Haemodynamic improvement of older, previously replaced mechanical mitral valves by removal of the subvalvular pannus in redo cardiac surgery

CASE REPORT – ADULT CARDIAC Interactive CardioVascular and Thoracic Surgery 24 (2017) 148–149 doi:10.1093/icvts/ivw276 Advance Access publication 1 September 2016 Cite this article as: Kim JH, Kim TY, Choi JB, Kuh JH. Haemodynamic improvement of older, previously replaced mechanical mitral valves by removal of the subvalvular pannus in redo cardiac surgery. Interact CardioVasc Thorac Surg 2017;24:148–9. Haemodynamic improvement of older, previously replaced mechanical mitral valves by removal of the subvalvular pannus in redo cardiac surgery Jong Hun Kima,b, Tae Youn Kima, Jong Bum Choia,b,* and Ja Hong Kuha,b a b Department of Thoracic and Cardiovascular Surgery, Chonbuk National University Medical School, Jeonju, Chonbuk, Republic of Korea Research Institute of Clinical Medicine of Chonbuk National University and Biomedical Research Institute of Chonbuk National University Hospital, Jeonju, Chonbuk, Republic of Korea * Corresponding author. Department of Thoracic and Cardiovascular Surgery, Chonbuk National University Medical School, 20 Geonji-Ro, Deokjin-Gu, Jeonju, Chonbuk 561-712, Republic of Korea. Tel: +82-63-2501486; e-mail: ( J.B. Choi). Received 16 April 2016; received in revised form 13 July 2016; accepted 20 July 2016 Abstract Patients requiring redo cardiac surgery for diseased heart valves other than mitral valves may show increased pressure gradients and reduced valve areas of previously placed mechanical mitral valves due to subvalvular pannus formation. We treated four women who had mechanical mitral valves inserted greater than or equal to 20 years earlier and who presented with circular pannus that protruded into the lower margin of the valve ring but did not impede leaflet motion. Pannus removal improved the haemodynamic function of the mitral valve. Keywords: Mitral valve • Subvalvular stenosis • Treatment After mechanical mitral valve replacement, other diseased heart valves may require surgery. Marked pannus may form along the upper and lower ring planes of previously placed mechanical mitral valves. Although the valve leaflet motion may not be impeded, the pannus may aggravate valve gradients and areas [1]. In redo cardiac surgery for other diseased heart valves, pannus removal from mechanical mitral valves may improve the valve haemodynamic function. subvalvular pannus inside the mitral valve ring was pushed from the atrial to ventricular side and removed through the aortic opening using small sinus forceps. In the patient who had tricuspid valve repair, pannus was removed through the previously replaced bileaflet mechanical aortic valve opening. Although 2 patients had normal mitral valve gradients, the marked pannus growth inside the mitral valve ring led to concern about possible valve malfunction. At 3–19 months after surgery, echocardiography showed that mitral valve areas increased 0.1–0.6 cm2 with decreased maximum and mean valve pressure gradients (Table 1). CASE REPORTS DISCUSSION Four women (age, 57–67 years) who had mechanical mitral valve replacement with posterior chordal preservation 20–29 years earlier underwent redo cardiac surgery to treat other diseased heart valves (Table 1). The older mitral valves worked well in all patients without any impaired bileaflet motion. Under moderate hypothermic cardiopulmonary bypass and cardioplegic cardiac arrest, pannus was removed from mechanical mitral valves through aortic valve openings and left atriotomies. Pannus evaluation was through the left atriotomy, which showed calcified circular pannus protruding 1.0–2.0 mm into the lower margin of the valve metal ring opening (Fig. 1) and less pannus present on the upper plane of the ring. In 3 patients who required aortic valve replacement, the aortic valve was removed and the Prosthetic mechanical valve dysfunction caused by valve thrombosis or pannus formation often requires mitral valve replacement [1, 2]. However, because mechanical valves have not substantially changed over the past two decades, pannus removal instead of valve replacement may be prudent to recover prosthetic mitral valve function [3]. Subvalvular pannus protruding into the valve opening may progressively grow into the valve opening, aggravating valve haemodynamics [4] or limiting leaflet motion [2–4]. For patients requiring redo surgery for valves other than the mitral valve, the older mechanical mitral valves that are hindered by pannus could be replaced. However, in patients requiring continuous anticoagulation, pannus removal alone can improve the valve haemodynamic INTRODUCTION © The Author 2016. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved. J.H. Kim et al. / Interactive CardioVascular and Thoracic Surgery 149 Table 1: Patient characteristics and echocardiographic findings before and after redo cardiac surgery Patient no. Sex/ Previous valve replacement Age Mo/Year Valve (years) 1 F/67 2/1987 2 F/64 6/1994 3 F/57 5/1991 4 F/66 1/1996 Follow-up Preop Max/Mean MVAa LAD PAP Stroke (mo) or MVGa (cm2) (mm) (mmHg) volume postop (mmHg) (ml) Redo valve surgery Mo/Year Valve MVR (St Jude 27 mm) 8/2014 AVR (St Jude 19 mm) MVR (St Jude 29 mm) 1/2015 MVR (St Jude 27 mm) 8/2015 AVR (St Jude 21 mm) MVR (Sorin 27 mm) 1/2016 Redo AVR (St Jude 19 mm) 19 AVR (St Jude 19 mm) TAP (MC3 ring 26 mm) TAP (MC3 ring 30 mm) AVR (St Jude 19 mm) TAP (MC3 30 mm) 14 8 3 Preop Postop Preop Postop Preop Postop Preop Postop 23/7 16/6 15/5 8/4 17/7 16/4 10/4 7/2 3.3 3.7 2.5 2.6 2.0 2.6 2.3 2.5 60 60 37 43 51 51 58 55 55 33 25 25 36 27 44 35 43 51 45 41 40 41 55 42 AVR: aortic valve replacement; LAD: left atrial dimension; MVA: mitral valve area; MVG: mitral valve gradient; MVR: mitral valve replacement; PAP: pulmonary artery pressure; Preop: preoperative; Postop: postoperative; TAP: tricuspid annuloplasty. Wilcoxon signed-rank test: P = 0.068 and 0.066 for pre- and postoperative MVG and MVA, and P = 0.125 for LAD. a function, reducing the possibility of future mechanical valve malfunction and the morbidity and mortality associated with redo mitral valve replacement. Funding Supported by funding from the Clinical Research of Chonbuk National University and the Biomedical Research Institute of Chonbuk National University Hospital. Conflict of interest: none declared. REFERENCES [1] Misawa Y. Valve-related complications after mechanical heart valve implantation. Surg Today 2015;45:1205–9. [2] Akay TH, Gultekin B, Ozkan S, Aslim E, Uguz E, Sezgin A et al. Mitral valve replacements in redo patients with previous mitral valve procedures: mid-term results and risk factors for survival. J Card Surg 2008;23:415–21. [3] Park B, Park PW, Park CK. Transaortic chordae and pannus removal without redo mitral valve replacement in prosthetic mitral valve malfunction. Eur J Cardiothorac Surg 2011;39:1057–8. [4] Smadi O, Hassan I, Pibarot P, Kadem L. Numerical and experimental investigations of (...truncated)