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.
External iliac remote endarterectomy restores the artery to normal, opening the way for EVAR, TAVR, TEVAR, and transplant: alternate applications of EndoRE
One of the nice things about practicing at the Clinic is being able to offer unique solutions. A severely diseased or occluded external iliac artery (EIA) can be a vexing problem, particularly if bilateral, in this endovascular era. Many cardiovascular devices require femoral access that has to traverse compromised iliac arteries -those with large (>16F) delivery systems require a sufficiently wide path to get the devices to the heart and aorta. Also, living related donor kidney transplantation is predicated on minimizing risk to maximize results and having significant iliac plaque negates one as a recipient for this high stakes elective procedure. In situations where the EIA is too small to accommodate devices because of atherosclerotic plaque, the typical solution is placement of a conduit to the common iliac artery or the aorta. The practice of “endopaving” with a covered stent graft and ballooning is also described, but its long term outcomes are not reported and the internal iliac artery is usually sacrificed in this maneuver.
This patient presents with lifestyle limiting claudication and an absent right femoral pulse. ABI is moderately reduced on the right to 0.57, and he had no rest pain. CTA at our clinic revealed an occluded EIA bracketed by severely calcified and nearly occlusive plaque of the common iliac artery (CIA) and common femoral artery (CFA).
The patient was amenable to operation. Traditionally, this would have been treated with some form of bypass -aortofemoral or femorofemoral with a common femoral endarterectomy. While endovascular therapy of the occluded segment is available, one should not expect the patencies to be any better than that of occlusive lesions (CTO’s) in other arteries. Hybrid open/endovascular therapy is an option as well with CFA endarterecotmy and crossing CIA to EIA stents, but I have a better solution.
The common femoral endarterectomy rarely ends at the inguinal ligament, and is uniquely suitable for remote endarterectomy, a procedure from the early to mid twentieth century.
The addition of modern fluoroscopic imaging and combining with endovascular techniques makes this a safe and durable operation.
The patient was operated on in a hybrid endovascular OR suite. A right groin incision was made to expose the common femoral artery for endarterectomy and left common femoral access was achieved for angiographic access, but also to place a wire across the occlusion into the common femoral artery.
All actions on the external iliac artery plaque are done with an up-and-over wire, allowing for swift action in the instance that arterial perforation or rupture occur. This event is exceedingly rare when the operation is well planned. With this kind of access, an occlusive balloon or repairing stent graft can be rapidly delivered.
The common femoral endarterectomy is done from its distal most point and the Vollmer ring is used to mobilize the plaque. A Moll Ring Cutter (LeMaitre Vascular) is then used to cut the plaque.
The plaque is extracted and re-establishes patency of the EIA.
The plaque end point is typically treated with a stent -in this case, the common iliac plaque was also treated.
What is nice about this approach is that this artery has been restored to nearly its original condition. I have taken biopsies of the artery several months after the procedure in the process of using the artery as inflow for a cross femoral bypass, and the artery clamped and sewed like a normal artery and the pathology returned normal artery.
This has several advantages over conduit creation which can be a morbid and high risk procedure in patients who require minimally invasive approach. A graft is avoided. The artery is over 8mm in diameter where with stenting up to 8mm with an occlusive plaque, the danger of rupture is present, and often ballooning is restricted to 6mm-7mm. This is insufficient for many TEVAR grafts and TAVR valves.
For patients being worked up for living related donor transplants who are turned down because of the presence of aortoiliac plaque, those with the right anatomy can undergo this procedure and potentially become candidates after a period of healing.
Removing Occluded Stents For Critical Limb Ischemia
The patient severe claudication and nocturnal rest pain and had undergone an inflow procedure at another hospital consisting of a common femoral endarterectomy and a single stent to the external iliac artery near its origin from the iliac bifurcation. He also had undergone a concurrent SFA atherectomy which closed and was treated with SFA stents extending from the SFA origin to the above knee popliteal artery. Unfortunately, his rest pain worsened.
