Tutorial

Transapical valve-in-ring mitral valve implantation through the anterior mitral valve leaflet

Published: August 28, 2018

DOI: 10.1510/mmcts.2018.031

Innovative

Transcatheter mitral valve implantation (TMVI) is a relatively novel intervention used to replace the mitral valve of individuals deemed too high risk or unsuitable for surgery. It is associated with a number of specific risks, including left ventricular outflow tract obstruction (LVOTO).

In this video tutorial we present the case of a 75-year-old man who was unable to undergo redo surgical repair and had a number of risk factors for LVOTO. To minimize these risks, we deployed the TMVI within the anterior mitral valve leaflet. The postoperative result was mild mitral valve regurgitation and no LVOTO.

The long-term outcome of this approach is yet to be determined but we believe this technique offers a novel method to manage a select group of patients suffering with mitral valve disease and at risk of LVOTO.

A transcatheter approach was considered, despite the high risk of LVOTO secondary to a large anterior mitral valve leaflet (AMVL) and relatively acute aorto-mitral angle (AMA) because conventional surgical repair had to be abandoned. The novel idea of deploying the valve within the AMVL was suggested as a possible solution.

A 75-year-old man presented with shortness breath secondary to torrential mitral regurgitation (MR) following a mitral valve repair 6 months previously. Unfortunately, conventional redo mitral valve surgery had to be abandoned intraoperatively as a consequence of being unable to achieve an activated clotting time (ACT) sufficient to safely institute cardiopulmonary bypass.

1 - Case history (0:00)

A 75-year-old man presented with increasing shortness of breath (New York Heart Association Class IV) and a significant reduction in quality of life 6 months after mitral valve repair (MVR) (30 Carpentier-Edwards Physio II ring, Edwards Lifesciences, Irvine, CA).
2 - Echocardiography (0:24)

Echocardiography demonstrated a well-seated ring with good opening of the anterior leaflets. P1 was thickened and did not appose P2, resulting in torrential MR. Right-sided heart pressure was significantly elevated (pulmonary artery pressure: 60 – 65 mmHg + right atrial pressure). Left ventricular function was normal with no hypertrophy or dilatation.
3 - Complicating factors (0:41)

The originally planned redo-sternotomy and surgical replacement had been abandoned intraoperatively due to a failure to achieve an activated clotting time sufficient to commence cardiopulmonary bypass (CPB) safely (ACT≈180). This occurred despite additional doses of heparin, fresh frozen plasma, and antithrombin III. The advice of perfusion experts in the UK & Europe was therefore sought and it was deemed unwise to commence CPB without adequate documentation of calibrated levels of anticoagulation.

Consequently, a transcathter approach was considered. It was however recognised that this would be likely to result in LVOTO given the individual’s large AMVL and acute aortomitral angle; both independent risk factors for systolic anterior motion. This led to the novel idea of implanting the replacement valve within the AMVL.
4 - Preoperative transesophageal echocardiography (1:29)

Preoperative transesophageal echocardiography (TEE) demonstrating torrential MR through P1 and P2 due to failed apposition and a large AMVL.
5 - Transesophageal long axis view of the aortic valve (1:50)

Illustrated long axis view of the aortic valve demonstrating the large AMVL and left ventricular outflow tract (LVOT).
6 - Wire placement & setup (2:13)

A venous pacing wire was placed in the right ventricle ensuring appropriate capture, and a pigtail catheter was positioned in the aortic non-coronary cusp.
7 - Puncture of the anterior mitral valve leaflet (2:42)

Following cannulation of the apex, a 15-cm needle was used to perforate the center of the AMVL near the annulus of A2, under TEE guidance. A soft guidewire was then passed into the left atrium and exchanged for a stiff wire, which was sited within the pulmonary vein.
8 - Intraoperative 3D reconstruction of the TEE (3:09)

Demonstration of penetration of the AMVL with the 15-cm needle.
9 - Advancement of the transcatheter mitral valve (3:30)

A 26-mm balloon-expandable SAPIEN 3 transcatheter valve (Edwards Lifesciences, Irvine, CA) was advanced along the stiff wire into position. This was then expanded with balloon deployment following rapid ventricular pacing.
10 - Deployed transcatheter valve (3:53)
11 - Post Procedure (4:16)

Following deployment of the transcatheter mitral valve no mitral regurgitation, paravalvular leak, or LVOTO was identified on TEE. The patient was discharged 3 days post-procedure.

This case presents a challenging situation in which an abnormal hematological response to heparin or an inability to accurately document anticoagulation via calibrated metrics prevented the safe institution of CPB and therefore ruled out standard surgical repair. It was recognised preoperatively that the patient’s large AMVL and acute aortomitral angle would pose a significant risk of LVOTO. For this reason, TMVI through the AMVL was considered.

Through intra-leaflet TMVI we demonstrated that the AMVL was anchored in place and therefore unable to obstruct LVOT. In addition, protrusion into the LA following deployment of the valve was avoided, possibly as a result of our deliberate decision to leave the subvalvular apparatus intact.

This technique offers a possible solution for patients presenting following prior mitral valve surgery with recurrent disease who are unsuitable for conventional re-repair and at high-risk of LVOTO. The risks of the procedure include possible hemodynamic compromise when the anterior leaflet is perforated (hence our prophylactic use of an intra-aortic balloon pump, and rupture of the anterior leaflet with embolisation of remnant tissue into the LVOT or protrusion into the left atrium following deployment of the valve.

The long-term results of this technique remain to be determined, particularly in relation to paravalvular leak.

As patient desire for less invasive techniques increases, technology improves, and the population of patients deemed too high risk for conventional repair grows, the utilization of transcatheter approaches will become more common. The described technique offers a novel method for managing mitral valve disease in those at risk of LVOTO.

Preprocedural planning is essential to identify risks on a case-by-case basis in order to decide the most appropriate intervention.

Bapat V, Pirone F, Kapetanakis, Rajani R, Niederer S. Factors influencing left ventricular outflow tract obstruction following a mitral valve-in-valve or valve-in-ring procedure, part 1. CCI 2015;86:747–760.
PubMed Abstract | Publisher Full Text
Paradis JM, Trigo MD, Puri R, Rodés-Cabau J. Transcatheter Valve-in-Valve and Valve-in-Ring for Treating Aortic and Mitral Surgical Prosthetic Dysfunction. JACC 2015;66(18):2019–2037.
PubMed Abstract | Publisher Full Text

The authors would like to thank Vinayak Bapat and Linda Zacharkiw.

None declared.

Authors
Luke J. Rogers^a, Jaime Villaquiran^a, Ian Cox^b, Malcolm Dalrymple-Hay^a, and Clinton Lloyd^a

Author Affiliations
^aDepartment of Cardiac Surgery, Plymouth Hospitals NHS Trust
^bDepartment of Cardiology, Plymouth Hospitals NHS Trust

Corresponding Author
Luke J. Rogers

Department of Cardiac Surgery, Plymouth Hospitals NHS Trust

Email: ljrogers@doctors.org.uk

This tutorial is based on the author's article "Transapical valve-in-ring mitral valve implantation through the anterior mitral valve leaflet", which is published in the European Journal of Cardio-Thoracic Surgery https://doi.org/10.1093/ejcts/ezy212.