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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.

Categories
chronic limb threatening ischemia edema iliocaval venous interstitium lymphedema opinion Practice techniques

The Squeeze Play: Managing a Lymphedema Emergency

When I was a young attending at the Allen Pavilion of Columbia Presbyterian Hospital, I was called into an operating room for a stat consult on a patient about to undergo a cholecystectomy. During the case, the IV had infiltrated and a bag of saline had filled the patient’s hand and forearm with saline, causing the hand to look like an inflated glove. The fingers were cool and white and the edema was firm but yielded to touch.

I elevated the hand and firmly squeezed the edema out of each digit, then gently massaged the edema from the hand onto the forearm. From there, I pushed the edema onto the arm. I then wrapped the hand up in an Ace wrap, and suspended it from an IV pole and returned to my case. Later, I returned and the hand was restored, warm, and perfused.

The lymphatics serve to move extracellular fluid (link). They can be overwhelmed much as drainage from a house can be overwhelmed resulting in puddles and ponds (link). This extracellular space has been “discovered” to be a new organ, but vascular surgeons have known about it for some time. Ultrastructurally, it is very close to a sea sponge with lattices of structural protein connecting cells to form tissues. And like a sea sponge, the salty water can be squeezed out or drained using gravity.

In olden times in central Europe, if you had chronic leg ulcers, you went to abbeys that specialized in their care. There, nuns would milk the edema out of your leg swollen typically from parasites and dress the leg and ulcer in linen cloth soaked in special oils. This is how Dr. Paul Gerson Unna came up with his eponymous Unna’s Boot, substituting Zinc Oxide paste which created a bacteriostatic environment.

Professor Paul Gerson Unna

Every year or so, I will be consulted for what I term a lymphatic emergency. A subset of this is phlegmasia. Whatever color you find -alba (white) or cerulea (blue) is really no matter -who really knows which comes first? It is an emergency in that the time clock for arterial ischemia -minutes to an hour for nerves, an hour to 6 for skeletal muscles, 6-12 for skin and bone, are all in play. The instinct is to go right to fasciotomy, but what you are usually doing is releasing the extracellular space, and the muscles are typically fine, even though their compartment pressures were very high.

Take this patient who developed severe upper extremity edema in the recovery phase after a cardiac arrest.

The ICU staff noted the had discoloration about four hours after the arrest. There were no arterial pulses and the forearm and hand were rock hard, the finger tips ice cold. Compartment pressures measured using the arterial line and needle method didn’t drop after the initial flush of saline below 70mmHg. While I could have been justified in performing upper extremity fasciotomy and even trying thrombectomy in a critically ill, coagulopathic patient on multiple pressors, I could just as easily have been on solid ground for saying the life was more valuable than the dominant hand. Both would have been the wrong move.

I performed the nun’s milking maneuver mentioned at the beginning and lacking an Unna’s boot, I compressed and elevated the best I could with double gloving using a small sized glove and ACE wrap.

Notice the edema has segregated into the arm.

In the morning, taking down the dressing, and re-compressing, there was now a radial artery signal and the fingers were a much improved color. The pulse-oximeter waveform was near normal. As an aside -the pulse oximeter uses the same technology as the digital photoplethysmography for generating toe waveforms in the vascular lab -ie. a vascular lab at every bedside! We have collected and are analyzing the data on this for publication.

The pulse oximetry waveform is the same tech as digital photoplethysmography. Cotton cast padding (Webril) and Coban wrap is a good method of compression that avoids the problems with ACE wrapping.

It’s a hard thing to not run off to the operating room in most cases because that is how we are trained, but understanding how a patient got to that point is crucial in deciding if compression alone will work. If they call you from the ER about a patient with a swollen cold foot with diminished signals, you have to figure out the mechanism. Was it arterial occlusion, rest pain, and chronic dependency of the foot that resulted in this? Typically the swelling appears late. Was it heart failure and inability to walk, resulting in the patient sitting all day in a chair that is the cause? Was it pregnancy with a DVT? Was it the deadly sin of sloth? Only in arterial occlusion in a chronic presentation would compression be contraindicate. In this ICU case, the lack of arterial signal is secondary to the swelling, not the cause of it.

Elevation alone does not manage edema well. Only hanging upside down or being in water up to your neck…

Compression is a necessary component of treating lymphedema emergencies because elevation alone may be insufficient, particularly in the leg.

Wrapping a leg is a critically, undertaught skill. Also, never cover the knee cap.

Elastic compression is ubiquitously available as the ACE wrap, but they can shift and move and roll, causing zones of excess and not enough compression. TED hose and compression stockings are definitely helpful in long term management, but with legs, compression needs to go up to the knee joint, or up to the groin, never halfway or the edema will create a line of ischemia at the end of the stocking that blisters when the stocking is removed, and can progress to full thickness necrosis. Cotton cast padding and Coban, or an Unna’s Boot may be the safest in terms of avoiding skin injury.

ACE wrapping is never taught adequately, and for it to work well and avoid injury to the skin, the wrapping has to be reapplied several times a day. It should be a prerequisite for nursing and medical student certification, as edema is the most common vascular disease.

Moving into our new home after four years out of country, I welcome an old friend from storage, but also unfortunately a health hazard, only mitigated by being fully reclinable.
Categories
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.