Proctored single surgeon learning curve for vaginal natural orifice transluminal endoscopic surgery (NOTES) hysterectomy

Abstract

Objective

We studied the learning curve of vaginally assisted NOTES hysterectomy (VANH) for individual surgical steps and competence scores.

Design

Single centre, prospective cohort study in a Belgian teaching hospital.

Measurements and main results

In a cohort of 57 women undergoing VANH we analysed 29 procedures performed completely or partly by the novice and 35 procedures performed completely or partly by the expert. Primary outcome was operation time dedicated to the endoscopic steps, unique to vNOTES. Operation time was determined by post hoc analysis of surgical videos. Standardised values of the operation time were expressed as a moving average. Adequate operation time, i.e. an operation time within 2 standard deviations of the average operation time of the expert, was after 16 cases. Secondary outcomes were operation time per step and competence scores based on Objective Structured Assessment of Technical Skills (OSATS). These measurements were used to determine critical steps in the learning process, which are not captured by reporting total operation time alone. Adequate operating times for critical steps (anterior colpotomy and right uterine artery), were obtained after 16 cases. Conversely, some vaginal and endoscopic steps on the right-hand side took longer. Competence was obtained after 18 cases.

Conclusion

We present the results of a proctored learning curve of a novice in vaginally assisted NOTES hysterectomy, expressed as operation time for different steps compared to an expert and with competence scores. For the primary outcome, the endoscopic operation time, adequate operation time was achieved after 16 cases. Regarding secondary outcomes, analysis per step showed that several vaginal steps and the endoscopic steps on the patient’s right-hand side required a longer learning period. Competence score expressed as a CUSUM chart suggest a learning curve of 18 cases. Identifying critical steps can be used to adapt training novices. Adding competence scores rather than focusing on operation time alone provides valuable insights in the learning process of a new technique by trained surgeons.