Historical Background
Dotter and Judkins first described percutaneous transluminal angioplasty (PTA) using a rigid catheter in 1964. By March 1977 approximately 1800 patients with femoral-popliteal arterial occlusions and stenoses had been treated using this technique, as reported in an international congress that included 12 European centers, to which Dotter contributed 322 cases. Grüntzig and Hopff introduced a high pressure balloon angioplasty catheter in 1974, and in 1979 Grüntzig and Kumpe reported a 2-year patency rate of 86% in 188 patients with femoral-popliteal arterial lesions that had been treated by balloon angioplasty.
The occurence of immediate recoil, dissection, and occlusion after angioplasty, as well as high rates of early recurrent stenosis, led to the development of intravascular stents. In 1987 Sigwart and colleagues described the earliest clinical experience with stenting for treatment of superficial femoral artery disease. Self-expanding stents were deployed for treatment of three patients with stenotic lesions of the superficial femoral artery and one patient after recanalization of a complete occlusion. The technique of subintimal angioplasty for recanalization of occlusions of the femoral and popliteal arteries was introduced by Bolia in 1990. This initial experience with 71 limbs was followed by a report detailing a 3-year experience in the treatment of 200 occlusions. Use of a polyester-covered stent-graft system for treatment of femoral-popliteal artery disease in 67 patients was described in 1996 by Henry. In 2000 Lammer and associates were the first to describe the use of a PTFE-covered stent-graft for treatment of superficial femoral artery disease. In 2005 the BASIL trial demonstrated that balloon-angioplasty was associated with similar amputation-free survival as surgery for patients presenting with severe limb ischemia resulting from infrainguinal arterial occlusive disease.
Indications
Endovascular treatment is the preferred approach for patients presenting with intermittent claudication or critical limb ischemia and Trans-Atlantic Inter-Society Consensus (TASC) class A and B femoral-popliteal lesions of up to 15 cm in length but not involving the popliteal artery ( Table 48-1 and Box 48-1 ). Although surgery is preferred for treatment of TASC C and D lesions, endovascular therapy may be considered for the high-risk symptomatic patient who is otherwise an unsuitable operative candidate.
| Lesion Type | Guidelines |
|---|---|
| A |
|
| B |
|
| C |
|
| D |
|
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TASC A. Endovascular therapy is the treatment of choice.
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TASC B. Endovascular treatment is the preferred treatment.
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TASC C. Surgery is preferred for patients with low operative risk.
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TASC D. Surgery is the treatment of choice.
Preoperative Preparation
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History, physical examination, and non invasive vascular studies. History, physical examination, and noninvasive diagnostic evaluation should be performed for all patients who present with intermittent claudication, rest pain, or gangrene of the forefoot., Acuity, clinical severity, and anatomic extent of arterial occlusive disease, as well as prior surgical or endovascular interventions, medical comorbidities, and current functional status, all influence the decision to intervene and the best method of treatment. Noninvasive vascular studies should include segmental lower extremity pressures, pulse volume recordings (PVRs), ankle-brachial index (ABI), and toe pressures. In patients with calcified, noncompressible, infrageniculate arteries, toe pressures are required for determining the severity of the underlying arterial occlusive disease.
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Duplex ultrasound. Duplex ultrasound is useful for determining the location and the severity of arterial disease. In addition, the absence of a suitable vein conduit as determined by a venous duplex study will likely influence the decision to perform a catheter-based intervention.
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CT angiography. If physical examination or other studies suggest the presence of inflow disease, computed tomography angiography can be used to assess aortoiliac disease and help plan intervention, such as the selection of an access site and potential need for femoral endarterectomy.
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Perioperative medications. All patients should be on aspirin and statin therapy before intervention, with initiation of clopidogrel when endovascular intervention is likely and the need for surgery is low.
Pitfalls and Danger Points
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Access site complications. Access site complications, including bleeding, pseudoaneurysm, or arteriovenous fistula, may be averted by using ultrasound guidance to aid in localizing and assessing the common femoral artery (CFA) with real-time visualization during access.
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Arterial dissection or rupture. The risk of arterial dissection or rupture may be minimized by avoiding excessive oversizing of angioplasty balloons. Dissections are treated with low-pressure, prolonged, repeat angioplasty or stenting, whereas rupture is treated with a stent graft.
