Modified endoscopic dacryocystorhinostomy with posterior lacrimal sac flap for nasolacrimal duct obstruction.

OBJECTIVES: To evaluate a new technique of modified endoscopic dacryocystorhinostomy involving the creation of a large posterior flap at the lacrimal sac and to compare its success rate with that of the conventional endoscopic method of excising the entire medial lacrimal sac wall as a surgical treatment for epiphora caused by nasolacrimal duct obstruction. DESIGN: Retrospective, interventional, and comparative case series. SETTING: University teaching hospital, Hong Kong. PATIENTS AND METHODS: Only adults with primary nasolacrimal duct obstruction were included. Consecutive endoscopic dacryocystorhinostomy was performed using two different techniques from July 1999 to June 2001. The new technique involved the creation of a large posterior flap at the medial lacrimal sac wall, reflecting it posteriorly, followed by removal of the remaining small anterior flap (the LSF group). Other patients had the entire medial lacrimal sac wall excised (the ELS group). MAIN OUTCOME MEASURES: Surgical success was defined by free fluorescein drainage from the conjunctival sac into the rhinostomy site at least 3 months after silicone stent removal. RESULTS: Ninety-nine procedures were performed in 99 patients. The success rate was 89.1% (41/46) in the LSF group and 71.7% (38/53) in the ELS group. The difference between the two groups was statistically significant (Chi squared test, P=0.031). CONCLUSIONS: Our new and modified technique of endonasal dacryocystorhinostomy has a greater success rate than conventional endonasal dacryocystorhinostomy. A large-scale prospective randomised controlled trial to further evaluate the efficacy and safety of this surgical technique is under way.