Totally Endoscopic Complex Multisegment Prolapse Repair

In this new CTSNet series, Dr. Mario Castillo-Sang presents innovative, totally endoscopic cardiac procedures for a variety of conditions. Stay tuned for more series videos in the coming weeks.   

The patient was a 48-year-old female who presented with dyspnea on exertion and fatigue. Her transesophageal echocardiogram (TEE) showed a P2 central to medial segment prolapse and P3 prolapse with a suspicious area of medial A2 and A3 prolapse, with severe mitral regurgitation with an anteriorly and laterally directed jet. 

The authors’ totally endoscopic approach involved a 2.5 cm working incision in the fourth intercostal space, expanded with an extra-small soft tissue retractor and no rib spreader. The camera port was a 10 mm trocar inserted in the third intercostal space, while a 5 mm incision was made in the fourth anterior intercostal space for the atrial lift retractor. Femoral bypass via cutdown was performed with direct arterial and venous cannulation. The aorta was dissected off the right pulmonary artery bluntly to create space for the cross-clamp, and the oblique sinus was opened bluntly. During this maneuver, a small tear was created in the posterior aspect of the superior vena cava (SVC), which was repaired using 4-0 polypropylene with RB needles. Once repaired, the heart was arrested with antegrade del Nido cardioplegia, and a cross-clamp was deployed in the chest. The left atrium was then opened through the interatrial groove, and the valve was exposed using the HV winged retractor.  

The valve analysis showed a very large prolapse of the medial P2 segment measuring approximately 3 cm, as well as a P3, A2, and A3 prolapses. The lateral P2 and P1 segments were also prolapsed. There were no normal length neochordae to compare to determine neochordal length. The authors’ practice for multisegmented prolapses is to apply the annuloplasty sutures to conform the valve and visualize it in an atomically correct manner. The prolapsed segment is pushed flat into the ventricle, and then measurements are taken from the edge of that segment to the prospective location of the neocortical anchoring on the papillary muscle head. This is facilitated using a nitinol ribbon retractor.  

The authors then selected a premeasured PTFE neochordal Chord-X system. The system, which consisted of three pairs of premeasured neochordae, was anchored to the posterior head of the posteromedial papillary muscle, and then the neochordae were anchored to the central portion of P2 and medially to P3. The depth of the anchoring into the leaflet was 1.5 cm from the edge, given the large 3 cm prolapsed segment. The knots were tied, and then the following system was anchored to the posterior head of the anterolateral muscle. These neochordae were anchored to the central and lateral portions of P2, and a third system was anchored to the anterior head of the anterolateral muscle to reanchor the P1 segment. A couple of CV 4 ePTFE sutures were used to reanchor the A2 and A3 segments from the posteromedial papillary muscle. The valve was static tested with del Nido cardioplegia between each of the neochordal system anchorings to confirm the uniform correction of the prolapsed segments. The annulus was sized, and a nitinol core 36 mm Memo 4D full ring was implanted using titanium fasteners. Final static testing and an ink test demonstrated no leaks and deep coaptation zones. 

The left atrium was closed in one layer, and the heart was reanimated. The patient was weaned off bypass without problems. TEE showed trace residual mitral regurgitation with a low mean gradient. The patient was extubated in the operating room and was discharged on postoperative day three. During a one-year follow-up, the patient was doing well. 

Totally endoscopic mitral valve surgery has been shown to be safe and effective, with excellent long-term durable results since 2003 (1). Premeasured neochordal reconstruction was pioneered in Leipzig and has become one of the most performed forms of mitral valve repair for primary disease with excellent long-term durability (2). The combination of totally endoscopic surgery and premeasured neochordae allows for reproducibility of repairs, reducing the artisan aspect of mitral repair surgery. 

References

1. Casselman FP, Van Slycke S, Dom H, Lambrechts DL, Vermeulen Y, Vanermen H. Endoscopic mitral valve repair: feasible, reproducible, and durable. The Journal of thoracic and cardiovascular surgery. 2003 Feb 1;125(2):273-82.
2. Pfannmueller B, Misfeld M, Verevkin A, Garbade J, Holzhey DM, Davierwala P, Seeburger J, Noack T, Borger MA. Loop neochord versus leaflet resection techniques for minimally invasive mitral valve repair: long-term results. European Journal of Cardio-Thoracic Surgery. 2021 Jan;59(1):180-6.

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