Trajectories of Transcutaneous Oxygen (TcPO2) and Healing in Chronic Limb-Threatening Ischemia: A 12-Month Longitudinal Study

Kawamura Haruka (Wound Care and Limb Salvage Unit, Hinodegaoka Hospital, Hinode, Japan)
Asmat Burhan (School of Nursing, College of Nursing, Taipei Medical University, Taipei, Taiwan)
Inoue Nanami (Wound Care and Limb Salvage Unit, Hinodegaoka Hospital, Hinode, Japan)
Fujita Kento (Wound Care and Limb Salvage Unit, Hinodegaoka Hospital, Hinode, Japan)

Journal of Wound Research and Technology
Vol. 2 No. 2 (2025): June - October 2025

Background: Chronic limb-threatening ischemia (CLTI) remains a major global burden with high amputation risk, while evidence on using transcutaneous oxygen pressure (TcPO₂) trajectories (level + slope) to guide healing decisions is limited. Most studies treat TcPO₂ as a static threshold, not a time-updated signal that could trigger earlier escalation. Purpose: This study aimed to estimate the association of TcPO₂ trajectories and revascularization with wound-healing probability among patients with CLTI over 12 months. Methods: In a prospective longitudinal cohort at a Japanese hospital (Mar 3, 2023- Mar 1, 2024), we enrolled 46 adults with tissue-loss CLTI meeting guideline ischemia criteria; acute limb ischemia and non-ischemic ulcers were excluded. Standardized wound care was provided; revascularization was time-varying (from procedure date). TcPO₂ was measured at baseline, 2, 4, 8, 12 weeks, and 6, 9, 12 months. The primary outcome was complete epithelialization sustained for ≥2 visits. Discrete-time survival models estimated adjusted odds ratios (aORs) with 95% CIs, adjusting for age, diabetes, infection, albumin, WIfI ischemia grade, and smoking; sensitivity analyses included competing risks and joint modeling. Results: Among 46 participants (mean age 71 years; diabetes 78%; CKD 41%), baseline mean TcPO₂ was 18.3 mmHg (standard care 21.2; revascularization 16.3). From baseline to Week 12, TcPO₂ rose +2.9 mmHg under standard care versus +15.8 mmHg post-revascularization. Higher time-updated TcPO₂ and positive slope independently increased healing (per 10 mmHg aOR 1.62, 95% CI 1.24-2.11; per 1 mmHg/week aOR 1.48, 1.12–1.97). Revascularization was beneficial (aOR 2.35, 1.18-4.68), while visit-level infection reduced healing (aOR 0.58, 0.36-0.92). Effects were directionally robust across sensitivity analyses. Conclusion: Trajectory-based TcPO₂ monitoring (level and slope) identifies an early, actionable window after baseline especially post-revascularization when timely escalation can improve healing. Findings support embedding serial TcPO₂ into CLTI care and motivate multicentre evaluations of effectiveness, cost, and equity.