Postoperative surveillance of infrainguinal reverse vein grafts: An hypothesis for improving examination efficiency

The purpose of this study was to develop a simplified technique of infrainguinal reverse vein graft (RVG) surveillance that minimizes missed >50% stenoses in the vein graft and its inflow and outflow vessels. A blinded, prospective study was conducted utilizing measurements of ankle- brachial systolic blood pressure rations (ABI) and duplex ultrasound graft surveillance. Examiner 'A' determined a mid-graft flow velocity only and recorded the peak systolic velocity (PSV) as ≥ or <45 cm/sec. Examiner 'B' examined the entire graft for the presence or absence of a high-grade lesion (intrastenosis PSV ≥200 cm/sec). ABI's were graded as normal (>0.9) or abnormal (≤0.9). On hundred four RVG surveillance examinations were performed according to protocol. 'A' recorded 78 mid-graft PSV's ≥45 cm/sec (Group I) and 26 <45 cm/sec (Group II). 'B' detected 11 high-grade graft lesions in Group I (14%) and 4 in Group II (16%), p = NS. In the 10 examinations with a mid-graft PSV ≥45 cm/sec, compressible vessels and high- grade lesions determined by 'B' that the ABI was abnormal in 8. Mid-graft PSV is not predictive of high-grade RVG lesions. Restricting full surveillance examinations to RVG's with mid-graft PSV ≤45 cm/sec and/or limbs with an abnormal ABI or incompressible vessels would have resulted in correct determination of the presence or absence of a duplex-detected high-grade stenosis in 98% (102/104) of studies. Examination of the entire length of RVG's can potentially be limited to those limbs with abnormal ABI's, incompressible vessels, or a mid-graft PSV <45 cm/sec.