Utilization of Near Infrared Spectroscopy* in Peripheral Arterial Disease and Angiosome Correlation

Introduction: Near Infrared Spectroscopy* (NIRS) is a non-invasive imaging device that measures oxygenated and deoxygenated hemoglobin in the wound and periwound tissues to assess the tissue oxygenation saturation percentage two to three millimeters below the epidermal surface.  Tissue evaluation with NIRS* provides immediate bedside assessment of tissue oxygenation and viability. NIRS* technology can be utilized in the clinical settings of Peripheral Arterial Disease (PAD) and angiosome correlation (1-4).Methods:Four patients, with nonhealing wounds to their lower extremities, presented to the wound center. Upon admission their nonhealing wounds were evaluated using NIRS to assess wound base and periwound tissue oxygenation saturation and viability. NIRS was used to assist in determining if there is enough oxygen present to heal, what lower extremity angiosome(s) is effected and the need for further diagnostic vascular evaluation with intervention due to PAD (5,6).Results:Four patients imaged using NIRS* that allowed for early identification and intervention of PAD and the correlated angiosome. With early identification and intervention, limb preservation was successfully achieved (6). For all nonhealing wounds, improved tissue oxygenation saturation was observed in the correlated angiosome post intervention  Discussion: Post vascular intervention, all nonhealing wounds showed a positive healing trajectory. Along with the improved healing rate, all wounds displayed an improved tissue oxygenation saturation and oxygenated hemoglobin, and a decrease in deoxygenated hemoglobin. NIRS assisted in monitoring and trending positive changes in tissue oxygenation, correlated angiosomes, wound healing, limb preservation, and responses to therapeutic interventions. Improved tissue oxygenation saturation directly linked to positive clinical findings and patient outcomes.References:1. Aday, A. W., & Matsushita, K. (2021). Epidemiology of Peripheral Artery Disease and Polyvascular Disease. Circulation research, 128(12), 1818–1832. https://doi.org/10.1161/CIRCRESAHA.121.318535 2. Armstrong DG, Swerdlow MA, Armstrong AA, Conte MS, Padula WV, Bus SA. Five year mortality and direct costs of care for people with diabetic foot complications are comparable to cancer. J Foot Ankle Res. 2020 Mar 24;13(1):16. doi: 10.1186/s13047-020-00383-2. PMID: 32209136; PMCID: PMC7092527 3. Hou, X., Guo, P., Cai, F., Lin, Y. and Zhang, J., 2022. Angiosome-guided endovascular revascularization fortreatment of diabetic foot ulcers with peripheral artery disease. Annals of Vascular Surgery, 86, pp.242-250. 4. Taylor GI, Palmer JH. The vascular territories (angiosomes) of the body: experimental study and clinical applications. Br J Plast Surg. 1987 Mar;40(2):113-41. doi: 10.1016/0007-1226(87)90185-8. PMID: 3567445. 5. Scully, R. E., Arnaoutakis, D. J., DeBord Smith, A., Semel, M., & Nguyen, L. L. (2018). Estimated annual health care expenditures in individuals with peripheral arterial disease. Journal of Vascular Surgery, 67(2), 558–567.https://doi.org/10.1016/j.jvs.2017.06.102 6. Palli, Swetha & Gunnarsson, C & Kotlarz, H & Martinsen, BJ & Zhao, R & Rizzo, John. (2016). Impact of a Limb Salvage Program on the Economic Burden of Amputation in The United States. Value in Health. 19. A45. 10.1016/j.jval.2016.03.098 . *SnapshotNIR, Kent Imaging LLC, Calgary, Canada