Functional angiograms after stent implantation into the femoropopliteal artery

BACKGROUND: This study investigates the frequency of functional stenoses (FS) after stent implantation into the femoropopliteal artery (FPA) detected on lateral angiograms with the knee flexed and evaluates the impact on additional treatment. 

METHODS: Retrospectively we identified 42 patients with stent-based revascularizations of the FPA in whom a final lateral digital subtraction angiography (DSA) with the knee in a flexed position (functional angiography [FA]) had been performed. In 32 patients' location, frequency and additional treatment of FSas well as stent-type, landing zones, angle of the knee-joint during FAand patency rates were evaluated. RESULTS: Mean lesion length was 12.9±20.16cm, 26/32 patients (81%) had a CTO. In 5/32 patients (15.6%) a FSwas detected by FA: in three patients FS was located proximal and in two patients distal to a Supera® stent (Abbott Laboratories, Chicago, IL, USA). FS of the proximal landing zones were within the distal SFA(N.=2) or P1 segment (N.=1) and FSof the distal landing zone were within the P3 segment (N.=2). In all three proximal FS additional overlapping stent implantation was performed. The distal FS went untreated in order to preserve the P3 segment for a bypass option. Mean angle of FAwas 98.~.7. Patency at 12 months did not differ between patients with (treated) FS(50%) and those without FS (72%) (P=0.240). 

CONCLUSIONS: Functional stenosis after stent-based revascularization of the FPAby use of a device with increased radial force occurs rather frequently. Proximal functional stenosis can be successfully treated by overlapping stent implantation. However, clinical relevance of functional stenosis needs further investigation.