Objectives/Hypothesis: Tissue-engineered tracheal grafts (TETGs) offer a potential solution for repair of long-segment airway defects. However, preclinical and clinical TETGs have been associated with chronic inflammation and macrophage infiltration. Macrophages express great phenotypic heterogeneity (generally characterized as classically activated [M1] vs. alternatively activated [M2]) and can influence tracheal repair and regeneration. We quantified and characterized infiltrating host macrophages using mouse microsurgical tracheal replacement models.Study Design: Translational research, animal model. Methods:We assessed macrophage infiltration and phenotype in animals implanted with syngeneic tracheal grafts, synthetic TETGs, or partially decellularized tracheal scaffolds (DTSs).Results: Macrophage infiltration was observed following tracheal replacement with syngeneic trachea. Both M1 and M2 macrophages were present in native trachea and increased during early tracheal repair (P = .014), with an M1/M2 ratio of 0.48 AE 0.15. In contrast, orthotopic implantation of synthetic TETGs resulted in a shift to M1 predominant macrophage phenotype with an increased M1/M2 ratio of 1.35 AE 0.41 by 6 weeks following implant (P = .035). Modulation of the synthetic scaffold with the addition of polyglycolic acid (PGA) resulted in a reduction of M1/M2 ratio due to an increase in M2 macrophages (P = .006). Using systemic macrophage depletion, the M1/M2 ratio reverted to native values in synthetic TETG recipients and was associated with an increase in graft epithelialization. Macrophage ratios seen in DTSs were similar to native values.Conclusions: M1 and M2 macrophages are present during tracheal repair. Poor epithelialization with synthetic TETG is associated with an elevation of the M1/M2 ratio. Macrophage phenotype can be altered with scaffold composition and hostdirected systemic therapies. DTSs exhibit M1/M2 ratios similar to those seen in native trachea and syngeneic tracheal replacement.

Background Fibula free flaps (FFF) are often considered the first choice for mandibular reconstruction, but scapular system free flaps (SFF) have increased in popularity due to versatility, donor site advantages, and patient factors. Methods Retrospective chart review of patients undergoing mandibulectomy with FFF or SFF reconstruction from 2016 to 2021. Results Hundred and seventy‐six patients (FFF n = 145, SFF n = 31) underwent the aforementioned procedures. Mean FFF operative time was 9.47 h versus 9.88 for SFF (p = 0.40). Two‐flap reconstructions required 12.65 h versus 10.09 for SFF with soft tissue (p = 0.002). Donor site complications were identified in 65.6% of FFF with skin grafting. Conclusions These findings suggest that SFF requires similar operative time and results in reduced donor site morbidity as compared to FFF. Supine, concurrent harvesting of SFF allows for single‐flap harvest with significantly shorter operative time. SFF could be considered a primary option for mandible reconstruction for complex defects and in select patients.