Midterm Outcomes of Salvage Angioplasty on Threatened Distal Bypass Grafts

Infra-popliteal bypass is an established and effective method for limb salvage in patients with critical limb ischaemia (CLI). Secondary interventions maybe required in order to maintain graft patency. The aim of this study was to look at the frequency and outcomes of such interventions. Consecutive patients undergoing bypasses onto the infrapopliteal vessels for CLI (Rutherford 4-6) at a single institution were analysed between 2009-2013. The primary end points were graft patency, limb salvage and amputation-free survival at 12 months by Kaplan-Meier analysis. A total of 122 infra-popliteal bypasses were performed in 108 patients. Distal anastomosis was on to the Anterior Tibial (n = 37), Posterior Tibial (n = 28), Peroneal (n = 24), Tibio-Peroneal Trunk (n = 24) or Dorsalis Pedis artery (n = 9). Primary-patency, assisted primary-patency and secondary-patency was 67%, 73% and 81% respectively at 12 months and 58%, 68% and 78% respectively at 24 months. Amputation free survival was 79% at 12 months and 73% at 24 months. There were 101 endovascular and 14 open secondary interventions performed on 61 (50%) threatened grafts. Endovascular interventions included angioplasty of inflow/proximal anastomosis (28%), outflow/distal anastomosis (39%), graft stenosis (17%) and thrombolysis (17%). Amputation-free survival was significantly better in salvaged threatened grafts compared to non-threatened grafts (Log rank test, P = 0.043) and in grafts requiring re-intervention later (>6 months from bypass) compared to those requiring early re-intervention (<6 months, P = 0.047). Secondary interventions in threatened distal bypass grafts are successful at maintaining graft patency. Careful duplex surveillance of these complex bypasses and timely intervention.