Defining the Learning Curve of Flexible Ureterorenoscopy and Laser Lithotripsy.

Purpose: To investigate the impact of learning curve (LC) on flexible ureterorenoscopy (f-URS).

Materials And Methods: Patients who underwent kidney stone surgery in a urology clinic from a tertiary health care institution with f-URS were enrolled in the study. Patient characteristics, the properties of kidney and kidney stones were recorded. Also, f-URS-related parameters, hospitalization time, the success of the procedure, and complications were noted. Patients were categorized equally into 4 groups, the first 20 f-URS cases in Group 1, and the last 20 f-URS cases in Group 4. Groups were compared according to patient preoperative parameters, intraoperative outcomes, success rate and complication rate.

Results: Time from the induction of anaesthesia to insertion of flexible ureterorenoscope was 18.6 min in group 1 and 17.2 min in group 2; then it significantly decreased to 15.0 min for cases 40 through 60 and 12.4 min for cases 60 through 80 (p = 0.001). Operation time in group 3 and group 4 was significantly shorter than in group 1 and group 2 (p = 0.001). Also, fluoroscopy time was significantly longer in group 1 (82.9 seconds) and reached a plateau in group 3 (50.3 seconds) and group 4 (41.7 seconds) (p = 0.001). Additionally, after the 20th case, we achieved a significantly higher success rate in comparison to the first 20 cases (65% in group 1, 85% in group 2, 85% in group 3, and 90% in group 4, p = 0.001).

Conclusion: Flexible ureterorenoscopy is a surgery that requires high technique and experience. The present study found that success of f-URS reached satisfactory levels after 20th cases. In addition, 40 cases may be enough for surgical proficiency regarding decreases in preparation time, operation time, and fluoroscopy time.