Author: docpark

golfist

Gadgets and the Next Healthcare Revolution

Post author By docpark
Post date 18 Sep 2015
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The picture above shows a vascular anastomosis created by an ingenious gadget that has struggled to find a place in my personal kit despite performing well. It really works well when you don’t have an assistant to follow your running suture to apply tension and keep the suture out of the way. I have have come up with four reasons why I don’t use it every day even though I like the device, find it performs well, and have used it in the past.
1. Training Vascular Surgeons- The vascular anastomosis is over a century old, and the various forms it takes, interrupted suture, continuous, end to side, end to end, side to side, native to prosthetic and so on, all have to be taught so that the trainee can function even in the absence of such gadgets.
2. Cost- The cost of the device is subsumed by the hospital and ultimately the healthcare system. Using the device is the equivalent of turning the air-conditioning on when opening the window will do.
3. Time savings- If operating room time were metered like taxi time, then there might be an argument for this device, but the difference in the end is still trivial. A hand sewn anastomosis, even done slowly, takes usually no more than 20 minutes. Using this device, the times are reduced to about 1-5 minutes. This almost never is enough to make a difference, unless ischemia sensitive tissues are being repaired, but no one would use this device to sew a graft to a renal artery.
4. Results- The argument that an interrupted anastomosis is superior to a running one only works when native tissues are sewn to native tissues. A prosthetic to artery anastomosis will not adapt and frankly is the easiest to create a technically acceptable anastomosis with. An interrupted anastomosis done by hand can be done in as much time as a running one (figure below).

There are many wonderful and ingenious inventions like this. Whole specialties and institutes are built around implantation of ingenious and life saving devices. Yet the costs are increasingly astronomical and unsustainable.

Can there be innovation without sticker shock? The answer is a qualified yes. To make this a reality, there has to be several changes in the way that devices and procedures are vetted and approved. It will not be easy.

To bring a new drug to the market, the Tufts Center for the Study of Drug Development estimates in 2014 that it costs $2.5 Billion. This barrier which we have erected against ourselves insures that pharmaceutical development is channeled through a narrow group of players. On the device side, there are similar barriers and price tags to bringing a discovery to market. There is a six letter C-word to describe this situation, but it isn’t polite to use.

It used to be that breakthroughs in surgery were not directly monetizable. The carotid endarterectomy didn’t make DeBakey or Eastcott anything but fame among a small group of surgeons, but there was great good from that. A lot of time and effort and money has been used in an effort to supplant the carotid endarterectomy with carotid stenting, but the devices come at a greater cost for dubious benefit except in very particular situations. I recently performed an eversion carotid endarterectomy in about an hour’s time closing with no patch or shunt. The procedure cost the price of 6-0 suture to repair the artery, and several packs of an absorbable suture to close the skin. Add to this some disposable drapes, suction tubing, a cautery and an energy device. Compare this to a carotid stent procedure that uses a stent (4 figures), wires (up to 4 figures), protection device (4 figures), sheaths, balloons and catheters (3-4 figures), resulting in upwards of 5 figures of cost. This is for a procedure that in head to head comparisons results in a higher stroke rate, the very complication it is meant to prevent.

Health care innovation will have to have cost disruption as a necessary condition for its adoption. Whatever is used, has to drop the cost by removing a zero from the end of the price tag while yielding at least as good or better results.

IVC Filter Migration Causing Acute Abdominal Pain

Post author By docpark
Post date 12 Sep 2015
5 Comments on IVC Filter Migration Causing Acute Abdominal Pain

The patient had a carotid dissection over five years prior to presentation and had a stroke and DVT. To protect her from pulmonary embolism, an IVC filter was placed, she was anticoagulated for a while. She rehabilitated and was doing well when several months prior to consultation she developed severe upper abdominal pain that occurred intermittently without triggers. She underwent a workup which included laboratory testing and endoscopy which were negative, and a CT scan showing the IVC filter had tilted and the legs had eroded through the vena cava to abut the duodenum and abdominal aorta. No other pathology could be found and after discussion operative resection was planned.

As mentioned in an earlier post, 3DVR image processing has become indispensable in planning not only aortic interventions but open surgery as well. An oblique incision was created, basically a high transplant incision, and we stayed in the retroperitoneum. The leg of the filter abutting the duodenum did not penetrate it and there was no leakage of bile. The end of the leg, of which there are two types on this filter, was in the vena cava, but the side had eroded out of the cava. Control of the IVC is always treacherous because of the fragile lumbar tributaries underneath the cava. Once heparinized and clamped, a longitudinal venotomy released the filter. The head was embedded in the cava wall and would not have been easily accessible with a snare.

The tine that was headed towards the aorta had to be removed from the filter to manipulate it out. No bleeding was noted from the aorta.

This is my fifth operative removal of an IVC filter that had eroded into adjacent organs. Recently I removed a filter which had eroded into the aorta -this required a pledgetted suture. In my first case, about 7 years ago, a filter placed in a teen, the victim of polytrauma due to an MVA, caused fevers and an upper GI hemorrhage which was diagnosed on upper endoscopy -somewhere I have a great picture of an IVC filter leg in the duodenum.

