Endovascular Treatment of a Long-Segment Iliac Artery Occlusion with a Stent Extending up to the Hip Joint

Aortofemoral bypass graft surgery is the treatment of choice for severe symptomatic aortoiliac occlusive disease.¹ An endovascular procedure may be preferred in patients who are at high risk for a major surgery under general anesthesia. We describe such a situation that required the deployment of a stent with its distal end extending up to the hip joint line in order to achieve optimal positioning. For this purpose, a special stent with adequate axial flexibility and tensile strength was chosen to prevent kinking during joint movement.

Case Report

A 60-year-old man presented with a non-healing ulcer of the left foot for 2 years and progressive claudication for a year. He had been diagnosed with squamous cell carcinoma of this foot and was treated with wide local excision 7 years ago. He was a chronic smoker but was neither diabetic nor hypertensive. On examination, a chronic ulcer was seen at the base of the third toe of the left foot. The fourth toe was absent. Two superficial inguinal nodes were felt ipsilaterally, each 1 cm in size. The common femoral, popliteal, and pedal pulses of this leg were not palpable. A diagnosis of occlusive disease of the left iliac artery causing critical limb ischemia was made. Computed tomography (CT) angiogram revealed a 15-cm occluded segment involving the left common and external iliac arteries, with a short proximal stump. Reformation of the common femoral artery was seen. Aortofemoral or cross-femoral graft surgery was deferred because of the possibility of the patient requiring block dissection of the left groin in the future. He was also in poor general health, with restrictive lung disease. An endovascular option was thus considered. In the angiography suite, the findings of the CT angiogram were confirmed and retrograde common femoral artery access was obtained bilaterally, with a lower puncture on the left. After an unsuccessful attempt to traverse the occlusion in a retrograde manner from the left side, it was crossed from the right side antegradely within the subintimal plane with the help of an 0.035'' Glidewire and a 5 Fr van Schie catheter using the Bolia technique.² After snaring the wire through the left femoral access, it was exchanged for an Amplatz wire. A 7 mm x 150 mm self-expanding stent (Lifestent Flexstar XL, Edwards Lifesciences) was deployed across the distal portion of the obstructed segment. To ensure optimal positioning, the distal end of the stent had to be placed at the level of the joint line of the hip. The proximal common iliac artery was then stented with a 7 mm x 38 mm balloon-expandable stent (Lifestent SDS, Edwards Lifesciences) after angioplasty using a 6-mm balloon. Both stents were deployed satisfactorily. A completion arteriogram showed adequate recanalization with good flow into the common femoral artery. In the post-angiography period, the effect of hip flexion on the stent was assessed. Fluoroscopic examination during hip flexion showed a slight bend but no kinking of the distal end of the stent. Duplex scan of the popliteal artery showed that there was no change in the peak systolic velocity or spectral pattern of blood flow on flexion of the hip. Good clinical improvement was seen as the distal pulses reappeared. The ankle-brachial pulse index of the left leg, which was zero on admission, improved to 0.66. Fine needle aspiration cytology smears of the left inguinal nodes were repeatedly inadequate. Since biopsy of the margins of the foot ulcer showed well-differentiated squamous cell carcinoma, he underwent transtarsal amputation with split-thickness skin grafting, which healed well. He was put on a lifelong course of aspirin and advised to stop smoking. A telephonic interview conducted a year later revealed that he was in good health.

Discussion

Aortofemoral bypass graft surgery is the standard of care for severe symptomatic aortoiliac occlusive disease, unless the lesion is localized when percutaneous angioplasty with or without stenting is considered.¹ The patency rate of bypass grafts has been found to be superior to stents, even though both have similar complication rates and overall cost.³ In this case, an endovascular option was preferred because of the clinical scenario. Since the external iliac artery was also occluded, it was necessary to place the distal end of the stent at the joint line of the hip for optimal positioning. Our patient showed good results in the immediate post-procedural period. Fluoroscopy showed a slight bend but no kinking of this stent during joint movements, and good arterial flow was demonstrable using duplex examination even during hip flexion. Stents are not usually placed at or across joints as they are prone to fracture or migration. However, experiments placing a similar flexible endovascular stent (Wallstent, Boston Scientfic Corp., Natick, Massachusetts) across the hip joint of pigs have shown intact vascular anatomy despite repetitive stresses over a 3-month period.⁴ A stent that lies very near or across a joint needs to have certain physical characteristics. The folding point of the external iliac artery has been described to be located anywhere between 2 to 6 cm cranial to the level of the acetabular roof.⁵ Therefore, while axial flexibility and conformability is important for the maintenance of integrity during joint movement, adequate radial strength and uniform support is needed to maintain blood flow even during flexion. This stent should be elastic enough to regain its shape in neutral position. Moreover, the stent should also be rugged and not prone to migration in order to stay in place and function well for many years. Advances in stent design and the experience accumulated over the years have widened the scope of their use in the management of peripheral arterial occlusive disease. Stent placement has shown better technical success and lower failure rates in the long term, as compared to angioplasty alone.⁶ However, primary stent placement alone shows similar technical success and clinical outcomes, as compared to stent placement preceded by angioplasty.⁷ Placement of a special, flexible endovascular stent at or across a joint may be considered in specific situations where surgery is not a suitable option. In this particular case, restoration of blood flow to the lower limb was necessary to promote healing and taking up of the skin graft after transtarsal amputation, which was indicated because the margins of the non-healing ulcer on his foot showed evidence of squamous cell carcinoma. Long-term follow up is needed before the routine use of these stents across joints in the treatment of lifestyle-limiting claudication caused by iliac artery occlusive disease.

