Congenital Heart Surgery

Comparison between Del Nido and conventional blood cardioplegia in pediatric open-heart surgery. Floh AA, Das S, Haranal M, Laussen PC, Crawford-Lean L, Fan CS, Mertens LL, Runeckles K, Honjo O.Perfusion. 2022 Feb 10:2676591211054978. doi: 10.1177/02676591211054978. Online ahead of print.PMID: 35143733    Take Home Points: Del Nido cardioplegia provides equivalent myocardial protection compared to blood cardioplegia. Although, right ventricular dysfunction was more seen in patients having Del Nido cardioplegia, this did not have impact on clinical outcome, such as hospital mortality and use of ECMO. Commentary from Dr. Yasuhiro Kotani (Okayama, Japan), chief section editor of Congenital Heart Surgery Journal Watch:   Summary: Single center retrospective study included 1534 patients having congenital cardiac surgery. Patients were divided into 2 groups: conventional blood cardioplegia (N=997) and Del Nido cardioplegia (N=537). Primary outcome was defined as a new postoperative more than moderate systemic ventricular dysfunction by echocardiogram. Secondary outcome was any severity of systemic ventricular dysfunction and right ventricular dysfunction. Surgical complexity was comparable between the groups. Cardiopulmonary bypass (CPB) time and aortic cross-clamp (ACC) time in Del Nido group were significantly longer (CPB: 117 vs. 108 min, p=0.04, ACC: 83 vs. 76 min, p=0.03), but the dose of cardioplegia was less in Del Nido group (2 vs. 3, p<0.001). Occurrence of systemic ventricular dysfunction was similar between the groups. Clinical outcomes, including hospital length of stay (p=0.07), postoperative ECMO (p=0.63), and hospital death (p=0.07) were comparable between the groups.   Comment: This study performed a comparison between Del Nido cardioplegia and conventional blood cardioplegia in high-volume center in North America. This is a single center, retrospective study but includes various complexity from neonates to small children which values this study compared to previous studies. Although Del Nido cardioplegia was introduced in 2015 in this institution and used nearly exclusively thereafter, both groups have similar surgical complexity and consistent surgical team, making this comparison reasonable. This study showed no difference in newly developed postoperative more than moderate systemic ventricular dysfunction between the groups which is not surprising. Interesting finding of the study is that Del Nido group had more right ventricular dysfunction compared to conventional cardioplegia group. The author’s speculation is that impairment of right ventricular function can be result from surgical duration (CPB and ACC time) not from source of cardioplegia. Theoretically, optimal myocardial protection in the right ventricle is difficult in the setting of congenital heart diseases. Patients may have right ventricular hypertrophy and abnormal coronary circulation in addition to general disadvantages, such as difficulty of temperature control compared to the left ventricle, etc. Further study focused on the distribution of cardioplegia in the right ventricle during cardiac arrest will answer the question.   

Hemodynamic Characteristics After Fontan Procedure in Patients with Down's Syndrome. Otsuka M, Kodama Y, Kuraoka A, Ishikawa Y, Nakamura M, Nakano T, Kado H, Umemoto S, Ishikita A, Sakamoto I, Ide T, Tsutsui H, Sagawa K.Pediatr Cardiol. 2022 Feb;43(2):360-365. doi: 10.1007/s00246-021-02727-6. Epub 2021 Sep 8.PMID: 34498105   Take Home Points: Higher mortality rates have been reported for patients with Down's syndrome undergoing Fontan surgery compared to patients with non- Down's syndrome patients. The causes of death are diverse, but pulmonary vascular obstructive disease is considered a contributing factor. In the study, they observed only one death, but there was a significant upward trend in central venous pressure in post-Fontan patients with Down's syndrome. Post-Fontan patients with Down's syndrome must be managed carefully, with regular evaluation for central venous pressure by cardiac catheterization.   Commentary from Dr. Masamichi Ono (Munich, Germany), section editor of Congenital Heart Surgery Journal Watch:   Summary: In this study, results after the Fontan procedure was compared between 7 patients with Down's syndrome and 35 patients with non-Down's syndrome. Main diagnosis of Down's syndrome was unbalanced AVSD in 6 patients and tricuspid atresia in 1 patient. There was 1 death in patients with Down's syndrome. The patients died of pulmonary thrombosis. At the last follow-up of median 19 years, creatinine, AST, ALT concentrations were significantly higher in the patients with Down's syndrome. There was no significant difference in medications except for the administration of pulmonary arterial hypertension-specifc therapies.   Postoperative cardiac catheterization data showed that central venous pressure, transpulmonray gradient, and pulmonary artery wedge pressure increased in patients with Down's syndrome, whereas these variables did not changed in patients with non- Down's syndrome. Arterial oxygen saturation decreased in patients with Down's syndrome, whereas it did not changed in patients with non- Down's syndrome.   Significance: The main significance of the study are that, there was a significant increase in central venous pressure and trans-pulmonary pressure gradient over time after the Fontan procedure in patients with Down's syndrome compared with patients with non-Down's syndrome. Whereas, there was no statistically significant difference in the change in calculated RpI over time.   Comment: Patients with genetic anomalies including Down’s syndrome are generally regarded as not being good candidates for the Fontan procedure. Although exact mechanisms are not still clear, we observe failing cavopulmonary shunt physiology more frequently in patients with genetic anomalies, compared with patients without genetic anomalies. As the causes, pulmonary vascular abnormalities in patients with genetic anomalies are speculated. It might not be apparent before bidirectional cavopulmonary shunt (BCOS) procedure, but emerged postoperatively as a failing BCPS physiology. Even after the Fontan completion, increase of central venous pressure and transpulmonary gradient in patients with Down's syndrome was reported in this study. Special attentions should be paid for patients with Down's syndrome, in respect to indication of BCPS procedure, postoperative management, and even after the Fontan completion.   As for the therapy, multiple classes of PAH-ST have been reported to reduce central venous pressure, reduce pulmonary vascular resistance, and increase exercise tolerance in Fontan patients. In this study, catheterization data before and after administering PAH-ST were obtained from 2 patients in the Down's syndrome group. In both patients, central venous pressure and transpulmonary pressure gradient decreased, which may be caused by macitentan as a PAH-ST. However, further studies are needed to determine the benefit of PAH-ST in Fontan patients with Down's syndrome.   In summary, central venous pressure tended to increase over time in patients with Down's syndrome after Fontan procedures compared with patients with non-Down's syndrome. Further research is warranted to clarify better management in patients with Down's syndrome after the Fontan procedure, including the efficacy of pulmonary arterial hypertension-specifc therapy.