Cavopulmonary Assist: (Em)powering the Univentricular Fontan Circulation

Abstract

Since the Fontan/Kreutzer procedure was introduced, evolutionary clinical advances via a staged surgical reconstructive approach have markedly improved outcomes for patients with functional single ventricle. However, significant challenges remain. Early stage mortality risk seems impenetrable. Serious morbidities -construed as immutable consequences of palliation -have hardly been addressed. Late functional status is increasingly linked to pathophysiologic consequences of prior staged procedures. As more single ventricle patients survive into adulthood, Fontan failure is emerging as an intractable problem for which there is no targeted therapy. Incremental solutions to address these ongoing problems have not had a measurable impact. Therefore, a fundamental reconsideration of the overall approach is reasonable and warranted. The ability to provide a modest pressure boost (2-6 mmHg) to existing blood flow at the total cavopulmonary connection can effectively restore more stable biventricular status. This would impact not only treatment of late Fontan failure, but also facilitate early surgical repair. A realistic means to provide such a pressure boost has never been apparent. Recent advances are beginning to unravel the unique challenges which must be addressed to realize this goal, with promise to open single ventricle palliation to new therapeutic vistas. Keywordsuniventricular Fontan circulation; cavopulmonary assist; mechanical circulatory support © 2011 Elsevier Inc. All rights reserved.Address for correspondence: Mark Rodefeld MD, Associate Professor of Surgery, Department of Surgery, Indiana University School of Medicine, Emerson Hall 215, 545 Barnhill Drive, Indianapolis, IN 46202. Tel: 317-274-7728; Fax: 317-274-2940; rodefeld@iupui.edu. Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. . It was known then that a pressure gradient of only 6 mmHg was needed to propel blood from the pulmonary artery through the lungs [3]. From these reports, it can be inferred that complete bypass of the right heart as a primary, direct intervention was nearly accomplished. With incorporation of the right atrium as a low energy right-sided power source, it ultimately was. Using a right-sided power source to supplement a univentricular Fontan circulation is highly compelling: it would biventricularize it toward more stable 2-ventricle physiology. This could serve not only to stabilize an existing Fontan circulation, but also serve in direct Fontan conversion as a facilitator for stable systemic transition to an unsupported Fontan. Presented at STS/AATSBecause a safe and reliabl...

An overview of mechanical circulatory support in single-ventricle patients

“…It could be used in the failing Fontan, specifically for patients with failing physiology. This could provide temporary support to improve the endorgan function in a patient prior to transplant (69). Further, it could improve patient selection by identifying those who recover end-organ function, presumably a marker for a good outcome post-heart transplant.…”

Mechanical circulatory support for the failing functional single ventricle

“…An important concept of MCS for the failing Fontan patient with relatively preserved ventricular function is cavopulmonary assist (18). This entails the implantation of a ventricular assist device in the Fontan circulation to propel blood into the pulmonary arteries and does not provide any other support to the systemic ventricle outside of improving preload.…”

Heart Failure in Adults with Congenital Heart Disease: An Emerging Challenge.

“…U proteklim četirima desetljeći-ma mnogo se naučilo o tom čudnovatom, ali funkcionalnom krvotoku s jednom klijetkom, ali još je mnogo preostalo naučiti 59, 66 . Fontanova se cirkulacija se opire konvencionalnim strategijama liječenja i zahtijeva nove pristupe 67 .…”

“…In the past four decades much has been learnt on this strange but useful single ventricle circulation, but much remains to be learned 59, 66 . Fontan circulation defies conventional treatment strategies, requiring new approaches 67 .…”