Safety and Efficacy of Thermosensitive Hydroxybutyl Chitosan and 5-fluorouracil Assisted Endoscopic Dacryocystorhinostomy in the Treatment of Chronic Dacryocystitis

Endoscopic dacryocystorhinostomy (En-DCR) has the advantages of less surgical trauma, shorter time, less postoperative bleeding, faster recovery, and no skin scars. However, the success rate of En-DCR surgery still varies greatly between 58% and 94% , and the main reason for the failure of the surgery is the membranous closure of the anastomosis. The application of new packing materials in dacryocystorhinostomy provides some new ways to improve the success rate of En-DCR. Hydroxybutyl chitosan (HBCS), with its non-toxicity, biocompatibility, biodegradability, antibacterial, moisturizing properties, water solubility and temperature sensitivity, is widely used in biomedicine to prevent postoperative adhesions. 5-Fluorouracil (5-FU) is an antimetabolite drug that is effective in the treatment of keloids. The application of 5-FU in glaucoma filtration surgery has demonstrated its good safety and efficacy. Studies have shown that antimetabolites as adjuvant therapy for DCR have a positive impact on improving the success rate of surgery In this study, thermosensitive hydroxybutyl chitosan will be applied to the anastomosis site of the nasal mucosal flap and the lacrimal mucosal flap, or 0.3ml of 5-fluorouracil solution (25mg/ml) was injected into the nasal mucosa around the anastomosis at the same time. The investigators would like to observe the different situations of clinical symptoms, lacrimal duct flushing, endoscopy, and bacterial flora changes in patients with chronic dacryocystitis, to compare them with the previous intraoperative packing of gelatin sponge wrapped with thrombin and Tobramycin Dexamethasone. Furthermore, the investigators intend to evaluate the safety and efficacy of HBCS and 5-FU adjuvant internal En-DCR in the treatment of chronic dacryocystitis, and provide new ideas for the adjuvant therapy of En-DCR.