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

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.

The Unclampable: Strategies for Managing a Heavily Calcified Infrarenal Aorta

Leriche Syndrome -one of those disease names that adds to our work in a way that an ICD codes and even the “aortoiliac occlusive disease” fails to describe. When I hear someone described as having Leriche Syndrome, I think about a sad, chain smoking man, unmanned, complaining of legs that cramp up at fifty feet, pulseless.

The CT scan will occasionally show an aorta ringed by calcium in the usual places that are targetrs for clamping below and above the level of the renal arteries. Even without the circumferential calcium, a bulky posterior plaque presages the inability to safely clamp the aorta. Woe to the surgeon who blithely clamps a calcified lesion and finds that the rocky fragments have broken the aorta underneath the clamp! The first way to deal with this is to look for ways not to clamp the aorta, by planning an endovascular procedure, but circumstances may necessitate the need to control the aorta despite the unclampability.

The traditional methods of avoiding clamping the calcifed peri-renal aorta are extra-anatomic bypasses including femorofemoral bypass and axillo-femoral bypass. I propose these following options for the consideration when the patient needs a more durable solution while avoiding a heavily diseased aorta.

Not Clamping I:

EndoABF.png
An EndoABF (actually EndoRE-ABF)

EndoABF does work to avoid clamping -these are common femoral endarterectomies supplemented by stenting of the aortoiliac segment, including in those with appropriate anatomy, a bifurcated aortic stent graft. This is often not possible to treat both sides, but one side is usually more accessible. Often, people will compromise and perform an AUI-FEM-FEM, but I have found the fem-fem bypass to be the weak link, as you are drawing flow for the lower half of the body through a diseased external iliac artery. The orientation of the proximal anastomosis is unfavorable and in the instance of highly laminar or organized flow, the bypass is vulnerable to competitive flow on the target leg, leading to thrombosis.

auifemfem.png
AUI prior to fem-fem bypass for acute aortoiliac occlusion causing critical limb ischemia

The femorofemoral bypass is the option of patients whose options have largely run out. It is made worse when fed by an axillofemoral bypass. Sometimes, you have no choice, but in the more elective circumstance, you do.

 

Not Clamping II:

The second method is performing a aorto-uni-iliac stent graft into a conduit sewn end to end to the common iliac aftery, oversewing the distal iliac bifurcation.

conduit.png

The conduit is 12mm in diameter, the key is to deliver the stent graft across the anastomosis, sealing it. The conduit is then sewn to the side of a fem-fem bypass in the pelvis, maintaining antegrade flow to both legs. The other option is to sew the conduit to a 14×7 bifurcated graft. Illustrated above is this 12mm conduit sewn end to end to the diseased common iliac artery with wire access into the aorta and a aorto-uni-iliac device. Typically, a small AUI converter (Cook, Medtronic) can be used, but the aorta is often too small even for a 24mm device, and an iliac limb with a generous sized docking segment (Gore) ending in a 12mm diameter fits nicely. Below is a CTA from such a case, where the stent graft is deployed across the anastomosis, sealing it off from anastomotic leaks (exoleaks).

AUI fem fem.jpg

Not Clamping III:

Often, the infrarenal aorta is soft anteriorly and affected only by posterior plaque at the level of the renal arteries. While a clamp is still not entirely safe (I prefer clamping transversely in the same orientation as the plaque with a DeBakey sidewinder clamp), a balloon is possible. I do this by nicking the aorta -simple application of a finger is sufficient to stop the bleeding if you have ever poked the ascending aorta to place cardioplegia line.

conduit1.png

A Foley catheter is inserted and inflated. The Foley’s are more durable and resist puncture better than a large Fogarty. This is usually sufficient for control, although supraceliac control prior to doing this step is advised. The aorta can be endarterectomized and sewn to the graft quite easily with this non-clamp. conduit2.png

This has worked well, Although pictured above with an end-to end anastomosis planned, it works just as well end-to-side. I actually prefer end to side whenever possible because it preserves the occluded native vessels for future intervention in line.

The Non-Thoraco-Bi-Femoral Bypass

The typical board answer for the non-clampable aorta is taking the inflow from the thoracic aorta or from the axillary artery -neither of which are good options. The first because the patient is positioned in right lateral decubitus and tunneling is not trivial. The second because of long term durability. The supraceliac aorta, technically it is the thoracic aorta, is often spared from severe plaque and clampable. Retropancreatic tunelling is straightforward, and a 12 or 14mm straight graft can be tunelled in this fashion from the lesser sac to the infrarenal retroperitoneum. It then sewn to the supraceliac aorta and then anastomosed to a 12x6mm or 14x7mm bifurcated aorto-bifemoral bypass, of which limbs are tunneled to the groins.

