Postcardiotomy Mechanical Circulatory Support in Two Infants with Williams’ Syndrome

Supravalvar aortic stenosis (SVAS) in patients with Williams’ syndrome is often accompanied by coronary, pulmonary, and even myocardial lesions and therefore associated with increased perioperative morbidity and mortality. Extracorporeal membrane oxygenation (ECMO) provides reliable short-term mechanical circulatory support to patients, especially young, in acute postoperative cardiac failure when conventional means are ineffective. The incorporation of centrifugal pumps in these systems has made their use more efficient and less traumatic. We describe our experience of using the Levitronix CentriMag pump in two patients with Williams' syndrome who underwent surgical correction of supravalvular aortic stenosis. 1. Introduction Supravalvar aortic stenosis (SVAS) is commonly found in patients with Williams’ syndrome. The association of SVAS and pulmonary artery stenosis with mental retardation and distinctive facial features is known as the Williams-Beuren syndrome [1, 2]. Prominent feature is the diseased media of the ascending aorta, which also may affect the coronary arteries as well as the pulmonary vasculature, causing stenoses. Although there is supporting evidence of a genetic defect in elastin, it is also true that the disease affects all layers of the major vessels along with other parts of the cardiovascular system, including the cardiac valves, the myocardium, and the peripheral vessels [3–5]. Although low cardiac output is not uncommon following surgery for congenital heart disease in the paediatric population, conventional methods of treatment prove that efficient and postcardiotomy mechanical support is, therefore, rarely required. Extracorporeal membrane oxygenation (ECMO) constitutes an effective and essentially the only available short-term circulatory support for acute postoperative severe cardiopulmonary failure in the paediatric population following cardiac surgery. Nonetheless, it has been associated with increased risk of complications including bleeding, thromboembolism, plasma leakage, and infection [6, 7]. 2. Case Report 2.1. Case I An 8-month-old boy with Williams’ syndrome and supravalvular aortic stenosis was admitted to our department for surgical treatment. Repair was achieved by extended aortoplasty with incision of noncoronary and right coronary sinuses and implantation of an inverted Y-shaped Dacron patch. Failure to wean from cardiopulmonary bypass (CPB) due to postcardiotomy cardiac failure resulted in the institution of extracorporeal membrane oxygenation (ECMO). Reexploration for bleeding was required the first day.