomy of carotid, femoral artery, any artery with patch angioplasty
27. Exposure and control of supraceliac aorta, suprarenal aorta for clamping
28. Exposure and control of thoracic aorta
29. Exposure and control of the great vessels via sternotomy and supraclavicular incisions
30. Exposure and control of the vertebral artery
31. Safe removal of vascularized tumors
32. Amputations of digits, legs and arms up to pelvis and shoulder
33. Exposure and control of radial and ulnar arteries
34. Hand surgical techniques of exposing arteries, tendons, and nerves in forearm and hand
35. Plastic surgical techniques of skin grafting and basic rotational flaps
36. Fasciotomy of arms and legs, hands and feet.
37. Exposure and control of celiac axis
38. Exposure and control of superior mesenteric artery
39. Exposure and control of left renal vein
40. Exposure and control of hepatic veins, portal vein
41. Exposure and control of renal arteries
42. Exposure and control of profunda femoral arteries
43. Safe removal of spleen
44. Transabdominal retroperitoneal exposures of the abdominal aorta and inferior vena cava
45. All of the above in a reoperative field
46. All of the above with limited visualization and by sense of feel only
47. Laparoscopic and thoracoscopic techniques
48. Orthopaedic surgical techniques of myodesis, bone grafting, precision osteotomies, infection control, external fixation, spinal exposure
49. Safe resection and anastomosis of bowel
50. Drainage of infection
51. Intensive care of SIRS, MOFS, CHF, Septic shock, postoperative fluid shifts
52. Nonsurgical and surgical management of lymphedema, seromas, and edema
53. First rib resection
54. Spinal exposure
55. Organ harvest and transplantation
56. Planning of complex open, hybrid, and endovascular procedures

Every year, it is apparent that endovascular options suffer from some flaw when outcomes are studied beyond 2 years, but progress will march on in that sphere. It has to. The loss of open capable surgeons to early retirement is accompanied by overapplication of endovascular techniques at least partly due to the lack of knowledge of these open surgical options and achievable good results and partly due to financial incentives. The solution lies in redistribution of reimbursement to open procedures and creation of open surgical fellowships and identifying and empowering mentors who still walk among us.

Categories
Commentary complications imaging limb salvage PAD popliteal artery entrapment syndrome techniques

Zebras, not horses: popliteal artery entrapment syndrome

mega mushroom
Adding a vascular surgeon to a hospital is like eating one of these. It turns Mario into Mega Mario. Vascular surgeons turn community hospitals into tertiary care centers.

Recalling the medical school adage, “when you hear hoofbeats, it’s probably horses, not zebras,” it is critical to think about rarities down on the differential list whenever you come across a patient. Vascular diseases suffer from inadvertent obscurantism arising from its absence from medical school curricula such that common disorders like mesenteric ischemia and critical limb threatening ischemia are frequently missed by even experienced medical practitioners. Vascular zebras are even harder to pin down because many experienced vascular specialists practice for years before they encounter, for example, adventitial cystic disease or dysphagia lusoria with a Kommerell’s diverticulum. Even so, real patients have these disorders, and we are all subject to inexperience bias -the feeling that something does not exist until you see it. You may completely miss something staring at you in the face or worse, deny its existence.

The patient is a middle aged man in his 50’s who aside from mild hypertension had no real risk factors. One day, at work, his right leg stopped working. He developed a severe calf cramp and the forefoot was numb and cool. He went to his local hospital and the doctors there appreciated the lack of pulses in the right leg and got a CTA, of which I only had the report which found a right popliteal artery occlusion.

The next morning, as he had signals and was not having rest pain, his doctors discharged the patient on clopidogrel and scheduled for angiography and stenting, per patient. As his debilitating claudication did not go away over the weekend, he came to our emergency room. While he had no rest pain, he did have minimal walking distance before his calf muscles seized up. On exam, his right foot was cool and cyanotic, with intact motor function and sensation. There was a weak monophasic posterior tibial artery signal. Bedside point of care photoplethysmography showed dampened waveforms (below).

dppg.png
Look at the blue line. The waveforms are dampened in the ischemic foot.

