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aortoiliac occlusive disease (AIOD) bypass chronic limb threatening ischemia Practice techniques

Durability is the Gift that Keeps Giving

The patient was a 50 something year old man who I took care of in 2016 before I left for Abu Dhabi. He had a background of hypertension, hypercholesterolemia, and IDDM with chronic immunosuppression for rheumatoid arthritis. For several weeks he had rest pain in his feet and impending gangrene of his left great toe. More worrisome was the development of punched out ulcers on his groin crease resulting in weeping wounds after a bout of cellulitis. He had no palpable femoral pulses. Pulse volume recordings showed flat lines from the thigh to the feet.

CTA of the abdomen and pelvis with runoff showed aortic occlusion due to heavily calcified plaque with reconstitution of the external iliac arteries via the internal iliac arteries. The common femoral arteries were only mildly diseased and there was patent runoff.

Centerline up right femoral into aorta shows occluded aorto-iliac segment and diseased external iliac artery.
Centerline up left femoral into aorta shows mirror image of disease on left side

He was one of the rare instances of chronic limb threatening ischemia due to aortoiliac occlusive disease, AKA Leriche syndrome. The added background of autoimmunity made him vulnerable to the ulcers in the groin crease, and the infections there made access challenging.

Leriche Syndrome

The choices were endovascular versus open surgical repair. The groins were a problem with recent cellulitis, immunosuppression and open wounds, but with careful prep, and coverage with Ioban, access was possible, even for stent grafting. The problem was the aortic bifurcation was heavily calcified, and manipulating this likely thrombotic material with an end stump of aorta can cause renal embolism. There was a small risk of rupture at the bifurcation and of renal failure.

Standard aortobifemoral bypass graft was out of the question because of the lack of a safely clampable aorta -there was circumferential aortic plaque below and above the renal arteries and the infections in the groins would jeopardize any prosthetic graft. You have to respect unclampable aortas but like anything else, there are ways around it (link).

Regarding the groins, during fellowship, Dr. Thomas Bower used to take the distal anastomoses to the external iliac arteries which could be exposed via short lower abdominal incisions if not through the midline incision itself, avoiding groin incisions in hazardous groins.


I performed an aorto-bi-iliac bypass using the balloon in the infrarenal technique after obtaining supraceliac control described in my technical post (link).

A small aortotomy can be controlled with a finger and a foley easily slipped in -just remember to clamp it
This typically provides adequate hemostasis and space to perform a proximal anastomosis

I was able to endarterectomize a nice segment of aorta and anastomose end to side -always end to side as it preserves endovascular options. The distal anastomoses was to the external iliac arteries. He did well in the immediate postoperative period but I soon left for Abu Dhabi.

In the five years since the operation, he has needed an SMA stent and has devloped worsening CKD and autoimmune diseases. But one of the gratifying things is he healed his wounds on this groins and thighs and the left hallux, and pain has never recurred. He had a contrast CT at the 5 year point (figure) showing a widely patent graft, and he sought me out when he heard that I was back in Cleveland.

His PVRs remain normal (figure).

The PVRs and ABI’s remain robustly normal even after 5 years

I’m not saying that iliac stents from the iliac bifurcation to the renal arteries was a bad option, but there is a particular sadness and weariness when I have to take care of occluded stents. As an engineer, what is worse than ballooning an occluded stent and placing another stent inside? Knowing what I know about cell biology, what is worse than lasering, drilling, cutting, that cicatricial scar tissue that is neointimal hyperplasia in terms of what you leave behind. This man still has decades left to live and he will have his bypass graft far longer than any stent. This durability, a byproduct of the technique, is a worthy virtue.

When I operated, he was in his mid fifties and despite his comorbidities, was able to undergo a big operation. Now he is in his sixties and his autoimmune issues have progressed to where he is suffering from stiff person syndrome with difficulty walking. His renal function is poor and overall he is a terrible open surgical candidate. If I had done interventions at that time, which I was tempted to, he could today be facing amputations in the setting of cytotoxic immunosuppression having run out of endovascular options.

We have lost too much to innovation. The fact is, aortic surgery for critical limb ischemia was once and it still is a thing, because it works.

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acute limb ischemia bypass chronic limb threatening ischemia cli clti cost innovation hybrid technique limb salvage Practice techniques vascular lab

MacGyvering as tactical innovation -set your mind free.

The patient is a 70 year old man with risk factors of cigarette smoking, type II diabetes mellitus, hypertension, and hypercholesterolemia who presents with rest pain and gangrene of the tip of his left great toe. Several weeks prior to this, he went to his pharmacy and received a flu vaccination and picked up over the counter topical medication for an ingrown toenail. who developed pain from an ingrown toenail. Several weeks later, the tip of his toe blackened and the pain became unbearable and he came to the hospital.

No pulses, dry gangrene of tip of toe

Physical examination was notable for the dry gangrene affecting the distal phalanx of the left hallux. There was a left femoral pulse, but nothing was palpable below. His forefoot was cool and painful and this pain was relieved with dependency.

Pulse volume recording showed a drop in flow across the left knee and flate waveforms at the ankle, foot, and digits. The ABI was zero. WIfI 2 3 2, Stage 4, potential benefit of revascularization high (reference 1). CTA was performed and revealed patent aortoiliac segment, patent common femoral and profunda femoral arteries, with occlusion of the mid to distal SFA, reconstitution of the above knee popliteal artery with 2 vessel runoff via a patent posterior tibial and peroneal arteries.

CTA VR Reconstruction Shows Reconstitution of AK POP and 2V Runoff via PT and Peroneal Arteries

The centerline reconstructions, adapted from aortic planning, lets me determine the character of the arteries for size, calcification, stiffness, collateralization, and length of occlusion. This was had low density and given the timecourse of the events -from claudication to gangrene, and the lack of collaterization implying an acute process possibly on a chronic lesion, I felt there was likely to be some thrombus burden over a chronic plaque across Hunter’s Canal with occlusion of the geniculate arteries. Usually, when the occlusion is chronic, femoropopliteal occlusions of this type come with an ABI of 0.5-0.7, not 0.

GLASS FP:3, IP: 0 Stage II: Intermediate complexity disease

Global Limb Anatomical Staging System (GLASS) Classification of CLTI (reference 2) through the easy to use SVS calculator came out Stage II: Intermediate Complexity. I had the good fortune of being in the audience when GLASS was presented to a rapt audience in Lyons, France, by Dr. John White in 2017, at the ESVS meeting. I include it because Dr. Devin Zarkowsky on a tweet that generated this post wanted WIfI and GLASS. WIfI I find helpful. GLASS I am still figuring out, because it tends to tell me what I already know: this is a lesion of intermediate complexity that could go either way to open or endovascular.

Treatment options include:

  1. Endovascular -starting with POBA and escalating to various additional therapies such as stents, covered stents, DCB, drug coated stents, atherectomy, thrombectomy, thrombolysis (then any of the previously mentioned).
  2. Bypass with PTFE
  3. Bypass with vein
White Arrows Show the Excellent GSV

The data tells us so far that open or endovascular is broadly equivalent, but experience guides me. For rest pain, any incremental increase of flow will do, and it does not necessarily have to be in-line. For healing major tissue loss, there really can’t be enough flow. Bypasses with good runoff deliver a lot of flow. Bypasses with vein have great longevity and the shorter they are, the longer they last.

