Pediatric Mechanical Support with an External Cardiac Compression Device

Minoo N Kavarana Howard M Loree Ii

doi:10.4172/2329-9517.1000105

Abstract

The PediBooster external cardiac compression device is a minimally invasive, non-blood contacting Biventricular Assist Device (BiVAD) intended for pediatric use. It is being developed as a palliative therapy for acute Postcardiotomy Shock (PCS). The PediBooster extracardiac wrap is pneumatically actuated to circumferentially compress the heart, providing co-pulsation support. Attachment is via a novel hydrogel coating. Early versions of the wrap were tested in vivo using a single ventricle congenital heart disease model with postcardiotomy shock, which proved unstable and demonstrated high peri-operative mortality. The final wrap design was tested in 4 acute studies with piglets (5.1 ± 0.3 kg), where the combination of ASD and PA banding induced acute right ventricular dysfunction. Data collected included routine hemodynamic values, TEE, video of the exposed heart, and cardiac histology. The model proved stable for support durations ranging from 2 to 16 hours. The wrap restricted the heart in 3 of the 4 animals, as evidenced by increased diastolic LVP during support compared to the baseline failure condition. TEE and video data showed good attachment and function of the wrap, particularly during the final 16 hr study. This model of congenital heart disease shows promise for chronic (24-72 hr) studies. Ventricular filling during support may be improved by adjusting wrap dimensions to eliminate end diastolic restriction.

Highlights

Mechanical devices have been successfully used to support impaired ventricular function secondary to acquired cardiac pathology in adults, little has been accomplished for postoperative pediatric myocardial mechanical stabilization in children with congenital cardiac disease [1]
Single ventricle conversion resulted in a reduction of mean aortic flow to 40-50% of the baseline with severe ventricular dysfunction
Under PediBooster support, aortic flow (AOF) of 60-75% of baseline was obtained for the Single Ventricle (SV) HF model, these results were not stable in most cases

Summary

Introduction

Mechanical devices have been successfully used to support impaired ventricular function secondary to acquired cardiac pathology in adults, little has been accomplished for postoperative pediatric myocardial mechanical stabilization in children with congenital cardiac disease [1]. Conditions such as anomalous origin of the coronary artery from the pulmonary artery, critical aortic stenosis, and tetralogy of Fallot which require surgical correction may suffer from postcardiotomy myocardial failure. Single ventricle patients undergoing the Norwood procedure have a significant incidence of postoperative myocardial dysfunction and often need mechanical cardiac support. Children do not tolerate right ventricular failure, either primary or secondary, and require right ventricle support for the subsequent elevation of central venous pressures

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Conclusion