Central and Peripheral Cannulation for Cardiopulmonary Bypass in Fetal Sheep: A Comparative Study.

Yun Teng,Xiaokang Luo,Jimei Chen,Wentao Wu,Chengbin Zhou,Bingxin Huang,Wei Pan,Qiuping Jiang,Jian Zhuang,Miao Tian

doi:10.3389/fcvm.2021.769231

Abstract

Objective: In-utero correction is an option for treatment of critical congenital heart diseases (CHDs). Fetal cardiac surgery for CHDs is dependent on the reliable use of fetal cardiopulmonary bypass (CPB), but this technology remains experimental. In this study, we established fetal CPB models with central and peripheral cannulation to explore the differences between the two cannulation strategies.Methods: Ten fetal sheep with 90–110 gestational days were randomized into central cannulation (n = 5) and peripheral cannulation (n = 5) groups. All fetal CPB models were successfully established. At each time point (0, 30, and 60 min after initiation of CPB), echocardiography was performed. Blood samples were also collected for blood gas analysis and tests of myocardial enzymes and liver and kidney function.Results: In the central cannulation group, right ventricular Tei index significantly increased (p = 0.016) over time. Compared with the peripheral cannulation group, the left ventricular Tei index of the central cannulation group was significantly higher (1.96 ± 0.31 vs. 0.45 ± 0.19, respectively; p = 0.028) and the stroke volume was lower (0.46 ± 0.55 vs. 2.13 ± 0.05, respectively; p = 0.008) at 60 min after CPB. Levels of liver and kidney injury markers and of acid-base balance, including alanine aminotransferase (ALT), aspartate aminotransferase/ALT ratio, blood urea nitrogen (BUN), BUN/creatinine ratio, base excess and bicarbonates, were significantly higher for peripheral than for central cannulation. Other important physiologic parameters, including heart rate, blood pressure, myocardial enzymes, umbilical artery beat index and resistance index, left ventricular Tei index, and left and right ventricular stroke volume, were comparable between the two groups.Conclusions: Both central and peripheral cannulations can be used to establish fetal CPB models. Central cannulation causes more adverse impacts for cardiac function, whereas peripheral cannulation is more susceptible to complications related to inadequate organ perfusion.

Highlights

Complex congenital heart disease (CCHD) is a major cause of infant death worldwide
A conventional fetal sheep cardiopulmonary bypass (CPB) model is established with median sternotomy and cannulation of the main pulmonary artery and right atrial appendage [9,10,11]
We explored differences between central and peripheral cannulation by comparing changes in cardiac function, hemodynamics, placental function and organ perfusion after a fetal CPB procedure

Summary

Introduction

Complex congenital heart disease (CCHD) is a major cause of infant death worldwide. For many patients with critical CCHDs, in utero correction of the structural malformation of the heart can be used to improve treatment success. Technological advances in the past decade have enabled the development of in-utero cardiac intervention that can partially alleviate disease severity and reduce postnatal mortality for some critical CCHDs, including pulmonary atresia with intact ventricular septum, aortic stenosis with evolving left heart hypoplasia, and hypoplastic left heart with restrictive foramen ovale [5, 6]. Fetal cardiac intervention is only indicated for a limited number of conditions, and the majority of fetuses diagnosed with CCHD have to wait for assessment and surgery after birth. A conventional fetal sheep CPB model is established with median sternotomy and cannulation of the main pulmonary artery and right atrial appendage (i.e., central cannulation) [9,10,11]. Since the pros and cons of different cannulation strategies are not clearly identified, the ideal cannulation strategy to establish a fetal sheep CPB model remains to be determined

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Conclusion