Objective: While del Nido (DN) cardioplegia is increasingly used in cardiac surgery, knowledge is limited in its safety profile for operations with prolonged crossclamp time (CCT). We have introduced a unique redosing strategy for aortic surgery: all operations use DN with a 1000-mL initiation dose (750 mL antegrade, 250 mL retrograde) composed of 1:4 blood:DN crystalloid. At 90 minutes CCT and every 30 minutes thereafter, a 250-mL dose was introduced retrograde in a 4:1 ("reverse") ratio. Additionally, at 90 minutes CCT and every 90 minutes thereafter, a reverse ratio dose of approximately 100 to 400 mL was introduced via the right coronary artery. Here, we analyze the outcomes of our unique redosing strategy used.
Methods: In total, 440 patients underwent aortic surgery between January 2015 and March 2021 under a single surgeon and received DN. Our primary end points were change in left ventricular ejection fraction (LVEF) and right ventricular systolic function based on echocardiography. Multivariable linear regression was used to analyze the relationship between CCT and outcomes.
Results: The median was 61 years old (interquartile range, 51-69), and 23% were female. Indication was aneurysm in 65% and dissection in 24%. Median preoperative LVEF was 60% (55%-62%). Median CCT and cardiopulmonary bypass times were 135 minutes (93-165 minutes) and 181 minutes (142-218 minutes), respectively. In-hospital mortality occurred in 3%. Multivariable linear regression showed CCT was not associated with change in LVEF or change in right ventricular systolic function.
Conclusions: Our unique method of redosing DN cardioplegia appears to provide safe and effective myocardial protection for aortic surgery.
Keywords: aorta; aortic surgery; cardioplegia; crossclamp; del Nido; myocardial ischemia.