Development and evaluation of vesicourethral anastomosis bench-top model for measurement of traction force on urethra in robotic surgery.

Abstract

In vesicourethral anastomosis (VUA), which is part of robot-assisted radical prostatectomy, surgeons must proceed carefully to avoid urethral damage. We developed and evaluated a VUA bench-top model that can measure the traction force on the urethra during robotic surgery. The VUA model included the urethra, bladder, pelvic bones, and a small force sensor that was capable of measuring the traction force on the urethra. Eight skilled and eight novice urologists performed a VUA task in robotic surgery. The skilled surgeons assessed the model's realism and usefulness as a training tool using a 5-point Likert scale. The evaluation items [task time, maximum force, force volume, and length of time that specific excessive forces were applied to the urethra (2, 3, 4, and ≥ 5 N)] were compared between the skilled and novice surgeons using the Mann-Whitney U test. Measurements were conducted in four directions with respect to the maximum force on the urethra: 11-1, 2-4, 5-7, and 8-10 o'clock. The quality of the model was scored 3.7 to 4.9 points for all 16 items in 4 domains except for "Usefulness compared with animal models." There were differences in the task time and almost all force parameters between the skilled and novice surgeons. We developed a relatively high-quality VUA bench-top model that measures traction force on the urethra, and we have revealed differences in the forces of action on the urethra in two groups of surgeons with different skill levels.