Because he did not bring his CT, I repeated the study. I have written extensively on the need to be able to share CTA studies without barriers. After his study, I brought it up on 3D reconstruction software.

paes.png

It clearly showed a Type II Popliteal Artery Entrapment affecting both legs (CTA images in series above). Stenting it would have failed.  I spoke with the patient about operating the next day. The plan was popliteal artery exploration and thromboendartectomy with myotomy of the congenitally errant medial head of the gastrocnemius muscle. The patient was agreeable and I took him to the operating room for a myotomy and popliteal thrombendarterectomy in the prone position. The medial head of the gastrocnemius muscle went over the  popliteal artery and inserted laterally onto the femur.

pop opened.png
Endofibrosis, cut medial head of gastrocnemius muscle to right of distal clsmp

The artery was opened and while there was fresh clot, the artery showed signs of chronic injury as evidence by endofibrosis which pealed off. Pathology showed to be fibrotic in nature.

04-SP-19-4119 Trichorme stain showing fibrous tissue as green
Trichrome stain showing chronic endofibrosis

The artery was repaired with a pericardial patch and flow restored to the tibials, not all of which were completely patent.

pop patched.png

The patient was discharged after about a week and will be scheduling repair of his contralateral popliteal artery entrapment.

The vascular surgeon has a vital role in a hospital’s medical ecosystem. One time, I heard hospital administrator say that with the advance of endovascular technologies, the vascular surgeon would become an expensive, redundant luxury easily replaced by the overlapping skillset of radiologists, cardiologists, general surgeons, trauma surgeons, cardiac surgeons, nephrologists, neurosurgeons, neurologists, podiatrists, infectious disease, and wound care specialists. When I identify these zebras, these rare diagnoses, I am neither replacing all those aforementioned specialties, nor having special insight unavailable to the uninitiated. I am keeping my eyes open. In a non-smoking, active, otherwise healthy and employed middle aged man with no cardiac history, it is very strange to have isolated popliteal occlusion with otherwise pristine arteries throughout the rest of the CT scan. That is a statistical outlier. People who occlude blood vessels in this fashion usually have more comorbidities, usually are older, and usually have more atherosclerotic disease burden. While not quite like the teenager who presented last year with the same diagnosis (after a month of misdiagnosis and delayed treatment), the cleanliness of the arteries elsewhere in the body was disturbing to me. This puts me on a zebra hunt and not the usual horse roundup.

A hospital needs vascular surgeons in the way that America need the US Marine Corps. Every decade, there is some congressional movement to see how the USMC, which has fighter jets, tanks, planes, aircraft carriers, helicopters, and riflemen, can be phased out because it seems to duplicate the services of the Navy, Air Force, and Army, and every generation a conflict proves these arguments wrong. Individuals who know things broadly and deeply, who can do many things across specialty lines, work from head to toe, and whose specialty is to customize solutions to complex problems is the special quality that is the difference between tertiary hospitals and quaternary hospitals. While these qualities are goals within Vascular Surgery, it is a generalizable goal for anyone working in healthcare. My favorite professor in medical school was Dr. Harold Neu, chair of infectious diseases at P&S. He knew everything and was interested in everything and took every moment in the hospital to increase his knowledge a little more. That’s how and why I diagnosed a case of schistosomiasis earlier this year -the upper abdominal pain was not from a coincidental aortic aneurysm, but the fellow did swim in the Nile.

I texted Dr. Sean Lyden, my former boss and partner at the Cleveland Clinic main campus, if there was any situation where an asymptomatic popliteal entrapment who had gone over 50 years of life without complications could just be watched -it was a question from the patient actually. Dr. Lyden treats popliteal entrapment weekly and maintains a clinic specializing in popliteal artery entrapment (link). One of advantages of working in vascular is that the community is small and highly accessible, and I have a group of living textbooks on speed dial (that term pegs me as antique). There is an active social network of vascular specialists and the SVS maintains SVS Connect (link) for posting and discussing difficult questions. Despite the horrible hour that he received the text (“What’s the matter? Are you in trouble?” he asked) because of the time differences between Abu Dhabi and Cleveland, he answered, “no.” Sorry, Sean, for texting you at 4 in the morning.

When you look for four leaf clovers, and you have never seen one in your life, the moment you find one must be transformative. I have never found one, but I keep my eyes open, lest I trod on one.