Free Flap Reconstruction of Xylazine-Associated Wounds: A Retrospective Review.

[BACKGROUND] Xylazine is a veterinary sedative that is added to illicit fentanyl to enhance its effects. Xylazine-associated wounds differ from those found in patients who inject other drugs. They are larger and frequently involve deeper structures, such as bone. The outcomes of reconstruction using free tissue transfer are not well understood.

[METHODS] All consecutive free flap reconstructions of xylazine-associated wounds at a tertiary care center in the northeast US between January 2021 and December 2024 were retrospectively reviewed. Data were stored in a HIPAA-compliant REDCap database.

[RESULTS] Eleven free flap reconstructions were performed among 10 patients. Median age was 34 years (IQR: 31-38), all were White, 20% were Hispanic, and 90% were female. Median BMI was 20.9 (IQR: 19.9-39.3). Comorbidities included HCV (70%) and active tobacco smoking (60%). Wounds were located on the neck (9.1%), chest (18.2%), upper extremity (45.5%), and hand (27.3%). 81.8% presented with exposed bone. Median debridements were two (IQR 1-3). Free flaps included: four anterolateral thigh (36.4%), three gracilis (27.3%), one rectus abdominis (9.1%), one scapular (9.1%), one latissimus dorsi (9.1%), and one lateral arm (9.1%) flap. Two patients were discharged against medical advice (18.2%). Median follow-up was 364 days (IQR: 287-710). All flaps were viable at 3 weeks. Roughly half of patients (45.5%) continued to use injection drugs after reconstruction. Early complications included: one venous congestion requiring exploration and one partial flap dehiscence. Late complications included two surgical site infections and two wound recurrences due to continued xylazine use resulting in trans-humeral amputation (40% of those who continued to inject drugs).

[CONCLUSION] Free tissue transfer can effectively reconstruct xylazine-associated wounds and is necessary for limb salvage in patients with exposed bone. All flaps were viable at 3 weeks. Late wound recurrence due to continued xylazine use is associated with poor outcomes, including amputation. Abstinence from injection drug use is critical to optimizing the chances of recovery, and a multidisciplinary approach is essential.