Development and Validation of a Simulation Model for Ureteral Stent Placement

Objectives: Currently, there are no validated training models for cystoscopy with ureteral stent placement. The objective of this study was to develop and validate a novel endoscopic simulation model designed for training and practicing ureteral stent placement.

Methods: A low-cost, low-fidelity training model was developed to simulate the performance of ureteral stent placement in the training environment. Construct validity was measured by comparing deidentified video recorded performances on the model. Participants were divided into three groups: Novices (PGY3/4 Obstetrics and Gynecology residents), Advanced Learners (Urogynecology and Reconstructive Pelvic Surgery fellows), and Experts (Urology residents, Urogynecology faculty, and Urology faculty). All performances were reviewed and scored by two blinded expert reviewers using validated scales: Global Operative Assessment of Laparoscopic Skills (GOALS) and Global Rating Scale (GRS). An additional set of procedure-specific metrics was used. Performance also was evaluated based on self-reported experience with ureteral stenting. Face validity was assessed via survey of participants prior to and following use of the model. The contrasting group method was used to determine a passing performance score based on metric total scores.

Results: The model was created using the following materials: an 8 cm diameter hollow Styrofoam sphere, blue plastic tubing from a retropubic sling, and a silicone pacifier. The ureters were placed proximally and distally to simulate various degrees of procedural difficulties (Figure 1). Additional equipment included: cystoscopy equipment, a ureteral stent, and a glide or guide wire. The total cost of the model, which could be used multiple times, was $19.79. This study enrolled 36 participants: the Novice group (n=7), the Advanced Learner group (n=17), and the Expert group (urology residents, n=7; urogynecology faculty, n=3; and urology faculty, n=2). The Experts performed significantly better than the Advanced Learners and Novices in total scores (out of 75, median (IQR): 75 (75-75), 61 (56.5-68.5), 45 (43-46), respectively; p< 0.001), and within each individual domain within the GOALS, GRS, and procedure-specific scales. Time to complete the tasks did not correlate with experience (Table 1). Increasing total previous experience with cystoscopy (rho 0.73, p< 0.001) and ureteral stent placement (rho 0.765, p< 0.001) had a strong correlation with better performance on the model. A minimum passing score of 63 was established using contrasting group methodology. On post-simulation assessment, most subjects “agreed” or “strongly agreed” that the model was useful in the learning environment, and that it closely approximates the feel of ureteral stent placement.

Conclusions: This ureteral stenting simulation model is easy to construct, affordable and reproducible. The model is valid and reliable for practicing the key steps of the procedure and evaluating trainee performance in preparation for live surgery.