Ann Thorac Surg 2006;81:242
© 2006 The Society of Thoracic Surgeons
Original article: Cardiovascular
Invited commentary
Ralph S. Mosca, MD
Department of Surgery, Columbia Presbyterian Medical Center, 3959 Broadway, CHN 274, New York, NY 10032
(Email: rm891{at}columbia.edu).
Managing neonates and young infants with critical aortic stenosis remains a significant clinical challenge. As with other perplexing lesions, there are multiple treatment options, each with their own proponents; open or closed surgical valvotomy, balloon valvotomy, and primary Ross-Konno procedure. All hope to provide palliation of left ventricular outflow tract obstruction, resuscitate the overworked left ventricle, and normalize cardiac output without producing significant aortic insufficiency.
Open surgical valvotomy affords the surgeon the best view of the valve and allows for debridement of abnormal cusps, mobilization of tethered leaflets, and creation of commissures along existing or crafted planes. Associated lesions can be treated further normalizing the circulation. However, this comes at the price of cardiopulmonary bypass and myocardial ischemia.
Interventional catheterization laboratory balloon valvotomy applies a radial force to the valve, causing it to tear along the lines of least resistance. It is less invasive, avoids cardiopulmonary bypass, and with the introduction of better vascular devices for small babies, the morbidity has improved.
Closed transventricular dilatation produces antegrade dilation likely with similar physical affects and results on the valve as the balloon valvotomy. When done without cardiopulmonary bypass, it requires manipulation of an often irritable myocardium. Although more invasive than balloon valvotomy, it allows the surgeon to deal with associated lesions and institute cardiopulmonary bypass if necessary.
The current article [1] is a nice review of the evolution of techniques to treat critical aortic stenosis. It spans more than 2 decades and deals with patients who have isolated, as well as complex aortic stenosis. The complexity of the anatomic substrate that makes up critical stenosis is stressed. The results show that closed transventricular dilatation is effective in enlarging the aortic valve orifice without producing an inordinate amount of aortic insufficiency. The mortality is era dependent and ranges from 17% to 29%. Morbidity remains substantial. Approximately 1 of 11 patients required extracorporeal membrane oxygenation support for either ischemia during the procedure or low cardiac output after the procedure. Surgeons should keep this technique in their armamentarium to deal with aortic valve stenosis associated with other congenital lesions as well. For example, aortic valve dilatation can also be performed through a large ventricular septal defect if present.
The authors state that patients with severe aortic annular hypoplasia and low ejection fraction are not good candidates for valvotomy [1]. We must also add those with true hypoplasia of the left heart complex to this group. However, delineating these borderline patients can be challenging. Several of the patients in the current series either underwent cardiac transplant or had progressive pulmonary hypertension develop as a result of inadequate left heart structures. Our next challenge is to develop and evaluate criteria for judging left heart adequacy with measurements such as those set forth in the current study [1] and in the recent review by the Congenital Heart Surgeons Society [2].
Finally, all techniques of aortic valve dilatation should be compared with an evaluation of the longevity of the palliation they afford and the physiologic shape of the ventricle (systolic and diastolic function) at the time of eventual aortic valve replacement. In turn, these should be compared with the intermediate and long-term results of primary neonatal and infant Ross procedures.
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References
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- Brown JW, Ruzmetov M, Vijay P, Rodefeld MD, Turrentine MW. Closed transventricular aortic valvotomy for critical aortic stenosis in neonatesoutcomes, risk factors, and reoperations. Ann Thorac Surg 2006;81:236-242.[Abstract/Free Full Text]
- Lofland GK, McCrindle BW, Williams WG, et al. Critical aortic stenosis in the neonate: a multi-institutional study of management, outcomes, and risk factorsCongenital Heart Surgeons Society. J Thorac Cardiovasc Surg 2001;121:10-27.
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