So is long patency important? Numerous studies have shown that patency does not impact limb salvage or amputation free survival, going to BASIL Trial (reference 3), but even stretching back to Dr. Frank Veith’s advocacy of PTFE bypass to infrageniculate targets (reference 4), patency does not add to limb salvage beyond the initial wound healing. The patency of a PTFE bypass to a tibial target is less than 20% at 5 years, but the limb salvage rate is a laudable 80% plus, and this is repeated in numerous evaluations of POBA, stents, and every new technology that has accrued in the nearly 4 decades since that paper.

What does patency buy you? Less reinterventions. There is nothing worse to me than having to reintervene within a year or two of an intervention. When a bypass works well, the patients just come for a hello-how-do-you-do for years. The BASIL trial concluded that bypass operations were more expensive, and I dispute this. In 2021, operations were far less expensive than the latest energy weapon, their box you have to purchase, and the catheters you use once and throw away. The argument given by interventionalists is that bypass operations are disfiguring and ridden with complications and that argument holds water as there are many points where vascular surgeons fail or have largely stopped work on investigating and optimizing open surgery. What if bypass surgery could be brought to the level of dialysis access surgery in terms of invasiveness? What if groin complications could be minimized? What if long filleting-type incisions of the thigh and leg could be eliminated entirely? What if edema could be prevented or minimized postoperatively to prevent serous drainage and infections? If you focus on the art of bypass surgery and choose patients well, you can get a quick, minimally invasive bypass with the overall physiologic impact of a Brescia-Cimino AV fistula. After considering endovascular, I chose bypass.

This patient had on mapping excellent saphenous vein between 3-5mm in diameter. He had excellent skin and was not obese. A vertical groin incision could be avoided by making a skin line incision over the saphenofemoral junction and transposing it to the adjacent SFA which was patent. Skin line oblique incisions in the groin heal much better than the standard vertical incisions, and it is possible to mobilize and expose the saphenous vein using an appendiceal retractor and clipping the generous proximal thigh tributary. In this patient, the most proximal incision was well away from the inguinal crease, the generator of wound infections in the groin. Essentially, if there is no groin incision there can be no groin complication.

The distal vein is mobilized first before dropping on the above knee popliteal artery which is exposed through a separate incision. This is because the AK POP space is best exposed over the sartorius, and the vein in this patient was well below (posterior) to the sartorius. The vein was tunneled under the sartorius to the AK POP. With the in-situ technique, the proximal anastomosis is completed, then the valves lysed with a retrograde LeMaitre valvulotome. Doing, after two or three passes, the pulse was strong, and the flow strong enough to fling the blood beyond the foot -a key step. If there is no such flow, if there is a weak pulse, or poor blood flight, I do one more pass of the valvulotome then duplex for any large diverting tributaries and tie them off one by one until good flow is achieved.

I do not mobilize the entire vein (and tie off every collateral) unless I cannot do an in-situ technique. It defeats the purpose of this beautiful minimally invasive procedure.

Femoral artery to above knee popliteal bypass with in-situ vein

He recovered rapidly and was discharged home after a partial hallux amputation by podiatry. In followup, he was feeling better. All of his surgical wounds had healed. Duplex and ABI did find this:

Retained valve, very hard to see but present on B-mode, causing a hemodynamically significant stenosis, with ABI of 0.57

I took him to the angiosuite for repair of this retained valve. Rarely, retained valves occur after in-situ bypasses, but require generally unsatisfactory solutions involving either open valvulectomy and patch venoplasty or stenting of a virgin vein. Valvulotomy is possible, but generally described as an open procedure as well, but I had other plans.

Downstream of this retained valve were tributaries which could be seen on duplex, and therefore accessible with a micropuncture needle. This would then allow for placement of a 4F sheath, through which the LeMaitre valvulotome would pass unhindered, allowing for valvulotomy. I would use this session in the angiosuite to deliver embolization coils to the diverting tributaries as well.

Arteriography reveals a retained valve and diverting AVF’s
Retained valve catches the catheter sent up and over from the other side

LeMaitre is a unique company in that it focuses on vascular surgical operations and arises from the original product and reason for the company the eponymous valvulotome. Because it comes sheathed in a low profile catheter, it is immediately familiar to modern surgeons even though it was made in another century.

Cutting of retained valve with LeMaitre valvulotome​ using ultrasound guidance​

Cutting the valves involved passing the valvulotome several under fluoroscopy through a 4F sheath placed through the tributary seen above. After the valvulotomy, the diverting tributaries, only one of which drained quickly into a deep vein, were coiled. At the end of the procedure, a manual cuff was found and an ABI checked. It was now 1.05.

Diverting tributaries coiled

In 2015, the Oxford English Dictionary added McGyver as a verb -“Make or repair (an object) in an improvised or inventive way, making use of whatever items are at hand.” A television show from the 80’s and early 90’s, the main character, McGyver, was able to make useful tools out of what was available, allowing him to come out victorious, but usually just survive. It is a useful concept that is a must have in managing complex and dynamic situations. Just because it hasn’t been done before to your knowledge doesn’t mean that it isn’t a simple solution. I have only one ask that LeMaitre flip their blades around and design an ante grade valvulotome. Those who know what I’m getting at know what I am getting at.

The LeMaitre valvulotome allows for in-situ saphenous vein bypass, a prototypical hybrid vascular procedure from the 80’s that portended the endovascular revolution that followed. It is meant to be used intraoperatively, but because of its low profile, it can be applied.

I will allow that this second procedure likely makes any argument to cost moot, but numerous incisions and extra time in the OR is avoided. The patient now has a vein bypass that could last many years which diminishes the need for follow up procedures to maintain assisted patency.

We will be arguing this point for years even after BEST-CLI is presented. BASIL-2 just closed enrollment. Hopefully we will get some clarity.

Reference

  1. Mills JL Sr, Conte MS, Armstrong DG, Pomposelli FB, Schanzer A, Sidawy AN, Andros G; Society for Vascular Surgery Lower Extremity Guidelines Committee. The Society for Vascular Surgery Lower Extremity Threatened Limb Classification System: risk stratification based on wound, ischemia, and foot infection (WIfI). J Vasc Surg. 2014 Jan;59(1):220-34.e1-2. doi: 10.1016/j.jvs.2013.08.003. Epub 2013 Oct 12. PMID: 24126108.
  2. Conte MS, Bradbury AW, Kolh P, White JV, Dick F, Fitridge R, Mills JL, Ricco JB, Suresh KR, Murad MH; GVG Writing Group. Global vascular guidelines on the management of chronic limb-threatening ischemia. J Vasc Surg. 2019 Jun;69(6S):3S-125S.e40. doi: 10.1016/j.jvs.2019.02.016. Epub 2019 May 28. Erratum in: J Vasc Surg. 2019 Aug;70(2):662. PMID: 31159978; PMCID: PMC8365864.
  3. Adam DJ, Beard JD, Cleveland T, Bell J, Bradbury AW, Forbes JF, Fowkes FG, Gillepsie I, Ruckley CV, Raab G, Storkey H; BASIL trial participants. Bypass versus angioplasty in severe ischaemia of the leg (BASIL): multicentre, randomised controlled trial. Lancet. 2005 Dec 3;366(9501):1925-34. doi: 10.1016/S0140-6736(05)67704-5. PMID: 16325694.
  4. Veith FJ, Gupta SK, Ascer E, White-Flores S, Samson RH, Scher LA, Towne JB, Bernhard VM, Bonier P, Flinn WR, et al. Six-year prospective multicenter randomized comparison of autologous saphenous vein and expanded polytetrafluoroethylene grafts in infrainguinal arterial reconstructions. J Vasc Surg. 1986 Jan;3(1):104-14. doi: 10.1067/mva.1986.avs0030104. PMID: 3510323.

