Volume 8, Issue 1 , Pages 42-50, February 2003
Mitral valve replacement after late failure of mitral valve repair☆☆☆
Article Outline
Mitral valve repair is the preferred surgical treatment for mitral valve dysfunction. Although the feasibility of mitral valve repair extends to 95% of patients with degenerative valvular disease and up to 75% of patients with rheumatic or ischemic valvular disease, nearly all reports describe patients who have required reoperation for recurrent mitral valve dysfunction.1, 2, 3, 4, 5 Late reoperation after mitral valve repair is required in 5% to 10% of patients with degenerative disease and 25% to 50% of patients with rheumatic disease.1, 2, 3, 4, 5
Reoperation after mitral valve repair poses specific challenges related to choice of procedure and surgical technique. Should the dysfunctional valve, which has been repaired once, be re-repaired or replaced? Except for instances of recurrent, localized degenerative disease and early technical failure (eg, suture or ring dehiscence), we favor valve replacement. How should the valve be approached? Median sternotomy with left atriotomy is our preferred approach. However, alternative strategies are useful in particular situations. Right thoracotomy may be used when patent grafts are in danger at resternotomy, and an extended transseptal incision on the heart exposes the mitral valve in the setting of a small left atrium (less than 4 cm in maximal dimension).
1 Standard left atrial approach to the mitral valve. A median sternotomy has been performed, and the right side of the heart and aorta dissected. Venous cannulation is achieved via cannulae in the superior and inferior vena cavae. After commencing cardiopulmonary bypass, the left side of the heart is dissected to improve exposure of the mitral valve; alternatively, the left pleural space is opened, allowing the heart to fall to the left. The mitral valve is approached via a standard left atriotomy anterior to the pulmonary veins. Dissection of the interatrial groove further improves exposure, bringing the surgeon closer to the anterior mitral annulus. The atriotomy is extended beneath the superior and inferior vena cavae.
2 Extended transseptal approach to the mitral valve. The heart is approached via median sternotomy, the right side and aorta dissected, and standard bicaval venous cannulation performed. The superior vena cava is mobilized widely, and adhesions between the aorta and dome of the left atrium are cut. It is not necessary to dissect the left side of the heart when the transseptal approach is employed. (A) After the caval snares are tightened, a right atriotomy is constructed. A retrograde cardioplegia catheter is placed at this time. (B) The septum is incised, and this incision is carried onto the dome of the left atrium superiorly. The incision should not come too close to the aorta, as this complicates closure. (C) The septum and dome of the left atrium are retracted with stay sutures and hand-held retractors, exposing the mitral valve.
3 Chordal-sparing mitral valve replacement for recurrent degenerative disease. The previous operation included posterior leaflet quadrangular resection and annuloplasty. (A) Now there is extensive chordal rupture of the anterior leaflet, and valve replacement is chosen. (B) The annuloplasty band is removed and the previous repair is taken down. (C) An ellipse of anterior leaflet tissue is resected, preserving the free edge and its chordae. The remaining posterior leaflet and its chordae are preserved. Sutures are passed through the annulus and leaflet tissue, with the pledgets on the atrial side. If the annulus is not pliable, pledgets may be placed on the ventricular aspect. (D) Sutures are passed through the sewing ring of the prosthesis, and the valve is seated.
4 Mitral valve replacement after previous repair for rheumatic disease. (A) After previous repair for rheumatic mitral regurgitation, the valve has developed typical features of mitral stenosis. Such a valve should be replaced. (B) The annuloplasty band is removed. Where possible, the subvalvular apparatus is preserved. Often, severe thickening of the subvalvular apparatus and calcification of the leaflets and annulus make resection necessary. In the pictured case, the free edge of the anterior leaflet can be preserved along with a portion of the posterior leaflet. Sutures are passed through the annulus and through remaining leaflet tissue, the pledgets positioned on the atrial side if the annulus is pliable or on the ventricular aspect if the annulus is very stiff. If the annulus is small, placement of pledgets on the ventricular side facilitates insertion of a prosthesis of adequate size. (C) The prosthesis is seated.
5 Mitral valve re-repair for recurrent degenerative disease. (A) The previous repair included posterior leaflet resection and annuloplasty. Now there is localized chordal rupture at the posterior leaflet, a situation favorable for re-repair. (B) The annuloplasty band is removed and a limited posterior leaflet resection is performed. (C) The annulus is plicated with a pledgetted suture and the leaflet edges reapproximated with running suture. (D) A new annuloplasty band is inserted.
Comments
Among 81 patients having reoperation for failed mitral alve repair, the most common causes of recurrent mitral valve dysfunction were procedure- and valve-related.4 Procedure-related failures represented technical errors, and with increased experience, have become infrequent. The most common cause of valve-related repair failure was progression of primary valve disease. This is a particular issue in patients with rheumatic etiology.
Before surgery, the precise mechanism of repair failure must be identified by echocardiography. Advanced age or a history of coronary artery disease mandate coronary angiography. If endocarditis is the cause of valve dysfunction, then antibiotics are started. In most patients, surgery can be performed electively.
Our preferred chest-wall incision is median sternotomy. This facilitates standard cannulation for cardiopulmonary bypass, excellent myocardial protection, coronary artery bypass grafting if necessary, and control of a patent internal thoracic artery graft. A right thoracotomy is used only in particular instances; these include a patent bypass graft at particular risk of injury with repeat sternotomy1 and very early reoperation (<6 months),2 at which time adhesions are particularly challenging. The right thoracotomy approach may be associated with postoperative low cardiac output syndrome, possibly related to inadequate myocardial protection.6
If the left atrium is large, then the mitral valve is approached via left atriotomy. If the left atrium is small or if the surgeon does not wish to dissect the left side of the heart, then an extended transseptal incision is employed.
In most instances, the valve is replaced. When possible, the subvalvular apparatus is preserved, although this may not be possible in patients with severe rheumatic disease. Occasionally patients with recurrent, localized degenerative disease can be treated by re-repair.
References
- Valve repair with Carpentier techniques: the second decade. J Thorac Cardiovasc Surg. 1990;99:990–1002
- Very long-term results (more than 20 years) of valve repair with Carpentier's techniques in nonrheumatic mitral valve insufficiency. Circulation. 2001;104(Suppl I):I8–I11
- Durability of mitral valve repair for degenerative disease. J Thorac Cardiovasc Surg. 1998;116:734–743
- Reoperation for failure of mitral valve repair. J Thorac Cardiovasc Surg. 1997;113:467–475
- Late results of mitral valve repairfor mitral regurgitation of the myxomatous valve. Ann Thorac Surg. 1993;56:7–14
- Mitral valve repair in redo cardiac surgery. J Card Surg. 2002;17:40–45
☆ Address reprint requests to A. Marc Gillinov, MD, Department of Thoracic and Cardiovascular Surgery, The Cleveland Clinic Foundation/F25, 9500 Euclid Avenue, Cleveland, OH 44195.
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© 2003 Published by Elsevier Inc.
Volume 8, Issue 1 , Pages 42-50, February 2003
