SLR - December 2019 - Ulyana Kulish
Reference: Kimura, T., Watanabe, Y., Tokuoka, S., Nagashima, F., Ebisudani, S., & Inagawa, K. (2019). Utility of Skin Perfusion Pressure Values with the Society for Vascular Surgery Wound, Ischemia, and Foot Infection Classification System. Journal of Vascular Surgery. doi:10.1016/j.jvs.2019.01.045Scientific Literature Review
Reviewed By: Ulyana Kulish, DPM
Residency Program: Cedars Sinai Medical Center – Los Angeles, CA
Podiatric Relevance: Wifi classification system is often used by podiatric surgeons to predict the likelihood of healing wounds and direct surgical treatment planning. Some patients are unable to have their toe pressures measured due to low pressures, toe wounds, or previous amputations. The addition of a skin perfusion pressure might be a good option for assessing the amputation level and probability of healing.
Methods: This is a level II prospective non-randomized cohort study in which 91 limbs of 76 patients were evaluated for skin perfusion pressures and monitored for one year to assess healing, or amputation level. All limbs were first staged using the Wifi classification and limb ischemia was measured by evaluating the Ankle Brachial Index, Ankle Pressure, or Toe Pressures, and were then evaluated with Skin Perfusion Pressures. The patients were then followed for one year and had proper wound treatments, medical management, and revascularization procedures. If the person had a revascularization procedure, they were reevaluated and followed for one year after the procedure. Outcomes assessed included wound healing status, level of amputation, and death. Skin perfusion pressure values were then statistically analyzed to develop boundary values. These boundary values were assigned to a Wifi stage and combined with other measurements to determine ischemia grade. The investigators then determined if probability of healing was more accurate with or without the inclusion of skin perfusion pressures. The study suggests that skin perfusion boundary values for the ischemia stages in Wifi should be as follows: 45mmHg boundary between stage 0 and 1, 35mmHg boundary between stage 1 and 2 and 25mmHg between stage 2 and 3.
Results: The addition of a skin perfusion pressure resulted in improved sensitivity, efficacy, and negative predictive value of the Wifi classification’s ability to predict outcomes.
Conclusions: Ischemic changes are often underestimated, especially in patients with non-compressible arteries. Skin perfusion pressure is a valuable study that is not currently utilized in any major wound classification system. It could be a valuable addition for podiatric surgery physicians and the question now is how feasible is it versus TcPO2. Skin perfusion pressures could substitute toe pressures for patients who can’t be evaluated with toe pressure measurements; however, a more extensive study should be conducted with a greater sample size and with TcPO2 measurements.