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Distal arterial embolization. Gentle passage of wires and catheters minimizes the risk of distal arterial embolization. Embolic protection may be used for high-risk lesions.
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Acute arterial thrombosis. Ensure adequate heparinization before instrumentation of the lesion. Observation and careful control of the wire tip during delivery and retrieval of guidance and treatment catheters is essential.
Endovascular Strategy
Angiographic Anatomy and Common Collateral Pathways
The femoral artery is the direct continuation of the external iliac artery and begins at the inguinal ligament and at the level of the femoral head. It passes down the anterior medial aspect of the thigh and ends in approximately the lower third of the thigh, where it passes through the adductor magnus to become the popliteal artery ( Fig. 48-1 ). As documented by Lippert and Pabst, variants in femoral artery branching exist and primarily involve variable origins of the profunda femoris and circumflex branches. If the common femoral artery is severely diseased, the main collateral pathways include anastomoses between branches of the hypogastric artery and profunda femoris artery and between branches of the external iliac artery and femoral tributaries. Branches from the profunda femoris artery provide a collateral route to the medial and lateral superior geniculate arteries in the event of superficial femoral artery occlusive disease.
Unfavorable Anatomic Features for Interventions on the Superficial Femoral AND Popliteal Arteries
Innate anatomic factors unique to the femoral-popliteal arterial segment adversely affect long-term patency after endovascular intervention. This arterial segment is subjected to recurrent mechanical forces that cause vessel deformation. Dynamic knee flexion and rotational and longitudinal compression of the SFA within the adductor hiatus may compromise outcomes after stenting. In addition, long or eccentric calcified lesions, multifocal stenoses, occlusions, and poor distal runoff are associated with poor endovascular treatment outcomes.
Access SITE Selection
Percutaneous access sites for femoral or popliteal artery disease include the femoral, popliteal, and pedal arteries. Brachial artery access has limited applicability because of available catheter lengths. The safest and most convenient site for most diagnostic and therapeutic interventions is the common femoral artery, which may be accessed in either an ipsilateral antegrade or a contralateral retrograde fashion. Retrograde access of the contralateral common femoral artery is typically the best approach for the initial study. From this access site, a therapeutic intervention may be performed on any lesion between the contralateral mid-common iliac artery and the peroneal or tibial vessels.
The ipsilateral antegrade femoral approach is technically more demanding, may increases radiation exposure to the operator, and is associated with an increased risk of local vascular complications. However, the presence of a contralateral infrainguinal bypass, endovascular aneurysm repair, or extreme tortuosity of the iliac system may preclude the use of a contralateral femoral artery access site. Both of these approaches may be of limited utility for the recanalization of a superficial femoral artery, when occluded flush with the profunda femoris artery. In this case, retrograde popliteal or pedal artery access provides an alternate option.
Stent Selection
Self-expanding stents are preferred in the femoral-popliteal region because of the proclivity of balloon-expandable stents to deform from external compression and dynamic movement. Early randomized trials examining short femoral-popliteal lesions demonstrated no improvement after primary balloon-expandable stenting compared with PTA alone. Recent data has suggested that nitinol stents may lead to improved primary patency for lesions of moderate length.
Drug eluting stents have been evaluated for the treatment of superficial femoral artery disease. Although promising early results were reported for sirolimus-eluting stents, little long-term benefit could be demonstrated. Superior 2-year primary patency has been recently reported for pacliaxel eluting stents as compared to bare metal stents (drug eluting stent, n = 61 vs. bare metal stent, n = 59). Paclitaxel-coated balloons have also been used to reduce restenosis, but the clinical effectiveness of this technology remains an area of active study.
Endovascular Technique
Retrograde and Antegrade Approaches for Arterial Access
With the patient supine on the fluoroscopic table, both groins are prepared and exposed for possible access. Percutaneous needle entry into the artery is performed with ultrasound guidance. Ultrasound guidance assists with precise placement of the puncture needle, facilitates an anterior wall puncture, allows the operator to note and avoid disease within the common femoral artery, enables access of a pulseless artery, and may assist in determining whether a percutaneous closure device should be used at the conclusion of the procedure.
