Effects of Lingual Mucosal Grafts with Different Thicknesses on Repair of Rabbit Bladder Defects.

PURPOSE: To investigate the survival of autologous lingual mucosal grafts of varying thicknesses within a rabbit bladder defect model, as well as their impact on vascularization, inflammatory response, and tissue contracture. METHODS: Twelve male New Zealand white rabbits were selected to establish a bladder wall defect model. Autologous lingual mucosal patches (5.0 mm×5.0 mm) of thin, medium, and thick thicknesses were harvested, transplanted to the bladder defects, and fixed with interrupted sutures. The lingual defects were directly sutured. Animals were sacrificed at 4 days, 3 weeks, and 3 months postoperatively for gross and histological observations. Hematoxylin-eosin (HE) and Masson staining were used to evaluate graft integration, detect neovascular density, inflammatory cell infiltration, and graft surface area contracture rate. Data were analyzed using one-way analysis of variance (ANOVA) and the Tukey HSD test. RESULTS: All three groups of lingual mucosal grafts survived in the bladder environment and formed continuous epithelial connections with the bladder mucosa. No significant differences were observed in neovascular density or inflammatory cell infiltration among grafts of different thicknesses at any postoperative time point. Neovascular density gradually increased, while inflammatory infiltration gradually decreased over time. At 3 months postoperatively, the contracture rate in the thick group (13.20%) was significantly lower than that of the thin group (35.33%) and the medium-thickness group (24.93%) (P < 0.01). CONCLUSION: Lingual mucosal grafts of different thicknesses can survive in the bladder environment with good vascularization and anti-inflammatory capabilities. The thickness of the graft mainly affects the tissue contracture rate. Therefore, moderately preserving submucosal tissue and avoiding excessive thinning may help improve the long-term stability of the graft.