Open Versus Endovascular Repair of Popliteal Artery Aneurysm Trial

Current therapy for patients with asymptomatic PAA, elective repair has been recommended for PAA > 2 cm and for smaller aneurysms with associated mural thrombus1. Treatment modalities are similar in that they exclude the aneurysm from the circulation. Current treatment options include both open surgical bypass (OPAR) with aneurysm exclusion and endovascular popliteal artery repair (EPAR) in which the PAA is excluded by a stent graft. Open repair of PAA has been shown to have excellent graft patency and limb salvage rates, however it is associated with the need for general or regional anesthesia, 10-20% surgical site infection rate, and other complications such as seroma, hematoma, and neurological injury. Endovascular popliteal aneurysm repair is a minimally invasive technique that can be performed under conscious sedation but may be associated with higher risk of graft thrombosis, stent fracture, and may have a lower long term success rate. A paucity of strong comparative data further increases this equipoise. An adequately powered, prospective, comparative study contrasting OPAR approach with EPAR will guide vascular specialists in their treatment of PAA and is very much needed.

Trial Conduct The trial will be conducted in compliance with the protocol, Good Clinical Practice (GCP) guidelines, Declaration of Helsinki and applicable federal regulatory requirements [Title 21 Code of Federal Regulations Parts 50, 54, 56, 812 and 45CFR46]. This trial will be registered on NIH clinical trial registry.

Description and Importance of the Population to be Studied One hundred and forty eights subjects aged 35 or older with asymptomatic ≥ 2.0 cm PAA undergoing repair will be randomized to undergo either OPAR or EPAR. These patients will be recruited at the participating VSGNE centers who agreed to enroll and randomize patients for this trial. This trial will be formally approved by respective Institutional Review Boards.

Investigators will focus on a population of subjects who are candidates for both open surgery and endovascular therapy as determined by the treating investigator. Such individuals represent patients who fall into the "grey area of treatment equipoise". Investigators will exclude subjects with associated acute limb ischemia and hyper-coagulable states. In the OPAR group the choice of conduit will be at the discretion of the surgeon. Vein or non-autogenous conduits will be allowed. In the EPAR group, a femoral cu-down for introduction of stent will be permissible. Percutaneous placement of stent-grafts will also be allowed. Investigators will exclude individuals who are deemed to be at prohibitive risk for open vascular surgery by standard American Heart Association AHA criteria as noted on formal preoperative evaluation or who have significant non-dialysis dependent renal dysfunction (Cr. >3.0). From an anatomic standpoint, investigators will exclude patients who cannot have their PAA treated by stent-grafts due to short "proximal or distal landing zones". Subjects without a patent outflow target vessel will, likewise, be excluded, as treatment options in such patients are usually limited to medical management, amputation or experimental therapies.

TRIAL OBJECTIVES AND PURPOSE