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 de velopment of stenotic lesions. In addition the implications of any signific ant correlation for duplex surveillance schedules ol surgical bypass techni ques was examined. Patients and methods: in a prospective three centre stud y, preoperative and peroperative data on 300 infrainguinal autologous vein grafts was analysed. All grafts were monitored by a strict duplex surveilla nce 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% di ameter reduction or greater on the angiogram. Results: the minimum graft diameter sons the only factor correlated signifi cantly with the development of a significant graft stenosis (PSV-ratio grea ter than or equal to 2.5) during follow-up (p = 0.002). Factors that correl ated 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). M ultivariate regression analysis revealed that the minimal graft diameter wa s the only independent factor that significantly correlated with an event-c ausing 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 ar m-vein grafts with minimal diameters greater than or equal to 3.5 mm were c ompared with grafts which consisted of a single uninterrupted greater saphe nous vein with a minimal diameter of <3.5 mm. One-year secondary patency ra tes 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 sign ificantly correlated with the development of a graft-stenosis. However, vei ns with larger diameters may still develop stenotic lesions. Composite vein and arm-vein grafts should be used rather than uninterrupted small caliber saphenous veins.