The surgical learning curve for artificial urinary sphincter procedures compared to typical surgeon experience

Abstract

Background: The artificial urinary sphincter (AUS) is a well-established treatment for male stress urinary incontinence.

Objective: We aimed to characterize the surgical learning curve for reoperation rates after AUS implantation.

Design, setting, and participants: The study cohort consisted of 65 602 adult males who received an AUS between 1988 and 2008, constituting close to 90% of all operations conducted during that time. Data on reoperations were obtained from the manufacturer, which requires documentation for warranty coverage.

Measurements: Surgeon experience was calculated as the number of original AUS implants performed prior to the index patient's surgery. Multivariable logistic regression models were used to examine the association between experience and reoperative rates, adjusted for case mix.

Results and limitations: There was a slow but steady decrease in reoperative rates with increasing surgeon experience (p=0.020), showing no plateau through 200 procedures. The risk of reoperation for a surgeon with five prior cases was 24.0%, which decreased to 18.1% for a surgeon with 100 prior implants (absolute risk difference [ARD]: 5.9%; 95% confidence interval [CI], 1.3-10.1%) and to 13.2% for a surgeon with 200 prior implants (ARD: 10.7%; 95% CI, 2.6-16.6%). Two-thirds of contemporary patients (having AUS procedure between years 2000 and 2008) saw a surgeon who had done ≤25 prior AUS implants; only 9% saw a surgeon with ≥100 prior procedures.

Conclusions: The learning curve for AUS surgery appears to be very long and without an obvious plateau. This is in contrast to typical surgeon experience, suggesting a considerable burden of avoidable reoperations. Efforts to flatten the learning are urgently needed.

Figure 1

The surgical learning curve for reoperative surgery required after implantation of AUS. Predicted probability (solid) and 95% confidence intervals (dashed) of reoperative surgery at 5 years after original device implantation are plotted against surgeon experience. Probabilities are given for a typical patient, i.e. Average age and US residency. Includes only surgeons with full case history (defined as at least one of the first 10 cases on record). The overlaying density plot shows the distribution of patients by surgeon experience in a contemporary cohort (treated between 2000 and 2008).

Figure 2

The surgical learning curve for reoperative surgery required after implantation of AUS. Predicted probability (black) and 95% confidence intervals (dashed) of reoperative surgery at a. 2 years, b. 6 months after original device implantation are plotted against surgeon experience. Probabilities are given for a typical patient, i.e. Average age, and US residency and includes only surgeons with full case history (defined as at least one of the first 10 cases on record