Application of Fish Skin Xenograft in a Patient with Critical Limb Ischemia and Gangrenous Wounds

Introduction: Critical limb ischemia (CLI) is a severe form of peripheral artery disease (PAD) characterized by significantly reduced blood flow to the extremities, usually the legs. This reduction in blood flow can lead to severe pain, tissue damage, and even tissue death (gangrene) if left untreated. Wound care remains essential part of treatment algorithm which may include surgical/office debridement and application of various skin substitutes if necessary. Several studies have reported that CLI is associated with a high risk of cardiovascular events and mortality. CLI carries significantly higher risk of all-cause mortality compared to those without CLI, with an estimated five-year mortality rate ranging from 30% to 50%1.This case report aimed to determine the clinical efficacy of intact fish skin graft in complex PAD gangrenous wounds with exposed tendons, fascia, and bones.Methods:62-year-old female with h/o hypertension, hyperlipidemia, coronary artery disease, peripheral arterial disease, chronic nicotine dependence was referred to vascular clinic for assessment regarding right foot non healing gangrenous wounds. She underwent emergent hybrid intervention which included right common femoral and distal external iliac endarterectomy, patch angioplasty, thrombectomy and retrograde iliac stenting. She underwent excisional debridement of skin and subcutaneous tissue, fascia, and tendon at right distal ankle/dorsum foot wound and right heel wound. She also needed right 2nd, 3rd and 4th toe open amputation. Necrotic eschar was sharply resected with debridement of underlying fascia tendons and bones. We applied fragmented fish skin graft and meshed 2:1 fish skin graft to cover the entire dorsum of foot and heel wounds followed by VAC therapy. Culture showed multidrug resistant pseudomonas and was treated with intravenous antibiotics.Results:After 4 applications of the fish skin xenograft at 2-4 weeks intervals, the wound is completely healed without needing a skin graft at heel area. Right dorsal foot wound is nearly healed with no exposed tendons or bones and ready for split thickness graft.Discussion: Intact fish skin xenografts are FDA approved for treating acute and chronic wounds2,3,4. The product is an acellular dermal matrix harvested from Icelandic cod fish with a similar 3-D microstructure like human skin with natural mechanical properties, molecular content, and organization. Characteristics of the fish skin include bacterial resistance, angiogenesis, and inflammatory cytokine mitigation5. This case report shows that a fish skin xenograft is suitable and cost effective for complex wounds healing in complex peripheral arterial disease patients with gangrenous wounds with exposed tendons and bones.References:1.Critical Limb Ischemia and Intermediate-Term Survival* Joshua A. Beckman, MD, Mark A. Creager, MD. JACC: VOL. 7, NO. 12, 2014. 2.Baldursson BT, Kjartansson H, Konrádsdóttir F, Gudnason P, Sigurjonsson GF, Lund SH. Healing rate and autoimmune safety of full-thickness wounds treated with fish skin acellular dermal matrix versus porcine small-intestine submucosa: a noninferiority study. Int J Low Extrem Wounds. 2015 Mar;14(1):37-43. doi: 10.1177/1534734615573661. Epub 2015 Mar 9. PMID: 25759413 3.Lullove, E. J., Liden, B., Winters, C., McEneaney, P., Raphael, A., & JC, L. I. (2021). A Multicenter, Blinded, Randomized Controlled Clinical Trial Evaluating the Effect of Omega-3-Rich Fish Skin in the Treatment of Chronic, Nonresponsive Diabetic Foot Ulcers. Wounds: a Compendium of Clinical Research and Practice. 4.Magnusson S, Baldursson BT, Kjartansson H, Rolfsson O, Sigurjonsson GF. Regenerative and Antibacterial Properties of Acellular Fish Skin Grafts and Human Amnion/Chorion Membrane: Implications for Tissue Preservation in Combat Casualty Care. Mil Med. 2017 Mar;182(S1):383-388. doi: 10.7205/MILMED-D-16-00142. PMID: 28291503.