Free Tissue Transfer for Skull Base Osteoradionecrosis: A Novel Approach in the Endoscopic Era.

OBJECTIVES: Osteoradionecrosis (ORN) of the skull base and craniovertebral junction is a challenging complication of radiation therapy (RT). Severe cases often require surgical intervention through a multi-modal approach. With the evolution in endoscopic surgery and advances in skull base reconstruction, there is an increasing role for microvascular free tissue transfer (MFTT). We describe an endoscopic-assisted approach for the management of ORN of the skull base using fascia lata for MFTT. STUDY DESIGN: Retrospective case series. METHODS: Between 2017 and 2021, a review of all cases in which fascia lata MFTT was utilized for skull base ORN was performed. Patient demographics, preoperative characteristics, and postoperative outcomes with long-term follow-up were reviewed. RESULTS: Five patients were identified. Mean duration to onset of ORN was 17 months following RT. A trial of antibiotics, hyperbaric oxygen (HBO), and/or limited debridement was attempted without success. Refractory pain and progressive osteomyelitis were unifying symptoms. All patients underwent endoscopic debridement of the affected region of ORN prior to MFTT. Vascularized fascia lata was inset through a combined endonasal and transoral corridor. There was improvement in chronic pain in the postop setting with no patients requiring continued antibiotics or HBO therapy. Mean post-op follow-up was 23 months. CONCLUSIONS: With continued evolution in endoscopic, minimally invasive approaches, there is an expanding indication for early surgical management in refractory ORN. Fascia lata MFTT is a novel and effective strategy for the management of ORN of the skull base and upper cervical spine with excellent postoperative outcomes and limited patient morbidity. LEVEL OF EVIDENCE: 4 Laryngoscope, 133:562-568, 2023.

Antibiotic-releasing microspheres prevent mesh infection in vivo.

BACKGROUND: Infection remains a dreaded complication after implantation of surgical prosthetics, particularly after hernia repair with synthetic mesh. We previously demonstrated the ability of a newly developed polymer to provide controlled release of an antibiotic in a linear fashion over 45 d. We subsequently showed that coating mesh with the drug-releasing polymer prevented a Staphylococcus aureus (SA) infection in vivo. To broaden the applicability of this technology, the polymer was synthesized as isolated "microspheres" and loaded with vancomycin (VM) before conducting a noninferiority analysis. MATERIALS AND METHODS: Seventy-three mice underwent creation of a dorsal subcutaneous pocket that was inoculated with 104 colony forming units (CFU) of green fluorescent protein (GFP)-labeled SA (105 CFU/mL). Multifilament polyester mesh (7 × 7 mm) was placed into the pocket, and the skin was closed. Mesh was either placed alone (n = 16), coated with VM-loaded polymer (n = 20), placed next to VM-loaded microspheres (n = 20) or unloaded microspheres (n = 10), or flushed with VM solution (n = 7). Quantitative tissue/mesh cultures were performed at 2 and 4 week. Mice with open wounds and explanted mesh were excluded. RESULTS: Twenty-two of 23 (96%) tissue-mesh samples from mesh alone or empty miscrospheres were positive for GFP-labeled SA at 2 and 4 wk. Six of seven (86%) samples from the VM flush group were positive for GFP SA at 4 wk. Thirty-eight of 38 (100%) VM-loaded crosslinked cyclodextrin polymers-coated mesh or VM-loaded microspheres were negative for GFP SA at 2 and 4 wk. CONCLUSIONS: Slow affinity-based drug-releasing polymers in the form of microspheres are able to adequately clear a bacterial burden of SA and prevent mesh infection.