On exam, he had a femoral pulse only and no distal pulses, only monophonic and weak pedal signals. The right groin wound had been treated for postoperative wound infection and there was still some swelling and a stitch abscess, but no deep infection. CTA showed that his profunda femoral artery had a focal dissection or stenosis at the origin along with overhang of his SFA stents across the origin of the PFA. The SFA stents were occluded along their whole length. There was remnant disease of the external iliac artery as well.
There was reconstitution of a diseased but patent above knee popliteal artery with three vessel runoff. He had had harvest of his greater saphenous vein. Treatment options included multisegment arm vein with redo profundaplasty, but given the inflammation around his recently operated, recently infected groin, I was concerned for wound infection. He was also quite disabled by his worsened pain. The other option was to access the left common femoral artery and placed a sheath up and over and wire across the diseased profunda and intervene on it, but with the stent in place, I would have to place likely another stent across the origin. I could then attempt a bypass with arm vein or prosthetic graft using this compromised artery as inflow for a bypass to the below knee popliteal artery or a tibial vessel but I doubted this would be durable, nor resistant to infection if prosthetic was used.
Remote endarterectomy (EndoRE) gave me a third option. It is a hybrid technique, but based on an old and established technique of open remote endarterectomy dating from the 60’s. Rings (Vollmer Rings, LeMaitre Vascular) are used to dissect occlusive plaque under fluoroscopy, and a cutting ring (Moll Ring Cutter, LeMaitre Vascular) is used to cut the plaque at the chosen location. Because the distal end point of dissection is not surgically exposed, but rather fluoroscopically guided, it is termed Remote Endarterectomy. Wire skills are required to access and repair any dissections that may occur.
I have presented in the past a series of cases where I removed occluded stents. Because the dissection is carried out outside the plaque, it is also outside the stent. Retrograde EndoRE of SFA plaque can be carried out up to the SFA origin, and avoid a groin incision which in this case was important. Therefore, a proximal thigh exposure of the SFA and EndoRE was planned with endovascular access by left CFA as described.
The SFA was a hard, calcified pipe and control was achieved with vessel loops which allow passage of the ring and occlusion of the artery once the plaque and stents were removed. The artery was opened via longitudinal arrteriotomy and the plaque mobilized and divided. The proximal SFA plaque was then dissected (above and below).
There was immediate establishment of a robust pulse in the proximal SFA after removal of the plaque.
Distally, the plaque would not mobilize at a point in the artery where there was laxity in the artery and especially adherent plaque and therefore, the distal SFA was cut down on to reaccess the stent from below.
The arteriotomies were repaired with patch angioplasties using bovine pericardium. This allowed for completing the procedure with endovascular techniques which included the distal end point dissection, profunda stenosis, and external iliac stenosis.
At completion, there was a palpable dorsalis pedis artery pulse. The composite angio with preop CTA centerline reconstruction are shown below.
He had relief of his symptoms. Prior to discharge, ABI and PVR’s show normalization of flow to his foot.
Conclusion: In my experience, the longevity of these lesions is dependent on the same factors dictating other revascularizations -excellence of inflow, optimization of profunda outflow, and good tibial outflow. The conduit, being the recanalized original artery, is not as good as a single vein, but it remodels and becomes normal artery based on micro pathology. Failure occurs at the stent with the usual restenosis that can occur in some but not all people, and in isolated points in the artery where likely remnant tissues scar creating focal lesions. Frequent surveillance achieves acceptable primary and secondary patencies. Thromboses do occur. Unlike PTFE grafts, thromboses in EndoRE is usually limited to the recanalized artery without distal embolization. Stent removal is challenging but feasible. In this patient, a second cut down was required to achieve plaque and stent removal. The groin was not re-entered, avoiding dissection in a recently infected, surgical wound. If the popliteal was occluded, a popliteal endarterectomy via a below knee cutdown is possible achieving total femoropopliteal plaque clearance, and the below knee popliteal artery can then be used for a very short bypass to one of the tibial arteries if indicated and if autologous vein is limited in availability.
EndoRE offers a third option after bypass and intervention and should be in a vascular surgeon’s armamentarium.