Sketch134215736.jpg

This worked very well recently, allowing a middle aged patient with severe medical problems, occluded aorta and iliac arteries, with critical limb ischemia, survive with minimal blood loss and home under 5 days. It delivers excellent flow to both legs in an antegrade fashion. Dr. Lew Schwartz gave me a list of references showing that this is not novel, but represents a rediscovery as the papers were published in the 80’s [reference], and buttresses the principle that innovations in open vascular surgery are exceedingly rare, largely because we have been preceeded by smart people. 

Conclusion: All of these come about through application of some common sense and surgical principles. The most important this is that the aorta is the best inflow source and reconstructing it with the normal forward flow of down each leg and not reversing directions as in a fem-fem bypass gives each of these options a hemodynamic advantage.

 

References for Supraceliac Aorta to Lower Extremity Bypass

  1. Surgery [Surgery] 1987 Mar; Vol. 101 (3), pp. 323-8.
  2. Annals of Vascular Surgery 1986 1(1):30-35
  3. Texas Heart Institute Journal [Tex Heart Inst J] 1984 Jun; Vol. 11 (2), pp. 188-91.
  4. Annals of Thoracic Surgery 1977 23(5):442-448

When both iliac systems are occluded below an abdominal aortic aneurysm: hybrid techniques on the cutting edge

preop CTA EVAR-ENDORE.jpg
AAA with iliac arterial occlusion -arrows point to right external iliac and left common iliac arterial occlusions

The patient is an 70 year old man referred for evaluation of claudication that occurred at under a block of walking. He reported no rest pain or tissue loss. He smoked heavily up to a pack a day, with congestive heart failure with an ejection fraction of 40%, prior history of myocardial infarction treated with PTCA, and pacemaker, and moderate dyspnea on exertion.

On examination, patient had a flaccid abdomen through which the AAA could be palpated, and he had no palpable femoral artery pulse bilaterally, nor anything below. He had a cardiac murmur and moderate bilateral edema. Preoperative risk evaluation placed him in the high risk category because of his heart failure, coronary artery disease, and his mild to moderate pulmonary disease.
CTA (pictured above and below) showed a 5.1cm infrarenal AAA with an hourglass shaped neck with moderate atherosclerosis in the neck, an occluded left common iliac artery with external iliac artery reconstitution via internal iliac artery collaterals, and a right external iliac artery occlusion with common femoral artery reconstitution. There was calcified right common femoral artery plaque.

Preop left and right centerlines EVAR-ENDORE.jpg

Treatment options included open surgical aortobifemoral bypass with exclusion of the AAA, total endovascular repair with some form of endo-conduit revascularization of the occluded segments of iliac artery, or a hybrid repair.

Open aortic repair in patients with heart failure and moderate COPD can be performed safely (ref 1). Dr. Hollier et al, in the golden age of open repair, reported a 5.7% mortality rate operating on 106 patients with severe category of heart, lung, kidney, or liver disease.

Typically, the hybrid repair involves sewing in a conduit to deliver the main body of a bifurcated or unibody stent graft when endovascular access is not possible. Despite techniques to stay minimally invasive -largely by staying retroperitoneal, this is not a benign procedure (ref 2). Nzara et al reviewed 15,082 patients from the NSQIP database breaking out 1% of patients who had conduit or direct puncture access.

Matched analyses of comorbidities revealed that patients requiring [conduit or direct access] had higher perioperative mortality (6.8% vs. 2.3%, P = 0.008), cardiac (4.8% vs. 1%, P = 0.004), pulmonary (8.8% vs. 3.4%, P = 0.006), and bleeding complications (10.2% vs. 4.6%, P = 0.016).

