The Utility of Duplex Ultrasonography Surveillance in Identify Failing Aortobifemoral Grafts.

OBJECTIVE The Society for Vascular Surgery stated there are a lack of studies describing long-term surveillance for aortobifemoral (AoBF) bypasses. Our goal was to investigate the value of DU studies as a surveillance tool for AoBF bypasses. METHODS We retrospectively identified patients in our prospectively maintained database who underwent AoBF bypasses between 1995-2018. Surveillance was performed routinely with DU post-operatively, every 6 months for 1 year, and then annually. We considered "abnormal" DU findings to include peri-graft fluid, pseudoaneurysm or, peak systolic velocities (PSVs) > 350 cm/sec or PSV ratio > 3.5 anywhere from the proximal aortic to distal femoral anastomosis. If abnormalities were identified patients underwent intervention or shorter surveillance intervals. RESULTS Of 153 AoBF bypasses, 60 patients with 120 graft limbs fulfilled our post-operative surveillance protocol with a mean follow-up of 4.0 years (0.5-24 years). "Normal" DU surveillance studies were documented throughout follow-up in 112 (93%) limbs. Of these, 2 (1.7%) developed acute limb occlusion. Eight (6.7%) limbs had "abnormal" DU findings: 5 failing grafts with focal elevated PSVs, 2 with peri-graft fluid leading to a diagnosis of an infected graft, and 1 with a pseudoaneurysm (PSA). Contrast arteriography or CT-angiography confirmed > 75% diameter stenosis, fluid or PSA in all 8 limbs. Graft revision (5 endovascular, 2 surgical) was performed in 7 of the 8 limbs initially or after 2 successive "abnormal" DU studies within 6 weeks of each other; 1 patient refused intervention. Without surveillance, urgent or emergent treatment might have proved necessary in 7.5% (7 + 2 = 9/120) of cases instead of only 1.7% (2/120) of cases. CONCLUSION Vascular surgeons should adopt DU as a useful surveillance tool to identify AoBF bypasses that are failing or have other problems not identified clinically. Persistence of "abnormal" DU findings should prompt operative or endovascular intervention.