Saving a patient from hip disarticulation with advanced hybrid inflow procedure and vein bypasses
The patient is an elderly man who had bilateral above knee amputations after failure of aortobifemoral bypass grafts at an outside institution. Unfortunately, he had no femoral pulses and his amputation on the right broke down (image above). His left stump had erosion of his femur to the skin with rest pain as well, but was at least covered by skin for now. He was declared too sick for hip disarticulations and was sent to a hospice where he failed to pass away. After a year there, he was sent to us for an evaluation.
He was suffering from rest pain and had complete breakdown of the skin over his amputation stump. More worrisome was the development of gangrenous scrotal and decubitus ulcers which were small but persistent and also foci of pain. CTA showed the following:
The aorta was occluded below his renal arteries. An AV fistula near his common femoral vein lit up his right iliac vein on the CT above. He had had a prior aortobifemoral bypass but this was occluded. Gratifyingly, it was anastomosed proximally end to side, giving us options. As with any revascularization, we had an inflow source -his aorta, and several potential outflow sources (CTA below, contrast filling iliac vein from AVF’s).
In particular, his distal profunda femoral artery showed promise. Vein mapping revealed a short segment of basilic vein in his arm to use as bypass, but we needed inflow from the aorta.
I have come to appreciate two things about aortoiliac recanalization. First is that passing the wire antegrade is far likelier to stay in the true lumen at least in the aortic inflow segment -retrograde wire passage inevitably dissects the occlusive aortic plaque and reentry into the true lumen of the diseased aorta is just as challenging as in the leg. The second is vein bypasses have excellent patency in challenging conditions -you just need excellent inflow and an arterial bed to perfuse.
My plan was to cross the aortoiliac occlusion with a wire from the left arm. Once the right iliac system was entered, it didn’t matter if I was in a subintimal plane. The wire could be seated in the common femoral artery to access with a surgical exposure. Once this was done, my intention was to perform remote endarterectomy of the external iliac artery and stent from the aorta to the common iliac artery. The endarterectomized external iliac artery would be the inflow source of a later staged ilio-cross femoral bypass to revascularize his left AKA stump. The common femoral artery at its origin would provide inflow to a short vein bypass to his profound femoral artery.
The wire passed readily into the right iliofemoral system and a groin exposure and common femoral arteriotomy allowed me to retrieve the wire which had been passed from the left arm. A remote endarterectomy was performed over the wire which I do to ensure access in case the artery ruptures (specimen below).
This allowed me to place a sheath into the right iliac system in the now reopened external iliac artery. Balloon angioplasty of the aortoiliac segment created working space for placement of balloon expandable stents from the infrarenal aorta to the common iliac artery, restoring an excellent pulse in the right groin.
The profunda femoral artery was encased in scar tissue, but following the occluded PFA from the CFA, I was able to expose an open segment and cut it open in the scar tissue. There was back bleeding, and I controlled the artery by placing a small Argyll shunt into the artery and reperfusing it from the recanalized right iliac system.
The Doppler flow in the shunt was excellent, suggesting great outflow potential. The bypass was performed over the shunt with reversed basilic vein. Completion arteriography showed excellent flow.
The amputation stump was debrided of dead bone and muscle and the graft was covered with a sartorius muscle flap.
Before and after images are shown. The remaining open wound granulated well, and ultimately accepted a split thickness skin graft. His scrotal and decubitus ulcers healed as well (below at 6 months post op).
His left AK stump subsequently degraded while he recovered so three months after this operation, he underwent a right external iliac to left profunda femoral artery bypass with cadaveric vein.
I don’t like using cadaveric vein, but we really had no options. The right external iliac artery was approached through a right lower quadrant (transplant) incision and a punch biopsy of the artery revealed only normal adventitia on pathology. The EIA was soft and sewed well -essentially a normal artery brought back from the dead. The left profound femoral artery was large after endarterctomizing its origin and accepted the bypass flow well.
The mortality from hip disarticulation in the setting of gangrene and infection is very high, and I feel that standard approaches to this problem -prosthetic axillo femoral bypasses, thoracobi-femoral bypasses, in the setting of advanced infection and gangrene were unlikely to succeed. In over 1.5 years of followup, everything has remained patent, and the patient lives independently.
