Performance and healing of an expanded polytetrafluoroethylene multichordal device at 6 months after repair of mitral leaflet flail in swine

• Type of Material: Article
• Authors: Surendra K. Chawla, St. Francis Hospital and Medical Center; Robert W. M. Frater, University of the Free State; Mark Cunningham, SURPASS; Muralidhar Padala, Emory University
• Language: English
• Date: 2019-03-01
• Publisher: MOSBY-ELSEVIER
• Publication Version: Author Accepted Manuscript (After Peer Review)
• Copyright Statement: © 2018 The American Association for Thoracic Surgery
• License: Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International
• Final Published Version (URL): http://dx.doi.org/10.1016/j.jtcvs.2018.07.103
• Title of Journal or Parent Work: JOURNAL OF THORACIC AND CARDIOVASCULAR SURGERY
• Volume: 157
• Issue: 3
• Start Page: 932
• End Page: +
• Grant/Funding Information: Dr. Padala was supported by grant awards NIH 1R01HL135145–01A1, 1R01HL133667–01A1, 1R01HL140325–01A1, and American Heart Association grant 14SDG20380081 when writing and editing this manuscript.
• Keywords: degenerative mitral disease; Life Sciences & Biomedicine; Cardiac & Cardiovascular Systems; APPARATUS; TENDINEAE; COMPLEX; ARTIFICIAL CHORDAE; Cardiovascular System & Cardiology; Surgery; VALVE; Respiratory System; neochordoplasty; REPLACEMENT; POSTERIOR; SECONDARY; mitral valve repair; Science & Technology; Barlow disease; CORRECT LENGTH; NEOCHORDAE; fibroelastic deficiency
• Research Categories: Health Sciences, Medicine and Surgery

Abstract

Objective: Repairing a prolapsed mitral valve that involves multiple cusps is procedurally complicated and carries a higher risk of failure when performed with individual neochordae. Inserting multiple neochordae into the papillary muscle, sizing, and aligning them in a manner that can restore coaptation is challenging. A multichordal mitral valve apparatus (MitraPatch) with a single neopapillary muscle section, 4 neochordae with each chord ending in a neoleaflet section, was developed. In this study, the 6-month outcomes of using this apparatus to repair mitral prolapse in swine is reported. Methods: Seven pigs (n = 7) with prolapse from mitral chordal transection were repaired with the device. One pig was used to develop the procedure, and 6 swine received the implant and were survived to 150 days (n = 4) and 180 days (n = 2), with monthly echocardiographic examinations. All hearts were explanted for gross necropsy and detailed histopathology. Results: Severe mitral regurgitation (MR) was observed after chordal transection in all pigs. Repairing the valve with the device reduced MR to none-or-trace levels in 3 swine, grade 1 in 3 swine, and 1 to 2+ in 1 swine immediately after surgery. In the pigs with none/trace/grade 1 MR, the device was intact and coaptation was fully restored as observed on serial echocardiograms. The device was intact, without dehiscence, stretching, or fibrosis at termination. The neoleaflet and neopapillary sections of the device elicited a host response, which is on track to produce living valve replacement tissue, but we cannot tell how controlled this might be several years later. In the pig with grade 1 to 2+ MR, accidental transection of both marginal and strut chordae in that region was observed at death, with dehiscence of the device at the site of its insertion into the leaflet. Conclusions: The anatomic principles that guide this multichordal design appear to be valid, with good hemodynamic performance and a controlled host response at 6 months.