Fish skin xenografting post Mohs surgery on the lower extremities: a single institution experience

Introduction: Mohs surgery is a tissue-sparing dermatologic surgery utilized to treat skin cancers. Reconstruction of soft tissue defects following Mohs surgery can be challenging on the lower extremities due to limited adjacent tissue laxity and higher rates of post-operative infections[1]. Fish skin xenografts (FSX) from Atlantic cod (Gadus morhua)* are known to promote healing, reduce pain, & prevent infection in various wounds [2,3]. Herein we summarize our institutional experience with fish skin xenografting post-Mohs on the lower extremities to evaluate utility & efficacy.Methods:Retrospective case-series of 12 patients xenografted following Mohs surgery on the lower extremity from 5/2023 to 12/2023. Wounds were grafted within 2 weeks of surgery and re-grafted q2-4 weeks PRN. Re-grafting was performed when 50% of xenograft remained intact. Between applications, xenografts were left unadulterated beneath a fenestrated silicone dressing with secondary absorptive dressings changed daily.Results:17 full-thickness wounds were grafted on 8 females and 4 males with ages ranging from 73 to 94 years (median = 79). Wounds ranged in depth from 1-6mm. Wound dimensions (excluding depth) ranged from 2.25 cm2 to 9.6 cm2, with a median of 5cm2. Healing rates ranged from 4 to 12. Median time to heal was 8 weeks. Xenograft application frequency ranged from 1 to 4, with a median of 2 applications needed to achieve complete healing. Minimal depression and contraction occurred for all wounds resulting in excellent cosmetic and functional outcomes. There was a high degree of patient satisfaction reported. Complications were rare, including 1 case of irritant dermatitis of peri-wound and a reactive keratoacanthoma. No reported post-operative pain or infections were noted.Discussion: Establishing safe & cost-effective reconstructive options for lower extremity Mohs surgery wounds is an unmet clinical need of increasing importance given the aging population and rising incidence of skin cancer[4]. Overall, FSXs expedited the course of wound healing and reduced the frequency of post-operative complications at our institution when compared to the standard of care (secondary intention healing). FSXs were easy to use, well-tolerated, and required infrequent applications. These results support FSXs as a safe, low-maintenance, and cost-effective reconstruction option following Mohs surgery[3].References:1. Alam M, et al. JAMA Dermatol. 2013 Dec;149(12):1378-85. 2. Magnusson S, et al. Mil Med. 2017 Mar;182(S1):383-388. 3. Kirsner R, et al. Wound Repair Regen. 2020 Jan;28(1):75-80. 4. Aggarwal P, et al. J Am Acad Dermatol. 2021 Aug;85(2):388-395. * Kerecis® Omega3 Wound, Kerecis, Isafjordur, Iceland