The "learning curve" for retropubic mid-urethral sling procedures: a retrospective cohort study.

ABSTRACT

INTRODUCTION AND HYPOTHESIS: Mid-urethral tape procedures brought a paradigm shift in surgery for stress incontinence; little research into the development and maintenance of surgical competence for the procedure exists. The hypothesis behind this study is that the "learning curve" for retropubic mid-urethral sling procedures, judged by the surrogate of bladder perforation, is longer than previously thought. METHODS: This was a retrospective single-centre database and case note review of retropubic mid-urethral tape procedures. Unadjusted rates of bladder perforation, operating time, postoperative voiding difficulty, tape extrusion, and patient reported outcome were calculated; progress was evaluated using the cumulative sum method. Outcomes were assessed for 1 consultant, 2 subspecialty trainees (fellows), 7 advanced training skills module (ATSM) trainees (senior residents) and 6 core specialty trainees (residents) in years 4-7 of training. RESULTS: A total of 1,568 women were identified as having mid-urethral tape procedures; 568 (36 %) had additional procedures concurrently; 259 (20 %) were secondary procedures. The overall perforation rate for individual surgeons varied between 0 and 31 % and averaged 10.3 % amongst the core and ATSM trainees (a mean of 11 procedures), 4.5 % amongst the subspecialty trainees (a mean of 66 procedures) and 1.3 % for the consultant (1,284 procedures). The number of perforations for individual surgeons peaked at between 10 and 30 procedures undertaken. The number of cases performed to reach a target level of ≤ 5 % perforations varied between 20 and 80. CONCLUSIONS: Whilst seductively simple in concept, mid-urethral tape procedures are not without risk; their inherently "blind" nature makes them difficult to teach. The "learning curve" to independent practice may be longer than previously considered.