Alternative technique of long acting cardioplegia delivery results in less hemodilution.

BACKGROUND: Preparation of del-Nido cardioplegia and its delivery technique can cause significant hemodilution. The resultant effects from hemodilution are largely proportionate to the use of a dual circuit. We opted for a custom-disposable single cardioplegia circuit instead of a dual circuit. METHODS: We describe an alternative technique of del-Nido cardioplegia delivery and initial clinical experience with it at National University Hospital, Singapore. This is a retrospective analysis of data from January 2017 to April 2019, comprising of 177 patients of heart surgery and reflecting a single center database survey under the National Health Care Group. RESULTS: Of the 177 patients who underwent surgery with del-Nido cardioplegia, 76 (42.9%) were valve-only procedures and 5 (2.8%) were coronary artery bypass graft-only procedures. Ultrafiltration was utilized in 132 (62.6%) patients, whereas filtrate volume was 2200 [150-9500] mL. The alternative technique of del-Nido cardioplegia delivery adopted by National University Hospital advocates for a single pump, single circuit system. The retrospective institutional data highlighted safe delivery of del-Nido cardioplegia using this technique in a range of procedures. CONCLUSION: Besides the safe delivery of del-Nido cardioplegia, the National University Hospital Technique reduces hemodilution and provides other technical benefits including a steeper temperature gradient, modification of circuit configuration to deliver another cardioplegia while on bypass, as well as re-configuration of clamps to spike the base solution.

Use of del Nido Cardioplegia for Adult Heart Surgery: How Long Is Not Too Long?

The most apparent practical advantage of del Nido cardioplegia (DNC) is that it allows the surgeon a longer arrest period before a subsequent dose is needed, as opposed to the conventional St. Thomas' cardioplegia solution where the recommended ischemic time is ∼15-20 minutes. In this study, we explored the incidence of arrhythmia after cross-clamp removal as a surrogate for a safe myocardial ischemic time with the use of DNC in adult heart surgery. A total of 113 patients who had undergone heart valve repair and/or replacement surgery at the National University Hospital, Singapore, were investigated. This single-center retrospective study was conducted on a population where DNC had been used for myocardial protection between January 2017 and April 2019. Cardioplegia ischemic time interval groups were not significant predictors of postoperative arrhythmia, defibrillation, and intraoperative intra-aortic balloon pump usage. Crude comparison of postoperative outcomes showed no significant differences in any other postoperative variables, including mortality and total hospital stay. From the results of the present study, it appears that there is no optimal ischemic time interval for the administration of DNC within a 120-minute time period. It is likely that DNC has a redosing interval of, and may provide adequate myocardial protection, for up to 120 minutes.