Predicting stump healing following amputation for peripheral vascular disease using the transcutaneous oxygen monitor

In patients with peripheral vascular disease requiring amputation, a below-knee stump is likely to result in improved function compared to above-knee. Unfortunately, clinical assessment of skin circulation is inaccurate, making the decision of amputation level difficult. The transcutaneous oxygen monitor has been investigated as a method of assessing skin circulation. A prospective study using the monitor in 51 amputations based on clinical assessment has shown that a transcutaneous oxygen tension (tcPO2) greater than 40 mm Hg is associated with stump healing, while measurements below that level lead to an unpredictable outcome. Half of the patients undergoing above-knee amputation had a tcPO2 level greater than 40 mm Hg at the below-knee site, suggesting that a successful distal amputation might have been performed. A further prospective study of 50 patients requiring amputation for peripheral gangrene showed that when amputations were performed at the lowest level in the limb with a tcPO2 greater than 40 mm Hg there was a higher rate of below-knee amputations (72%) and a higher rate of successful stump healing. Review of the literature confirms the potential of the monitor as a non-invasive, simple and accurate method of predicting stump healing.