Which brings me to my last point. The guidelines for placing these filters has evolved and it is clear now that they are not as benign as once thought. They are not only associated with migration but also iliocaval thrombosis. Stenting across them can push the legs out into organs. Their migration into the retroperitoneum can cause an atypical abdominal pain syndrome -in this patient, the pain was immediately gone. If placed, plan should be made for removal if feasible, anticoagulation maintained if possible, and filter choice limited to those that have long track records.

The treatment of venous thromboembolism remains primarily pharmacologic. When the indication for the filter expires, the filter should be removed unless the risks of removal exceed the risks of leaving it in.

Tags complicaiton ivc filter, ivc filter migration, venous thromboembolism

amputation BKA techniques

An Easy Way to Perform BKA -Treat it Like Plastic Surgeon

Post author By docpark
Post date 12 Sep 2015
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At one time, I was performing below knee amputations in the same way that most textbooks prescribe. This patient presented with severe foot and leg infection with exposed tendons and cellulitis secondary to advanced diabetic neuropathy and arteriopathy.

My sketch above showed the situation which we treated with two stage guillotine and final BKA. At the final stage, standard technique involves creating the classic flap shown below.

This is a tricky flap to make well because there are many variables -the amount of muscle left, the thickness of the subcutaneous fat, the vascular supply, etc. The biggest criticism I have of this flap is that it is prone to edema particularly in the meaty posterior flap, putting great stress on the skin sutures or staples. This then creates fat or skin necrosis in the posterior flap, or muscle necrosis resulting in wound infections and hospital readmissions, which are particularly at risk for need for further leg amputation in these patients with diabetes. I have to confess, while I could figure out how to cut the flap in the end, it was really hard to teach, and if it is hard to teach, you have to figure out a better way.

Here is the better way. The idea goes to the concept that the weight is borne in a distributive ring around the stump. The muscle on the tibia does not create a heel to bear weight on and so serves only the purpose of delivering blood to the overlying skin. So you only need the gastrocnemii and Achilles tendon for fascial closure, and maybe a little soleus. The elimination of posterior compartment muscle bulk greatly reduces the tension on the fascia and skin.

The incision can be simplified by cutting the flap along an oblique 2D plane -a light saber cut!

The posterior flap is reduced to just Achilles and a layer of soleus muscle, but otherwise, the internal bone and muscle organization is cut as below:

The skin at this point is never touched with a surgical instrument, only the subcutaneous later or fascia. Using interrupted absorbable heavy gauge monofilament (single strand of the double looped PDS used for abdominal closure is plenty of suture), interrupted buried sutures are placed in the fascia from middle outwards.

Sketch12684859 This closes the fascia and allows the skin to be closed without tension using only occasional interrupted dermal sutures and a running 3-0 or 4-0 absorbable monofilament.

The skin is dress with a single layer of Xeroform and fluff gauze and gently a compressive dressing is applied from stump to above the knee, while keeping the knee cap exposed -the knee cap is prone to skin necrosis with ACE wraps that are left unattended.

The wound’s ability to heal is now largely a function of keeping the suture line tension and edema free. Edema is the great killer of these flaps and the problem with sutures or staples here is that edema creates zones of skin necrosis under these staples that then results in a postop wound breakdown and infection. With these simple steps largely copied from our plastic surgical confreres, I have been able to create very functional stumps with low morbidity.

This patient is 3 months from her 2 stage amputation and is walking on her prosthetic leg and is very happy. Notice, the dog ears have contracted!

Tags below knee amputation techniquer, leg amputation, postop wound infection

AIOD CTA imaging techniques

3DVR -Very Helpful in Planning Open Surgical Cases

Post author By docpark
Post date 8 Sep 2015
No Comments on 3DVR -Very Helpful in Planning Open Surgical Cases

The images above show a patient with on isolated occlusion of his left common iliac artery. He was young, in his forties, but was a heavy smoker and suddenly developed claudication of his left leg which interfered with his work. He quit smoking and did not progress with exercise. Discussion involving possible stenting was made and initially offered but he turned it down because erroneously he assumed that his father’s coronary stents were the same as an iliac stent in terms of longevity. I do think that common iliac and aortoiliac occlusive disease is well treated with stents, but I felt it was possible to do a common iliac endarterectomy. We went over these images together and he settled on proceeding with endarterectomy.

The images show how well the 3D Volume Rendering, which I mentally call Virtual Reality, of CTA makes it possible to plan out operations and exposures virtually. The bottom left image shows the surgeon’s eye view of the exposed vessel.

Below, the virtual and the actual are juxtaposed.

The outline on the virtual image (volume rendered) shows the areas of retraction -for the trainees, the retractor systems work to make quadrilaterals out of linear incisions, and as a rule, the incision should be twice the length of the square that you want to expose. The end points of the endarterectomy were at the aortic and iliac bifurcations.

The arteriotomy was repaired with a patch at the iliac bifurcation -the common iliac was large and was repaired primarily.

The specimen below was fibrocalcific. The thing about this disease is that the plaque truly has no endpoint -intimal thickening and mild plaque was present that could be taken all the way to the aortic root and to the feet on the other end!

This patient did very well and had palpable pulses. He did not develop neointimal hyperplasia and successfully quit smoking.