Despite these risks, I have performed AUI-FEM-FEM with good results with the modification of deploying the terminus of the stent graft across an end to end anastomosis of the conduit graft to the iliac artery (below), resulting in seal and avoiding the problems of bleeding from the usually heavily diseased artery

AUI fem fem.jpg
Aorto-uni-iliac stent graft across end to end conduit anastomosis to fem-fem bypass

The iliac limbs of some stent graft systems will have proximal flares and can be used in a telescoping manner to create an aorto-uni-iliac (AUI) configuration in occlusive disease. The Cook RENU converter has a 22mm tall sealing zone designed for deployment inside another stent graft and would conform poorly to this kind of neck as a primary  AUI endograft which this was not designed to act as. The Endurant II AUI converter has a suprarenal stent which I preferred to avoid in this patient as the juxtarenal neck likely was aneurysmal and might require future interventions

I chose to perform a right sided common femoral cutdown and from that exposure, perform an iliofemoral remote endarterectomy of the right external iliac to common femoral artery. This in my experience is a well tolerated and highly durable procedure (personal data). Kavanagh et al (ref 3) presented their experience with iliofemoral EndoRE and shared their techniques. This would create the lumenal diameter necessary to pass an 18F sheath to deliver an endograft. I chose the Gore Excluder which would achieve seal in the hourglass shaped neck and allow for future visceral segment intervention if necessary without having a suprarenal stent in the way. I planned on managing the left common iliac artery via a percutaneous recanalization.

The patient’s right common femoral artery was exposed in the usual manner. Wire access across the occluded external iliac artery was achieved from a puncture of the common femoral artery. Remote endarterectomy (EndoRE) was performed over a wire from the common femoral artery to the external iliac artery origin (pictures below).

File Mar 31, 13 41 31.jpeg
External iliac to common femoral artery plaque removed with Moll ring cutter (LeMaitre Vascular) over a wire

The 18F sheath went up with minimal resistance, and the EVAR was performed in the usual manner. The left common iliac artery occlusion was managed percutaneously from a left brachial access. The stent graft on the left was terminated above the iliac bifurcation and a self expanding stent was used to extend across the iliac bifurcation which had a persistent stenosis after recanalization.

The patient recovered well and was sent home several days postprocedure. He returned a month later with healed wounds and palpable peripheral pulses. He no longer had claudication and CTA showed the aneurysm sac to have no endoleak (figures below).

post CTA EVAR-ENDORE

postop centerline EVAR-ENDORE
Composite imaging showing normal appearing right iliofemoral segment (EIA + CFA) and patent left common iliac artery.

Discussion
I have previously posted on using EndoRE (remote endarterectomy) for both occlusive disease and as an adjunct in EVAR. Iliofemoral EndoRE has excellent patency in the short and midterm, and in my experience has superior patency compared to the femoropopliteal segment where EndoRE is traditionally used. This case illustrates both scenarios. While the common iliac artery occlusions can be expected to have acceptable patencies with percutaneous interventions, the external iliac lesions typically fail when managed percutaneously especially when the stents are extended across the inguinal ligament. The external iliac artery is quite mobile and biologically, in my opinon, behaves much as the popliteal artery and not like the common iliac. Also, the common femoral arterial plaque is contiguous with the external iliac plaque, making in my mind, imperative to clear out all the plaque rather than what can just be seen through a groin exposure.

On microscopy, the external iliac artery is restored to a normal patent artery -I have sent arterial biopsies several months after endarterectomy and the artery felt and sewed like a normal artery and had normal structure on pathology. This implies that the external iliac can be restored to a near normal status and patients that are turned down for living related donor transplantation of kidneys can become excellent recipients. In this case, this hybrid approach effectively treated his claudication but also sealed off his moderate sized AAA while not precluding future visceral segment surgery or intervention with a large suprarenal stent.

 

Reference

  1. Hollier LH et al. J Vasc Surg 1986; 3:712-7.
  2. Nzara R et al. Ann Vasc Surg. 2015 Nov;29(8):1548-53
  3. Kavanagh CM et al. J Vasc Surg 2016;64:1327-34

The femoral bifurcation does not tolerate endovascular miscalculation

Sketch185115048

The patient presented with complaints of leg and foot pain with sitting and short distance calf claudication, being unable to walk more than 100 feet. This is unusual because sitting usually relieves ischemic rest pain. He is in late middle age and developed claudication a year prior to presentation that was treated with stent grafting of his superficial femoral artery from its origin to Hunter’s canal at his local hospital. This relieved his claudication only briefly, but when the pain recurred a few months after treatment, it was far worse than what he had originally. Now, when he sat at his desk, his foot would go numb very quickly and he would have to lie down to relieve his pain.

