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Introduction

Critical limb ischemia (CLI), a complication of peripheral arterial disease defined as ischemic rest pain or tissue loss, is associated with high morbidity and mortality. Among patients presenting with CLI, approximately 75–80% will be alive at 1 year, 30% will have undergone major amputation, and only 45% will be alive with both limbs . The five-year mortality rate reaches 50%, which is as high as in many types of cancer . Prior to the introduction of revascularization therapies, limb-salvage rates with conservative treatment were as low as 5%, so almost all of the patients with CLI had to undergo primary amputation . At the beginning of the revascularization era, bypass surgery was the only available strategy for the treatment of CLI. However, in the following years, endovascular revascularization became available as an alternative therapeutic approach to surgery. Further evolution of endovascular technologies and techniques now allows for the endovascular treatment of lesions previously considered to be unsuitable for this approach. Importantly, successful endovascular revascularization is associated with reduction of morbidity and mortality in patients with CLI . Therefore, endovascular therapy is considered as the first line of therapy for limb salvage in CLI .

To maximize the success rates of endovascular treatment, obtaining an optimal vascular access is paramount. A suboptimal access may limit the ability to collect appropriate imaging views and/or to successfully achieve revascularization . Furthermore, it may be associated with increased risk of complications. Therefore, planning must include determining the best access prior to the procedure. Fundamental elements of a successful access are an understanding the normal arterial anatomy and its variants, the collection of a complete medical and surgical history, the detailed review of noninvasive imaging studies, and the planning for possible alternative vascular access strategies . Traditionally, percutaneous endovascular interventions (PEI) were performed using an antegrade approach. However, patients with peripheral arterial disease and CLI tend to have diffuse, complex, and calcified lesions for which a traditional antegrade approach is frequently not adequate. However, alternative approaches are becoming more common, allowing for treatment of lesions previously considered beyond reach.

In this article, we describe the main technical aspects of PEI, with a focus on procedures performed for the treatment of CLI, and discuss outcomes of the various access sites. In the femoral arterial access section, we highlight the optimal point of access at the level of the common femoral artery (CFA) and the ways of guidance for access, and compare the specific advantages and complications of antegrade access in the CFA or superficial femoral artery (SFA). Also, we review the indications of retrograde pedal or trans-metatarsal approach, the ways of guidance, the methods of anticoagulation, the prevention strategies of vasospasm, the ways of hemostasis, and clinical outcomes in retrograde pedal or trans-metatarsal access section.