One of the exciting developments is the ongoing development of wearable virtual reality and display solutions -particularly from the gaming industry. The gaming industry ironically drives all computer imaging because that is where the money is at. The advances in imaging trickle down to medicine -the VR images seen here are the result of the same algorithms that drive first person shooting games. It would be great to see this displayed intraop on a HoloLens, on a virtually positioned screen behind the assistant!

Tags 3D VR, aortoiliac occlusive disease, Aquarius, CTA

EndoRE PAD remote endarterectromy

My First Intentional Stent Removal Case -Arterial Restoration

Post author By docpark
Post date 4 Sep 2015
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In 2007, at which I had performed about 20 standard EndoRE (Remote Endarterectomy, LeMaitre Vascular) cases over about two years, this patient in his later 40’s presented to me with ischemic rest pain of his right foot. He was a current heavy smoker who initially had severe claudication and a TASC D occlusion of his right superficial femoral artery. Prior to being referred to me, he had undergone a mitral valve replacement from which he recovered uneventfully. He then had treatment of claudication starting with iliac stenting and a vein bypass. He had undergone a femoral artery to below knee popliteal artery bypass with reversed greater saphenous vein which became occluded after being complicated by MRSA wound infections. When this graft developed problems at the distal anastomosis, he underwent revision with a jump graft from the arm. This graft went down after he developed MRSA infection of the cephalic vein harvest site. He then underwent SFA stenting with 5 femoral stents (at that time, long stents were not available), but these occluded and his access site was the nidus of MRSA based sepsis. He had had multiple hospitalizations for MRSA infection from phlebotomy sites when he presented. He had reintervention for in-stent restenosis, first with balloons, then an extra stent, then cryoballoon therapy, each episode complicated by MRSA infection. He presented with severe claudication and nocturnal rest pain. On exam, he had dependent rubor, elevation pallor and absence of pulses, despite having fairly benign anatomy on CTA.

There was two vessel runoff below a reconstituted popliteal artery, with stent occlusion and visible stump of the vein bypass.

My options included bypass with PTFE, cadaveric vein, endovascular recanalization of the occluded stents, or EndoRE. While considering the MRSA which had been extensively worked up prior to presentation by ID including TEE and multiple cultures, it was decided that he was firmly colonized with MRSA despite efforts at eradication, and PTFE was not an option. Cadaveric vein I have used in infections with acceptable short term results -never great long term except for one individual who I inherited from a surgeon in Kansas who maintained a decade of patency of a cadaveric vein to tibial artery bypass with coumadin alone. This patient was not likely to be so lucky. Endovascular recanalization with atherectomy versus laser was considered, but I had at that point become disillusioned with those modalities in such extensive disease.

EndoRE made the most sense because it was my observation in a prior patient in whom I had unintentionally removed a 4cm stent with plaque that stents are placed inside plaques and when you remove plaque, theoretically, the stents have a layer of plaque between them at the adventitia. Also, he had none of the extensive calcium that made regular EndoRE challenging. Also, it would be repaired with native tissues through a single groin incision, and covered with a sartorius flap. And that is what I did.

The common femoral artery was exposed and the SFA controlled. The plaque dissection was started and the ring fitted around plaque and stent. There was a little more friction than expected, but I did inject via a catheter cold LR with the idea that it would shrink the nitinol a bit. Also, the wire that guided the catheter did double duty as a dissector as I was subintimal with it. The rings traveled well to the end point which I achieved with little difficulty.

Vollmer Ring Dissector around plaque & stents

The end point was dissected and required a short self expanding stent. The patient recovered well and was discharged, but as in prior admissions, developed a cellulitis on the groin wound that resolved with Vancomycin, presumably with MRSA. A CTA done at that admission showed excellent patency and he had palpable pulses.

Three years later, he underwent intervention by one of my partners in cardiology at that time for a restenosis in the mid SFA and had ballooning and a stent -the second set of stents in this patient, and by the time I left Iowa, he was still patent and walking.

This operation fails with randomly distributed TASC A lesions that develop in sites of remnant smooth muscle. I think today, I would treat with a drug eluting balloon. Thrombosis is the other failure mode, but unlike PTFE grafts, there is no thromboembolism of the outflow, rather, the SFA thromboses with reconstitution of the original state, and is amenable to thrombolysis. Smokers such as this patient and those with limited outflow are anticoagulated with warfarin.

The Europeans call this now arterial restoration. The vessel is returned to its baseline state with a full complement of collaterals which are revived. Also, compliance is restored and I believe this plays a significant role in maintenance of patency. Also, as the native tissues heal, they return to a normal ultrastructure -I have taken pathology specimen with aortic punches to perform bypasses to the other leg from external iliacs treated so, and they were microscopically and visibly normal.

Tags arterial restoration, endoRE, stent removal

open aneurysm surgery taaa thoracabdominal aortic aneurysm

Ruptured Thoracoabdominal Aortic Aneurysm In 88 Year Old -a survival

Post author By docpark
Post date 22 Aug 2015
1 Comment on Ruptured Thoracoabdominal Aortic Aneurysm In 88 Year Old -a survival

The patient, an active 88 year old man, was transferred from an outside institution after a CT scan revealed a 9cm thoracoabdominal aortic aneurysm on workup of sudden onset back pain. On transfer, his blood pressure was stable but low in the 90’s. On arrival, his blood pressure dropped into the 60’s but responded to resuscitation, and after a detailed conversation with him about the risks of emergent repair, we brought him to the operating room.

