Abstract 6054: Immersing Feet in CO2-Rich Water-Bath Improves Ulcer Healing on Ischemic Limb after Infrainguinal Bypass Surgery
Background: We have shown that immersion of feet in warmed water enriched with carbon dioxide (CO2 immersion) improves subcutaneous microcirculation in critical limb ischemia (CLI) with ischemic ulcer/gangrene. Using an animal model, other group has reported that the CO2 immersion enhances collateral blood flow in ischemic limb via mobilization of endothelial progenitor cells and activation of NO-cGMP system. For CLI patients with ulcer/gangrene, infrainguinal bypass surgery is the standard therapy. However, ulcer healing and prevention of amputation still remain suboptimal. In order to know whether the CO2 immersion improves the clinical efficacy, here we performed the CO2 immersion after infrainguinal bypass surgery.
Methods: This study was designed as a prospective controlled trial. Fifty-five patients with ischemic ulcer/gangrene underwent the standard care including successful infrainguinal bypass surgery were enrolled and were randomly divided into the two groups; patients underwent standard care added CO2 immersion (CO2 group, 27 patients with 30 limbs) and patients received standard care alone (control group, 28 patients with 30 limbs). The patients in the CO2 group immersed their feet in CO2 enriched water (depth of 20 –30 cm, 37–38°C, duration for 10 minutes) twice a day. Primary endpoint was defined as complete healing of ischemic ulcers.
Results: Baseline demographical data, traditional risk factors, surgical procedure, ankle pressure and transcutaneous oxygen pressure (tcPO2) were comparable between the two groups. Rate of the complete ulcer healing after 1-year was much higher in the CO2 group than in the control group (43.3% vs. 20.0%, HR 2.72, 95%CI 1.03–7.17, p=0.043). Cox multivariate analysis revealed that CO2 immersion (HR 4.13, 95%CI 1.09 –15.75, p=0.038), diabetes (HR 0.020, 95%CI 0.01–.303, p=0.005) and tcPO2 (HR 1.04, 95%CI 1.00 –1.09, p=0.050) were independent predictors for complete ulcer healing. In contrast, rates of 1-year mortality, graft patency and limbs salvage showed no significant differences between 2 groups (p=0.55, p=0.47 and p=0.16, respectively).
Conclusion: The CO2 immersion after infrainguinal bypass surgery provided additional benefit for the ulcer healing in CLI patients with ulcer/gangrene.