The learning curve of robot-assisted laparoscopic pyeloplasty in children

To explore the learning curve of robot-assisted laparoscopic pyeloplasty (RALP) in children. The clinical data, surgical information, and postoperative complications of consecutive cases of RALP performed by the same surgeon in Shanghai Children's Hospital from January 2014 to July 2020 were retrospectively analyzed; the surgeon is a senior pediatric urologists who is proficient in laparoscopic pyeloplasty; the data consist of console time (CT), suture method when anastomosing ureteropelvic junction (UPJ), number of stitches (N), anastomosis time per stitch (t_n), the average suture time per stitch (T) = (suture time of first stitch (t₁) + second stitch (t₂) + … + t_n)/N, postoperative complications, and surgical outcome. The learning curve was depicted by cumulative sum method (CUSUM) and validated by cumulative method (CUM). Of the 88 cases, 64 cases were included in present study. Median CT was 104 (83-117) min, mean T was 109 ± 17 s. There were ten cases of Clavien-Dindo Grade I complication and two cases of Clavien-Dindo Grade IIIb complication. The median follow-up time was 237 (87-627) days. The learning curve of CT has three stages, with inflection points at 11th and 57th case, and T has two stages, with inflection points at 19th case. There was a statistically significant difference between the console time and length of stay on both sides of the inflection point (P < 0.05), but there was no statistically significant difference in age, gender, etiology, clinical manifestation, surgical outcome, and complication (P > 0.05). For a senior pediatric urologists who is proficient in laparoscopic pyeloplasty, the learning curve of RALP can be divided into three stages, preliminary exploration stage, mastery stage, and proficiency stage. It takes about 11 cases to achieve the mastery stage, and it takes about 57 cases to achieve the proficiency stage. The learning curve focused on the suture technique of the surgeon is divided into two stages, and after a learning period of 19 cases, it will reach the proficiency stage of suturing UPJ.