Historical Background
Initial series demonstrating the feasibility of infrapopliteal angioplasty were reported in the late 1980s and early 1990s concomitant with the development of increasingly small, strong, low-profile balloons; steerable hydrophilic guidewires; and improved road-mapping techniques. These reports, largely for the treatment of critical limb ischemia, described acceptable technical success rates and promising short-term patency and clinical outcomes.
The technique of subintimal angioplasty, first reported in 1990 by Bolia and colleagues for treatment of occlusions in the femoral-popliteal artery, was subsequently extended for treatment of occlusions of the tibial and peroneal arteries, as reported in 1997. Laser angioplasty for lower extremity atherosclerotic disease was first described in 1984, but was initially associated with unacceptably high complication rates of vessel perforation. Subsequent technical improvements led to promising results for limb salvage in poor candidates for surgical revascularization. Serino and associates reported 2-year patency rates of 83% and limb salvage of 94% for laser-assisted balloon angioplasty in which the laser is coaxial to the balloon to increase the vessel diameter.
Feiring and co-workers were among the first to describe primary stenting of tibial lesions using coronary stents, and the first randomized trial evaluating the use of bare metal stents to treat infrapopliteal disease was conducted by Rand and colleagues. Subsequent studies have observed limb salvage rates of 89.3% with a 12-month primary patency rate of 62.8%. The Chromis Deep stent (Invatec, Roncadelle, Italy) designed for treatment of infrapopliteal lesions was found to have a 91.5% limb salvage rate with a primary patency of 52.9% at 12 months. In 2005 the first small series to use a drug-eluting, sirolimus stent for tibial occlusive disease described improved 6-month outcomes, with an in-segment restenosis rate of 32% compared with 66% for bare metal stents.
Indications
In an effort to guide recommendations for treatment and standardize methodology for reporting anatomic-specific outcomes, lesion morphology has been classified in a Trans-Atlantic Inter-Society Consensus document. Recent recommendations suggest that catheter-based interventions for infrapopliteal disease are most suitable for patients with critical limb ischemia in association with significant medical comorbidities.
Preoperative Preparation
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History and assessment of risk factors. Patients with a history of significant coronary or pulmonary disease may be better served by an endovascular intervention. However, renal insufficiency increases the risk of contrast-induced nephropathy. Minimizing known atherosclerotic risk factors through smoking cessation, treatment of diabetes or hypertension, and use of statins can reduce morbidity and improve outcomes. Patients should be placed on an antiplatelet regimen, such as aspirin and clopidogrel.
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Physical examination. A complete pulse examination should be performed, along with an assessment of skin integrity in the lower extremities, including the presence of web space ulcers, open wounds, and gangrene.
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Noninvasive vascular laboratory studies. The ankle-brachial index (ABI) and pulse volume recordings provide an objective analysis of both the location and the severity of peripheral arterial disease (PAD). ABI of less than 0.9 is indicative of PAD, whereas an ABI of less than 0.4 is consistent with critical limb ischemia. Treadmill exercise testing may help identify underlying PAD, particularly in those patients with appropriate symptoms and normal ABIs at rest. Duplex ultrasonography can be performed to determine the presence and extent of arterial disease and to evaluate potential target points for arterial reconstruction.
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Imaging studies. Computed tomography angiography or magnetic resonance angiography may help to characterize the location and severity of arterial lesions and the presence of calcification.
Endovascular Strategy
Angiographic Anatomy and Common Collateral Pathways
The anatomy of the infrageniculate vasculature begins at the adductor hiatus, where the superficial femoral artery (SFA) transitions to the popliteal artery, which tracks caudally through the popliteal fossa and down to the bifurcation of the anterior tibial artery and the tibioperoneal trunk. The popliteal artery occasionally bifurcates into its terminal branches in the popliteal fossa behind the knee, leading to a high takeoff of the anterior or posterior tibial artery. The popliteal artery rarely divides into the anterior tibial, posterior tibial, and peroneal arteries without the formation of a tibioperoneal trunk.
The popliteal artery gives rise to several branches, including the superior and inferior sural muscular branches, the cutaneous branches, the medial and lateral superior genicular arteries, a middle genicular artery, and the medial and lateral inferior genicular arteries. Rich collateralization is found around the patella, which becomes pronounced in patients with popliteal or distal SFA occlusions.
The anterior tibial artery commences at the popliteal bifurcation and extends to the dorsalis pedis artery, giving off several muscular branches, as well as the malleolar arteries, which supply the ankle joint. The posterior tibial artery extends from the tibioperoneal trunk and travels obliquely down behind the medial malleolus. Muscular, communicating, and nutrient branches arise from the posterior tibial along its course to the foot, where it divides into the medial and lateral plantar arteries. Finally, the peroneal artery arises at the bifurcation of the tibioperoneal trunk below the popliteus muscle and traverses along the posteromedial fibula to the level of the calcaneus.
Unfavorable Anatomic and Physiologic Features for Interventions on the Tibial or Peroneal Vessels
Several anatomic features of tibioperoneal disease have increased the technical challenges and reduced the long-term durability associated with endovascular intervention, including densely calcified arteries, long-segment disease, serial stenoses or occlusions, small-diameter vessels, and compromised runoff beds.
Selection of Antegrade or Retrograde Access
Balloon angioplasty and stent placement of infrageniculate arteries are performed either through the ipsilateral femoral artery in an antegrade approach or through the contralateral femoral artery using an up-and-over approach. The advantages of the antegrade approach include better guidewire and catheter control; the ability to reach distal lesions with shorter wire lengths, which occasionally cannot be reached using the up-and-over approach; and avoidance of tortuous aortoiliac vessels. Nonetheless, the up-and-over approach permits the use of a simple retrograde femoral puncture and evaluation of the aortoiliac and femoral arteries before treatment of infrageniculate lesions. Both groins are always prepared in case an alternative approach is required during the procedure.
Selection of a Stent
Percutaneous transluminal angioplasty (PTA) remains the treatment of choice for infrapopliteal disease, with stent implantation restricted to suboptimal outcomes after PTA. In the absence of an approved tibial stent, coronary stents have been used.
Endovascular Technique
Tibial Artery Angioplasty and Stenting
Positioning
After lying the patient supine on a fluoroscopic table, the patient is positioned with the hip externally rotated and knee slightly flexed. The foot is padded and taped in the lateral position to maximize visibility of tibial runoff.
Arterial Access
Antegrade femoral access is preferred, because it allows easier guidewire and catheter control and “pushability,” along with the opportunity to reach distal lesions with a shorter wire. Access is obtained using a 21-Ga needle and a 0.018-inch wire commonly found in a micropuncture kit. The needle and 0.018-inch guidewire are exchanged for a 3-Fr sheath, and sheath placement in the SFA is confirmed by intraluminal injection of contrast ( Fig. 49-1 ). A 0.035-inch guidewire is advanced, and the 3-Fr sheath exchanged for a 5-Fr sheath. Once the sheath is secured, serial angiograms with runoff are performed in the anteroposterior projection to better characterize the inflow, pinpoint the lesion, and assess collateralization and outflow.