The CT scan showed an 8.3cm extant III thoracabdominal aortic aneurysm which originated slightly above the diaphgragmatic hiatus and extended to the aortic bifurcation in two lobes. The larger lobe involved the visceral vessels and the infrarenal component was about 5cm.

While there was no frank rupture on the CT, the outside report mentioned haziness of the posterior wall consistent with ongoing rupture. Examination was significant for hypotension, abdominal and back pain, and a large pulsatile mass in the abdomen.

Despite the lack of contrast on this study, I was able to get a centerline reconstruction. The 3D virtual reality view then allows me to plan the operation virtually. The red and blue lines above bracket the beginning and end of the aortic aneurysm with the patient in a right lateral decubitus projection. A thoracoabdominal incision starting on the 8th rib was planned.

The patient remained stable through the intubation with a dual lumen endotracheal tube. The chest was entered and the left lung collapsed and the thoracic aorta in the chest was controlled for clamping. The retroperitoneum was dissected and the abdominal contents allowed to fall away exposing the remainder of the aneurysm. The diaphragm was taken down circumferentially. The aneurysm was leaking -not frankly but there was blood visible on the surface like a bruised, overripe plum of unusually large size.

The aorta was clamped in the chest after giving the patient 5000 units of heparin -I often don’t if there is a lot of blood loss and I anticipate factor depletion. The transdiaphragmatic aorta was controlled and the celiac axis (CA), superior mesenteric artery (SMA), and left renal artery were controlled with vessel loops. The aortic bifurcation was controlled as well after I considered anastomosing to the narrow segment of aorta around the renal arteries. While saving the infrarenal aneurysm for later has an appeal, I feel that if you cut the graft and start sewing to the aorta and find that it is not of good quality, you have wasted time. The aortic clamp was moved down from the chest to the transdiagphragmatic aorta which was now mobilized. This avoided for me some spinal cord ischemia but can be a risky move because the aorta was not healthy even in the nonaneurysmal segments. A 32mm Dacron graft what had 4 branches was brought into the field and anastomosed proximally with 4-0 polypropylene suture.

I picked up using narrow gauge suture for aortic anastomoses from my cardiothoracic surgery confreres at the Clinic (Eric Roselli, MD). They will use 5-0 polypropylene with the idea that the smaller needles result in smaller needle holes. I used to use 2-0 suture with an MH needle and have seen my partners be successful at it, often buttressing the anastomosis with a gusset (Dan Clair), but this patient had the tensile strength to take suture well so I went with the smaller SH needle and smaller gauge suture. Other maneuvers include sewing to a strip of Teflon, or in the case of terrible aortic tissues, using interrupted sutures which give some added stability but at the cost of time (credit to Tom Bower).

Time is the killer. While cell salvage gives you some margin for blood loss, this is lost with coagulopathy and hypothermia. The grafts to the viscera were sent from distal to proximal -I feel this greatly eases wire access if needed from a femoral access. There can be a problem with twisting, and I avoid this two ways -by allowing for generous length with looping around the main graft to create forgiveness -closing the retroperitoneum inevitably twists the graft -this I credit to my former partner Pat O’Hara who retired last year. The right renal artery received the first graft while cold saline was given to the left renal artery which was revascularized last. Neither had ostial lesions which I have learned to stent with a bare metal stent directly with the artery open -this I credit to Jeanwan Kang, MD, one of my current partners. The CA graft resulted in great back bleeding from the SMA. The SMA graft and left renal artery grafts completed the visceral segment of the case.

The distal anastomosis was challenging because the bifurcation was heavily calcified. I have to say, the distal often will give me fits when the proximal does not because of the calcium. I generally do perform an endarectomy, but this often results in very poor remnant adventitia. The advice here is be prepared to go distally, but consider that it may add time to the case.

The hemostasis was obtained -the most important factor in hemostasis is early and successful repercussion. The wound was restored with repair of the diaphragm, closure of the chest over two chest tubes and closure of the abdomen.

The success of these patients only begins with the operation which I cannot do without the active participation of our cardiac anesthesia, nursing, and trainees -our fellow Eric Shang did his work competently. I am fortunate to have strong help in our vascular intensive care unit. There, my patient was actively resuscitated with blood product, stabilized, and weaned off the ventilator within 2 days. Fortunately, he was not paralyzed by this operation which can happen in up to 10% of patient. Also, his renal function stabilized and he never required dialysis. He was eventually discharged to rehab in under 2 weeks. He returned to my office about a month after the rupture, walked in, accompanied by his family. He was making progress with his rehab, and his wounds had healed well.

Various indices are formulated to predict outcome, which traditionally are viewed as poor for open repair on octogenarians. I am still old fashioned and rely on the “eyeball” test. Several risk stratifying schemes have been published. Most recently, the group from Harborview (link, another link) published a simple stratification scheme for infrarenal AAA rupture. Garland et al (in press) found that having combinations of the following factors predicted mortality well for ruptured AAA including:

Age >76
preop Cr>2.0mg/dL
BP<70mmHg at any point
arterial pH<7.2

Mortality risk based on number 1-4 of positive risk predictors — Mortality risk

If this was a ruptured infrarenal AAA, the patient had two of the risk factors -age>76 and BP<70mmHg, which conferred a risk of 80% mortality for open repair, which translates to a higher number for thoracoabdominal aortic aneurysm repair.

