Quantifying the Learning Curve in Robotic Peritoneal Flap Vaginoplasty.

Background: The learning curve (LC) is the process of mastering a new technique. This study assesses the LC for robotic-assisted peritoneal flap gender-affirming vaginoplasty (RPGAV).

Methods: A retrospective chart review of all consecutive patients undergoing RPGAV between 09/2017 and 02/2023 at a single center was performed. Operative times (OT) were analyzed to describe the LC. A cutoff point was determined after which OT stabilized, and this was used to compare perioperative and postoperative outcomes.

Results: Five hundred RPGAVs were performed. Median OT was 125 (interquartile range 105-181) minutes and decreased significantly over time. The minimum number of cases required to observe a plateau in OT is 300 patients.After adjusting for the LC, 2 variables significantly affected OT: a 1-point increase in body mass index increased OT by 1.4 minutes [95% confidence interval (1.0, 1.9), P < 0.001] and the single port robot decreased OT by 34 minutes [95% CI 1 (-43.1, -25.0), P < 0.001] as compared to the traditional multiport Xi robot.When comparing the first 300 cases (learning phase) to the last 200 (expert phase), length of stay, blood transfusions, and rates of elective revision surgery were lower in the expert phase.

Conclusions: The LC for RPGAV in this large cohort was 300 cases. Patient body mass index causes a dose-response increase in OT and the single port robot dramatically decreases OT. Although OT is just one facet of overall efficiency, differences between learning and expert phases are evident in decreased length of stay, transfusions, and rates of revision surgery.