On examination, the patient was moderately obese with overhanging belly. He had a palpable right femoral pulse, but nothing below was palpable. He had multiphasic signals in the dorsalis pedis and posterior tibial arteries. The left leg had a normal arterial exam. Pulse volume recording and segmental pressures were measured:

preop PVR2

These are taken with the patient lying down which was the position that relieved his pain, and the PVR’s show some diminishment of inflow. It would be easy at this point to declare the patient’s pain to be due to neuropathy or spinal stenosis, but because of his inability to walk more than a hundred feet and because of his severe pain with sitting, I went ahead and obtained a CTA.

3DVR

The CTA showed he had an occluded superficial femoral artery (SFA) with patent profunda femoral artery (PFA) with reconstitution of an above knee popliteal artery with multivessel runoff. The 3DVR image showed his inguinal crease to be right over the femoral bifurcation which is not an unsual finding, but his stent graft was partially occluding his profunda femoral artery.

CTA centerline

I decided to take him to the operating room to relieve his PFA of this obstruction. My plan was to remove the stent graft at the origin of the SFA and at the same time, remove the plaque and occluded stent graft from his SFA to restore it to patency.

In the OR, on exposing his SFA, I discovered that because of his overhanging belly, his inguinal ligament had sagged and was compressing his femoral bifurcation.

Sketch185115048

This explained his presentation. The stent graft really had no chance as when he sat, the belly and ligament compressed it at the origin, and because it partially occluded the origin of the PFA, sitting probably pinched off flow completely. The 3dVR image shows the mid segment of PFA to have little contrast density -this is not because of thrombus, but because of the obstruction, the PFA was getting collateral flow from the hypogastric artery.

The stent graft was removed at its origin via a longitudinal arteriotomy after remote endarterectomy of the distal graft.

IMG_7228

In this case, the Multitool (LeMaitre) was useful in dissecting the plaque and stent graft because of its relatively stiff shaft compared to the standard Vollmer rings. The technique of EndoRE has been described in prior posts (link).

procedure picture

The stent graft came out in a single segment -they come out easier than bare stents.

IMG_7230

IMG_7232

post angio compositeThe patient regained palpable pulses in his right foot and recovered well, being discharged home after a 4 day stay.

While one could argue that just taking out the short piece of occlusive stent graft over the PFA was all that was necessary, I feel that there is no added harm in sending down a dissector around the stent, and in this patient there was restoration of his SFA patency which was the intent of the original procedure.

Unlike PTFE bypasses that sometimes fail with thromboembolism, SFA EndoRE fails with development of focal stenoses. From a conversation I had with Dr. Frans Moll at the VEITH meeting, I found that he has had good experience with using drug coated balloons in the treatment of these recurrent stenoses.

At the time of discharge, the patient was relieved of his rest pain, and was no longer claudicating. The common femoral artery, its bifurcation, and the profunda femoral artery remain resistent to attempts at endovascular treatment, and remain in the domain of open surgery. And in retrospect, the history and physical examination had all the clues to the eventual answer to the oddities of the patient’s complaints. The combination of inguinal crease, abdominal pannus, and low hanging inguinal ligament meant these structures acted to crush the stent graft and femoral bifurcation.

The Ilio-femoral-popliteal remote endarterectomy -The Concept Behind Extended Remote Endarterectomy is Moving Inflow from the Groin to the Knee

IMG_6805

Why perform such an extensive endarterectomy when just a few stents will do? This is a valid question, given the relative safety of interventions and the durability of bypasses. There are three reasons why ilio-femoral-popliteal endarterectomy works well in my practice.

  1. Minimally invasive
  2. Restore elasticity and collaterals
  3. Move the inflow point from the groin to the knee

The procedure is minimally invasive. Take for example this patient whose plaque is shown above. He had a common femoral occlusion for which a common femoral endarterectomy was aborted when the prior surgeon ran into excessive bleeding. Workup for coagulopathy was negative and the patient came to me with rest pain. Pedal level pulses were not palpable, and the signals were barely there.

pvr2

CTA showed that he had a CFA occlusion as well as SFA occlusion.

no annotation_9

Because the common femoral plaque is contiguous with the external iliac plaque, it is often simpler to complete a remote endarterectomy over wire up to the external iliac origin than to try to get a satisfactory end point at the inguinal ligament -I do not like stenting across the ligament into the patch which is the usual bailout if the end point causes a stenosis. It is far simpler to apply a stent at the external iliac origin.

