Introduction

Abstract

This issue of Operative Techniques in Thoracic and Cardiovascular Surgery is dedicated to complex operations of the mitral valve. The authors of the topics contained in this volume are experienced mitral valve surgeons and describe their approaches to managing the various problems encountered in clinical practice. Doctor Cohn describes mitral valve surgery through a right thoracotomy, an alternate approach to the standard mediansternotomy. This technique is useful in patients with complex intrapericardial anatomy such as patent grafts that need not to be redone or in patients who had muscle flaps after mediastinitis following a mediansternotomy. Access to the ascending aorta may be difficult but not impossible if one needs to cross-clamp it. In addition, a submammary anterior thoracotomy may be cosmetically more attractive to women than a mediansternotomy if they need mitral valve surgery and have never had a sternotomy. Doctor Zacharias describes the operative management of a dreadful complication of mitral valve replacement, i.e., spontaneous rupture of the ventricular wall. I believe that the best approach for this problem is to place the patient on cardiopulmonary bypass, remove the prosthetic valve, and repair the ventricular tear from the inside of the heart. A generous patch of fresh autologous or glutaraldehyde-fixed bovine pericardium sutured to healthy endocardium around the defect guarantees hemostasis. It is, however, much simpler to prevent this problem than to deal with it, and this often can be accomplished by preserving the attachments between the papillary muscles and mitral annulus. If retention of the posterior leaflet and its chordae tendineae is not possible because of extensive calcification or infection, then resuspension of the papillary muscles to the mitral annulus and sewing ring of the prosthetic valve with expanded polytetrafluoroethylene sutures is equally effective. Doctor Gillinov reviews the techniques used to treat patients who have had previous mitral valve repair. Re-repair is usually feasible in patients with degenerative disease and a new ruptured or elongated chordae tendineae or when the problem was a technical error such as repairing the posterior leaflet but leaving an unrecognized prolapse of the anterior leaflet. Although it is not described in that article, chordal replacement with expanded polytetrafluoroethylene sutures, I believe, is the simplest method of correcting leaflet prolapse. Doctor Feindel describes techniques of reconstruction of the mitral annulus in patients with abscess. Although not as common as aortic root abscess, mitral annulus abscess is an even more serious problem. I firmly believe that the best chance to cure a mitral annulus abscess and give the patient a stable prosthetic mitral valve is by meticulous debridement of all necrotic and infected tissues and reconstruction of the mitral annulus with a generous, tension-free patch of fresh autologous pericardium. It is important that the prosthetic valve has no rocking motion after its implantation because the patch will either tear or become detached from the left ventricle. Another formidable problem in mitral valve surgery is the so-called “horseshoe” calcification of the mitral annulus. Doctor Smedira describes the various approaches we can use to secure a prosthetic valve in the left atrioventricular position in these patients. Although a complex operative procedure, it is feasible to detach the posterior leaflet, remove the calcium bar, reconstruct the mitral annulus, and repair the mitral valve in cases of degenerative disease. If replacement is necessary because of inadequate leaflets, then we prefer to take the calcium bar out and create a new mitral annulus of either autologous or heterologous pericardium. Doctor James L. Cox, the Editor of this journal, and I want to thank Drs. Cohn, Zacharias, Gillinov, Feindel, and Smedira for their excellent contributions to this issue of operative techniques.