A Surgical Training Simulator for Quantitative Assessment of the Anastomotic Technique of Coronary Artery Bypass Grafting

Abstract

Here we describe a personal training simulator that improves manual dexterity required for the anastomotic technique of Coronary Artery Bypass Grafting (CABG). The simulator-based surgical training is termed "DRY Lab". The system evaluates surgical skill hydrodynamically as well as visually. This report focuses on the effects of regular DRY Lab for an inexperienced surgeon. A cardiac surgeon with no experience in CABG volunteered for the DRY Lab. The model of a coronary artery consisted of a three-layered silicone rubber tube. To ensure its suitability for suturing, the tearing strength of the tube was 0.14N. In the course of training, the surgeon made 62 anastomosis in 80 days. During this time, we recorded the number of sutures, operation time, and hydrodynamics of the anastomosis made early and late in the training sessions. Hydrodynamic testing measured the pressure difference due to suturing in steady flows. At a flow rate of 100ml/min, the Reynolds number was 350. On the period of the training, the mean number of sutures was 16.9 ± 2.5. Thereafter, it decreased gradually, converging to 14.0 ± 0.0 on the last day. This indicated that the surgeon eventually established own particular design of an anastomosis throughout the trainings. Pressure loss of the anastomosed model in the final training was 65.8% lower than that in the initial training. The difference appeared to be due to the stenosed effective orifice area of the anastomosis. In sum, the findings suggest that quantitative assessment of simulator-based surgical training is an effective way to improve anastomotic technique in CABG.