Developments in subintimal angioplasty in the infrainguinal segment

Since it was first described in 1990, subintimal angioplasty (SIA) has become an established percutaneous procedure for the treatment of symptomatic lower limb arterial occlusions. The concept of this technique is to create a dissection in the subintimal plane in order to cross an occluded intraluminal segment, then to re-enter the true lumen of the patent distal artery. Balloon dilatation of this subintimal channel results in a new extraluminal lumen that is free of atheromatous plaque. It is a safe and effective procedure with advantages over intraluminal angioplasty and open surgery, thereby increasing the scope of endovascular therapy to include complex infrapopliteal occlusions and high-risk patients with limb-threatening ischaemia who are unsuitable for surgical revascularization. It has good primary success rates, long-term outcomes and does not compromise future surgical revascularization, resulting in a paradigm shift in the management of lower limb ischemia with many centres adopting SIA as first-line therapy. This article aims to review the indications of SIA, variations and developments in the technique, outcomes and factors affecting patency, and complications associated with the procedure.