Clinical Outcomes in Japanese Patients with Chronic Limb Threatening Ischaemia Undergoing Tibial and Pedal Bypass with a Single Segment Great Saphenous Vein Graft.

Abstract

A single segment great saphenous vein (GSV) with a diameter ≥ 3.0 mm is widely accepted as the standard conduit for tibial and pedal bypass in chronic limb threatening ischaemia (CLTI) based on studies in European and American populations. However, this threshold may not be appropriate for Asian patients who generally have smaller body habitus and vein diameter. The aim of this study was to evaluate clinical outcomes and the optimal conduit diameter in Asian patients with CLTI undergoing tibial or pedal bypass. Data were analysed from a multicentre retrospective observational study of 1 016 CLTI cases treated with tibial or pedal bypass using autologous vein conduits at seven Japanese centres between 2013 and 2022. Pre-operative vein diameters were assessed by duplex ultrasound (DUS), computed tomography (CT), or both, and were categorised into three groups (< 2.5 mm, 2.5 - 3.0 mm, and ≥ 3.0 mm) for each evaluation. The primary endpoint was primary patency. Secondary endpoints included secondary patency, limb salvage, and wound healing. Among 871 patients (72.0% men; mean age 73 ± 10 years) who received single segment GSV grafts, the three year primary and secondary patency rates were 57.1% and 79.6%, respectively. Limb salvage at 3 years was 90.9% and the twelve month wound healing rate was 83.8%. A DUS evaluated diameter ≥ 2.5 mm and a CT evaluated diameter ≥ 3.0 mm (reflecting a mean difference of 0.30 mm) were significantly associated with improved primary patency after adjustment for patient backgrounds and procedural characteristics. Although approximately 20% of cases had pre-operative diameters < 2.5 mm, these grafts showed comparable three year secondary patency, limb salvage, and wound healing after adjustment. DUS and CT evaluated graft diameters were significantly associated with graft patency, but not with limb salvage or wound healing in a Japanese cohort. Further studies of the appropriate graft diameter are needed in Asian patients with CLTI.