Transcutaneous oxygen tension monitoring after successful revascularization in diabetic patients with ischaemic foot ulcers.

OBJECTIVE: To monitor transcutaneous oxygen tension (TcPO2) after percutaneous transluminal angioplasty (PTA) in diabetic patients with ischaemic foot ulcers. RESEARCH DESIGN AND METHODS: Twenty-three diabetic patients with ischaemic foot ulcers who underwent successful revascularization by PTA (SR group) were retrospectively selected. Twenty diabetic patients who underwent unsuccessful revascularization (UR group) were also included. Transcutaneous oxygen tension was measured at the dorsum of the foot before and 1 (+/- 1), 7 (+/- 1), 14 (+/- 1), 21 (+/- 1) and 28 (+/- 1) days after the surgical procedure.
RESULTS: After PTA, TcPO2 progressively improved in the SR group, reaching its peak 4 weeks after angioplasty. A concomitant decrease of cutaneous carbon dioxide tension (TcPCO2) was also observed immediately after PTA which reached the lowest levels 3 weeks later. In the UR group, TcPO2 showed a slight improvement immediately after PTA but remained stable throughout the observation, while TcPCO2 levels did not change. Finally, the percentage of SR patients with a TcPO2 > or = 30 mmHg was 38.5% 1 week after PTA, while it increased to 75% 3 weeks later.
CONCLUSION: Transcutaneous oxygen tension monitoring showed that after successful revascularization it takes 3-4 weeks for cutaneous oxygenation to improve and reach the optimal levels for wound healing. Transcutaneous carbon dioxide tension monitoring may be more useful to identify the negative outcome of a revascularization procedure. Our findings suggest that, when the surgical approach can be delayed, the best timing to perform a more aggressive debridement or minor amputations is 3-4 weeks after successful revascularization.