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bypass complications graft infection mycotic aneurysm open aneurysm surgery peripheral aneurysm pseudoaneurysm skunk works techniques

EIA pulldown transposition: another way to treat infected common femoral pseudoaneurysm

Patient with infected femoral pseudoaneurysm, skin necrosis, about to blow

A surgeon from Nepal posted a case of a ruptured common femoral pseudoaneurysm infected from IV drug abuse on LinkedIn. The comments centered around typical textbook responses which were:

  1. Ligate, debride, obturator bypass
  2. In situ bypass with femoral vein +/- sartorius flap
  3. Rifampin soaked graft or crypreserved allograft
  4. Ligate only

My preferred treatment is #2, in-situ bypass with harvest of adjacent deep femoral vein. I never liked that procedure because in general in these patients, everything bleeds. Then I had a thought -how about if you mobilize the external iliac artery in the pelvis over its entire length and pull it out from under the inguinal ligament to sew to the femoral bifurcation or SFA? That is, when you enter the pelvic retroperitoneum to gain proximal control:

The external iliac artery is usually redundant and elastic in young people

You mobilize the external iliac artery from the iliac bifurcation to the inguinal ligament, detaching the inferior epigastrics as a last step. And then you pull it out from under the inguinal ligament, and anastomose it to the femoral bifurcation or the SFA.

The mobilized external iliac artery is pulled down to reach normal femoral artery. The distance x is the length of CFA that needs replacing

This makes sense because in young people and those with AAA and minimal atherosclerosis, the external iliac artery is both redundant and elastic, making it suitable for a pull down transposition. But then, how do you know as you mobilize the artery in the pelvis that you have enough to pull down?

Pythagoras figured that out two an a half millenia ago. If you measure the straight line distance from iliac bifurcation to the takeoff of the inferior epigastric arteries, you get the straight line external iliac artery distance. The length of the common femoral artery which is the excess EIA length needed, is assigned the value x. Then the height of the stretched artery off the line between the iliac bifurcation and the inguinal ligament will determine how much extra artery you have.

Taking these values, I did some maths.

The solution for h, the height, is highlighted in yellow below. (note, the variable x in my notes is half the length of CFA, l is half the length of EIA, ie. 2x is CFA length).

Creating a spreadsheet for CFA lengths from 2 to 6cm and EIA straight distances of 5-10cm, the ratio of height H to CFA length varies from a minimum of 0.7 to maximum of 1.7 with an average of 1.1. That means the majority of the time, if you get 1.5x the length of CFA height off the pelvis, you should reach.

If you are short, you can detach the profunda and mobilize the SFA, pulling upwards, then reattach the PFA. Though this is entirely a thought experiment, there is no reason why it should not work. As with most things, I predict that it already has been done!

The advantages are using autologous tissues and leveraging the natural anatomy. There is a cost benefit in that OR time is shorter with less time for venous harvest and avoiding grafts, patches, and devices. The patient would avoid ischemia as would happen in the staged repair. The disadvantage is when you are short, but if you mobilize the appropriate amount (height off pelvis at least 1.5x the CFA length) you should be okay. The more curvature and tortuosity seen on 3DVR recontstruction and absence of significant atherosclerosis would predict feasibility.

Categories
AIOD aortoiliac occlusive disease (AIOD) bypass complications cost innovation graft infection techniques

The Story Should Fit: Repair of a Stent Graft Infection with Aortoiliac Endarterectomy and Bovine Pericardial Graft

One of the greatest surgical texts, Cope’s Early Diagnosis of the Acute Abdomen, is something every surgical resident, vascular or general, should read. The mid-century edition which I owned during my residency, has since been updated, but the central message of the book is this: every complaint or pain the patient has comes from a nerve, either peripheral or visceral, and understanding the nature of the pain, you narrow the diagnosis to only a few possibilities. Irritation of the psoas muscle results in a characteristic pain that years of diagnosing appendicitis the old fashioned way -by exam, then operation, makes it easy to recognize, like Marilyn Manson showing up as your substitute teacher (I would have said Alice Cooper, but that completely dates me). When the psoas muscle is irritated, by a hematoma, injury, inflammation, or abscess, the muscle relays intense pain localized to the retroperitoneum. Stretching the muscle worsens the pain, and the patient is often seen with the ipsilateral hip flexed. The genitofemoral nerve which rides on top of the psoas, is triggered and there is pain referred to the groin and proximal anterior thigh. Seeing this, and fitting the story allows for a diagnosis, before imaging. Without this insight, there is no swift vector to treatment and resolution.

Patient with inability to straighten left hip after iliac stent placement

The patient, a middle aged man, had undergone a redo-iliac angioplasty and stent for left iliac in-stent restenosis. He relayed that on the table, he felt immediate left lower quadrant abdominal pain and the desire to flex his left hip. He was restrained, sedated, and the procedure finished -a covered stent had been placed. When he came to my office a month after his initial procedure done elsewhere, he was in wheel chair, unable to straighten his leg. He claimed before coming to see me, he had gone to another hospital, where he had a CT scan and was told nothing was wrong (will have to confirm). He was having subjective fevers at home.

On examination, he sat on the exam table with left hip flexed. His pedal pulses were easily palpable. He had furuncles in his groins which he relayed he had had all of his life. I sent him for CTA and subsequently admitted him for surgery.

left iliopsoas abscess

The CT showed a large collection around the left iliac artery and stents and on the psoas muscle, an abscess. The blood cultures on admission were positive for Staphylococcus lugadensis sensitive to penicillin.

Putting the story together after the fact is much easier than when you are in the moment, but being aware of the location and type of pain should give you a clue. Very likely, he had a brief rupture on the angiosuite table resulting in his sudden pain, drowned out by the sedatives typically given in response to a patient moving when a stent is deployed. Inflating a balloon in an artery typically causes some discomfort -as the vessels are lined with visceral nerve fibers which are quite sensitive but less localizable than say a pin poking on the index finger. If you ever had bloating with gas, that general discomfort localizable to the mid abdomen, that nausea and discomfort is from stretched visceral pain fibers. If you have ever had dull aching pain of distended spider veins, that is visceral pain. It’s there, but you would not be able to pinpoint it exactly. That is not what this patient had when he flexed his hip on the angio suite table. While the covered stent was deploying, he likely briefly ruptured causing both somatic and visceral pain around his left common iliac artery and iliopsoas muscle. Additionally, if the sheath had been entered through an area of a skin abscess, likely the sheath, wires, and gloves were contaminated. Any handling of the balloon expandable stent graft, which I highly discourage, would have contaminated it, resulting in a device infection, which was made more likely due to his diabetes. As the hematoma got infected, it resulted in the worsening symptoms he was having of left lower quadrant abdominal pain, groin pain, thigh pain, and inability to straighten his hip without pain.

