Sprayable chitosan/starch-based sealant reduces adhesion formation in a sheep model for chronic sinusitis.

OBJECTIVES/HYPOTHESIS: Postoperative adhesion formation after endoscopic sinus surgery (ESS) remains a complication associated with high revision rates. This study determines the efficacy of a sprayable chitosan/starch-based sealant for reducing adhesions in an ESS sheep model for chronic sinusitis. STUDY DESIGN: Prospective, blinded, randomized controlled trial. METHODS: Sheep (n = 14) with eosinophilic rhinitis (determined by the presence of eosinophilia in nasal secretions) underwent ESS with middle turbinectomies, standardized mucosal injuries created on the lateral nasal wall, and partial thickness wounds created around the ethmoid cell region. Surgery was performed bilaterally (28 nasal cavities). Animals were randomized into treatment with sprayable chitosan/starch-based sealant (n = 7, 14 nasal cavities) or no treatment (n = 7, 14 nasal cavities). Two animals in the treatment group expired due to anesthetic complications associated with the turbinectomies, leaving five animals (10 sites) that completed the study. Presence of adhesions was assessed by endoscopic evaluation at days 14 and 28 after initial surgery. Adhesion formation was confirmed via necropsy of sinus cavities at day 28 after initial surgery. RESULTS: Adhesions were observed in all seven control animals, resulting in an 86% (95% confidence interval [CI], 65-100) adhesion rate (12 of 14 sites). The five surviving treatment animals had a 10% (95% CI, 0-33) adhesion rate (one of 10 sites). Treatment with the sprayable chitosan/starch-based sealant resulted in a 76% reduction (95% CI, 32-100) of adhesions (P < .002). CONCLUSIONS: In this sheep model for chronic sinusitis, treatment with sprayable chitosan/starch-based sealant reduced adhesion formation by 76% after ESS (P < .002).

A chitosan-based sinus sealant for reduction of adhesion formation in rabbit and sheep models.

OBJECTIVE: Chronic sinusitis is the most prevalent chronic disease in the United States in adults aged 18 to 44 years, with approximately 250,000 operations performed annually. Although often successful, sinus surgery fails in greater than 15% of patients. Adhesion formation is a common complication and cause for subsequent revision surgery. Here, the authors evaluate a sprayable chitosan/starch-based sinus sealant and demonstrate its ability to reduce adhesion formation both in vitro and in 2 animal models. STUDY DESIGN: Randomized, controlled, animal trials. SETTING: Academic medical center (fibroblast experiments) and animal laboratories (sheep and rabbit studies). SUBJECTS AND METHODS: This sinus sealant was applied to human cultured fibroblasts obtained from surgically removed polyps to examine its ability to inhibit fibroblast migration and proliferation. The sinus sealant was applied to New Zealand White rabbits (n = 20) in an established cecal-sidewall abrasion model and to sheep (n = 10) in a sinus surgical adhesion model to examine its ability to reduce adhesion formation. RESULTS: This sinus sealant inhibited migration and proliferation of human cultured fibroblasts and reduced the total adhesion score from 4.9 to 0.3 for a total reduction of 94% (95th percentile confidence interval [CI], 78%, 100%; P < .001) in a well-established rabbit cecal-sidewall model commonly used for adhesion testing. Moreover, this sealant reduced adhesion formation from 80% to 10% for a total reduction of 70% (95th percentile CI, 57%, 93%; P = .003) in a sheep sinus adhesion surgical model. CONCLUSION: This chitosan-based sealant demonstrates promise for reducing adhesion formation in sinus surgery.