How Would You Treat This Patient?

Lawrence A. Garcia, MD

Beth Israel Deaconess Medical Center/ Harvard Medical School, Boston, Massachusetts

Critical limb ischemia (CLI) is a clinical condition where intervention is mandated for limb salvage. This form of therapy has undergone dramatic changes in the last 10 years. In the past, only a surgical option existed; now, the endovascular option predominates. CLI usually indicates “multi-level” disease, but it may occur both very proximally (where proximal collaterals are affected) and distally in a terminal vascular bed. In the case report by Chiramel et al, the authors describe an endovascular approach for a patient with critical limb ischemia and ulceration, with noted occlusion of the left aorto-iliac and reconstitution of the common femoral artery at the level below the lateral circumflex artery. As an interventionalist, I have no concerns about the authors’ approach to dealing with this patient and the iliac occlusion. Several aspects are, however, noteworthy and deserve some additional comments. First, although appealing, many times a retrograde approach to an aorto-iliac occlusion is difficult and leads to subintimal channels that make entering the “true” lumen difficult. As was done in this case, ultimately, an antegrade approach worked well. Several key anatomic elements make this approach appealing in this particular case. Initially, the long entry segment of the common iliac artery is enough to provide more than adequate support for catheters and sheaths to aid in the intervention. Further, distally, there is mild calcification to serve as a good “target” for devices in crossing the occlusion. Secondly, this case illustrates how many interventionalists are “dogmatic” to “avoid” a catheter or surgical site for future use when treating the common femoral artery. As this was true in the past, there are now many devices available or becoming available to allow therapy in this difficult location without a critical downside (i.e., stenting bailout). These devices, such as directional atherectomy, laser atheroablative atherectomy/percutaneous transluminal angioplasty (PTA), scoring balloon/cutting balloon PTA, rotational atherectomy, or cryoplasty PTA, have all been used in this location with excellent acute results. The rigors of dedicated scientific data for long-term success are not currently available for this location. Also, for this case, the location of the occlusion engaged but did not occupy the full extent of the CFA, rather only the origin, as it begins from the retroperitoneum. Lastly, the outcome for this case and its success is predicated on limb salvage or continued limb viability. Based on several iliac trials, we should all equate aorto-iliac disease with endovascular repair as the standard of care.

How Would You Treat This Patient?

Frank J Criado, MD

Vascular Surgery and Endovascular Intervention; Union Memorial Hospital/MedStar Health, Baltimore, Maryland

The indication for revascularization was clear-cut and undoubted. No argument here. As a vascular surgeon who is also an interventional expert, I do have several comments related to the authors’ rationale for choosing the procedure performed. First, to make the unqualified statement that “aortofemoral bypass graft surgery is the treatment of choice for severe symptomatic aortoiliac occlusive disease” is incorrect and potentially misleading. Their patient had unilateral iliac artery occlusion, and an essentially normal contralateral iliac artery. Very few, if any, vascular surgeons today would propose doing an aortobifemoral bypass for such an extent of disease, especially not for a high-risk patient. A minimally-invasive crossover femoro-femoral bypass would be the standard surgical approach for such a case presently. The operation could easily be performed under local anesthesia — supplemented with intravenous sedation, if necessary. So the authors’ additional argument (for the endovascular approach) that the patient may not tolerate a general anesthetic is not valid or even realistic. The performed endovascular intervention did produce a good result, and it is difficult to argue against success! However, this was an acute outcome only that may or may not be durable. Furthermore, as acknowledged by the authors, the placement of an iliac stent down into the region of the common femoral artery is undesirable at best and may be (at times) contraindicated. Disease involving the common femoral artery or disease that may necessitate stenting into the common femoral artery remains as the only “surviving” indication for a surgical approach and an area where most experts would agree on the wisdom of surgical treatment as opposed to endovascular. The surgery involved tends to be simple and safe. And, as stated above, it can be performed easily under local anesthesia.