I took him to the operating room and drained his abscess, assisted by Dr. Andrew Tang, chief resident headed to CT Surgery fellowship here at the Clinic, and Dr. Jenny Chang, PGY 2 Surgery. I gave Dr. Chang a copy of Cope’s with the admonition to read it soon and pass it on, as most of the current generation claim no knowledge of this important text. While I am not against interventional drainage, it takes time to drain the collection through a tube whereas sticking your hand in, sampling the collection, observing the injury, and breaking up collections and washing out with brown-bubbly -a mix of betadine/peroxide diluted in saline, I believe speeds the recovery from the infection. His drainage was done through a retroperitoneal approach from the left side and notably, his psoas muscle while viable, did not retract to cautery energy, suggesting some degree of rhabdomyolysis. The iliac artery was an indurated, thickened, and hard from the calcium and plaque that was the original problem affecting his distal aorta and iliac arteries (see left arteriogram centerline). I placed a pair of JP drains, removed one that wasn’t draining much on POD #3, and the other about a week after discharge on POD#5. His WBC elevation which was never high promptly resolved. I kept him on oxacillin with consultation from ID, and waited. After 3 weeks, I repeated his CTA.

His right iliac centerline showed patent stent with diffuse plaque and calcium starting in mid infrarenal aorta.

His abscess had significantly resolved and his pain was gone. He was ambulating again.

Before and after abscess drainage

The choices at this point were the following

  1. Continue treatment of patient with supressing antibiotics for life
  2. Resection of left iliac stent graft which is presumed to be infected

If resection chosen, the options for repair that I considered included:

  1. NAIS (ref 1). Neoaortoiliac System graft using femoral vein
  2. Aortoiliac homograft
  3. Rifampin soaked gelatin coated graft (ref 2)
  4. Extra-anatomic bypass with axillofemoral bypass or femorofemoral bypass.
  5. Aortoiliac endarterectomy and repair with bovine pericardial patch and graft

The choice of replacement is becoming clearer in that while rifampin soaked grafts offer immediacy and expedience, all grafts seem to be prone to reinfection at a higher rate than autologous material (ref 3). The NAIS bypass is a great option, but is hampered by the addition of several hours invested in harvest of the femoral veins. While it can be staged with mobilization done one day and harvest another, those added hours add complications. We often forget that the simple metric of procedure time is the most important determinant of complication rate. Any operation going over 2 hours risks wound infection for example simply from ambient colonization of the open wounds from the rain of dead skin from the surgeon’s face, aerosolized fecal flora from flatii (prohibited in my ORs). The microenvironment of the open wound is also room temperature and not 37, having an impact on organ function and hemostasis. The homograft is the original aortic graft -before Arthur Voorhees invented the cloth vascular graft as a resident at Columbia P&S (my medical school alma mater, ref 4), major hospitals had tissue banks of aortic homografts harvested from the recently deceased. Having homografts is now an outsourced function, but does require having proper refrigeration for the cyropreserved grafts and generally can’t be ordered with short notice.

Rifampin soaked grafts work well, especially wrapped in omental flap, in the short and medium term but suffer a reinfection rate that is higher than seen with autologous tissues, and prosthetic grafts without rifampin, such as PTFE for extraanatomic bypass, have the highest rates of reinfection (3), despite being the board answer decades ago.

Endarterectomy allows for use of native tissues for repair. The adventitia around plaque and stents, while thin, can support physiologic pressures, even when they have been occluded for years. And while practice of aortoiliac endarterectomy is a bit of a lost art, it has both a long history stretching back nearly a century and a modern track record with carotid and femoral endarterectomy. It is merely a matter of scale. Pinch and zoom in on a femoral endarterectomy at the bifurcation and you have the same case as with an aortic one.

The question is, is bovine pericardium more autologous than prosthetic? It is a decellularized sheet of collagen from a cow’s pericardium, used in heart valves and vascular patches, but only recently applied as a graft (ref 5-7). I have long used bovine pericardium as a patch with some caution, but the rule of thumb is are there well vascularized tissues around it? A layer of Scarpa’s fascia and fat in a groin wound are not sufficient to protect a bovine patch, but a sartorius flap is. For me, once the infected stent graft is out, knowing if the surrounding tissues bleeds well is an important one.

I chose to do aortoiliac endarterectomy. The patch and graft would be made with bovine pericardium, unless I found the left iliac segment to be devitalized and foul with anaerobic vapors, then, I would close and go NAIS or extra-anatomic. The key point is that choices have to be on the table and constantly rearranged during the conduct of the operation.

The patient was preoperatively vein mapped and had suitable deep femoral vein for bypass conduit, having robust duplicated systems that would impact the patient minimally. The patient was placed in a supine position and via a midline laparotomy, the infrarenal aorta and the common iliac arteries beyond the short iliac stents exposed. I chose this limited exposure as any further into the phlegmon on the left risk injury to ureter and vein. The aorta had a palpable demarcation between plaque and mildly diseased proximal segment, predicted by the CTA to be at the IMA. A longitudinal arteriotomy was created on the right side from mid aorta to mid right iliac, and the left side had a separate arteriotomy to release the stent. The plaque came out in a single specimen (image).

The exposed stent is the left iliac stent holding within a stent graft.

The left iliac artery was destroyed by the infection but the tissues around it bled avidly and were not foul or infected. I avoided excess debridement here as the iliac vein was intimate with the phlegmon. There was a 3cm gap. Again, I thought briefly about taking femoral vein, but proceeded to make a graft from the bovine pericardium. This was sewn around the rod portion of a renal vein retractor from the OMNI set. The finished product resembled Voorhees’ graft. It was sewn into the orifice of the iliac from inside the aorta and end to end to the freshened iliac stump. Unfortunately, the omentum was atropic across the transverse colon, but the tissues around the resected artery and stent graft bled well, indicating good penetration of antibiotic. The retroperitoneum was closed after hemostasis obtained. Dr. Shashank Sharma, our chief resident headed to a vascular surgery fellowship at the renown Houston Methodist next year got to see what is unfortunately a rare occurrence -an aortoiliac endarterectomy, which through me puts him three degrees of separation from Cid Dos Santos (ref 8). Dr. D’Andre Williams, PGY-2 Vascular Surgery Resident, got important lessons on sewing the aorta. She’s part of a fortunate cohort that get exposed to open aortic surgery at our main campus which is unfortunately rare throughout the world.

The pericardium was soaked in rifampin, but probably did not bond to the collagen.

The final graphic shows the operative end result.

The patient recovered well and was discharged within the week with another month of IV antibiotics planned.

