The use of transcutaneous oximetry to predict healing complications of lower limb amputations: A systematic review and meta-analysis

Abstract

Objective: To determine the validity of transcutaneous oximetry (TcPO 2) as a predictor of lower limb amputation healing complications. Design: A systematic review and meta-analysis. Methods: We searched five major medical databases, relevant review articles and reference lists and included all studies that evaluated TcPO 2 for its ability to predict lower limb amputation healing failure. We selected eligible articles and conducted data abstraction independently and in duplicate. Results: Thirty-one studies, enrolling 1824 patients with 1960 amputations, met our inclusion criteria. Only one study reported undertaking a multivariable analysis, which demonstrated that a TcPO 2 level below 20 mmHg was an independent predictor of re-amputation occurrence (adjusted odds ratio (OR) 3.08, 95% confidence interval (CI) 1.19-7.98). Fourteen prospective cohort studies reported data that allowed for the calculation of an unadjusted relative risk of lower limb amputation healing complications leading to amputation revision associated with a TcPO 2 level below cut-offs of 10 mmHg (1.80; 95% CI 1.19-2.72), 20 mmHg (1.75; 95% CI 1.27-2.40) 30 mmHg (1.41; 95% CI 1.22-1.62) and 40 mmHg (1.24; 95% CI 1.13-1.39). Conclusions: This review suggests that TcPO 2 predicts healing complications of lower limb amputations. A value of less than 40 mmHg results in a 24% increased risk of healing complication compared to over 40 mmHg and the risk further increases as the TcPO 2 decreases. There is, however, insufficient evidence to judge whether this tool adds important information beyond clinical data or to suggest an optimal threshold value. There is a need for a large, sufficiently powered study that adjusts for appropriate clinical variables. © 2011 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.