One of our recent aortic fellows, Muhammad Aftab, published the Baylor experience on open repair of TAAA when he was there and found that for open repair, rupture conferred an independent risk for death with a OR of 5.7.

Despite the dismal statistics, several intangibles did favor survival in the patient. He was at 88 still a working professional. He exercised everyday and was fit. He did not drink to excess and never smoked. And he had complete understanding during our preoperative conversation and had a strong grip. And he survived waiting several hours at his hospital for workup and eventual transfer which is a stress test. This last factor accounts for the higher mortality rates for rupture that occurs in hospitals and in places like Seattle where the EMS transport is highly efficient, and better mortality rates at rural referral centers like Mayo where the filtering effect of time leaves a greater proportion of patients likely to survive an operation for rupture.

Reference

Aftab et al. J Thorac Cardiovasc Surg 2015;149:S34-S41

Tags open aortic aneurysm repair, ruptured aortic aneurysm, ruptured thoracoabdominal aortic aneurysm

acute mesenteric ischemia aortic dissection tbad techniques TEVAR type b aortic dissection visceral malperfusion

Acute Aortic Syndrome Unit -TBAD with SMA Dissection and Thrombosis with Acute Mesenteric Ischemia

Post author By docpark
Post date 19 Aug 2015
No Comments on Acute Aortic Syndrome Unit -TBAD with SMA Dissection and Thrombosis with Acute Mesenteric Ischemia

The figure above shows the summarizes the problem that brought the patient to his local hospital and triggered his transfer to our acute aortic syndrome unit. The concept is that all chest pain of cardiovascular origin gets intake through a vast intensive care unit staffed by cardiovascular intensivists. Stabilization, workup, transfer to operating room or interventional suite all happens in an ICU that encompasses almost a city block.

The patient is an older middle aged man with sudden onset of back and abdominal pain. He was on coumadin for a prior SMV thrombosis and treatment for a ruptured appendicitis -antibiotics with plan for staged appendectomy. CT at his local hospital revealed a type B aortic dissection (TBAD) that extended into his superior mesenteric artery.

Bovine arch in 3DVR view on TeraRecon Aquarius reconstruction. — Bovine arch and TBAD in 3DVR view on TeraRecon Aquarius reconstruction.

The aortic dissection terminated in the infrarenal aorta. The celiac and SMA had true and false lumen perfusion, the right kidney was perfused through the false lumen, the left through the true. Both legs received true lumen flow.

The dissection started at the left subclavian artery origin. The false lumen compressed the true lumen up at the proximal descending thoracic aorta. This is an important finding because in this configuration with much of the filling of the dissection from the distal reentry sites, the false lumen acts like a pressurized, compressive lesion. With time, the adventitia around the false lumen may become aneurysmal if the false lumen fails to thrombose or obliterate. When the dissection is acute, the flap may cause a direct obstruction to flow or a dynamic one that depends on the pressure difference between true and false lumen.

In this patient, thrombosis occured in the SMA beyond the origin due to dissection and decreased flow. This was consistent with the patient’s complaint of generalized abdominal pain and examination findings of pain out of proportion to the exam, indicating acute mesenteric ischemia.

His laboratory findings were within normal ranges, indicating this was early in the process. It is important to remember that no lab value correlates with acute mesenteric ischemia except very late in the process, and acute mesenteric ischemia remains a clinical diagnosis (reference 1) that is associated with a high mortality rate.

He was taken to the hybrid operating room. Right groin access was achieved and wire access to the arch was achieved. IVUS (Intravascular ultrasound, Volcano) was used to confirm the location of the wire -I believe this is an important adjunct as simply passing the wire doesn’t guarantee travel up the true lumen.

IVUS confirming true lumen access, and dissection flap compressing SMA origin

A conformable TAG endograft (CTAG, Gore) was delivered through a 24F sheath into position. Two devices were used to cover the thoracic aorta from the left subclavian artery to a position immediately above the celiac axis. The left subclavian was partially covered -the bare stents covering the rest.

Partial coverage of the left subclavian artery confirmed by persistence of strong left brachial artery pulse

Post Deployment of two 40mmx20cm CTAG (Gore) endografts

This excluded the proximal entry tear of the TBAD. IVUS (image below) showed improved lumenal diameter of the true lumen into the SMA.

After stent graft placement in the thoracic aorta, the true lumen into the SMA expands

Once this was done, wire access into the SMA was achieved. This was technically challenging from the groin, and the backup plan was access from the left brachial artery which had been prepped. With patience, 6French access into the SMA was achieved. The origin was stented with a balloon expandable 8mm x3cm stent -sizing was based on IVUS and CT. This creates an alarming arteriogram as the stent appears oversized on subsequent runs -it is important to remember that the false lumen still takes up space beyond. Arteriography located the thrombosed segment and the reconstituted SMA beyond.

