State-of-the-Art Review: Technical and Imaging Considerations in Novel Transapical and Port-Access Mitral Valve Chordal Repair for Degenerative Mitral Regurgitation

Abstract

Degenerative mitral regurgitation (DMR) based on posterior leaflet prolapse is the most frequent type of organic mitral valve disease and has proven to be durably repairable in most cases by chordal repair techniques either by conventional median sternotomy or by less invasive approaches both utilizing extracorporeal circulation and cardioplegic myocardial arrest. Recently, several novel transapical chordal repair techniques specifically targeting the posterior leaflet have been developed as a far less invasive and beating heart (off-pump) alternative to port-access mitral repair. In order to perform a safe and effective minimally invasive mitral chordal repair, thorough knowledge of the anatomy of the mitral valve apparatus and adequate use of multimodality imaging both pre- and intraoperatively are fundamental. In addition, comprehensive understanding of the available novel devices, their delivery systems and the individual procedural steps are required.

Keywords: Beating Heart Mitral Valve Repair; Harpoon; chord implantation; minimally invasive MV repair; minimally invasive mitral valve surgery; mitral valve repair; mitral valve surgery; transapical.

FIGURE 1

The set-up for a minimally invasive port-access approach through a right anterolateral thoracotomy, as performed in the Sint Antonius Hospital Nieuwegein. The patient is positioned in a 30* left lateral position with the right arm placed posteriorly, with a sand bag under de right scapula. A soft tissue retractor is used without additional rib spreading. Depicted are the atrial roof retractor, camera port and aortic cross-clamp (from medial to right lateral).

FIGURE 2

Intraoperative long-axis TEE view showing part of the left atrium, the left ventricle and the left ventricular outflow tract, before repair with the HARPOON device. The measurement of the tissue/gap-ratio is demonstrated. Tissue-length (red), 2.1 cm; gap-length (blue), 0.97 cm. Tissue/gap-ratio = 2.1/0.97 = 2.2.

FIGURE 3

Intraoperative long-axis TEE view showing part of the left atrium, the left ventricle and the left ventricular outflow tract, before repair with the HARPOON device. The measurement of the tissue/gap-ratio is demonstrated. Tissue-length, 1.98 cm; gap-length, 1.14 cm. Tissue/gap-ratio = 1.98/1.14 = 1.74. The anteroposterior diameter is 3.76 cm.

FIGURE 4

The set-up for Harpoon Beating Heart Mitral Valve Repair through a left anterolateral thoracotomy, as performed in the Sint Antonius Hospital Nieuwegein. The left shoulder and elbow are slightly flexed dorsally. A soft tissue retractor is used without additional rib spreading. Four pericardial stay sutures are placed. The hemostatic introducer is inserted and secured with two concentric purse-string sutures.

FIGURE 5

The end effector is used to stabilize the HARPOON device on the underside of the pMVL at the targeted implantation site. pMVL, posterior mitral valve leaflet.

FIGURE 6

Intraoperative three-dimensional TrueVue photo-realistic rendering of the mitral valve before repair with the HARPOON System. A surgical view of the atrial side of the mitral valve is shown on the right. The anteroposterior diameter of the mitral valve is 3.96 cm.