Chordal force profile after neochordal repair of anterior mitral valve prolapse: An ex vivo studyCentral MessagePerspective

Shin Yajima, MD, PhD; Yuanjia Zhu, MD, MS; Charles J. Stark, MS; Robert J. Wilkerson, BS; Matthew H. Park, MS; Elde Stefan, MD; Y. Joseph Woo, MD

JTCVS Open (Sep 2023)

Chordal force profile after neochordal repair of anterior mitral valve prolapse: An ex vivo studyCentral MessagePerspective

Shin Yajima, MD, PhD,
Yuanjia Zhu, MD, MS,
Charles J. Stark, MS,
Robert J. Wilkerson, BS,
Matthew H. Park, MS,
Elde Stefan, MD,
Y. Joseph Woo, MD

Affiliations

Shin Yajima, MD, PhD: Department of Cardiothoracic Surgery, Stanford University, Stanford, Calif
Yuanjia Zhu, MD, MS: Department of Cardiothoracic Surgery, Stanford University, Stanford, Calif; Department of Bioengineering, Stanford University, Stanford, Calif
Charles J. Stark, MS: Department of Cardiothoracic Surgery, Stanford University, Stanford, Calif
Robert J. Wilkerson, BS: Department of Cardiothoracic Surgery, Stanford University, Stanford, Calif
Matthew H. Park, MS: Department of Cardiothoracic Surgery, Stanford University, Stanford, Calif; Department of Mechanical Engineering, Stanford University, Stanford, Calif
Elde Stefan, MD: Department of Cardiothoracic Surgery, Stanford University, Stanford, Calif
Y. Joseph Woo, MD: Department of Cardiothoracic Surgery, Stanford University, Stanford, Calif; Department of Bioengineering, Stanford University, Stanford, Calif; Address for reprints: Y. Joseph Woo, MD, Department of Cardiothoracic Surgery, Falk Cardiovascular Research Center, Stanford University School of Medicine, 300 Pasteur Dr, Stanford, CA 94305.

Journal volume & issue: Vol. 15
pp. 164 – 172

Abstract

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Objective: This study aimed to biomechanically evaluate the force profiles on the anterior primary and secondary chordae after neochord repair for anterior valve prolapse with varied degrees of residual mitral regurgitation using an ex vivo heart simulator. Methods: The experiment used 8 healthy porcine mitral valves. Chordal forces were measured using fiber Bragg grating sensors on primary and secondary chordae from A2 segments. The anterior valve prolapse model was generated by excising 2 primary chordae at the A2 segment. Neochord repair was performed with 2 pairs of neochords. Varying neochord lengths simulated postrepair residual mitral regurgitation with regurgitant fraction at >30% (moderate), 10% to 30% (mild), and <10% (perfect repair). Results: Regurgitant fractions of baseline, moderate, mild, and perfect repair were 4.7% ± 0.8%, 35.8% ± 2.1%, 19.8% ± 2.0%, and 6.0% ± 0.7%, respectively (P < .001). Moderate had a greater peak force of the anterior primary chordae (0.43 ± 0.06 N) than those of baseline (0.19 ± 0.04 N; P = .011), mild (0.23 ± 0.05 N; P = .041), and perfect repair (0.21 ± 0.03 N; P = .006). In addition, moderate had a greater peak force of the anterior secondary chordae (1.67 ± 0.17 N) than those of baseline (0.64 ± 0.13 N; P = .003), mild (0.84 ± 0.24 N; P = .019), and perfect repair (0.68 ± 0.14 N; P = .001). No significant differences in peak and average forces on both primary and secondary anterior chordae were observed between the baseline and perfect repair as well as the mild and perfect repair. Conclusions: Moderate residual mitral regurgitation after neochord repair was associated with increased anterior primary and secondary chordae forces in our ex vivo anterior valve prolapse model. This difference in chordal force profile may influence long-term repair durability, providing biomechanical evidence in support of obtaining minimal regurgitation when repairing mitral anterior valve prolapse.

Published in JTCVS Open

ISSN: 2666-2736 (Online)
Publisher: Elsevier
Country of publisher: United States
LCC subjects: Medicine: Internal medicine: Specialties of internal medicine: Diseases of the circulatory (Cardiovascular) system; Medicine: Surgery
Website: https://www.journals.elsevier.com/jtcvs-open

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