The popliteal end point was chosen where the visible plaque was no longer apparent in the patent artery. The goal is to cut across thin intima, and frequently no distal stent is required because a secure end point is achieved much like the “feathered endpoint” seen in carotid endarterectomies.

Termini

distal end point

My intention was to endarterectomize the atherosclerotic plaque from the external iliac origin to popliteal artery via the groin incision marked in orange.

3DVR allows for planning the operation in great detail
3DVR allows for planning the operation in great detail

The video shows the setup and motion in dissecting the plaque.

The plaque came out easily (first image, top).The proximal and distal end points required stents.

Before and after
Before and after

The patient regained palpable dorsalis pedis and posterior tibial artery pulses. Total OR time was less than 2 hours. An ilioinguinal field block allowed for good pain control and the patient was discharged the next morning, having to heal only a 10cm wound. There is no good endovascular option for common femoral disease, and while stenting the whole SFA can be done, on more than a few occasions I have had to treat occluded “full metal jacket” SFA stents, usually by removing them. EndoRE has been shown to be superior to PTFE and almost as good as vein in the REVAS Trial when compared to fem-AK POP bypass. Going home the next day after such an extensive revascularization is not a stunt -it’s the direct result of limiting the incision and blood loss and OR time.

2. Restore Elasticity and Collaterals -Arterial Restoration

One of the components of arterial flow that is lost with atherosclerotic disease is arterial elasticity. That is the stretchiness of the artery in response to pressure. Elastic distension and recoil account for significant portions of forward flow during diastole which is lost with atherosclerotic plaque. As plaque builds up, and the artery becomes stiffer. The artery that goes through remote endarterectomy regains this elasticity. Ultrastructure from a recanalized external iliac artery sampled from a punch arteriotomy for a cross ilio-femoral bypass showed that three months after endarterectomy, the external iliac artery was ultrastructurally normal per pathology report.

Also, collaterals that were previously occluded are seen to be restored to patency. This has an important impact on patency and any future failures. The endarterectomized arteries fail due to the presence of isolated, random fragments of medial smooth muscle which cause focal TASC A restenoses. These are easily amenable to balloon angioplasty. If the revascularization fails, there is no catastrophic thromboembolism that is typical of PTFE thromboses -rather the collaterals keep segments open and it is straightforward to thrombectomize or lyse the artery and intervene as necessary.

3. Moving the inflow point from groin to the knee.

This is an important concept. One of the principles of inflow restoration is delivering large flow and pressure directly from the aortic source to the leg. Recanalizing from the external iliac to the below knee popliteal artery creates this situation below the knee, allowing for very short bypasses to be performed from the popltieal artery to tibial targets -a very useful circumstance when vein is limited. This next patient is a presented with gangrene of his fifth toe after esophagectomy for cancer, and had severe diabetes.

prepvr2

He had useful saphenous vein in his thigh only, some of it having been harvested in the proximal thigh for a common femoral endarterectomy. CTA showed a dilated common femoral and profunda femoral artery, severely calcified SFA and popliteal artery which were occluded, and only a patent peroneal artery as runoff.

no annotation -_3

The plan was to harvest the short segment of vein then through the same incisions, below the knee and in the mid thigh, expose the below knee popliteal artery and tibial origins, and the mid SFA. I intended to avoid the groin. The plaque was removed from the tibioperoneal trunk to the SFA origin, and the origin was stented.

IMG_6637

This reestablished a normal inflow at the level of the below knee popliteal artery. I also did an eversion endarterectomy of the anterior tibial artery which resulted in significant back bleeding -a good sign. A short bypass was performed from the below knee popliteal artery to the peroneal artery.

IMG_6639

This resulted in a palpable dorsalis pedis artery pulse and excellent peroneal and posterior tibial artery signal.

completion

The ABI improved and the waveforms predicted healing for his 5th ray amp.

post abi2

This last case illustrates the point that once the conceptual inflow point is moved to the below knee popliteal artery, bypasses can become short, and durable tibial revascularizations become feasible. By avoiding a redo groin, avoiding multisegment arm vein bypass, and keeping the procedure time under 5 hours, the operation remains less invasive.

When Better is Better Than Good

original bypass

The dictum that better is the enemy of good is one of the old chestnuts carried around surgery training forever. It is an admonition against an unhealthy perfectionism that arises from either vanity or self doubt, and in the worse cases, both. The typical scenario is a surgeon trying to make a textbook picture perfect result and finding the patient’s tissues lacking, will take down their work to make it better, and repeat this process while the patient and everyone else in the room lingers.

