title: 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.
authors.affiliation: Cardiac Unit, Alder Hey Children NHS Foundation Trust, Liverpool, UK. Antonio.Corno@alderhey.nhs.uk
authors.forename: Antonio F
authors.initials: AF
authors.lastname: Corno
authors.forename: Christian
authors.initials: C
authors.lastname: Vergara
authors.forename: Chellappan
authors.initials: C
authors.lastname: Subramanian
authors.forename: Robert A
authors.initials: RA
authors.lastname: Johnson
authors.forename: Tiziano
authors.initials: T
authors.lastname: Passerini
authors.forename: Alessandro
authors.initials: A
authors.lastname: Veneziani
authors.forename: Luca
authors.initials: L
authors.lastname: Formaggia
authors.forename: Nelson
authors.initials: N
authors.lastname: Alphonso
authors.forename: Alfio
authors.initials: A
authors.lastname: Quarteroni
authors.forename: Jonathan C
authors.initials: JC
authors.lastname: Jarvis
mesh_terms: D000818:Animals; D002496:Central Venous Pressure; D003198:Computer Simulation; D004567:Electrodes, Implanted; D018729:Fontan Procedure / Q000009:adverse effects / Q000379:methods; D006353:Heart-Assist Devices; D006439:Hemodynamics / Q000502:physiology; D066298:In Vitro Techniques; D023421:Models, Animal; D008955:Models, Cardiovascular; D010369:Pectoralis Muscles / Q000601:surgery; D010865:Pilot Projects; D011652:Pulmonary Circulation / Q000502:physiology*; D013552:Swine