Before and After

Conclusion: The operation was started at 8 in the morning and was done by lunch time. For aortic cases, this is a crucial metric, as when the clock winds past the surgeon’s comfort, the patient suffers even more. Adding the femoral vein for a NAIS may have been the textbook thing to do, but we don’t do extra-anatomic bypasses that much either. I don’t believe that adding two more hours for retrieving the femoral vein would have enhanced the procedure, and would have served to add potential areas for complication. Technically, the aorta closes much as with a carotid or femoral endarterectomy, but the adventia is thin and really should be sewn with 5-0 or 6-0 Prolene. The larger needles such as the SH size creates unnecessary bleeding unless sewn with a line of felt which could become infected. Despite the thinness, it will hold pressure if it is not infected. Clamps that bend out of the “airspace” above the laparotomy, such as the Cherry Supraceliac Clamp and Wiley Hypogastric Clamp, prevent limiting the operative space with long clamps such as aortic Fogarty or DeBakey clamps, while being stronger than the Zenker.

A final comment for Staphyloccocus lugudensis. This is the second major vascular graft infection with this organism I encountered this year. The other was an infected aortic stent graft. Lugudensis means from Lyons. I do not know why that is, but it is so far not the nasty player that is S. aureus. I am sure it will share some plasmids, and become resistant one day, but in the earlier case in Abu Dhabi and now this, it is sensitive to penicillin, and came from the skin at the femoral puncture site, and for this we are fortunate. Major vascular infections are one of the few areas that still demand open surgical skills, and we foresake them at great peril. It’s critical to remember all the collective memory of surgery from the past, or we will become mere technicians fixing whatever comes out of the radiologist’s report with whatever knowledge obtained from a Zoom meeting for the latest, greatest device.

Acknowledgement

Gratefully, the patient gave his permission, as with all patient, for use of his case for educational purposes.

References

  1. Chung J, Clagett GP. Neoaortoiliac System (NAIS) procedure for the treatment of the infected aortic graft. Semin Vasc Surg. 2011 Dec;24(4):220-6. doi: 10.1053/j.semvascsurg.2011.10.012. PMID: 22230677.
  2. Oderich GS, Bower TC, Hofer J, Kalra M, Duncan AA, Wilson JW, Cha S, Gloviczki P. In situ rifampin-soaked grafts with omental coverage and antibiotic suppression are durable with low reinfection rates in patients with aortic graft enteric erosion or fistula. J Vasc Surg. 2011 Jan;53(1):99-106, 107.e1-7; discussion 106-7. doi: 10.1016/j.jvs.2010.08.018. PMID: 21184932.
  3. Smeds MR, Duncan AA, Harlander-Locke MP, Lawrence PF, Lyden S, Fatima J, Eskandari MK; Vascular Low-Frequency Disease Consortium. Treatment and outcomes of aortic endograft infection. J Vasc Surg. 2016 Feb;63(2):332-40. doi: 10.1016/j.jvs.2015.08.113. PMID: 26804214.
  4. Smith RB 3rd. Arthur B. Voorhees, Jr.: pioneer vascular surgeon. J Vasc Surg. 1993 Sep;18(3):341-8. PMID: 8377227.
  5. Almási-Sperling V, Heger D, Meyer A, Lang W, Rother U. Treatment of aortic and peripheral prosthetic graft infections with bovine pericardium. J Vasc Surg. 2020 Feb;71(2):592-598. doi: 10.1016/j.jvs.2019.04.485. Epub 2019 Jul 18. PMID: 31327614.
  6. Lutz B, Reeps C, Biro G, Knappich C, Zimmermann A, Eckstein HH. Bovine Pericardium as New Technical Option for In Situ Reconstruction of Aortic Graft Infection. Ann Vasc Surg. 2017 May;41:118-126. doi: 10.1016/j.avsg.2016.07.098. Epub 2016 Nov 27. PMID: 27903471.
  7. Belkorissat RA, Sadoul C, Bouziane Z, Saba C, Salomon C, Malikov S, Settembre N. Tubular Reconstruction with Bovine Pericardium Xenografts to Treat Native Aortic Infections. Ann Vasc Surg. 2020 Apr;64:27-32. doi: 10.1016/j.avsg.2019.10.104. Epub 2020 Jan 10. PMID: 31931127.
  8. Barker WF. A history of endarterectomy. Perspectives in Vascular and Endovascular Therapy. 1991;4(1)1-12. doi:10.1177/153100359100400102
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 aortic dissection bypass chronic mesenteric ischemia complications ruptured AAA taaa tbad techniques TEVAR thoracabdominal aortic aneurysm training type b aortic dissection visceral malperfusion

Life imitates social media: a ruptured type V thoracoabdominal aortic aneurysm or IT saves a life

ARTERIAL (2) (2)
Type V TAAA Rupturing into Right Pleural Cavity

It was only last month when I came across a post of an aortic aneurysm in a difficult spot (link) and I couldn’t help chiming in some comments. Reading it now, I sound insufferable, because I wrote,

“Depends on etiology and patient risk stratification. Also assuming aneurysm goes to level of SMA and right renal artery origins and involves side opposite celiac. Options depending on resources of your institute: 1.Open repair with cannulation for left heart bypass and/or circulatory arrest 2.Open debranching of common hepatic, SMA, R. Renal from infrarenal inflow and then TEVAR 3.FEVAR from custom graft from manufacturer on protocol 4.Parallel grafting to CA, SMA, R. RA with TEVAR 5.Surgeon modified FEVAR 6.Open Repair We would have a multidisciplinary huddle around this patient -Vascular, Cardiac Surgery, Cardiology, Anesthesia, and ID (if needed) to help choose. Be ready to refer to a center with more resources -including prepping patient for transfer and imaging -including uploading images to the cloud for transfer with patient’s permission. More info please”

More Info Please, Indeed

The post I commented on was of a saccular aneurysm in the transdiagphragmatic segment of aorta. Ironically, only a few weeks later, I got called from hospital transfer center about a patient with a leaking aortic aneurysm, a type V thoracoabdominal aortic aneurysm as it turned out, from an outside hospital, needing urgent attention, and we accepted in transfer based on the conversation I had with the tranferring physician. And that was the problem -usually in taking these inter-hospital transfers, you have to pray that the precious CT scans come along with the patient burned correctly onto a CD-ROM. You can buy and watch a movie in 4K resolution over the internet -about 4 gigabytes, but a patient’s CT scan which is about 200 megabytes -because of various self imposed limits, overly restrictive interpretations of laws, and lack of computer skills, these life saving images get transferred on CD in 2019. That last time I purchased a CD for anything was over 15 years ago.

An Interested Party

The technical solution –to use the internet to transfer critical life saving information between hospitals – came about when our IT folks took an interest in my quarterly complaint email about using the newfangled internet for sharing files. After mulling various solutions ranging from setting up a server to using commercial cloud solutoins, we came upon the compromise of using our internal cloud with an invitation sent to the outside hospital. I would send this invitation to upload the DICOM folder of the CD-ROM to an outisde email address. It was simple and as yet untried until this night. “Would the patient agree to have his CT scan information transmitted to us electronically?” I asked the other physician. He assured me that the patient was in agreement.