The best last conduit is your own artery
The patient is a 60 year old with severe peripheral vascular disease. Risk factors included smoking, hypertension, and type I diabetes. The patient had developed gangrenous eschar over toes 1, 2, and 3. He had had prior bilateral femoropopliteal bypasses with saphenous vein, which was occluded on his symptomatic side, and stent grafts had been placed on his distal femoral to popliteal artery, but these were occluded. He also had chronic edema with some early lipodermatosclerosis and pitting edema. He was emaciated and had a low prealbumin.
CTA showed diffuse aortoiliac atherosclerosis with a severe stenosis in the proximal common femoral artery.
The femoropopliteal stent grafts were occluded but the popliteal artery reconstituted into a diseased set of tibial vessels -only the posterior tibial artery remained patent into the foot and remained as a target.
Preoperative angiography corroborated the CT findings.
The preoperative vein mapping suggested there was an acceptable anterior thigh tributary vein and marginal segments of vein below the knee. Arm vein was available as well.
My plan was to explore the veins on his legs and expose his CFA and BKPOP along with the posterior tibial artery. If the veins were inadequate, I would proceed with open endarterectomy of the common femoral artery and remote endarterectomy of the external iliac artery and stenting of the diffusely diseased common iliac artery and remote endarterectomy of the femoropopliteal segment above the stent to use as inflow for a shorter bypass with the vein we had.
Exploration showed that the anterior thigh vein was thin walled and became diminutive in the mid thigh. The infrageniculate veins were numerous and too small. I thought I might have enough for a short bypass from a recanalized mid SFA.
The remote endarterectomy of the external iliac and stenting of the common iliac went without complications. I do this over a wire to ensure access in case of rupture. A postop CTA shows the results in the aortoiliac segment.
Remote endarterectomy of the SFA went smoothly but was held up by calcified plaque above the occluded stents.
I cut down on the SFA and found that the vein from the thigh would be short. I mobilized the plaque and re engaged the Vollmer ring and was able to dissect the stents. By starting another dissection from the below knee popliteal artery, the stent was mobilized and removed.
The figure below shows the procedure angiographically. I used a tonsil clamp to remove the mobilized stents.
The common femoral and mid SFA arteriotomies were repaired with patch angioplasties. The infrageniculate popliteal arteriotomy was used as inflow to a very short reversed vein bypass with the best segment of thigh vein to a soft posterior tibial artery.
The patient had a palpable posterior tibial artery pulse at the ankle. CTA predicted the plaque found in the tibioperoneal trunk which compelled me to do the short bypass. In my experience, remote endarterectomy, sometimes with short single segment bypass, successfully restores native vessel circulation without need for lengthy multisegment arm vein bypass. Remote endarterectomy of the external iliac artery avoids the difficult CFA plaque proximal end point that often requires stenting across the ligament down to the patch. Only a single common iliac stent is required. I generally anticoagulate these patients with warfarin, especially if they are likely to resume smoking or have poor runoff. I hope to show this is the equal of multisegment vein bypass, and superior to it by virtue of avoiding long harvest incisions which are the source of much morbidity and now readmissions which are penalized.
External iliac remote endarterectomy in lieu of a conduit for TEVAR
The patient had diffuse atherosclerosis with small luminal area even in areas without calcified plaque. It predicted inaccessibility for the 22 French sheath required to deliver the 32mm C-TAG device to be placed for a symptomatic type B thoracic aortic dissection associated with a small but expanding proximal aneurysm.
My options included direct aortic puncture, an aortofemoral conduit, or an endoconduit. The aorta was heavily calcified and the bifurcation was narrowed by circumferential plaque down to 6-7mm at its narrowest and the left iliac had a severe narrowing due to this plaque. The common femoral artery was severely diseased with a lumen diameter of 4mm due to heavily calcified plaque.
