Experienced surgeons versus novice surgery residents: Validating a novel knot tying simulator for vessel ligation

Vessel ligation with a knot is one of the most fundamental tasks surgeons must master. We developed a simulator designed to enable novices to acquire and refine gentle knot tying capabilities. A bench-top, knot-tying simulator with computer-acquired assessment was tested on expert surgeons and surgery residents at an academic medical center during the years 2016 to 2018. Each participant tied a total of 8 knots in different settings (superficial versus deep) and techniques (1-handed versus 2 hands). The simulator measured vertical forces and task completion time. Fifteen experienced surgeons and 30 surgery residents were recruited. The expert group exerted considerably less total force during placement of the knots than the novice residents (3.8 ± 2.0 vs 9.2 ± 6.1 N, respectively; P = .0005) and the peak force exerted upward was less in the expert group (1.31 ± 0.6 vs 1.75 ± 0.84 N; P = .02). The experts also completed the task in less time (10.9 ± 3.4 vs 18.3 ± 7.2 seconds; P = 0.001). The simulator can offer residency programs a low-cost, bench-top platform to train and assess objectively the knot-tying capabilities of surgery residents.