title: Long-term in vivo study of gas diffusion in bilaminar compliance chambers.
abstract: The problem of gas diffusion from compliance chambers in long-term pulsatile blood pump implantation continues. To evaluate and predict gas diffusion at the intrathoracic tissue interface, eight air-filled static bilaminar compliance chambers were implanted in four calves for a mean duration of 191 days. Mean volume loss was 40.3 +/- 6.2 ml (0.2 ml/day) compared with previous results of 1.2 ml/day for pure Hexsyn diaphragms. The residual gas in the chamber was analyzed as nitrogen = 89.6 +/- 0.6%; oxygen = 1.5 +/- 1.1%; and carbon dioxide = 8.8 +/- 0.6%. The resulting gas composition is assumed equivalent to that of the tissue interface and was used in developing a diffusion model. For a complete left ventricular assist system (LVAS), gas diffusion at the arterial blood and tissue interface was simulated. The predicted time to reach a minimum volume of 90 ml (compliance volume equal to full pump stroke volume) was in excess of 1 year.
authors.affiliation: Department of Artificial Organs, Cleveland Clinic Foundation, OH 44106.
authors.forename: N
authors.initials: N
authors.lastname: Sakakibara
authors.forename: R R
authors.initials: RR
authors.lastname: Navarro
authors.forename: M
authors.initials: M
authors.lastname: Nasu
authors.forename: L K
authors.initials: LK
authors.lastname: Fujimoto
authors.forename: R J
authors.initials: RJ
authors.lastname: Kiraly
authors.forename: Y
authors.initials: Y
authors.lastname: Nosé
mesh_terms: D000818:Animals; D002245:Carbon Dioxide / Q000097:blood*; D002417:Cattle; D004058:Diffusion; D006354:Heart, Artificial; D006353:Heart-Assist Devices; D008297:Male; D008567:Membranes, Artificial; D008955:Models, Cardiovascular; D009584:Nitrogen / Q000097:blood*; D010100:Oxygen / Q000097:blood*; D013318:Stroke Volume / Q000502:physiology*
chemical_list: D008567:Membranes, Artificial; D002245:Carbon Dioxide; D009584:Nitrogen; D010100:Oxygen