Application of actuator-driven pulsed water jet for coronary artery bypass grafting: assessment in a swine model.

Actuator-driven pulsed water-jet (ADPJ) dissection is an emerging surgical method for dissecting tissue without heat and mechanical injury to vessels. We elucidated the mechanical properties of the piezo ADPJ and evaluated its usefulness and safety in coronary artery bypass grafting procedures. The relationship between the input voltage (10-100 V) and peak pressure of the pulsed water jet was evaluated. The tissue strengths of swine internal thoracic and coronary arteries and the surrounding tissues were measured to assure tissue-selective dissection. Internal thoracic arteries were harvested by conventional electric cautery and the water jet in four swine, and eight coronary arteries surrounded by myocardium were attempted to be exposed with the water jet. The dissected specimens were histologically evaluated. The peak pressure of the pulsed water jet was positively correlated with the input voltage (R  = 0.9984, P < 0.001). The breaking strengths of the target vessels (internal thoracic and coronary arteries) and the surrounding tissues were significantly different (P = 0.002 and P < 0.001, respectively). Histologic examination revealed that internal thoracic arteries were isolated with less heat damage using the pulsed water jet (P = 0.002) compared with electric cautery, and coronary arteries also were dissected without apparent histologic damage. ADPJ has the possibility of assuring tissue selectivity among the internal thoracic and coronary arteries. The results also indicated that the use of ADPJ may enhance safe procedures to harvest grafts during coronary artery bypass grafting.