Abstract Transcatheter mitral valve implantation is a relatively novel intervention that replaces 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. In this report, 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 left ventricular outflow tract obstruction. To minimize this risk, we deployed transcatheter mitral valve implantation within the anterior mitral valve leaflet resulting in mild mitral valve regurgitation postoperatively and no left ventricular outflow tract obstruction. Long-term durability of this approach is yet to be determined, but we believe that this intervention adds to the armamentarium of the heart team. Transcatheter mitral valve implantation , Mitral valve replacement , Left ventricular outflow obstruction , Valve-in-ring , Anterior mitral valve leaflet INTRODUCTION Transcatheter valve implantation is an increasingly common alternative to open surgery, especially in those deemed too high-risk or unsuitable for surgery. This has led to the relatively novel idea of attempting transcatheter mitral valve implantation (TMVI) in those who have already undergone valve replacement (valve-in-valve) or ring annuloplasty (valve-in-ring) [1, 2]. Previous mitral valve replacement (MVR) offers valve-in-valve procedures the advantage of a rigid ring and prior resection of the anterior leaflet subsequently providing a stable landing zone . Previous mitral valve repair (MVr) poses more of a problem for TMVI with irregular shaped annuloplasty rings providing less stable anchorage due to the semirigid or flexible nature of the rings and conservation of the anterior mitral valve leaflet (AMVL) which can subsequently result in left outflow tract obstruction (LVOTO) secondary to systolic anterior motion . This report presents a case where the intentional puncture of the AMVL allowed intraleaflet TMVI for MR in a patient unable to undergo conventional repair. HISTORY 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 MVR (30 Edwards Physio II ring). 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 (Fig. 1A). Right-sided heart pressure was significantly elevated (PA pressure 60–65 mmHg + RAP). Left ventricular function was normal with no hypertrophy or dilatation. Figure 1: View largeDownload slide (A) Colour Doppler image demonstrating MR through P1 and P2, (B) large anterior mitral valve leaflet (AMVL), (C) illustration of AMVL puncture site, (D) 3-dimensional reconstruction of AMVL punctured with guidewire and (E) deployed transcatheter mitral valve implantation (TMVI). Figure 1: View largeDownload slide (A) Colour Doppler image demonstrating MR through P1 and P2, (B) large anterior mitral valve leaflet (AMVL), (C) illustration of AMVL puncture site, (D) 3-dimensional reconstruction of AMVL punctured with guidewire and (E) deployed transcatheter mitral valve implantation (TMVI). Redo sternotomy and surgical replacement were abandoned intraoperatively because of a failure to achieve an activated clotting time sufficient to commence cardiopulmonary bypass safely (ACT ≈ 180). This occurred despite additional doses of heparin, FFP and antithrombin III. Cardiopulmonary bypass (CPB) was ill-advised by a consensus of UK and perfusion experts as a consequence of being unable to document calibrated levels of anticoagulation. Consequently, a transcatheter approach was considered. This was likely to result in LVOTO given the individual’s large AMVL (Fig. 1B) and relatively acute aortomitral angle (AMA), both independent risk factors for systolic anterior motion. The novel idea of placing the valve within the AMVL was, therefore, suggested as a possible solution. The concept was discussed with multiple specialities, including haematology and cardiology, leading practitioners in the field of valve-in-valve implantation and valve-in-ring implantation and the local ethics committee. The patient was thoroughly counselled on this innovative technique and inherent risks. The procedure was performed in the catheterization laboratory following preoperative insertion of an intra-aortic balloon pump under general anaesthesia. Access was achieved via a small left thoracotomy in the 5th intercostal space. Percutaneous access of the right femoral artery and vein was achieved for the insertion of a pigtail catheter and pacing wire, respectively. Following cannulation of the apex, a 15-cm needle was used to perforate the centre of the AMVL near the annulus of A2 under TOE guidance (Fig. 1C and D). A soft guide wire was passed into the LA and exchanged for a stiff wire, which was sited within the pulmonary vein. A 26-mm balloon expandable SAPIEN 3 transcatheter valve (Edwards Lifesciences, Irvine, CA, USA) was then deployed through the AMVL (Fig. 1E) without prior balloon dilatation during rapid ventricular pacing, obliterating the AMVL between the ring and the introduced valve. There was no MR or LVOTO on completion. The patient was discharged the following day on standard medical therapy. Two months post-procedure mild MR was evident on echocardiography. Routine follow-up is ongoing. DISCUSSION This case presents a challenging situation in which an abnormal haematological response to heparin or inability to accurately document anticoagulation via calibrated metrics prevented the safe institution of CPB and surgical repair. It was recognized preoperatively that as a consequence of the large AMVL and AMA, this would pose a significant risk of LVOTO. For this reason, TMVI through the AMVL was considered. Through intraleaflet TMVI, we have demonstrated that the AMVL is anchored in place and, therefore, unable to obstruct the left ventricular outflow tract. In addition, protrusion into the LA following deployment of the valve was avoided, possibly by the deliberate decision to leave the subvalvular apparatus intact. This technique offers a possible solution for patients presenting with recurrent disease following MVr who are unsuitable for conventional re-repair or replacement and at high risk of LVOTO. The risks of the procedure include possible haemodynamic compromise while the anterior leaflet is perforated, hence the use of an IABP prophylactically, rupture of the AMVL with embolization of remnant tissue into the left ventricular outflow tract or protrusion into the left atrium. The longevity of this technique remains to be determined, particularly in relation to paravalvular leak. As patients desire for less invasive techniques, technology improves and an increasing population are unsuitable for conventional repair the utilization of transcatheter approaches will increase. The described technique offers a novel method to manage mitral valve disease in those at risk of LVOTO. Preprocedural planning is essential to identify risks on a case-by-case basis and ensure the most appropriate intervention is performed. ACKNOWLEDGEMENTS The authors thank Vinayak Bapat, Jaime Villaquiran and Linda Zacharkiw. Conflict of interest: none declared. REFERENCES 1 Bapat V , Pirone F , Kapetanakis S , Rajani R , Niederer S. Factors influencing left ventricular outflow tract obstruction following a mitral valve-in-valve or valve-in-ring procedure, part 1 . Catheter Cardiovasc Interv 2015 ; 86 : 747 – 60 . Google Scholar CrossRef Search ADS PubMed 2 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 : 2019 – 37 . Google Scholar CrossRef Search ADS PubMed © The Author(s) 2018. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved. This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model (https://academic.oup.com/journals/pages/about_us/legal/notices)
European Journal of Cardio-Thoracic Surgery – Oxford University Press
Published: Jun 2, 2018
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