In vitro assessment of mitral valve function in cyclically pressurized porcine hearts. Issue 4 (April 2016)

• Record Type: Journal Article
• Authors: Vismara, Riccardo; Leopaldi, Alberto M.; Piola, Marco; Asselta, Chiara; Lemma, Massimo; Antona, Carlo; Redaelli, Alberto; van de Vosse, Frans; Rutten, Marcel; Fiore, Gianfranco B.
• Is Part Of: Medical engineering & physics. Volume 38:Issue 4(2016:Apr.)
• Page Start: 346
• Page End: 353
• Publication Date: 2016-04
• Subjects: In vitro -- Circulatory mock loops -- Mitral valve; Biomedical engineering -- Periodicals; Biomedical Engineering -- Periodicals; Physics -- Periodicals; Génie biomédical -- Périodiques; Biomedical engineering; Electronic journals; Periodicals; 610.28
• DOI: 10.1016/j.medengphy.2016.01.007
• Languages: English
• ISSNs: 1350-4533

Abstract

Highlights: We compared mitral valve functioning in two state of the art mock loops for passive beating hearts. Mitral valve functioning was evaluated with high speed video and echo. Available coaptation areas and coaptation lengths were used as valve functioning indexes. Each Mock loops showed potential for physiologic or pathologic reproduction of valve biomechanics. Abstract: Recent approaches to the in vitro experimental study of cardiac fluid mechanics involve the use of whole biological structures to investigate in the lab novel therapeutic approaches for the treatment of heart pathologies. To enhance reliability and repeatability, the influence of the actuation strategy of the experimental apparatuses on the biomechanics of biological structures needs to be assessed. Using echography and intracardiac high-speed imaging, we compared the mitral valve (MV) anatomo-functional features (coaptation areas/lengths, papillary muscles-valvular plane distances) in two passive-beating-heart mock loops with internal (IPML) or external (EPML) pressurization of the ventricular chamber. Both apparatuses showed fluid dynamic conditions that closely resembled the physiology. The MVs analyzed in the EPML presented coaptation areas and lengths that were systematically higher, and exhibited greater variability from early-to peak-systole, as compared to those in the IPML. Moreover, in the EPML, the MV leaflets exhibited a convexity with high curvature toward the atrium. With the IPML, MV coaptation lengths ranged similar to available clinical data and the papillary muscles-valve plane distances were more stable throughout systole. In conclusion, both the apparatuses allow for reproducing in vitro the left heart hemodynamics, in terms of flow rates and pressures, with proper mitral valve continence. Results suggest that the IPML is more suitable for replicating the physiological MV functioning, while the EPML may have more potential as a model for the study of MV pathologies.