It Takes Two to Tango

Of course, being able to transfer these pictures requires a willing partner on the other side, and the referring physician made it clear he did not have the technical expertise to do so. It took a bit of social engineering to think about who would have that ability. Basically, aside from myself, who spend all their time in dark rooms in the hospital in front of giant computer monitors? The radiologists! I got through to the radiologist who had interpreted the report and explained the simple thing I needed. Gratefully, he agreed, and I sent him a link to our cloud server. I explained to him, “When you receive this, clicking the link opens a browser window and then you open the CD-ROM and find the DICOM folder and drag and drop it on the browser window.” The 200-500 megabytes of data then get sent in electronic form, as it was meant to in 2019.

The Internet Saves a Life

The brutal truth is that in locking down a computer system, many hospitals make it impossible to even load an outside CD-ROM, creating many self imposed barriers to care. Thankfully, at CCAD, we were able to work together to find a secure solution. With the CTA on our servers, I was able to review the study within 15 minutes of accepting the patient, and arrange for the right team to be assembled, and confirm that we had the right material (stent grafts) for treating the patient. When the patient arrived, OR was ready to go, saving hours of time that normally would have been required if the CT scan had to be reviewed from the CD-ROM that came with the patient. Sometimes, the CD-ROM does not come, and in a critical situation, the CTA has to be repeated with some risk to the patient for complications of the contrast and radiation.

What to Do

The patient had a 8cm sphere shaped aneurysm arising in the transdiagphragmatic aorta, leaking into the right pleural cavity.

Screen Shot 2019-06-19 at 9.29.15 PM

The patient was otherwise a healthy middle aged man with risk factors of smoking and hypertension. The centerline reconstructions showed the thoracic aorta above the aneurysm to be around 20mm in diameter and same below, with the celiac axis and superior mesenteric artery in the potential seal zone of a stent graft. The only plaque seen was around the level of the renal arteries and was focal and calcified. Looking at the list I had made as a comment to the Linked-In post, I realized that I really only had one viable option.

ARTERIAL (10).jpeg

Open repair, usually the most expeditious option, was made challenging by the right hemothorax, making a left thoracotomy hazardous if the lung had to be deflated. Cardiopulmonary bypass would have to be arranged for, and that adds a metabolic hit that greatly raises the stakes. Of the endovascular solutions, the only viable option was TEVAR to exclude the rupture and debranching of the celiac axis and superior mesenteric artery. To those who would advocate for parallel grafts, there was no room in the normal 20mm diameter aorta. And branch systems for rupture are some time in the future. Also, the patient was becoming hypotensive. So the planned operation was first TEVAR to stop the bleeding, and then open surgical debranching. A hybrid repair.

plan sketch.PNG

The smallest stent graft we have is a 21mm graft, but it would not be suitable for this aorta. In practice, the normal aorta is quite elastic and will dilate much more than what is captured on a CTA. The next size we have is 28mm graft and I chose this to exclude the rupture, which was done percutaneously.

TEVAR angio.png

As seen below, the graft excluded the celiac and SMA. Late in the phase of the final aortogram (second panel) there was an endoleak that persisteed despite multiple ballooning. The timing suggested the intercostals and phrenic vessels contributed to a type II endoleak, but it was concerning.

postangio.png
Find the Endoleak

The bypasses were sent from the infrarenal aorta to the common hepatic artery and the SMA close to its origin, and the origins of the celiac axis and SMA were clipped. The bypasses were then done with a 10x8mm bifurcate Dacron graft originally for axillofemoral bypassing. It had spiral rings which I removed at the anastomosis and this resulted in a kink at the closer bypass. Usually, I loop this for iliomesenteric bypass but there was not enough distance from the infrarenal aorta. I have to add a little trick I modified from my pediatric surgery experience as a resident -a Heinecke-Mikulwicz graftoplasty:

IMG_2646.JPG

This worked to relieve the kink as evidenced on the aortogram above. After closing the laparotomy, I placed a chest tube in the right chest. The patient had a course prolonged by a classic systemic inflammatory response syndrome, with fevers, chills, and leukocytosis. He bled for a while but stopped with correction of his coagulopathy. All blood cultures were negative, but a CT scan was performed out of concern for the endoleak, and the possibility of continued bleeding.

postCTA.jpg

No endoleak was detected as the sac was fully thrombosed. There was a consolidation of the blood in the right chest, but it resolved with fibrinolytic therapy.

Discussion

This case illustrates several points I have been making on this blog.

  1. Hybrid repairs are not some kind of compromise but the full realization of a complete skill set. When students ask me how to judge a training program, one of the best metrics is how frequently are hybrid operations performed. It means either the endovascularist and open surgical operator are in complete synchrony or there are individual surgeons competent in both open and endovascular surgery. Hybrid operations, rather than being a compromise, are an optimization.
  2. Time -Laying the stent graft across the celiac and SMA origins starts a warm ischemia clock. The liver and intestines, in my reckoning, should be able to tolerate the 2 hours of work to get the bypasses working. Cardiopulmonary bypass may give you less ichemia but at the metabolic cost of the pump time. These negative factors add up, but were surmounted by the fact that early control of hemorrhage was achieved. Stopping the bleeding and restoring flow are the core functions of vascular surgery.
  3. Planning and preparation. The ability to see the CT images and prepare the teams and materiel before the patient transferred was lifesaving. This is where our IT gets credit for responding to a critical need and formulating a solution that meets internal policies, external regulations, and saves a life. It illustrates so many opportunities particularly with electronic medical records and their processes which focus more on documentation for billing. A discharge summary should be multimedia like this blog post and it should be normal and easy to generate. And finally, as clinicians, we should mind technology with as much attention as we give to the latest medical devices and techniques.
Categories
AIOD aortoiliac occlusive disease (AIOD) bypass Commentary EndoRE opinion ultrasound

Arterial Restoration in CLTI with Remote Endarterectomy (EndoRE).

preop PVR

The patient is a man over 70 years of age who came to the hospital with severe pain of his right foot and leg with walking short distances and at night while recumbent. He had a history of hypertension, diabetes, and coronary artery disease, and several years ago had his left common iliac artery stented. On examination, he had no lesions of his foot, and his pulses were only palpable (barely) in the femoral arteries only. He did have strong monophasic signals in the anterior tibial arteries bilaterally.

Initial vascular lab testing showed only mildly depressed ankle brachial (above), with dampened waveforms consistent with inflow and femoropopliteal disease on the right. He underwent arteriography by our vascular medicine specialist and cardiologist Dr. Faisal Hasan, and it showed bilateral common iliac stenoses, a severely calcified and nearly occlusive plaque in the right common femoral artery, and a long segment occlusion in the superficial femoral artery with diffuse calcified plaque extending into the popliteal artery. There was diseased but patent 3 vessel tibial runoff.

aortogram

R SFA arteriogram

To Act As A Unit are the Cleveland Clinic’s words and it shows the Clinic’s roots as an US Army field hospital on the vasty fields of World War I France a little over a century ago, and we take it seriously. It may come as a surprise to some that a cardiologist referred me this patient after mutually deciding that the common femoral disease and the TASC D SFA occlusive disease, but we both decided that a surgical approach was the best one. The question then is how much more flow?

