Peak Mechanical Loads Induced in the In Vitro Edge-to-Edge Repair of Posterior Leaflet Flail

• Published in: The Annals of thoracic surgery Vol. 94; no. 5; pp. 1446 - 1453
• Main Authors: Rabbah, Jean-Pierre M., BS, Siefert, Andrew W., MS, Spinner, Erin M., PhD, Saikrishnan, Neelakantan, PhD, Yoganathan, Ajit P., PhD
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 01.11.2012; Elsevier
• Subjects: Anesthesia. Intensive care medicine. Transfusions. Cell therapy and gene therapy; Animals; Biological and medical sciences; Biomechanical Phenomena; Cardiology. Vascular system; Cardiothoracic Surgery; Medical sciences; Mitral Valve Insufficiency - physiopathology; Mitral Valve Insufficiency - surgery; Pneumology; Surgery; Swine; Transducers, Pressure; 35; Corrective surgery; Treatment; Peak load; Posterior; Mechanical load; Anesthesia; Circulatory system; Cardiology; Repair; Edge; In vitro
• ISSN: 0003-4975; 1552-6259
• DOI: 10.1016/j.athoracsur.2012.05.024

Background Percutaneous edge-to-edge mitral valve (MV) repair is a potential therapeutic option for patients presenting with mitral regurgitation, who may not be suitable for surgery. We characterized the edge-to-edge repair forces in a posterior leaflet flail MV model to identify potential modes of mechanical failure. Methods Porcine MVs were evaluated in two different sizes (Physio II 32 and 40) in a left-side heart simulator under physiologic hemodynamic conditions. Edge-to-edge repair was simulated by suturing miniature force transducers near the free edge of the anterior and posterior leaflets, on the ventricular side, resulting in a double orifice MV. Posterior leaflet flail was created by selective chordal cutting. Results Chordal cutting resulted in posterior leaflet flail and mitral regurgitation; all valves coapted normally before chordal cutting. Peak systolic control forces (size 32, 0.098 ± 0.058 N; size 40, 0.236 ± 0.149 N) were not significantly different from systolic flail forces (size 32, 0.136 ± 0.107 N; size 40, 0.220 ± 0.128 N) for either MV size. No correlation was observed between force magnitude and flail height or width. Peak systolic force was greater ( p = 0.08) for the larger MVs (size 40 compared with size 32). Finally, peak diastolic force was significantly smaller ( p = 0.04) than peak systolic force regardless of valve size. Conclusions For the first time, forces imparted on an edge-to-edge MV repair were quantified for a posterior leaflet flail model. Force magnitude was not significantly altered with flail compared with control; it was greatest during peak systole and increased with valve size.