To assess whether stent-grafts crossing the hinge point (HP) in the popliteal artery are associated with increased complications and decreased patency rates, after endovascular treatment of the popliteal artery aneurysm. This was a single-center, case-control study. Patients were allocated to either the HP group (subjects with stent-grafts crossing the HP) or the control group (subjects with stent-grafts above and/or below the HP) based on stent-graft location in the femoropopliteal artery. HP was defined as the main curve in the popliteal artery in the most acute angle toward the femur that appeared during knee flexion, which was identified by reviewing postoperative angiograms. Independent, blinded reviews were performed for all imaging data. Graft evaluation by CTA or duplex ultrasound was performed at 1, 3, 6, and 12 months and annually thereafter. Outcomes measured included: stent-graft patency, stent-graft fracture, other stent-related complications, and major adverse events, including reintervention, death, amputation, stroke, and myocardial infarction. A total of 44 limbs treated with placement of heparin-bonded Viabahn endoprostheses were included in this study. Twenty and twenty-four patients were allocated to the HP group and the control group, respectively. Primary patency rates of the HP group at 1, 2, 3, and 5 years were 84.1 ± 8.4%, 84.1 ± 8.4%, 84.1 ± 8.4%, and 72.1 ± 13.3%, respectively. The primary patency rates of the control group were 87.0 ± 7.0%, 82.4 ± 8.0%, 82.4 ± 8.0%, and 82.4 ± 8.0%, respectively. There was no significant difference between the 2 groups (P=0.81). No reintervention was performed in the control group. In the HP group, 5 limbs (25.0%) developed endoleak, 3 (15.0%) developed thrombosis, and 1 (5.0%) developed a stent fracture followed by thrombosis. Thrombosis occurred in 2 limbs (8.3%) of the control group, and stent-graft migration was observed in another 2 cases (8.3%). Neither group demonstrated stent-graft infection or acute popliteal artery embolism. Overall, incidence of stent-related complications were significantly higher in the HP group (P= 0.04). Event-free survival rates of the HP group at 1, 2, 3, and 5 years were 75.0 ± 9.7%, 69.6 ± 10.4%, 61.9 ± 11.8%, and 29.0 ± 12.8%, respectively. Corresponding rates in the control group were 79.2 ± 8.3%, 79.2 ± 8.3%, 79.2 ± 8.3%, and 79.2 ± 8.3%, respectively. The difference was not statistically significant between the 2 groups (P=0.20) CONCLUSIONS: crossing the HP with femoropopliteal artery stent-grafts increased the risk of stent-related complications and reinterventions but did not decrease stent patency or event-free survival.
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