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This Article Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Add to Personal Folders Download to citation manager Author home page(s): Vivek Rao Richard D. Weisel Tirone E. David Permission Requests Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Demirtas, M. M. Articles by David, T. E. Search for Related Content PubMed Articles by Demirtas, M. M. Articles by David, T. E.

Ann Thorac Surg 1997;63:600-601
© 1997 The Society of Thoracic Surgeons

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Correspondence

Prosthetic Mitral Valve Thrombosis After Replacement With Preservation of All Chordae

M. Murat Demirta, MD

Siyami Ersek Thoracic Cardiovascular Surgery Center, Ihlamurdere Cad 149/5, Beikta 80690, Istanbul, Turkey

To the Editor:

I read with great attention and interest the article by Rao and associates concerning represervation of the chordae tendineae during redo mitral valve replacement [1].

I congratulate them for their excellent work. I agree with Rao and associates that when the mitral valve apparatus is suitable, preservation of chordae tendineae seems to have beneficial effects on postoperative left ventricular performance, especially in mitral regurgitation and to a certain degree in mitral stenosis [2]. The effects of the natural subvalvular apparatus on the flow dynamics and thrombotic obstruction of the mechanical valves, however, have not been well documented.

Between 1993 and 1996, 53 patients with mitral valve disease underwent mitral valve replacement with complete chordal preservation in Siyami Ersek Thoracic and Cardiovascular Surgery Center, Turkey. In one of them, a 38-year-old woman, who was operated on for the implantation of a 29-mm Carbomedics prosthetic mitral valve on January 1994, prosthetic valve thrombosis developed on April 1996 despite well-established oral anticoagulation. She was in atrial fibrillation and her preoperative echocardiographic findings were as follows: left ventricular systolic diameter, 37 mm; left ventricular diastolic diameter, 53 mm; left atrial diameter, 50 mm; and pulmonary artery pressure, 38/10 mm Hg. Transprosthetic valvular gradient was 23 to 32 mm Hg. She was emergently reoperated on and a 29-mm Hancock bioprosthesis was implanted after resection of all subvalvular structures. The mechanical prosthetic valve was completely covered with thrombus and pannus, without any motion of the leaflets. She tolerated the operation well and was discharged on the 12th day with standard oral anticoagulation.

There is no reoperation related to thrombotic obstruction in the series by Rao and associates, but I would like to know what their policy would be if they found such a case. Is there any potential role of the subvalvular apparatus in the thrombotic obstruction of the mechanical valve, and do they think that represervation of all chordae may be justified in such a case?

The large and impressive experience of Rao and associates may certainly answer my questions.

References

1. Rao V, Komeda M, Weisel RD, et al. Results of represervation of the chordae tendineae during redo mitral valve replacement. Ann Thorac Surg 1996;62:179–83.
2. Alhan C, Kayaciolu I, Tayyareci G, et al. Comparative assessment of chordal preservation versus chordal resection in mitral valve replacement for mitral stenosis. J Heart Valve Dis 1995;4:453–9.

Reply

The Toronto Hospital, 200 Elizabeth St, Toronto, ON M5G 2C4, Canada

To the Editor:

We thank Dr Demirtas for his interest in our recent article concerning represervation of the chordae tendineae during redo mitral valve replacement [1]. In our series of 241 patients, 19 were reoperated on because of a thrombosed mechanical valve. Of these 19 patients, only 2 had preservation of the chordae tendineae at their initial operation. The thrombosis was not thought to be due to the retained subvalvular apparatus, and after excision of the thrombosed valve a new St. Jude Medical prosthesis was implanted with represervation of chordae tendineae in both patients.

Inadequate anticoagulation is usually the cause of valve thrombosis, but probably any interference with the motion of the leaflets of an artificial valve can be a predisposing factor. We use only biological or bileaflet mechanical valves for mitral valve replacement with preservation of the chordae tendineae. Bileaflet valves are oriented in antianatomic fashion, that is, the leaflets are perpendicular to the left ventricular outflow tract. It is extremely important that both leaflets move freely after implantation. Miki and associates [2] described a case of papillary muscle represervation in the setting of prosthetic valve thrombosis. In their patient, the bileaflet mechanical valve had been oriented in an anatomic position and the posterior leaflet was found to be thrombosed. At reoperation, a new bileaflet valve was implanted with represervation of the chordae tendineae and the valve oriented in an antianatomic position.

We believe that the beneficial effects of chordal preservation on left ventricular function [3] outweigh any incremental risk of valve thrombosis. In patients with abnormal leaflets, we excise the valve entirely and resuspend both papillary muscles with 4-0 sutures of expanded polytetrafluoroethylene [4].

References

1. Rao V, Komeda M, Weisel RD, et al. Results of represervation of the chordae tendineae during redo mitral valve replacement. Ann Thorac Surg 1996;62:179–83.
2. Miki S, Ueda Y, Tahata T, Okita Y. Mitral valve replacement with preservation of chordae tendineae and papillary muscles. Ann Thorac Surg 1995;60:225–6.
3. Komeda M, David TE, Rao V, Sun Z, Weisel RD, Burns RJ. Late hemodynamic effects of the preserved papillary muscles. Circulation 1994;90:190–4.
4. David TE. Papillary muscle-annular continuity: is it important? J Card Surg 1994;9(Suppl):252–4.

This Article Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Add to Personal Folders Download to citation manager Author home page(s): Vivek Rao Richard D. Weisel Tirone E. David Permission Requests Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Demirtas, M. M. Articles by David, T. E. Search for Related Content PubMed Articles by Demirtas, M. M. Articles by David, T. E.