New Trends in Management of Popliteal Artery Aneurysm

Abstract

Popliteal aneurysms (PAAs) are the most common peripheral aneurysms and occur almost exclusively in men. The majorities of these aneurysms are degenerative in nature and are associated with contra lateral PAA in 64.1% and abdominal aneurysm in 41%. PAA is probably a multifactorial disease: in elderly patients atherosclerosis seems to be the main cause, whereas in younger patients other causes have been hypothesized, such as popliteal artery entrapment syndrome, cystic adventitial degeneration, osteochondroma, and trauma. Popliteal aneurysms are frequently asymptomatic; however, Symptoms include; Intermittent claudication, Rest pain & The Main Complications Of PAA Include; Distal Embolization, Thrombosis & Rupture; Acute Leg Ischemia due to thrombosis of the PAA is a dangerous complication of this pathologic feature Duplex ultrasonography has been shown to be superior to physical examination in detecting popliteal aneurysms, beyond detection, duplex ultrasonography provides critical information relevant to treatment, including the diameter, presence of intra-luminal thrombus, velocity of blood flow, and patency of out flow artery. Other imaging tests, such as a computed tomography (CT) or magnetic resonance imaging (MRA) scan confirm the diagnosis . The elective surgical repair for all asymptomatic aneurysms 2.5 cm or larger is the golden choice unless the risks associated with treatment are excessive because of health status of the patient. In modern era, the arterial bypass with ligation or interposition grafting is the gold standard for treatment, Small or fusiform aneurysms are best approached medially by conventional bypass with aneurysm ligation. For large aneurysms confined to the popliteal space that are causing symptoms from compression or in which the aneurysm has caused distortion & displacement of the normal anatomy as a result of tortuosity, elongation & kinking the posterior approach is preferred. This is also an appropriate approach for a smaller aneurysm, but it is not applicable for aneurysms that extend proximally beyond the popliteal space. Surgical management of complicated popliteal aneurysm as Patients with acute limb ischemia require urgent intervention to avoid amputation. In a patient with a viable limb & no symptoms of sensory or motor dysfunction, intravenous heparin can be administrated to stabilize the patient. Arteriography & surgery are performed during The same administration. If the aneurysm is fully occluded & patent distal outflow vessel is identified on arteriography, a vein bypass to the patent outflow vessel is performed as described previously. If no outflow vessel is identified & the patient’s limb is not immediately threatened, intra-arterial thrombolysis is started with the objective of restoring flow to potential outflow target vessels. Intra-arterial thrombolytic therapy has become an important adjunct in the management of acute ischemia resulting from popliteal aneurysm. Result of surgical treatment of popliteal aneurysms are affected by the absence or presence of symptoms, whether the repair is done electively or on an emergency basis, and whether the conduit used is saphenous vein or synthetic graft. Equally good results have been reported with either the medial or posterior approach. In most series, saphenous vein grafts have generally been superior regardless of the approach used & may be most indicated in disadvantaged situations. An endovascular approach to repair of a PAA is attractive because of the potential to minimize patient morbidity, duration of hospitalization, and recovery time. These are all important issues, particularly in a frail patient population that may require multiple interventions. However, the patency of endovascular stent grafts in the popliteal artery should not be inferior to that obtained with open bypass surgery. The feasibility of an endovascular approach to the management of patients with a PAA was demonstrated in early case reports and small clinical series. Limitations for endovascular repair are the lack of proximal or distal landing zones, or compromised inflow or outflow arteries also large discrepancy in the diameter between the proximal and distal landing zones is a technical contraindication, The caliber of the attachment site should be 10% to 20% smaller than the diameter of the stent-graft & free of excessive calcification, thrombus, tortuosity, or angulations & The aneurysm itself should not contain excessive amounts of thrombus or debris so all this limitations decrease the rate of use the endovascular technique in PPA repair .