Learning Curve for Endoscopic Endonasal Dacryocystorhinostomy.

PURPOSE: To elucidate the learning curve for endoscopic endonasal dacryocystorhinostomy (EE-DCR) based on the results of EE-DCR performed by three surgeons at three different tertiary hospitals.

METHODS: A retrospective review of the medical records of 386 eyes of 337 patients who had undergone EE-DCR by three surgeons at three tertiary hospitals and who were available for a >6-month postoperative observation period was conducted. The success of a given surgery was determined based on the results of a test performed during the patient's last outpatient visit to the hospital. The learning curve was identified by dividing the patients into four groups (20, 30, 40, and 50 eyes in each respective group) and comparing their success rates.

RESULTS: The overall success rate of the entire study population was 86.3%. The success rates for each of three surgeons was 83.3%, 85.6%, and 88.1%, respectively. After dividing the patients into groups of 30 eyes each, all three surgeons showed a significant increase in surgery success rates after their first group of 30 eyes (p < 0.05). The overall success rate excluding the first 30 eyes was 92.9%, and all three surgeons exhibited a significantly improved success rate of >90% (A, 94.4%; B, 90.8%; C, 95.4%).

CONCLUSIONS: A surgeon should be required to perform at least 30 EE-DCR procedures to obtain stable surgical skill for this procedure.