Intraoperative angioscopy may improve the outcome of in situ saphenous vein bypass grafting: a prospective study

The Fate of Unrevised Stenoses in Infrainguinal Autologous Vein Grafts as Detected by Intraoperative Duplex Scanning

Intraoperative infrainguinal autologous vein graft stenoses are common, and some authors advise revision of these stenoses. But the natural history of these lesions is not clear. This study was undertaken to determine the natural history of duplex-detected intraoperative stenoses with a nonrevision policy. Intraoperative duplex scanning was performed in 46 infrainguinal autologous vein bypasses. The surgeon was blinded for the results of the intraoperative duplex scan and no intraoperative graft revision or modification of the routine postoperative protocol was performed after the duplex scan. Intraoperative duplex parameters and patient and bypass characteristics were correlated with the occurrence of an early graft event (occlusion or revision of a patent graft within 6 weeks postoperatively), which was the study's primary endpoint. Early graft event rate was 37% (17/46). PSV ratio and PSV-max were the only parameters with a significant correlation with the occurrence of an early graft event. An intraoperatively measured PSV ratio of =3.0 was the best predictor of an early graft failure with a sensitivity of 71% (95% CI: 50–83%) and a specificity of 90% (95% CI: 78–97%). In 12 of the 15 (80%) grafts matching this criterion an early graft event occurred, while only 5 (16%) early graft events occurred in the remaining 31 grafts (ie, a negative predictive value of 84%). When a PSV ratio of =3.0 was used as a cutoff value to predict early postoperative graft events, the likelihood ratios for a positive and negative test result were respectively 6.82 (95% CI: 2.23–20.8) and 0.33 (95% CI: 0.16–0.69). Unrevised intraoperative duplex-detected stenoses in infrainguinal autologous vein graft stenoses are a serious threat to early graft patency. The presence of an intraoperatively detected graft stenosis with a PSV ratio =3.0 is a strong predictor of early graft failure.

A randomized prospective study of valvulotome efficacy in in situ reconstructions

OBJECTIVES

To compare the efficacy of valvulotomes during in situ bypass surgery.

DESIGN

A randomized prospective blinded study.

MATERIALS AND METHODS

Thirty PAD patients scheduled for infrainguinal greater saphenous vein bypass were randomized to use of adjustable or fixed valvulotomes for valve destruction. Valvulotomy was performed after construction of the proximal anastomosis. The efficacy of valve destruction was determined by angioscopy after completion of the distal anastomosis by a separate blinded examiner.

RESULTS

A total of 123 valves were evaluated, 61 after use of an adjustable and 62 with a fixed valvulotome. There was no difference ( p = .88) in number of retained valves between the two groups ( n = 16, 17, respectively). The majority of incompletely destroyed valves were found in the proximal parts of the graft (46%, 13 out of 28). The primary patency at 30 days was 100 and 79%, respectively, p = .09).

CONCLUSIONS

No significant difference in efficacy between valvulotomes was found. Both types tend to miss a large proportion of proximal valves.