Ann Thorac Surg 2005;80:2291-2292
© 2005 The Society of Thoracic Surgeons
Original article: Cardiovascular
Invited commentary
Fernando A. Atik, MD,
Gosta B. Pettersson, MD, PhD
Department of Thoracic and Cardiovascular Surgery, The Cleveland Clinic Foundation, 9500 Euclid Ave/H35, Cleveland, OH44195
(Email: atikf{at}ccf.org).
The article by Horer and colleagues [1] addresses the issue of total correction of tetralogy of Fallot (TOF) in adult patients. A few TOF patients remain undiagnosed into adulthood and another subset escape repair for different reasons, some after previous palliative procedures, which is true for more than one third of Horer and colleagues' [1] patients, usually more than a decade before the total correction.
It seems that operative mortality is higher, and long-term outcomes are worse after adulthood repair compared with repairs in infancy. How different is the correction in adults? Why should we expect a higher risk in those patients? Prolonged cyanosis causes myocardial and other organ dysfunction. The heart is chronically volume overloaded, especially in the presence of previous palliative procedures and aortopulmonary collaterals. Chronic cyanosis may predispose stroke, brain abscess, and endocarditis, and will certainly lead to erythrocytosis, one of the significant predictors of early death. Bleeding tendency is also important. These issues and the morphology transform this into a technically more demanding procedure. The noncompliant hypertrophic adult right ventricle seems to tolerate pulmonary valve regurgitation poorly, the second significant predictor of early mortality being the need for right ventricular outflow patch. Moreover, the intracardiac portion of the repair seems to be more difficult due to the modeling of the heart secondary to the uncorrected Fallot. The native pulmonary valve is of course preserved and repaired whenever possible, and the annulus size is adequate most of the time. All these factors should be taken into consideration for patient selection.
The next question that needs to be answered is whether the higher operative mortality is justified in terms of improving survival and quality of life. Although several studies have shown improvements in functional class, it would be interesting to see an objective confirmation with exercise tolerance tests. The question about improved survival is more difficult to answer. The most favorable anatomic forms of TOF with well balanced circulation at the same time constitute those with the most favorable natural history and lowest surgical risk. Those forms will probably have long-term survival after repair in comparison with an age-matched population, but that was not explored in this article. Reoperations are also determinants of additional risk and reduced quality of life. Arrhythmias (supraventricular or ventricular) are highly prevalent and responsible for many late deaths, although this was not deeply explored in this article. Close monitoring and expanded use of implantable pacemakers and defibrillators in patients with prolonged ventricular complex on electrocardiogram (QRS) and ventricular arrhythmia could reduce the risk of sudden death.
Are there any contraindications for surgery at this age? The article suggests that erythrocytosis is associated with multiorgan failure. The lack of statistical power in the presence of competing factors makes risk factor analysis uncertain, but there is no substitute for perfect preoperative workup in order to establish the conditions for a successful repair. Ventricular function data is missing in Horer and colleagues' [1] article, but there is some evidence that long-term survival can be influenced by impairment of left ventricular function, suggesting a subgroup with doubtful benefit after repair.
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References
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- Horer J, Friebe J, Schreiber C, et al. Correction of tetralogy of Fallot and of pulmonary atresia with ventricular septal defect in adults Ann Thorac Surg 2005;80:2285-2292.[Abstract/Free Full Text]
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