Wire access was achieved across the thrombus. At this point, I had a range of options for thrombectomy including simply aspirating which retracting a catheter. This was not optimal as I could lose subsequent wire access or reenter the false lumen. The other option was an open thrombectomy and patch angioplasty -the thighs were prepped in case we had to harvest vein. Again, in the setting of dissection and going into the mesentery, an open revascularization while feasible, is challenging.

Thrombectomy catheters like Angiojet were available, but I chose to try the Export aspiration catheter (Medtronic). It is simple to set up and goes over a 0.14 wire. It is designed for the coronaries which have a similar lumenal diameter as the SMA. It worked well in this setting in retrieving thrombus which had a pale element that may have indicated some chronicity.

The completion arteriogram was satisfying.

The SMA completely filled as did the celiac axis and both renal arteries. I opted not to treat the right renal artery as we had given 250mL of contrast, and it was filling well without intervention. The patient was making excellent urine and his blood pressure had been maintained with mean arterial pressures above 70mmHg. At this point, IVUS confirmed good deployment of the stent.

The sheath was removed and the access site repaired. The general surgeons explored the patient and found all the bowel to be well perfused with pulsatile flows seen in the mesenteric arcade. The appendix was removed.

On waking, the patient was noted to not move his legs. A spinal drain was expertly placed by our cardiac anesthesia staff and his blood pressure was raised to MAP’s above 80. He recovered motor function in his legs soon after. I usually don’t place preop CSF drains in this scenario in the presence of good pelvic circulation, no history of infrarenal aortic interventions, and patency of the left subclavian artery. That said, with TEVAR of TBAD, there is a small incidence of paraplegia (1-5%) which I emphasize in my preoperative discussion.

He was started on heparin anticoagulation postop because of his history of SMV and now SMA thrombosis, interrupting it briefly to remove the CSF drain. A CTA was obtained to confirm absence of bleeding showing obliteration of the dissection in the aorta and good patency through the true lumen of the SMA.

Most importantly, he had complete relief of his abdominal pain.

The treatment of acute mesenteric ischemia has greatly evolved since I presented my paper in 2002. While open revascularization remains a gold standard, it is becoming increasingly apparent that good to better results may be obtained with an endovascular approach. Dan Clair, our chair, has made the comment that early revascularization with endovascular technique is analogous to emergent PTCA in occlusions of the coronary system and that re-establishing flow is a critical first step.

Open exploration still is the mainstay of managing acute mesenteric ischemia, but laparoscopic exploration remains feasible. This patient underwent open conversion after an initial laparoscopic exploration to remove a ruptured retrocecal appendix that had been treated for over a month on antibiotics. Without bowel necrosis, a second look is usually unnecessary, but is critical when threatened bowel is left behind.

Reference

Park WM et al. J Vasc Surg. 2002 Mar;35(3):445-52.

Tags acute mesenteric ischemia, aortic dissection, dissection, TBAD, thoracic aortic dissection, type b aortic dissection, visceral malperfusion

EVAR peripheral aneurysm techniques

Parallel Grafts in the iliac bifurcation -an option at least until branched grafts become commercially available

Post author By docpark
Post date 13 Aug 2015
No Comments on Parallel Grafts in the iliac bifurcation -an option at least until branched grafts become commercially available

This patient had developed metachronous common iliac artery aneurysms after aorto-bi-iliac graft placement of a AAA a decade ago. This is not infrequent occurence in a significant number of patients with aneurysmal degeneration seen in the thoracic or visceral segment abdominal aorta, iliac arteries, and popliteal arteries, years after a primary AAA repair. The patients are often older than they were at the original repair, with concomitant risk factors, and so a minimally invasive option is preferred.

Right CIAA -vulnerable tissue

The teaching during my fellowship was that aorto-iliac bypasses for aneurysmal disease were to be taken to the iliac bifurcation to go around vulnerable tissues. These tissues vulnerable to aneurysmal degeneration were infrarenal aorta up to the renal artery origins, common iliac and internal iliac arteries, and popliteal arteries. An anastomosis to the iliac bifurcation however normal appearing may degenerate given enough time. This patient developed a saccular aneurysm on the right iliac bifurcation and a small internal iliac artery aneurysm (1.5cm).

This was treated with coil embolization and stent graft from the right iliac limb to the external iliac artery.

This is the standard endovascular therapy for common iliac artery aneurysms, and acceptable in the setting of unilateral disease, and in a staged fashion has been considered acceptable for bilateral disease, acknowledging there is a 10-40% incidence of buttock claudication and when the contralateral hypogastric is occluded or when the patient is diabetic, the risk of buttock or colorectal necrosis is not insignificant. The patient had transiently some buttock claudication and hip and thigh neuralgia with walking but this improved in the weeks leading up to treating his left common iliac artery aneurysm.

Left CIAA

The left common iliac artery bifurcation is sometimes challenging to access from a midline incision and exposure requiring a separate sigmoid mobilization. In men, the narrow pelvis can increase the challenge, so it is without fault that sometimes common iliac artery is left behind. This is what became aneurysmal, developing into a 3.0cm fusiform aneurysm beyond the left limb of the graft.

The internal iliac artery had a moderate 50-75% stenosis at its origin but was not aneurysmal, and I chose to revascularize this. The patient was sexually active and walked for exercise. My options included proceeding with left hypogastric embolization and stent grafting, mirroring the right but with a significant risk for buttock claudication, sexual dysfunction, and a small risk for colorectal ischemia. Other option is an external iliac or common femoral to internal iliac artery bypass which is an excellent option in good risk patients.

