How Secure is the Anastomosis between the Proximal and Distal Body Components of a Fenestrated Stent-Graft?

Abstract Objectives To examine the longitudinal migratory force required to cause disconnection of the bifurcated distal body component from the tubular proximal body of a fenestrated stent-graft. Methods Using a previously reported mathematical model distal distraction forces were calculated prior to performing in vitro pullout testing. The top end of the proximal body and the iliac limbs of the distal body were attached to the grips of a tensile tester via plastic sealing plugs and pneumatic clamps. Channels within the plugs allowed pressurisation of the inside of the stent-graft. Pullout tests were conducted in the vertical plane. Force and displacement data were recorded and tests repeated 8 times at room temperature with the stent-grafts either dry or wet and unpressurized, at 100 mmHg or at 120 mmHg. Results The median maximum pullout force was 2.9 N (2.6–4.1) when dry, 3.9 N (3.5–5.4) when wet and unpressurized, 6.3 N (4.8–8.3) when wet and pressurized at 100 mmHg and 6.5 N (4.8–7.2) when wet and pressurized at 120 mmHg. There was a significant difference between pressurized and unpressurized conditions ( P