I ordered a CTA (CT angiogram) particularly for endarterectomies as I find it imperative to know the actual end point of plaque. Arteriography only hints at it, and while a 5mm lumen may look large and patent, it may be a channel in a 10mm wide plaque that when a stent terminates within it, breaks and becomes biologically active as intimal hyperplasia at best or embolizes at worst. CTA shown below revealed the plaque where contrast angio showed only the lumena of the vessels.

The 3D reconstruction function also allowed me to see and plan the operative approach and predict the lack of saphenous vein confirmed on duplex ultrasound.

For the students reading this, ischemic rest pain is often simpler to treat because it requires only a little more blood flow. There is a neurologic ischemia component that is not well studied, particularly in diabetics, as ischemia may result in anesthesia in someone who has underlying diabetic neuropathy, but that is not an indication for revascularization while rest pain is, and someone should investigate this. This little more blood flow in the form of treating inflow disease only may be sufficient in relieving rest pain while avoiding interventions on the superficial femoral, popliteal and tibial arteries which have limited longevity.

The common femoral artery on the other hand is the throttle of inflow and as a principle, inflow can be considered as the infrarenal aorta to profunda femoral artery, and repairing the common femoral necessitates an operation. There is no durable or laudable endovascular procedure for occlusive disease of the common femoral artery, a feature shared with the subclavian artery at the thoracic outlet and the celiac axis at the median arcuate ligament. All three are externally compressed by hard structures and revascularization must be ever mindful of the inguinal ligament, the thoracic outlet, and median arcuate ligament. The only exception to the “you must operate” rule of the CFA is calcified atherosclerotic disease in high risk individuals, and I make careful exception here with rotational atherectomy devices.

Claudication is another thing entirely. Claudication limits lifestyle and can be corrected by changing lifestyle -either with more exercise or limiting exercise. The thing is, when a patient has reached a certain age, that lifestyle may be walking slowly from chair to commode, and if that activity is limited, no amount of haranguing may be able to induce that person to embark on an ambitious exercise program. Sometimes, you have to be realistic about telling a frail old man to go for a 60 minute walk. But if that person has difficulty getting to the bathroom because of leg cramps, then either they have to get assistance or more bloodflow, and ironically, a little more blood flow represented by improving inflow, may not be enough.

That was what I was thinking when I was planning this operation. Improve the inflow with stents to the common iliacs and a right CFA endarterectomy, but use the opportunity of surgical exposure to extend the endarterectomy to the distal external iliac and through the entire SFA.

My fondness of remote endarterectomy is well known from my many blog posts on it (link). It is a modern update on a very old procedure -the ring endarterectomy, done since the middle of the last century when bypass grafts were unavailable. The occlusive plaque is removed, and an end-point reached and cut with a scissor like device (available from LeMaitre). It is the ultimate hybrid operation (below) requiring open and endovascular skills. I tell prospective trainees to judge training programs by how facile are the surgeons and how many are the procedures with and involving a hybrid approach, because any program can have few (getting fewer) old surgeons doing only open surgery and a lot of young surgeons doing only endovascular procedures, but a rare few will do a lot of hybrid procedures. endore-graphic.jpg

I chose to add femoral EndoRE. This would bring the extra blood flow needed to kickstart any walking program, barring cardiopulmonary limitations.

The patient was brought to our hybrid operating theatre and prepped from nipples to toes. The right common femoral artery was exposed for endarterectomy, and accessed then with a sheath along with a left femoral sheath for kissing balloon angioplasty and stenting of the common iliac artery stenoses (below).

preinterventionpost kissing stents

Afterword, the CFA was opened and endarterectomized, and the SFA was remote endarterectomized (below).

EndoRE setupEndoRE

The endpoint was chosen in the above knee popliteal artery to avoid having to stent the dissected end point plaque well into the popliteal artery. If I wanted to go all the way to the below knee popliteal artery, I would have to open it to manage the plaque and artery at the so-called trifurcation, typically with a patch angioplasty. The plaque came out in one piece (below):

EndoRE plaqueplaque in toto

The terminus of the plaque in the POP where it was cut has to be managed with a stent, unless you open and complete the endarterectomy and patch the artery. I was able to cross the dissection (no small feat) and plaque a stent. The artery was widely patent and even the small branches off the previously occluded SFA were now reopened.

Endpoint managementbefore and after endoRE

His pulse volume recording done after intervention reflects the improved flows (below).

PVR before and after

His rest pain resolved, but more gratifyingly, he has regained the confidence to walk and exercise, which he now does without limitation up to 45 minutes a day. In two month followup, we performed a duplex which showed his right SFA to be basically normal (below), including an intimal stripe and media. This is not an anomaly. When I took a punch out of restored artery to perform an anastomosis (from this case link), I sent it. Previously it had been an artery that was obstructed for nearly a decade, but after EndoRE, had become an elastic, compliant vessel. The pathology returned as “normal artery.”

postop duplex at 2 months

When these fail, they typically do so a random points on the endarterectomized vessel and on the stent. While stent grafting may have better outcomes with regard to restenosis, doing so covers collateral vessels and PTFE grafts behave poorly by embolizing while clotting off, and PTFE stent grafts are no different. Data from over a decade ago suggests that EndoRE of the SFA while inferior in patency to vein grafts, are equivalent to PTFE [reference 1] and superior to endovascular revascularization [reference 2] in terms of primary patency. When they occlude, they achieve a “soft landing” without the furious acute ischemia and embolization seen with PTFE bypasses.

I think these handful of cases I performed here in the UAE represent the first in the region. The main difference here is that the arteries tend to be smaller by about 20%, and in one instance, the smallest Vollmer ring was too large for the vessel in a case where I abandoned the SFA revascularization -the profunda and inflow revascularization proved sufficient in reversing rest pain. The intriguing property of endarterectomy is something that we all try to do with surgery but rarely achieve -a restoration to an earlier time. I believe this patient’s right femoral artery is now back to a youthful state.

References:

  1. Eur J Vasc Endovasc Surg 2009;37: 68-76

  2. J Vasc Surg 2012;56:1598-605.
Categories
AIOD aortoiliac occlusive disease (AIOD) bypass CTA pheocromacytoma

Incidental Pheochromacytoma

An oldie but a goodie from my first blog, “The Pipes Are Calling” on Medscape. This case came to mind when I recently diagnosed a pheochromacytoma from my clinic -middle aged man with difficult to control hypertension and unilateral renal artery stenosis. One of the most critical lessons learned from medical school, the Columbia University College of Physicians and Surgeons, was to be a complete physician, to be curious and engaged in the well being of your patient even outside the narrow focus of your specialty. This I learned especially from people like Drs. Harold Neu and Mark Hardy.