Endovascular options

Iliac branched stent grafts are undergoing trial. My center is participating in both available industrial FDA approval trials (disclosure, I am site PI for the Gore trial), but this patient’s presentation and anatomy exclude him from the trials. The final option is placing a parallel stent grafts -one to the internal iliac artery and the other to the external iliac artery from a large common iliac stent graft. While not ideal, until branched grafts become available, this remains a viable option. The principle is to size the grafts to minimize potential gutters between the grafts, and have long seal zones to minimize the impact of the gutters. Access from two points is required to get two grafts into position. With the acute angle of the aortobi-iliac graft, up and over access is generally not possible. The 10mm Viabahn graft that I chose to place in the hypogastric requires a 12Fr sheath, which cannot be placed from the brachial artery, so I prepped for an axillary cutdown. The left common femoral access was percutaneous.

The left CFA access allowed placement of a 16mmx10cm Excluder iliac graft limb to cover the aneurysm down to the iliac bifurcation. The left axillary arterial cutdown access allowed placement of a 12Fr sheath (Flexor) to allow access of the left internal iliac artery and safe delivery of a 10mm Viabahn stent graft. The left external iliac artery was sealed with a 13mm Viabahn stent graft that was deployed simultaneously. Ballooning was performed to both.

No leak was seen. The axillary access was repaired directly and the CFA access was repaired with two Perclose S devices.

Discussion

Despite initial acceptance of bilateral hypogastric occlusion, even staged, it can be the cause of significant disability aside from buttock claudication, which sometimes does not remit with exercise. Ischemia of the pelvis can drive a plexopathy that can result in motor and sensory neuropathy and disability. Death can occur. Preserving one of the hypogastrics can go a long way to preventing these complications, and everyone eagerly awaits adding iliac branched grafts to the armamentarium.

Tags coil embolization, common iliac artery aneurysm, parallel graft

PAD remote endarterectromy techniques

Arterial Restoration: more than just a pretty name

Post author By docpark
Post date 7 Aug 2015
No Comments on Arterial Restoration: more than just a pretty name

Progression — CTA on left shows occlusive plaque in SFA but contiguous plaque from external iliac origin into the popliteal artery. This was removed with EndoRE resulting in restoration of original artery patency -arteriogram on right. A single short stent was placed in the EIA origin and the above knee popliteal artery received a short stent as well.

This patient is a 90 plus year old man who developed ever worsening claudication to the point he was disabled and more worryingly, had developed pain over his left heel. His ABI’s were severely diminished.

CTA showed that he had an occluded SFA with above knee reconstitute, but also had only single vessel runoff to the foot via a heavily diseased posterior tibial artery that had serial mild to moderate stenoses.

An attempt at endovascular recanalization was performed at an outside institution, but the SFA lesion could not be crossed. Bypass was not a good option -the ipsilateral saphenous vein had been harvested for CABG, and a long operation was going to have a significant impact on this patient who also had mild dementia and drank 2-3 glasses of wine a day. It is not uncommon to have a successful operation, but have the patient lose 2-3 months in recovering from the physical effects of a long operation as well as from perioperative delirium.

I felt that removing the occlusive plaque from his arteries offered a minimally invasive solution. The plaque was easily accessible via an oblique, skin line incision in the groin, and clearance could be performed from the external iliac artery origin to the planned endpoint slightly beyond Hunter’s canal. While the outflow was not perfect, in my experience, aside from a single native vein bypass, long segment restoration of vessel elasticity results in very acceptable patency rates.

Remote endarterectomy is a bit of a lost art from the early days of vascular surgery. A ring dissector (Vollmer Ring Dissector, LeMaitre Vascular) is used to liberate the plaque from the remnant adventia. A cutting device (Moll Ring Cutter, LeMaitre Vascular) shown third from left below is used to divide the plaque.

The common femoral artery plaque is usually contiguous with plaque in the external iliac artery and surgeons who perform a lot of CFA endarterectomy have various maneuvers to remove as much plaque as possible, up to stenting the end point of the plaque down to the endarterectomy patch. I have never been satisfied with this because the EIA behaves differenty than the CIA (am looking into this!) in my experience and placing stents even minimally across the inguinal ligament is not desirable. Sending the dissector up to the EIA origin frees the plaque to be removed completely with the CFA plaque. The clip below shows the Vollmer Ring dissecting plaque up to the EIA origin. I do this over a wire in the pelvis because in the rare instance of leak or rupture, rapid control is possible without having to open the abdomen.

Once freed, the cutter is used to transect the plaque and the end point is tacked down with a stent at the distal common iliac/EIA origin which is a better place for a stent than the inguinal ligament.

The PFA in this patient did not require endarterectomy and reconstruction, but if it did, I would have made the arteriotomy go onto the profunda from the CFA. The SFA plaque is then mobilized with the Vollmer ring. I don’t do this over a wire, but have a definite end point in mind based on what I see on CTA.

The CTA (images earlier) shows that the above knee popliteal artery has no significant calcified plaque. This doesn’t mean there isn’t fibrotic plaque. Cutting the plaque as in the clip below results in a coned in antegrade dissection which has to be crossed in the true lumen.

