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
Nattawut Wongpraparut MD1, Parichart Junpaparp MD2, Chanean Ruangsetakit MD3, Nongnuch Weerapakorn MD1, Kamin Chinsakchai MD3, Natee Sirinvaravong MD1, Damras Tresukosol MD4, Pramook Mutirangura MD3, Rungtiwa Pongakasira BSc4
Affiliation : 1 Division of Cardiology, Department of Medicine, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand 2 Department of Medicine, Albert Einstein Medical Center, Philadelphia, Pennsylvania, USA 3 Division of Vascular Surgery, Department of Surgery, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand 4 Her Majesty’s Cardiac Center, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
Background : Critical limb ischemia [CLI] is a serious cardiovascular condition that causes high morbidity and mortality. CLI can be
identi(cid:976)ied by ankle pressure of less than 50 mmHg, toe pressure of less than 30 mmHg, or transcutaneous oxygen tension [TcPO2]
of less than 30 mmHg.
Objective : To investigate the ef(cid:976)icacy of TcPO2 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 TcPO2. 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 signi(cid:976)icantly improved from 0.70±0.17 to 0.89±0.26 (p<0.001). In isolated below-the-
knee DES patients, ABI was signi(cid:976)icantly improved from 0.74±0.18 to 0.99±0.25 (p = 0.019), and TcPO2 was signi(cid:976)icantly 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 TcPO2.
Keywords : Below-the-knee critical limb ischemia, Drug-eluting stent, Transcutaneous oxygen tension, Wound healing
