It is well known that Down's syndrome is a strong risk factor for mortality after Fontan operations. We performed two lung biopsies in a Down's syndrome patient who underwent staged Fontan operations. The pathological findings revealed severe pulmonary arterial hypertrophy and a quantitative real-time polymerase chain reaction revealed the overexpression of endothelin and a decline in the eNOS level at the Fontan operation. Although the preoperative hemodynamic studies revealed that all of the criteria for Fontan had been fulfilled, the patient died of acute cardiac insufficiency, 35 days after the Fontan operation.
Keywords: Down’s syndrome; Endothelial nitric oxide synthase; Endothelin system; Fontan circulation.