Natural Remodeling of the Distal Anastomosis of an Above-Knee Femoropopliteal Bypass Depicted by CT Angiography of Lower Limbs Improves Geometry of the Reconstruction

Abstract

The geometry of the distal anastomosis of a femoropopliteal bypass influences local hemodynamics and formation of intimal hyperplasia. We hypothesized that the distal anastomosis of an above-knee femoropopliteal bypass undergoes remodeling that results in displacement of the original course of the popliteal artery and change in the anastomosis angle. We identified 43 CT angiography examination with proximal femoropopliteal bypass and either a preserved contralateral popliteal artery or previous CTA before construction of the bypass for comparison. In these examinations, we measured the displacement distance and angle at the level of the distal anastomosis and compared these measurements with clinical and imaging data. The displacement distance was 8.8±4.9 mm (P<0.0001) and the displacement angle was -1° (IQR=44°). The angle between the inflow and outflow artery was 153±16° (P<0.0001). There was a negative association between the displacement angle and the angle between the bypass and the outflow artery (r=-0.318, P=0.037). Patients with reversed venous grafts had a greater displacement of the anastomosis (14.7±3.0 mm) than patients with prosthetic grafts (8.0±4.5 mm, P=0.0011). We conclude that construction of a distal anastomosis of proximal femoropopliteal bypass results in displacement of the original course of the popliteal artery towards the bypass and this effect is more pronounced in reversed venous grafts.