Asian Cardiovasc Thorac Ann 2001;9:356
© 2001 Asia Publishing EXchange Pte Ltd
Is It Time to Look for an Alternative?
A Thomas Pezzella, MD
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Department of Cardiac Surgery Good Samaritan Hospital 605 North 12th Street Mt. Vernon, IL 62864, USA
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I read with interest the editorial by Dr. Kabbani,1 who clearly outlined three approaches to mitral valve replace-ment in developing countries. He compared availability, ease of implantation, and durability. His emphasis on the thromboembolic complications of valve replacement and the difficulties with anticoagulation in the developing world are well known and accepted. There are, however, two other alternatives to consider: complex mitral valve repair, and the Deac procedure. The concept of the irreparable rheumatic mitral valve needs to be reassessed and debated. It is accepted that the actuarial freedom from reoperation following mitral valve repair ranges from 60% to 70% at 10 years, with the highest failure rates during the first 2 to 3 years, especially in the under 20-year-old age group.2,3 It may, however, be appropriate to accept a higher failure rate when one considers the higher morbidity and mortality of valve replacement requiring anticoagulation. Yet, economics and access may mitigate against the subsequent increased rate of re-operation in the repair group. The Deac procedure is an ingenious technique utilizing the patient's own pericardium.4 In 18 patients reported in 1995, autologous pericardium preserved with 0.7% glutaraldehyde solution was used to construct a mitral valve. Anecdotally, two patients at 6 and 8 years follow-up had a normally functioning mitral valve (oral communication, Radu Deac, MD, August 2000).
The pulmonary autograft mitral valve replacement ("top hat") championed by Kabbani clearly has merit. Two concerns are with the younger age group and a semilunar valve implanted in the mitral position. Kabbani's series is in adults with a mean follow-up of less than two years. Will the hemodynamics of a nonrigid supported semilunar valve in the mitral position be durable in a young population? Since autograft growth cannot occur because of fixation within the prosthetic conduit, will late stenosis occur?
Clearly, with over 400,000 deaths annually worldwide from rheumatic heart disease predominately involving the mitral valve apparatus, there is a need for a safe and durable operation for mitral valve disease. Mechanical valves, despite preservation of the native mitral valve apparatus, still have the attendant risks of endocarditis and thromboembolism. Point-of-care testing with inter-national normalized ratio monitoring may offer future help in that area. The bioprosthetic valve may be appropriate for childbearing females, yet chronic atrial fibrillation may still necessitate some degree of anticoagulation. A concomitant modified maze procedure may be helpful in that regard. The use of low-molecular-weight heparins during pregnancy may decrease the incidence of congenital anomalies and spontaneous abortion. Subsequent redo surgery in women after childbearing age may be appropriate, despite a higher operative risk.
This challenge will rise as more and more open-heart programs emerge in the developing countries. Un-fortunately, randomized prospective studies are difficult and in many cases prohibitive and unfeasible.
REFERENCES
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Kabbani SS. Is it time to look for an alternative? Asian Cardiovasc Thorac Ann
2001;9:79–81.[Free Full Text]
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Phan NV, Phuong PK, Vinh PN, Yen DTB, Trung DH, Hiep CT, et al. Mitral valvuloplasty with Carpentier'stechniques. Asian Cardiovasc Thorac Ann
1998;6: 158–61.[Abstract/Free Full Text]
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Choudhary SK, Talwar S, Dubey B, Chopra A, Saxena A, Kumar AS. Mitral valve repair in a predominantly rheumatic population: long-term results. Tex Heart Inst J
2001;28:8–15.[Medline]
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Deac RFP, Simionescu D, Deac D. New evolution in mitral physiology and surgery: mitral stentless pericardial valve. Ann Thorac Surg
1995;60:S433–8.
