Acquisition of Objective Data During Transapical Neochordae Implantation

Summary

Mitral Valve repair (MVr) is the gold standard treatment for primary Mitral Regurgitation. Implantation of artificial Gore-Tex chordae (or neochordae implantation) is often used for MVr.

The NeoChord DS1000 (NeoChord Inc., Minneapolis, USA) is a device designed to deploy neochordae through transapical access in a beating heart and without cardiopulmonary bypass. NeoChord System is CE marked and therefore authorized for use in Europe. Procedure is conducted under 3D transesophageal echocardiography (TEE) guidance. The device is introduced through the apex of the left ventricular (LV) and the prolapsed leaflet is grabbed and harpooned.

The neochordae are thus stretched between the valve and the LV apex. Neochordae length can be precisely adapted to restore a normal coaptation, to treat the regurgitation.

Recently, the principal investigator's teams (heart surgery department at Hospices Civils de Lyon and Laboratoire de Génie Electrique et Ferromagnétique lab at Institut National des Sciences Appliquées (INSA) de Lyon, France) created a platform allowing the measurement of the tension applied on neochordae during a NeoChord procedure. A dedicated protocol was designed and approved by the ethical committee of the French Society of Cardiology. The measurement was performed in 7 patients. This preliminary study shows that the technic is safe. It also suggests that chordal tension might be correlated to the quality of MVr: the sub-valvular apparatus appears to be in a low stress state when the structure and the function of the valve are restored.

These first findings raise new questions:

1. The mechanism involved in the changes in tensions during chordal length adjustment cannot be understood with current standard medical imaging tools. Numerical simulation technologies could bring physical data in order to approach physical phenomenon underlying these findings.
2. Novel chordal tension measurement tools could lead to a change in current paradigm enabling a MVr based on objective data measurement, instead of sole morphological analysis. Prognostic value of chordal tension must be studied through a larger clinical study and a systematic protocol.

A large consortium involving physicians and scientists has been created to address those questions, and a large national funding has been raised to fulfil our objectives over a 4 years period (SIMR project). The present clinical study is the core of this large project.

Conditions

• Mitral Valve Insufficiency
• Mitral Regurgitation

Interventions

PROCEDURE

Chordal tension measurement

The chordal tension measurement will be performed during surgery. The neochordae are connected to the measuring device through "crocodile" clips (e.g. machine-patient interface).We start to apply traction on the chordae that is in the center of the flailing area thanks to a millimeter screw and under TEE control. After obtaining a stable tension (plateau value), the other chordae are then tracked, one at a time, with an individual screw. When we achieve an equivalent tension on all chordae, a traction on all chordae is applied thanks to the principal screw under TEE control until obtaining a perfect coaptation. When the correction is optimal (good echocardiographic result, chordal tension low and equally spread on each chordae), the measurements are then stopped, and the chordae are fixed at the apex of the left ventricle at the optimal length.

OTHER

Cardiac Magnetic Resonance Imaging (MRI)

Patients will undergo 2 MRI exams: 1 MRI before surgical intervention (maximum 21 days before) and 1 MRI three months after surgery (+/- 14 days), with intravenous administration of gadolinium.

Sponsors & Collaborators

• Hospices Civils de Lyon

  lead OTHER

Principal Investigators

• Daniel GRINBERG, MD · Hôpital Pneumologique et Cardiovasculaire Louis Pradel

Study Design

Allocation

NA

Purpose

OTHER

Masking

NONE

Model

SINGLE_GROUP

Eligibility

Min Age

18 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2021-05-01

Primary Completion

2024-05-01

Completion

2024-05-01