Atheromatous Occlusive Lesions of the Popliteal Artery Treated with Stent Grafts: Predictive Factors of Midterm Patency

Abstract

Because of its location, the popliteal artery is exposed to important biomechanical constraints, inducing a specific risk of thrombosis of stents, little studied in the literature. The objective of this monocentric retrospective study was to evaluate the patency of stents implanted in the popliteal artery to treat atheromatous lesions and the risk factors predisposing to thrombosis. Between January 2009 and July 2013, all the patients receiving stents for a residual stenosis or a complication of angioplasty in the popliteal artery or the distal anastomosis of a femoropopliteal bypass were included retrospectively and in an intention to treat. Forty-six patients (17 women), with a 71.5years median age (range, 45-90years), including 17 diabetic patients (37%) and 7 hemodialysis patients (15%), were operated in 51 limbs for claudication (n=25, 49%), critical ischemia (n=18, 35%), or acute ischemia (n=8, 16%). Thirty stenoses >70% (59%) and 21 thromboses (41%) were treated with 56 autoexpandable stents, with an average diameter of 6mm (range, 5-8mm) and an average length of 5cm (range, 4-15cm), including 39 lesions in P1 (above the patella), 8 in P2 (articular), and 4 in P3 (distal popliteal artery). The following factors were analyzed according to univariate and multivariate models: age, gender, Society for Vascular Surgery score, symptomatology, type and location of lesion, number of stents deployed, and dimension of stents. Technical success was of 98% (n=50), including 1 insufficient result of the endovascular treatment. At 30days, one patient treated for critical ischemia died (2%) and one residual popliteal stenosis was treated by bypass (2%). After a 27.6±10.07month follow-up, restenosis (>50%) was detected in 5 cases including 4 asymptomatic and a popliteal thrombosis occurred in 9 cases, including 3 asymptomatic cases. Eight secondary interventions were necessary, including 4 endovascular procedures, 3 bypasses, and only 1 major amputation (thigh). The primary and secondary patencies at 12months and 24months were 80% and 65%, and 90% and 74%, respectively. The multivariate analysis showed that the type of lesion (stenosis versus occlusion; odds ratio [OR], 5.1; 95% confidence interval [CI], 1.2-22.9, P=0.032) and the number of stents implanted (1 vs. 2 stents; OR [95% CI], 12.7 [1.8-88.5]; P=0.011) were independent predictive factors of secondary thrombosis. The endovascular treatment of the atheromatous popliteal lesions appears to be a satisfactory alternative. The implantation of 1 stent in the popliteal artery is recommended in the event of popliteal occlusion, whereas for a stenosis, it must be reserved for patients with residual stenosis or in the event of complications of angioplasty, such as dissection or elastic recoil. Stent must be single, with deployment of a long stent in the event of long lesion.