For retrograde common femoral artery access, the ultrasound probe is first used transversely to clearly identify the bifurcation of the common femoral artery into the superficial femoral artery and profunda femoris artery and to scan through the course of the common femoral artery. Once the bifurcation is identified, the probe is turned longitudinally and followed cephalad until the femoral head is located while maintaining visualization of the bifurcation distally. This ensures common femoral artery access below the inguinal ligament. Sites with substantial anterior or posterior calcification should be avoided. Lidocaine is injected into the skin and the subcutaneous tissue, a small nick in the skin is made with a scalpel, and a hemostat is used to develop a tract. Antegrade common femoral artery access is performed in a similar manner.
A 21-Ga needle is visualized as it punctures the anterior wall of the artery, and a short 0.018-inch wire is inserted. Fluoroscopic confirmation is performed to document puncture over the femoral head and confirm wire placement in the external iliac artery. The wire is advanced, and a 3-Fr microsheath is placed, followed by exchange to a 0.035-inch wire and a 4-Fr short introducer sheath.
Angiography of the Lower Extremity
An Omni Flush diagnostic catheter is advanced over the wire to the L1 vertebra, and an abdominal aortogram is obtained. The Omni Flush catheter can then be used to obtain contralateral access or, if unsuccessful, an angled Glidecath, Rösch inferior mesenteric, or Sos selective catheter may be used. Once a catheter is advanced into the contralateral external iliac artery, angiography of the affected limb is performed. Visualizing the common femoral artery bifurcation requires positioning the image intensifier in an ipsilateral oblique angle of 20 to 30 degrees. Below the bifurcation, femoral-popliteal disease is well visualized in an anteroposterior projection, although occasionally oblique views may be necessary. Tibial and pedal runoff vessels are imaged before intervention and at completion of the procedure.
Endovascular Treatment of FemorAL-popliteal Artery Stenosis
A long interventional sheath is inserted once the target lesion is identified. A stiff, 0.035-inch, angled Glidewire is inserted through a diagnostic catheter and into the artery or bypass graft to be treated. The length and diameter of the sheath are determined by the anticipated intervention, with a 5- or 6-Fr sheath of 45 to 70 cm in length most commonly used. A 5-Fr sheath may be used if the lesion is less than 8 cm in length, since self-expanding stents of up to 8 cm in length are available for 5-Fr systems. However, for treatment of longer lesions, a 6-Fr system should be used. The sheath is passed over the stiff Glidewire and positioned approximately 10 cm proximal to the lesion. The sheath should be placed beyond the common femoral artery bifurcation when feasible to avoid the need for repeated selection of the superficial femoral artery.
After sheath placement, heparin (100 units per kilogram of body weight) is administered to achieve an activated clotting time (ACT) of 250 seconds. The stiff Glidewire is exchanged for a 0.014-inch wire to traverse the lesion. A hydrophilic-coated wire tip, such as the ChoICE PT Extra Support (Boston Scientific, Natick, Mass.), is preferred for stenoses, and a braided wire with a weighted tip, such as the ASAHI MiracleBros 6 (Abbott Vascular, Abbott Park, Ill.), is preferred when crossing an arterial occlusion is anticipated. The wire may be supported by a 0.018-inch angioplasty balloon catheter selected to treat the lesion. For complete occlusions, a 0.018-inch Quick-Cross catheter (Spectranetics, Colorado Springs, Colo.) may be used to support the wire, facilitate passage across severely diseased segments, and facilitate exchange for a stiffer wire if one is needed to deliver the balloon or stent. If the 0.018-inch catheter crosses the lesion, the balloon catheter will most likely cross as well. If the 0.018-inch catheter is unable to traverse the lesion, a 0.014-inch catheter may be used, but predilation of the lesion with a 0.014-inch balloon will likely be necessary. The wire is advanced beyond the lesion to support the treatment, keeping the wire tip in view to avoid inadvertent injury to the distal vasculature. An appropriately sized balloon catheter is advanced over the wire with sizing based on an adjacent healthy vessel, lesion characteristics, and sheath size ( Fig. 48-2 ). Once placed, the balloon catheter is inflated to profile, typically to 10 to 14 atm of pressure, with inflation maintained for 1 minute. Although the average diameters of the superficial femoral artery and popliteal artery are approximately 6 mm, these vessels may range from 4.5 to 7 mm in diameter.