Trying to avoid this, many surgeons will try to avoid any difficulties -the bad patch of scar tissue, irradiated body parts, areas of prior infection. But the mental contortions involved in avoiding “perfect” can result in actual physical contortions that in the end don’t pay off in good enough. I have not been immune to this, and I don’t think any physician or surgeon can honestly say they haven’t experienced some variation on this.

This patient is a younger middle aged man who in his youth experienced a posterior dislocation of his left knee, resulting in an arterial transection. This was repaired with an in-situ graft. Subsequently, he had complications of osteomyelitis and had his knee fused after resection of his joint. He did well with this bypass for several decades, but it finally failed several years ago, and a new one was created (image above).

Rather than directing the graft in line as in the previous one, this was was taken from a medial exposure of the femoral artery and tunneled superficially around the fused knee to coil lateral, ending in the anterior tibial artery.

This graft in turn thrombosed and was lysed by the outside surgeons and underwent serial interventions of proximal and distal stenoses at the anastomoses. The patient, when I met him, was contemplating an above knee amputation as a path to returning to work as a nurse in a rural hospital.

While there should be no reason long bypasses should do any less better than short bypasses, I do have to say these things about this patient’s bypass:

  1. No vein is perfect and the longer your bypass, the more chances you will have that a segment of bad vein will end up in your bypass
  2. Turning flow sharply can cause harsh turbulence. Turbulence can cause transition of potential energy into kinetic energy which acts to damage intimal, resulting in intimal hyperplasia.
  3. Thrombosis is a sure sign that your graft is disadvantaged, and the longer the period of thrombosis, the longer the intima “cooks” in the inflammatory response that accompanies thrombosis, making the vein graft even more vulnerable to subsequent intimal hyperplasia, thrombosis, or stricture.
  4. A high flow, small diameter vein graft entering a larger, disease free bed results in more turbulence but also Bernoulli effects that cause the graft to close intermittently, vibrating like one of those party favors that make a Bronx Cheer (a Heimlich valve). This is the cause I think of the distal long segment narrowing on this graft.

This patient was decided on amputation when our service was consulted, and after reviewing his CTA, I offered balloon angioplasty as his symptoms were primarily of paresthesia and neuropathic pain. I used cutting balloons and got angiographically satisfactory results.

intervention

The patient, although he admitted to feeling much better, was sad. He relayed that he had felt this way several times before, only to have his life interrupted by pain and weakness signaling a restenosis.

 

A direct graft would require about 10 centimeters of vein
 
It was only a month later when I heard the patient had returned with the same symptoms. He wasn’t angry nor full of any “I told you so” that frankly I was muttering to myself. Reviewing his CTA, he had restenosed to a pinhole. The vein, to use a scientific term, was “no good.”

The other interesting finding was that he had an abundance of very good vein. Following surgical dictum, his original and subsequent surgeons had used his vein from his contralateral saphenous vein. His right leg, fused at the knee, lacked a good calf muscle pump action. While there were no varicose veins, the greater and lesser saphenous veins were large and generous conduits, at least by 3DVR imagery, confirmed on duplex (image below, white arrows).

veins
3DVR showing presence of potential conduit

The extant arteries were smooth and plaque-free. I decided to harvest his lesser saphenous vein and through the same incision expose his distal superficial femoral artery and tibioperoneal trunk. While I anticipated some scarring, I was confident that the sections of artery I wanted to expose were easy to access because of some distance from the fused knee.

IMG_6478
On left short saphenous vein was harvested then same exposure used to expose TP Trunk

The picture shows the exposure and reversed vein graft in-situ, using the segment of lesser saphenous vein. As in prior experience in redo surgery, you can never know if a dissection will be easy or hard simply based on fear or concern for breaking something. It’s not until you start bushwacking –carving through scar and dealing with extraneous bleeding will you learn whether it was easy or hard. You can only be certain it was necessary. The only hitch was the femoral artery while well exposed, was buried in scar, and I chose not to get circumferential control as I was fairly deep, and had avid backbleeding from a posteriorly oriented collateral that required a mass clamp of the deep tissues.

Will this work better? Don’t know but it has a good chance, and I think a better chance. It is a large vein oriented in a straight path over a short distance going from good artery to good artery. This is better theoretically than a long meandering bypass with smaller vein.