A new beating-heart off-pump coronary artery bypass grafting training model

OBJECTIVES: Training models are essential in mastering the skills required for off-pump coronary artery bypass grafting (OPCAB). We describe a new, high-fidelity, effective and reproducible beating-heart OPCAB training model in human cadavers.

METHODS: Human cadavers were embalmed according to the 'Thiel method' which allows their long-term and repeated use. The training model was constructed by bilateral ligation of the pulmonary veins, cross-clamping of the aorta, positioning of an intra-aortic balloon pump (IABP) in the left ventricle (LV) through the apex (tightened with pledget-reinforced purse strings) and finally placing of a fluid line in the LV through the left atrial appendage (tightened with a pledget-reinforced purse string). The LV was filled with saline to the desired pressure through the fluid line and the IABP was switched on and set to a desired frequency [usually 60-80 beats per minute (bpm)].

RESULTS: A high-fidelity simulation has known limitations, but a more complex, realistic training environment with an actual beating (human) heart strengthens the entire training exercise and is of incremental value. All types of coronary artery anastomosis can be trained with this model. Training should be performed under the supervision of an experienced OPCAB surgeon and training progress is best evaluated with serial Objective Structured Assessment of Technical Skills (OSATS). A score of at least 48 points on the final OSATS ('good' on all components) is recommended before trainees can start their training on patients.

CONCLUSIONS: The entire set-up provides a versatile training model to help develop and improve the skills required to safely perform beating heart OPCAB anastomoses.