I have come to favor direct aortic puncture over conduits, but the heavily calcified aorta and the absence of safe areas to clamp made me think about other options. My experience with endoconduits has been limited to revising problems of endoconduits from elsewhere, but others report it as a feasible option.
The problem with a long artery narrowed with irregular plaque and even intimal thickening is that it will readily expand to accommodate a large sheath but removing it involves the frictional resistance of the whole artery and typically the “iliac on a stick” avulsion involves the whole length of external iliac artery, likely because the common iliac is anchored by the aortoiliac plaque, the smaller diameter of the EIA, and the longer more tortuous path offering greater resistance in the EIA compared to the aorto-common iliac segment.
Remote endarterectomy, a technique involving endarterectomizing an artery through a single arteriotomy, offers the possibility of increasing the lumen of even a mildly diseased artery and reducing the frictional coefficient, assuming the remnant smooth adventitia is less resistant than rough irregular intimal plaque.
The plan was to expose the right common femoral artery and endarterectomize it and gain wire access from the R. CFA. A wire would be placed on the left iliofemoral system to protect it for later kissing iliac stents. A right EIA remote endarterectomy would be performed, and then the right aorto-common iliac segment would be balloon dilated to 8mm.
The operation went as planned. The external iliac plaque was removed in a single piece from the EIA origin.
Arteriography showed the right EIA to be free of intimal disease, and dilators and ultimately the 22F sheath went in easily.
The TEVAR also went uneventully -the left subclavian which had a prior common carotid to subclavian bypass, was covered and the aneurysm and flap were excluded from the left CCA to the celiac axis.
The most difficult part of the operation was removing the sheath, as is usually the case with a tight iliac, but the friction point was largely at the common iliac and not the external iliac. No artery could be seen extruding with the sheath at the groin while steady tension was applied to the sheath under fluoro. The aortic bifurcation was repaired with kissing iliac stent. The patient recovered well and her chest pain resolved.
I have done this for EVAR, including reopening occluded external iliac arteries, and even for a 26F access for TAVR, avoiding the need for placement of a conduit in selected patients.
Addendum: in followup, I had the chance to check up on the repair -the EIA remained large and patent.
The EIA is more like SFA than CIA with regard to stent patency
From my case files, this was a case which I performed in 2010 and published in a prior blog.
CCx: Patient is a 56 year old man with complaints of pain in right leg with walking short distances and discomfort in the foot at night.
HPI: The patient has had cramps in his right calf with walking about a block for over a year, but over the past three months, he has developed pain with walking less than half a block which is incapacitating. He has developed pain at night which wakes him and he has taken to sleeping with his right foot dangling off the edge of the bed. This has resulted in some swelling of that leg which makes it doubly uncomfortable to wear shoes. He works as a manager at a local big box store and walks constantly. He used to smoke but quit last week. He feels this has worsened the pain.
Past Medical History: Hypertension, dyslipidemia, acid reflux
Past Surgical History: Ruptured appendix at 22
Medications: Zantac, Hydrochlorothiazide, Lipitor, Aspirin
Allergies: Penicillin (rash in 1972)
Social History: Employed, 30 pack year smoking history, quit last week
Examination: T 98 BP 142/88 HR 88 RR 12 Ht 68inch Weight 192lbs
HEENT: PERL, EOMI
Chest: Bilaterally CTA
Cor: RR
ABd: Soft, scar right lower quadrant
Ext: Cool right foot with dependent rubor, elevation pallor. Warm left foot
Neuro: Motor and sensory examination normal
Skin: Loss of hair over toes of right foot, and distal right leg pretibium
Pulses: No palpable pulses right leg. Left leg femoral, popliteal, and dorsalis pedis artery pulses are easily palpable
Labs: WBC 9.8 Hb 13.2 HCT: 40 PLT 332 Cr 0.8
Testing: Segmental pressures R/L: Brachial 144/138 High Thigh 88/150 Low Thigh 77/140 Calf 72/132 Ankle 71/140 Metatarsal 68/122
Pulse volume recordings notable for moderately diminished signals right high thigh cuff.
