title: Evaluation of the appropriate root pressure for maintaining heartbeat during an aortic cross-clamp for primary repair of the aortic arch in premature infants with associated cardiac anomalies.
abstract: We developed a new cardiopulmonary bypass (CPB) method to minimize myocardial damage during aortic arch reconstruction. In this method, coronary flow and heartbeat were stabilized by maintaining the aortic root pressure with an adjusted preload of the ventricle during aortic cross-clamping. This study was performed to determine the appropriate root pressure to maintain the heartbeat without causing deterioration of ventricular function. Study 1. Under partial CPB, the ascending aorta was cross-clamped in 6 pigs (group 1). Experimental data at various systolic aortic root pressures was analysed to determine the appropriate root pressure. Study 2. In group 2 (control, n＝6), the aorta was not clamped, while in group 3 (n＝6), the aorta was cross-clamped for 60 min and the systolic aortic root pressure was maintained at the pressure determined in study 1. Study 1. The diastolic coronary flow was stabilized at values comparable to that before initiation of CPB (6.6±1.4 ml/beat) when the systolic aortic root pressure was above 80 mmHg. Intracardiac pressure and the myocardial oxygen consumption (MvO2) seemed to be acceptable when the systolic aortic root pressure was below 100 mmHg. Therefore, 90 mmHg was selected for study 2. Study 2. Perioperative cardiac function did not differ between the groups. We concluded that 90 mmHg was the systolic aortic root pressure appropriate for this method.
authors.affiliation: Department of Cardiovascular Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Science, Okayama 700-8558, Japan.
authors.forename: Takanori
authors.initials: T
authors.lastname: Suezawa
authors.forename: Kozo
authors.initials: K
authors.lastname: Ishino
authors.forename: Osami
authors.initials: O
authors.lastname: Honjo
authors.forename: Satoru
authors.initials: S
authors.lastname: Osaki
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Kotani
authors.forename: Shunji
authors.initials: S
authors.lastname: Sano
mesh_terms: D000818:Animals; D001011:Aorta / Q000502:physiology; D001013:Aorta, Thoracic / Q000601:surgery*; D001794:Blood Pressure / Q000502:physiology*; D002315:Cardiopulmonary Bypass / Q000295:instrumentation / Q000379:methods*; D005260:Female; D006330:Heart Defects, Congenital / Q000601:surgery*; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D023421:Models, Animal; D013525:Surgical Instruments; D013552:Swine; D013599:Systole / Q000502:physiology; D013997:Time Factors