RANDOMIZED COMPARISON OF ULTRASONIC ASPIRATION VERSUS CONVENTIONAL ELECTROCAUTERY FOR DISSECTION OF THE HUMAN INTERNAL THORACIC ARTERY

The most common technique currently employed to harvest the internal t horacic artery for coronary artery bypass grafting is conventional ele ctrocautery, This study compared an alternative method, electrocautery with an ultrasonic aspirator, for harvesting the internal thoracic ar tery. Patients were randomly assigned to one of six experimental group s (conventional electrocautery, ultrasonic aspirator at settings of 60 %, 80%, and 100% power output, and ultrasonic aspirator in 100% CAVI-P ulse modes 1 and 3). Ring segments of internal thoracic artery were st udied in an organ bath, Contraction responses were elicited with 123 m mol/L potassium physiologic salt solution, KPSS, KPSS solution contain ing noradrenaline, and a cumulative noradrenaline dose-contraction cur ve. Relaxation studies were performed with the vasodilators acetylchol ine, bradykinin, and sodium nitroprusside, Forty percent of the electr ocauterized vessels were traumatized or damaged and failed to respond to contractile stimuli, whereas only 10% of the vessels in ultrasonic aspirator groups 60%, 80%, and 100% failed to respond. All vessels in the group harvested by ultrasonic aspirator in 100% CAVI-Pulse mode 1 responded, whereas 20% of the vessels in the group harvested by ultras onic aspirator in 100% CAVI-Pulse mode 3 failed to respond. All settin gs of electrocautery with an ultrasonic aspirator produced a greater c ontractile response to KPSS and noradrenaline. Acetylcholine and sodiu m nitroprusside produced similar relaxations in all groups, but the br adykinin responses were significantly improved in all groups undergoin g 100% electrocautery with an ultrasonic aspirator, These results sugg est that 100% electrocautery with an ultrasonic aspirator, particularl y in 100% CAVI-Pulse mode 1, resulted in less damage and trauma than c onventional electrocautery during harvesting of the internal thoracic artery.