Incidental Pheochromacytoma

W. Michael Park, MD, Surgery, Vascular, 05:24PM Jun 23, 2010

The patient is a middle aged man who developed rest pain of his left leg after CABG for 3VCAD/MI. Workup revealed an occluded left iliac arterial system with diffuse atherosclerosis of his aorta and iliac arteries. He had a long history of bilateral calf claudication and his right SFA was occluded and his left SFA was diffusely diseased. CTA was performed and showed the described anatomy

And a “2.2cm peripherally enhancing mass” probably representing a lymph node with central necrosis, adjacent to the aorta.

I proceeded with aorto-right iliac and left femoral bypass, planning on later leg revascularization as needed after establishing inflow. During the retroperitoneal dissection over the aorta, I ran into this purplish mass and on manipulation, the patient’s blood pressure shot to 210mmHg. As my brain processed, my resident who had just finished reading his chapter on endocrine, said, “this could be a pheochromocytoma.”

That tumor was out quicker than you could say “snit.” Frozen section, and later final pathology returned paraganglionoma.

The patient recovered well and graciously gave permission, as all my patients here do, to allow this to be discussed. He noted that hypertension kept him out of Vietnam. Records showed an uneventful CABG.

Applying the retrospectocsope, I will now be far more wary of midline retroperitoneal lesions that are highly vascularizad.

Categories
amputation aortoiliac occlusive disease (AIOD) BKA bypass Commentary complications limb salvage Lymphatic techniques tibial revascularization training Uncategorized Wounds

Exovascularist’s Dilemma: Where Is Our LIMA to LAD

During our daily morning huddles, peopled by cardiologists and cardiac surgeons, one thing impresses me more than anything else. The assembled interventional cardiologists, world class and renown, they who can place a stent in any part of the body, will defer to the unassailable superiority of the LIMA to LAD bypass over any existing intervention. I am always a little sad that the analog for this, the vein bypass in the leg does not get the same love. The open surgical bypass of the leg is the great straw man at international symposia. It is fast becoming a diminishing and curious habit of a fading generation.

The acknowledged superior hemodynamics and patency of the bypass is diminished in the literature by pooling patency loss with other factors such as amputation, heart attacks, and death. Some vascular surgeons dogmatically cling to habits learned in training that favor complications, making themselves their own worst enemies both in the literature and in the marketplace. These bad habits involve long incision length, closure techniques that do not anticipate edema, and wound orientation that makes failure more likely.

Operations require far more support and resources to succeed than do interventions that soon go home. Brilliant operations alone will not heal the patient. It is pathways and postoperative care infrastructure and staff that prevent these secondary complications -the very complications that keep the leg vein bypass from being as respected, if not loved, as the LIMA to LAD.

The postoperative care of these patients devolves to management of leg edema. No medical or nursing school adequately teaches the basic science nor management of edema, which is the most common vascular condition

The incisions are too long in the classic vein bypass. When you create and then close an incision, the inflammation drives the accumulation of fluid in the extracellular space – creating edema. This postoperative edema, poorly managed, results in complications that leave the patient hobbled with time lost to healing wound complications, pain, and excess limb weight. Additionally, vein bypasses usually involve groin exposure and the delicate lymphatics that coalesce there are perturbed or destroyed during exposure. Postop, this damage and the inflammation rapidly overcomes the capacity of a lymphatic system. The traditional vein harvest also involves cutting through deep layers of fat. The fat is typically closed by broad sutures that create areas of fat necrosis -potential fodder for bacteria. The best ways the complications of long and deep incisions is to avoid them altogether. The calculus of the operative moment – “I must see the vein,” must include the vision of a patient losing months to wound therapies to heal a gaping, necrotic, infected wound. I recommend skip incisions or adopting in-situ bypass technique with endovascular management of fistulae. Or corral your cardiac PA to harvest the vein segment in the thigh after mobilizing the vein in the leg with the endoscope.

The incisions are often closed with Nylon sutures and skin clips which can become potential foci of infection. With edema, they create zones of ischemia around them, killing skin and creating entry points for skin flora as the skin expands under an unyielding clip or suture. Placed under a pannus, these sutures or clips fester in an anaerobic environment. Closure should adhere to anatomy. The body relies on connective tissue planes to keep itself together. In the groin, these are Scarpa’s layer and the dermis. They should be closed with absorbable monofilament in a buried interrupted fashion at the dermis with a final running subcuticular layer of 4-0 absorbable monofilament. Steristrips or glue at the skin finishes the job. If you use sutures, particularly at the distal anastomotic site, take care to realize that you have about 12 hours before the skin dies in the best of circumstances, and less with microangiopathy of diabetes and ESRD. Squeezing out the edema before closure with a sterile Esmarch or short counterincisions or even a large one to allow for tension free closure over an anastomosis will prevent wound complications over your graft.

The classic longitudinal groin incisions that cut across the inguinal crease divides a tension point -that crease is like a cord that supports the pannus that is slung over it and when divided and then closed with a stitch, that stitch then bears the weight of that pannus every time the patient sits up or stands. If you are observant, wound necrosis typically starts at the groin crease under a surgical clip or suture. Incisions in the groin should be obqlique and parallel to this crease, or if you can, even inside this crease. When these wounds are closed, the natural lines of tension are in line with the incision rather than orthogonal to it. The natural forces keep the wound shut.

This is only the first step. The next is keeping the wound clean and dry for at least 5 days. At the Mayo Clinic, where I trained, the nurses up on 5 Mary Brigh were trained to blow dry the groin wounds every few hours on cool setting and redressing the wound with dry gauze. You can get something close to it by ensuring the wounds painted with betadine, allowed to air dry, and dressed with dry gauze. If there is a constant leak of fluid, you have a serious problem as there is too much edema in the leg, or the wound isn’t closed, or there is a lymph leak. It needs to be actively dried out or you get a wet, macerated, infected wound like a grenade went off in the groin.

They don’t teach compression wrap techniques in medical or nursing school

The simplest thing to avoid lymph leaks is to not make them. Cutting near lymph nodes is hazardous, and once below Scarpa’s you have to orient your dissection directly over the femoral artery. Stray horizontally and you will undoubtedly cut one of the 4 to 10 invisible lymph channels.

They are invisible but detectable -after you break them, you will see a constant wetness in the wound. Think about injecting a cc or two of Lymphazurin (Isosulfan Blue, for those not allergic to Sulfa) into the intertriginous space on the same foot and you will see the lymph channel in bright blue, or stare carefully at the likely spots for a lymph leak and clip it, burn it, Ligasure or Harmonic scalpel it.

Lymph leak identified from saphenectomy incision (for CABG)

So how did we get to a rather dry discussion about edema? Wound complications are tremendously debilitating and offset any benefit from vein bypass operations. These long incisions become terrible big wounds if not prevented. It takes the concerted effort of a team and particularly nursing in actively managing edema. And at the end, the patient too must be included in this discussion. For the vein bypass of the leg to get the same respect and love as the LIMA to LAD bypass, surgical wound complications must become never events.

Water goes downhill

Categories
AIOD amputation aortoiliac occlusive disease (AIOD) BKA bypass complications EndoRE innovation PAD remote endarterectromy techniques Wounds

Arterial Restoration -Something New, Something Old

Something that I recently promised Dr. James S.T. Yao, I will be working to publish on my stent removal and extended remote endarterectomy cases and techniques. Meanwhile, here is a talk.