The surgical learning curve of artificial urinary sphincter implantation: Implications for prosthetic training and referral

Purpose: We investigated the surgical learning curve of artificial urinary sphincter implantation using a large, consecutive, single surgeon series. Materials and Methods: We retrospectively reviewed the results of the first 150 consecutive, virgin artificial urinary sphincter implantations performed by a single surgeon between 1992 and 2003 for post-prostatectomy male stress urinary incontinence. Complication and reoperation rates, and continence outcomes (daily pad use and number of patients with a functional artificial urinary sphincter at last followup) were analyzed as a function of consecutive implant cases. Results: There was a significant decrease in the number of patients with complications (12 vs 3, relative risk 4.0, p = 0.012) and the number with reoperation (11 vs 3, relative risk 3.7, p = 0.026) when the first 25 patients who underwent artificial urinary sphincter implantation were compared to the second 25. No further decrease was noted beyond the first 25 cases. Despite significantly higher complication and reoperation rates in the first 25 cases, equivalent functional outcomes (same postoperative daily pad use and number of patients with a functional artificial urinary sphincter at last followup) were still achieved after artificial urinary sphincter revision. Conclusions: The surgical learning curve of placing a virgin artificial urinary sphincter was about 25 cases, as measured by complication and reoperation rates. This case number was high compared to typical exposure during residency and clinical practice. There is an urgent need to improve urological prosthetic training and emphasize the referral of artificial urinary sphincter cases to regional centers of excellence or to high volume, artificial urinary sphincter implanters to improve the surgical outcome.