The impact of hydroxybutyl chitosan and 5-fluorouracil on the procedure of endoscopic endonasal dacryocystorhinostomy

Purpose: To investigate the effects of hydroxybutyl chitosan (HBCS) with and without 5-fluorouracil (5-FU) during endoscopic endonasal dacryocystorhinostomy (Endo-DCR). In addition, the present study observed the impact of HBCS and 5-FU on the functions of the nasal mucosal cell population in vivo. Methods: Patients were randomized into HBCS (group A), HBCS combined with 5-FU (group B), and gelatin sponge control group (group C). 16S rRNA high-throughput sequencing technology examined the conjunctival sac and nasal flora changes. In addition, CCK8, cell scratching, and flow cytometry were used to investigate the effects of HBCS and 5-FU on the nasal mucosal cell populations. Results: Subjects in groups A, B, and C had anastomotic areas of 21.83 ± 12.69 mm2, 21.57 ± 14.53 mm2, and 12.45 ± 8.16 mm2, respectively (P = 0.0359). Group A had less severe epiphora than the other two groups at 1-, 2-, and 12-week postoperative follow-up (P < 0.05). Complications around the anastomosis in group A were the least severe of the three groups (P = 0.0259). After surgery, the proportion of pathogenic bacteria in the conjunctival sac and nasal cavity was higher in groups A and B than in healthy adults. At the 2-week follow-up, the structure of nasal flora in group A was more similar to that of the healthy adults compared to group B. Conclusion: Intraoperative use of HBCS at the anastomose improves the postoperative outcome of En-DCR. 5-FU cannot give better postoperative results in En-DCR and is detrimental to the normalization of the postoperative flora in patients with chronic dacryocystitis. At the cellular level, both HBCS and 5-FU inhibit the migration of nasal mucosal cell populations, and 5-FU inhibits proliferation but does not promote apoptosis.