| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Ann Thorac Surg 1997;64:1680-1681
© 1997 The Society of Thoracic Surgeons
Division of Cardiovascular-Thoracic Surgery, M/C 22, Children's Memorial Hospital, 2300 Children's Plaza, Chicago, IL 60614
Doctor Fukada and associates have reviewed their results with 10 patients (mean age, 38.9 years) who had bioprosthetic heart valves placed in the pulmonic position. The primary indication for pulmonary valve replacement was pulmonary insufficiency after tetralogy of Fallot repair. Aside from 1 patient who required reoperation for infective endocarditis and 1 patient who had pulmonary valve replacement at age 15 years, no bioprosthetic valve dysfunction has been observed on Doppler echocardiography during a mean follow-up of 5.5 years. The patients all had considerable improvement in their New York Heart Association functional class and a significant decrease in their right ventricular end-diastolic pressure (mean right ventricular end-diastolic pressure of 13.3 to 5.8 mm Hg). The mean diastolic transprosthetic pressure gradient was measured at 9.4 mm Hg, and Fukada and associates attribute the longevity of the bioprosthesis in the pulmonic position to this minimal hemodynamic stress.
The management of pulmonary insufficiency after repair of tetralogy of Fallot is controversial. The two key issues are indications for pulmonary valve replacement and the type of valve that should be inserted. These issues relate to the natural history of right ventricular dysfunction secondary to pulmonary insufficiency versus the operative risk and longevity of a prosthetic pulmonary valve. Some surgeons and cardiologists think that pulmonary valve replacement is almost never indicated and that pulmonary regurgitation is well tolerated by the right ventricle for long periods of time. At Children's Memorial Hospital, in contrast, we have long advocated the aggressive use of pulmonary valve replacement for certain patients with pulmonary insufficiency after tetralogy of Fallot repair [1]. Our indications for pulmonary valve replacement have been progressive cardiomegaly, hemodynamic evidence of right ventricular dilatation or dysfunction, and exercise intolerance [2]. In our series of pulmonary valve replacements, the operative mortality is 2% and the functional actuarial life at 10 years of the Carpentier-Edwards porcine bioprosthesis is 85%. Other institutional reviews have confirmed that pulmonary regurgitation reduces exercise capacity [3] and is associated with right ventricular enlargement [4], late arrhythmias, and sudden death [5]. This gathering tide of information regarding the long-term outlook for patients with significant pulmonary regurgitation would indicate that there is a clear role for pulmonary valve replacement in a subset of postoperative tetralogy of Fallot patients.
For these patients, surgical alternatives for pulmonary valve replacement include porcine bioprostheses, pericardial bioprostheses, mechanical valves, allografts, and polytetrafluorethylene or pericardial monocusps. Fukada and associates allude to the possible superiority of pulmonary and aortic allografts, but cite their unavailability in Japan as the reason for their conspicuous absence in this review. Lamberti and associates [6] reported on the midterm evaluation of cryopreserved homograft valves in the pulmonary position and concluded that longer follow-up is required to confirm the superiority of homograft versus heterograft valves. In that series, however, the pulmonary allografts clearly fared better than the aortic allografts. Mechanical valves in the pulmonary position are known to have a high incidence of early valve failure secondary to thrombosis [7]. Monocusps tend to work well in the immediate postoperative period, but the effective time of valve competence is limited [8]. From a technical standpoint, in a patient with a wide-open pulmonary outflow tract from a prior transannular patch, I find insertion of a porcine bioprosthesis more straightforward than implantation of a homograft. The bioprosthesis sits nicely in the outflow tract and supports itself. In fact, most of the pulmonary autografts described have been placed as a conduit between the right ventricle and pulmonary artery, not as a simple valve insertion. The contribution of Fukada and colleagues is to demonstrate the outstanding longevity of porcine bioprostheses when placed in the pulmonic position in adult patients. The fact that they did have one hospital death in the 10 patients reminds us to carefully assess and weigh the indications for pulmonary valve replacement versus the risk of valve insertion.
References
Related Article
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| ANN THORAC SURG | ASIAN CARDIOVASC THORAC ANN | EUR J CARDIOTHORAC SURG |
| J THORAC CARDIOVASC SURG | ICVTS | ALL CTSNet JOURNALS |
