Transcutaneous oxygen tension and ankle-brachial index for predicting limb salvage outcomes in patients treated with drug-eluting stent for below-the-knee critical limb ischemia

Abstract

© 2018, Medical Association of Thailand. All rights reserved. Background: Critical limb ischemia [CLI] is a serious cardiovascular condition that causes high morbidity and mortality. CLI can be identified by ankle pressure of less than 50 mmHg, toe pressure of less than 30 mmHg, or transcutaneous oxygen tension [TcPO 2 ] of less than 30 mmHg. Objective: To investigate the efficacy of TcPO 2 and ankle-brachial index [ABI] as predictors of limb salvage outcomes in patients treated with drug-eluting stent [DES] for below-the-knee CLI. Materials and Methods: This retrospective study was conducted in patients treated for CLI with below-the-knee [BTK] percutaneous transluminal angioplasty [PTA] with DES placement between January 2007 and June 2015 study period. The primary endpoints were pre-and post-procedural ABI and TcPO 2 . The secondary endpoints were limb salvage rate, time-to-major amputation, and ulcer healing. Results: Seventy-two patients (79 limbs) were included. Of those, 40 were men and 39 were women, and the mean age was 73.8±8.0 years. The median follow-up time was 349 days and the 1-year limb salvage rate was 95%. Complete wound healing at one year was observed in 76% of patients. Overall ABI was significantly improved from 0.70±0.17 to 0.89±0.26 (p<0.001). In isolated below-the-knee DES patients, ABI was significantly improved from 0.74±0.18 to 0.99±0.25 (p = 0.019), and TcPO 2 was significantly improved from 17.50±9.62 to 35.50±11.84 mmHg (p = 0.035). Conclusion: Long-term outcome of DES placement at BTK level was associated with high limb salvage rate and wound healing, as evidenced by increased ABI and TcPO 2 .