Factors influencing the development of vein-graft stenosis and their significance for clinical management

Objectives: to assess the influence of clinical and graft factors on the development of stenotic lesions. In addition the implications of any significant correlation for duplex surveillance schedules ol surgical bypass techniques was examined. Patients and methods: in a prospective three centre study, preoperative and peroperative data on 300 infrainguinal autologous vein grafts was analysed. All grafts were monitored by a strict duplex surveillance program and all received an angiogram in the first postoperative year. A revision was only performed if there was evidence of a stenosis of 70% diameter reduction or greater on the angiogram. Results: the minimum graft diameter sons the only factor correlated significantly with the development of a significant graft stenosis (PSV-ratio greater than or equal to 2.5) during follow-up (p = 0.002). Factors that correlated with the development of event-causing graft stenosis, associated with revision or occlusion, were minimal graft diameter (p = 0.001), the use of a venovenous anastomosis (p = 0.005) and length of the graft (p = 0.025). Multivariate regression analysis revealed that the minimal graft diameter was the only independent factor that significantly correlated with an event-causing graft stenosis (p = 0.009). The stenosis-free rates for grafts with a minimal diameter <3.5 mm, between 3.5-4.5 and greater than or equal to 4.5 mm were 40%, 58% and 75%, respectively (p = <0.05). Composite vein and arm-vein grafts with minimal diameters greater than or equal to 3.5 mm were compared with grafts which consisted of a single uninterrupted greater saphenous vein with a minimal diameter of <3.5 mm. One-year secondary patency rates in these categories were of 94% and 76%, respectively (p = 0.03). Conclusions: a minimal graft diameter <3.5 mm was the only factor that significantly correlated with the development of a graft-stenosis. However, veins with larger diameters may still develop stenotic lesions. Composite vein and arm-vein grafts should be used rather than uninterrupted small caliber saphenous veins.