Photo-Optical Transcutaneous Oxygen Tension Measurement Is of Added Value to Predict Diabetic Foot Ulcer Healing: An Observational Study

Currently, transcutaneous oxygen tension measurement (TCpO2) is the most favorable non-invasive test for diabetic foot ulcer (DFU) healing prognosis. Photo-optical TCpO2 is novel, less time-consuming and more practical in use compared to regular electro-chemical TCpO2. We prospectively investigated the clinical value of photo-optical TCpO2 to predict DFU healing. Patients with suspected DFU undergoing conservative treatment underwent an ankle pressure, toe-pressure and photo-optical TCpO2 test. The primary endpoint was DFU wound healing at 12 months. Based on their clinical outcome, patients were divided into a DFU healing and DFU non-healing group. Healing was defined as fully healed ulcers and non-healing as ulcers that deteriorated under conservative treatment or that required surgical amputation. Differences between groups were analyzed and an optimal TCpO2 cut-off value was determined. In total, 103 patients were included, of which 68 patients (66%) were classified as DFU healing. The remaining 35 patients (34%) had deteriorated ulcers, of which 29 (83%) eventually required surgical amputation. An optimal TCpO2 cut-off value of 43 mmHg provided a sensitivity, specificity and odds ratio of 0.78, 0.56 and 4.4, respectively. Photo-optical TCpO2 is an adequate alternative tool to validate the vascular status of the lower extremity indicating healing prognosis in patients with DFU. Therefore, we recommend that photo-optical TCpO2 can be safely coapplied in clinical practice to assist in DFU treatment strategy.

Applicability of Transcutaneous Oxygen Tension Measurement in the Assessment of Chronic Limb-Threatening Ischemia

Transcutaneous oxygen tension measurement (TcPO2) is widely applied for the evaluation of chronic limb-threatening ischemia (CLTI). Nevertheless, studies that focused on the clinical value of TcPO2 have shown varying results. We identified factors that potentially play a role in TcPO2 measurement variation such as probe placement, probe temperature, and the use of a reference probe. In this review of the current literature, we assessed the application of these factors. A systematic search was conducted. Parameters that were assessed were probe placement, probe temperature, and mentioning and/or use of a reference probe. In total, 36 articles were eligible for analysis. In 24 (67%) studies, probes were placed on specific anatomical locations. Seven (19%) studies placed probes, regardless of the location of the ulcer, adjacent to an ischemic lesion or ulcer (perilesion). Selected temperature setting of the probe differed; in 18 (50%), a default probe temperature of 44°C was selected, and in 13 (36%), a different temperature was selected. In 31 (84%) studies, the use of a reference probe was not reported. Transcutaneous oxygen tension measurement is applied diversely in patients with CLTI. Homogeneity in TcPO2 protocols is warranted for reliable clinical application and to compare future TcPO2 research.