Complications of Flexible Ureteroscopic Treatment for Renal and Ureteral Calculi during the Learning Curve.

Background: The flexible ureterorenoscope (URS) and associated devices have developed rapidly. However, despite its therapeutic benefits, URS may be associated with some complications. To the best of our knowledge, there are no studies discussing the complications of flexURS during the learning curve.

Methods: A retrospective review of the records of patients who underwent flexURS from January 2005 to June 2013 was performed. To compare the complications after the introduction of flexURS, patients were divided into four groups based on the surgeon's training experience, that is, based on the number of cases performed by the surgeon. A total of 219 cases underwent flexURS. Groups 1, 2, 3, and 4 included 35, 50, 50, and 84 cases, respectively. The complications were classified using the Clavien system (I-IV).

Results: The mean operation time and stone-free rate were significantly different (p < 0.001, p = 0.013, respectively). The total complication rates were 13.6, 10, 8.3, and 3.2%, respectively (p = 0.068). The more the surgeon's experience, the less was the complication rate. Despite our best efforts, the incidence of urosepsis was not reduced (p = 0.902).

Conclusions: To reduce severe complications, it is necessary to have performed about 100 cases. Increased surgeon experience tended to decrease the risk of severe complications, but the incidence of urosepsis was not reduced.