Assisted Fontan procedure: animal and in vitro models and computational fluid dynamics study☆☆☆

Abstract

Fontan connection with intermittent compression by wrapped latissimus dorsi (LD) was tested in vivo, in vitro and by means of computational fluid dynamics (CFD). Experimental study: LD was conditioned in four pigs for three weeks before Fontan connection by valved conduit wrapped with LD. Mock circuit: Inflatable cuff wrapped around valved conduit provided intermittent external compression, with pressure and flow measured at driving pressure of 8 or 16 mmHg. CFD study: A circuit was tested for possible increase above basal flow (4 l/min) with intermittent external compression. Experimental study: Intermittent conduit compression by LD provided mean 7% decrease of baseline PA pressure, with simultaneous flow increase of 2%. Mock circuit: By raising the driving pressure from 8 to 16 mmHg, the flow increased with baseline PVR (56%) and with elevated PVR (80%). Total pulmonary flow was reduced during intermittent external compression with both baseline and elevated PVR. CFD study: Compression with 13.0 mmHg provided 4.9% increase of total pulmonary flow with substantial increase of the peak flow (92%). In vivo and in vitro, the increased flow produced by compressing a conduit was confounded by the inevitable intermittent flow restriction. Mathematical model using lower pressure for intermittent external compression showed potential for increase in pulmonary flow.

A computational study of the Fontan circulation with fenestration or hepatic vein exclusion

“…The Norwood physiology has also been studied using geometric multiscale models; some representative research includes the work of Qian et al, Hsia et al, and Moghadam et al [33,38,43]. Lastly, one–dimensional blood flow modeling for the Fontan physiology has appeared in the work of Corno et al [44]. …”

Towards a Tissue-Engineered Contractile Fontan-Conduit: The Fate of Cardiac Myocytes in the Subpulmonary Circulation

“…As heart transplantation is a limited option, several technologies, including mechanically assisted Fontan circulation and cardiomyoplasty procedures have been attempted[12–14]. As an alternative to aforementioned approaches the field of cardiac tissue engineering is emerging[15–17].…”

Progress in experimental and clinical subpulmonary assistance for Fontan circulation

“…Atrial cardiomyoplasty was investigated as a potential method to increase pulmonary flows in the Fontan circulation. 20,[25][26][27] In a canine model, atrial cardiomyoplasty was used to increase pulmonary blood flow by ''ventricularization'' of the RA. 20 A modified atriopulmonary Fontan connection was created by surgical closure of the tricuspid valve and placement of a conduit between the RA appendage and the distal PA trunk.…”