A Beating-Heart Biostimulator for Training in Minimally Invasive Direct Coronary Artery Bypass (MIDCAB) Surgery

All articles of this category (opens in new window) Background: Minimally invasive direct coronary artery bypass (MIDCAB) is technically demanding due to restricted access, specialized instrumentation, and the challenge of performing anastomoses on a beating heart. Simulation-based training can support skill acquisition, yet realistic beating-heart models are scarce. We developed a high-fidelity BioSimulator using porcine hearts to reproduce the anatomical and haptic conditions of MIDCAB. Methods: The BioSimulator was built from a torso-like chest model with an access port replicating a left anterior mini-thoracotomy. A porcine heart was mounted in a reproducible position. To simulate cardiac motion, an intra-aortic balloon pump (IABP) was surgically implanted: a ventricular septostomy was performed, and the catheter was advanced through the mitral valve so that half of the balloon resided in each ventricle. The pump was run at 70 cycles/minute with maximum inflation, producing synchronized inflation/deflation and realistic biventricular motion. Standard MIDCAB instruments, including stabilizer arm and coronary shunts, were applied to expose porcine coronaries and perform off-pump anastomosis. Five senior cardiac surgeons with extensive OPCAB experience conducted training sessions. At the end, all surgeons completed a structured Likert-scale questionnaire (10 items, 5-point scale) assessing face validity (realism) and content validity (educational value). All procedures were video-recorded and evaluated by blinded observers. Results: The IABP-driven system successfully produced reproducible biventricular motion, simulating beating-heart surgery. All surgeons completed coronary anastomoses using shunts without simulator-related limitations. The questionnaire confirmed high ratings for thoracic access (5.0), anatomical orientation (4.8), vessel handling (4.8), and stabilizer/shunt realism (4.8). Beating-heart motion (4.6) and training adequacy for exposure and anastomosis (4.6) were also rated positively. Skill improvement, safety, recommendation for training, and overall value all scored 5.0. The overall mean rating was 4.86/5, and surgeons unanimously described the simulator as a valuable bridge between dry-lab and clinical training. Conclusion: This novel beating-heart Biostimulator provides realistic training conditions for MIDCAB and was validated by senior OPCAB surgeons. By integrating cardiac motion and coronary shunts, it enables safe practice of key procedural steps under near-clinical conditions and represents a promising tool for structured MIDCAB training curricula. Publication History Article published online: 17 February 2026 © 2026. Thieme. All rights reserved. Georg Thieme Verlag KG Oswald-Hesse-Straße 50, 70469 Stuttgart, Germany