This is technically the most difficult part of the EndoRE procedure and it requires good imaging and wire skills. The trick here is that an ultrasound guided puncture of the popliteal or tibial vessel can give you distal true lumen access if needed. It was not necessary in this patient. The better maneuver is if the end point is surgically accessible is to cut down and tack down the plaque and patch the arteriotomy.

The patient regained multiphasic PT and DP signals at the end of the case, after the common femoral artery was patched and flow restored. The small groin incision was closed with a running absorbable monofilament after multilayer deep closure. The patient had a blood loss of 50mL. An ilioinguinal field block and local anesthesia provided excellent pain control. Postoperative ABI was improved to 0.82 from 0.34 and all pain was relieved. The patient felt good enough to go home on postoperative day 1.

This illustrates what I feel to be a best application of both open and endovascular techniques. The above knee popliteal stent is short and in a position that is not going to result in fracture. The external iliac stent is in a protected position in the pelvis and quite large -10mm, which I expect will stay open for the life of the patient. The profunda femoral artery, the rescue artery, is widely patent, and numerous collaterals off the SFA have been restored to patency which I feel aid in maintaining the patency of this repair, along with the restored elasticity of the artery which mimics the biomechanics of autologous vein.

In most patients with compromised outflow, I start warfarin along with ASA at 81mg. Because of his age, I opted for Plavix+ASA. These fail with the development of random TASC A restenoses along the SFA which are amenable to balloon angioplasty. The role of drug eluting balloons in this situation is unknown but theoretically promising. Occlusion through thrombosis does not result in embolization and limb loss as in failure of prosthetic bypass grafts (another option in this patient), but rather leaves a situation where endovascular thrombectomy or lysis is technically feasible.

The great thing is that this is by far superior to stenting of a TASC D femoral arterial lesion.

Tags endoleak, external iliac artery remote endarterectomy, iliac remote endarterectomy, minimally invasive femoropopliteal revascularization

imaging Lymphatic training

Mind the Lymphatics: managing a persistent postoperative seroma

Post author By docpark
Post date 22 Jul 2015
2 Comments on Mind the Lymphatics: managing a persistent postoperative seroma

The patient was referred from an outside institution for the development of a large tender mass in her below knee incision after a femoropopliteal bypass done with PTFE for ischemia after a aorto-bifemoral bypass. The patient reported swelling that grew in the months after the operation to the point that she was unable to walk without pain. On examination, she had a Nerf football sized swelling in her previous below knee incision without erythema. It was quite tender. CTA showed a patent aorto-bifemoral bypass and a femoropopliteal bypass to the below knee popliteal artery. Incidentally noted was the absence or occlusion of the profunda femoral artery. There was bland lymphedema below the knee.

Differential diagnosis included:

Graft Infection
Seroma from PTFE ultrafiltration leak
Seroma from lymph leak.

Graft infections can present like this, but also drive local and systemic inflammation and in the absence of fevers and white counts, was highly unlikely. Occasionally, indolent infections with S. epidermidis will present with fluid collections but typically this is a late presentation. Ultrafiltration leaks from PTFE are fairly rare in my practice but can occur randomly. Most PTFE grafts nowadays come with an external wrap that acts as a seal against microporosity, but on occasion, I have seen protein rich fluid accumulated around PTFE grafts. This typically is not high pressure and accumulates along significant or whole length of graft. I used to treat that with graft excision and replacement, but I have had success with relining the graft with PTFE based stent grafts and externally draining the seroma.

I suspected this to be a seroma from lymphatic leak. The lymphatics are an unusual system of vessels in that they are remnants of an earlier circulatory system that was designed to move and mix nutrients and primitive phagocytic immune cells throughout the external compartment of an organism. They are diaphanous vessels that have smooth muscles that periodically contract like cardiac muscle, propelling fluid and cellular components past valves. Typically, cautery, suturing, and the inflammation of wound healing are sufficient to close lymphatics, but when there is potential space and a large lymphatic trunk that has been divided within it, that space will be filled with fluid, particularly with edema fluid that accumulates post surgically with dependency.

This patient was treated with I&D, but the lymphatic was identified by injection with Isosulfan blue in the subcutaneous space of the foot (between the toes). The dye is avidly taken up by the lymphatics and it can be used to identify the leak, allowing for extirpation and closure.

Isosulfan blue is injected into the subcutaneous spaces between the toes.

The vital dye will be cleared by the kidney -the pee will be greenish blue for a day or two. This is contraindicated in patients with known sulfa allergies.

The dye is seen in the wound within minutes without any added measures -no pumping or massaging was required. The patient had begun spontaneously draining the night before her operation.

The dye concentrates in the lymphatics which are easily identified.

The lymphatics were ablated and a VAC dressing was applied. Two weeks later, there has been significant healing with complete resolution of the seroma.

Loss of lymphatics at this level does not cause permanent injury but clearance of edema is slowed. Clearly, the avoidance of lymph leaks is the first step in preventing seromata, but when they occur, it is simple enough to identify and treat them using this technique.

They are one way self circulating pipes and therefore treating the afferent termini is all that is necessary.

Tags lymph leak, postop fluid collection, seroma

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