PREDISCHARGE DUPLEX IMAGING OF INFRAINGUINAL VEIN GRAFTS DOES NOT PREDICT THE DEVELOPMENT OF STENOSES

Background The aim of this study was to determine whether predischarge duplex imaging of an infrainguinal vein graft could predict the subse quent development of graft stenosis. Methods Patients with infrainguin al vein grafts underwent a duplex scan of the entire graft before disc harge from hospital. Grafts were classified as abnormal or normal base d on the presence or absence of flow abnormalities (peak velocity rati o 1.5 or greater). All grafts were re-examined 1 month after surgery, at 3-monthly intervals for the first year and then every 6 months ther eafter. A significant stenosis requiring correction was defined by a d uplex-derived peak systolic velocity ratio of 3.0 or more. The relatio nship between the predischarge scan and subsequent development of sten osis was examined. Results Forty-four grafts were recruited. Two occlu ded soon after a normal predischarge scan and were excluded from subse quent analysis. Predischarge abnormalities were found in 16 grafts. Th e abnormality in one graft required immediate correction. A further fo ur grafts subsequently developed significant stenoses and required ang ioplasty. Of the 26 grafts with no predischarge abnormalities, 11 deve loped significant stenoses and underwent angioplasty. Abnormal predisc harge duplex scans had a sensitivity and specificity of 31 and 58 per cent respectively for the development of stenoses. The positive and ne gative predictive values were 31 and 58 per cent respectively. Conclus ion Predischarge duplex imaging cannot be used to predict the developm ent of stenoses in infrainguinal vein grafts.