VEIN GRAFT SURVEILLANCE - IS GRAFT REVISION WITHOUT ANGIOGRAPHY JUSTIFIED AND WHAT CRITERIA SHOULD BE USED

Purpose: The objective of this study was to assess the accuracy of col or-now duplex surveillance parameters to detect infrainguinal vein gra ft stenoses and to investigate whether graft revision without angiogra phy is justified. Methods: In a prospective study in which three cente rs participated, the data of graft surveillance in 300 patients were a nalyzed. for the evaluation of surveillance criteria all patients unde rwent a digital subtraction angiography if a graft stenosis was suspec ted. To create a control group, in patients with normal grafts a conse nted digital subtraction angiography was performed also. From these da ta the accuracy of seven duplex and three ankle blood pressure-derived variables was assessed. The relation between various surveillance cri teria and continued graft patency was determined with life table analy sis with the transient state method. Results: The mean follow-up perio d was 20 months (range, 1 to 40 months). At univariate and multivariat e analysis the peak systolic velocity (PSV) ratio provided the best co rrelation with angiographic stenoses greater than or equal to 70% (PSV ratio cutoff 3.0: sensitivity 80%, specificity 84%). This finding did not differ between the participating centers. With life table methods it was demonstrated that the best combination of efficacy (limitation of the number of unnecessary revisions), safety (minimal number of co rrectable lesions missed), and reduction of angiograms was obtained by a two-parameter surveillance algorithm. This algorithm included a PSV ratio <2.5 to delineate patients in whom a conservative approach with out angiography or revision was appropriate, a PSV ratio greater than or equal to 4.0 to indicate patients in whom vein graft revision witho ut angiography could be scheduled, and a group with PSV ratios between 2.5 and 4.0 in whom angiography was to be performed to determine clin ical management on the basis of the stenosis severity. This algorithm had a positive predictive value of 93% and a negative predictive value of 89%. In addition, it resulted in a reduction of the number of angi ograms of 49% compared with a policy of angiographies in all patients with a PSV ratio greater than or equal to 2.5. Conclusions: The best c riterion to identify a failing graft is the PSV ratio. With a two-para meter algorithm for vein graft surveillance, the incidence of unnecess ary revisions and of missed high-grade lesions was acceptably low, whe reas the number of angiograms was reduced by one half.