CTA: Moderate atherosclerosis of infrarenal abdominal aorta and its bifurcation with severe plaque of the right common iliac artery and occlusion of the external iliac artery. There was reconstitution of the common femoral artery on the right via collaterals. The left common iliac artery was affected by a moderate (50-75%) stenosis due to low density plaque.
Impression: PVD with rest pain of right leg due to severe aortoiliac occlusive disease and occlusion of right external iliac artery.
Plan: After discussing treatment options, we decided to try a right external iliac artery remote endarterectomy with angioplasty and stenting of his common iliac disease. This was chosen over aorto-bifemoral bypass because he had limited time off from work and work did require that he lift more than 20 pounds.
Operation:
Remote endarterectomy of right external iliac artery with aortography, bilateral common iliac artery angioplasty and stenting.
This operation was done via a single right groin exposure and percutaneous access of the left groin. The common femoral artery had severe posterior plaque which was the starting point of the endarterectomy. Up and over access of the right external iliac artery was achieved and a wire was passed across the occluded external iliac artery and into the right femoral system. With clamping of the common femoral artery, the wire was brought out and controlled with a Fogarty clamp -this allowed for excellent stabilization and control and possible emergent balloon occlusion in the case of a perforation.
A Vollmer ring dissector was sent over wire and plaque up the external iliac artery under fluoroscopy and dissection was stopped at the iliac bifurcation which was heavily plaqued. A Moll Ring cutting device (LeMaitre) was used to transect the plaque which was removed.
The right and left common iliac arteries were stented with self expanding nitinol covered stents and post-dilated. I chose this as I have had occlusions occur in the setting of diffuse TASC C disease with low density plaque -I suspect that thrombus propogates across open cells like weeds growing through chicken wire. The stents on the right were extended across the iliac bifurcation.
A completion angiogram is here to the right. The common femoral artery was repaired with a patch angioplasty (bovine pericardial patch, LeMaitre).
The groin was closed and the patient recovered and was discharged in a few days with excellent palpable pulses on the right and improved pulses on the left. He was without symptoms of claudication or rest pain in the right leg.
Discussion:
Remote endarterectomy allows for removal of plaque via a single groin incision, obviating the need for an abdominal exposure required in an aorto-bifemoral bypass. This minimally invasive technique is associated with a low complication rate and earlier return to full work status because the abdominal incision is avoided.
Smeets et al [reference] reviewed with 7 year experience with 48 patients and had a technical success rate of 88%. One patient died due to a myocardial infarction within 30 days of the operation. The complication rate was low. 6 patients required coversion (retroperitoneal flank exposure) for additional arteriotomy (3 patients) and bypass (3 patients). The primary and assisted patencies shown to the right were acceptable with a secondary patency of 94% at 3 years.
These cases require more surveillance than an aortobifemoral bypass. Intimal hyperplasia does occur in random loci in the SFA remote endarterectomy and this should apply to the external iliac artery. I chose the title because the external iliac artery biologically behaves like the superficial femoral artery in relation to endovascular patencies and not like the common iliac artery or aorta -probably because it shares a common embryology with the SFA, not the CIA. It is a troublesome artery that is often overlooked by vascular surgeons when femorofemoral bypass is performed for occlusive disease -the supplying external iliac artery though patent is usually diseased and has a small lumen. With a fem-fem bypass, both legs are supplied often through an artery with the caliber of a child’s drink straw. I have seen the donor leg become symptomatic through what is termed steal, but in fact reflects the hemodynamic inadequacies of a diseased external iliac artery.
I feel that 5mm is the minimal lumen caliber for an external iliac artery, and a 4mm lumen in an adult will clearly show a hemodynamic effect particularly after exercise or application of vasodilators in the endo suite. Stenting an occluded external iliac artery though technically feasible even in this case is not a durable solution in my experience. This operation allowed the patient to return to work without an extended convalescence.
I think removing the plaque offers advantages over stenting to the inguinal ligament. The common iliac stents have superior potency to external iliac artery stents and moving the stent point to the CIA and not stenting the EIA in my experience has better long term potency.
Reference
Smeets L, et al. J Vasc Surg 2003;38:1297-1304.
