[A Case of Undiagnosed Extra-adrenal Pheochromocytoma in an Adult Patient with Single Ventricle Circulation after the Bidirectional Glenn Operation].

We experienced a case of undiagnosed extra-adrenal pheochromocytoma in an adult patient with single ventricle circulation after the bidirectional Glenn operation. A 32-year-old woman was scheduled for open abdominal surgery for incidental retroperitoneal tumor. She had undergone the bidirectional Glenn operation for complex congenital heart disease consisting of double outlet right ventricle, ventricular septal defect, and pulmonary artery stenosis. She had not undergone the Fontan operation because of insufficient development of pulmonary circulation. Her physical status was New York Heart Association (NYHA) functional class II, and her oxygen saturation was 80% in room air. She reported no symptoms for the abdominal tumor preoperatively. The surgery was performed under general and epidural anesthesia. After induction of general anesthesia, she developed hypertension and tachycardia, and the manipulation of the tumor worsened them. Landiolol, a short acting beta blocker, and nicardipine were administrated. After the resection of the tumor, hypotension refractory to volume replacement emerged, and we administrated low dose noradrenaline. She was extubated in'the operating room and was transferred to the intensive care unit. The histopathological examination of the tumor revealed extra-adrenal pheochromocytoma (paraganglioma). Catecholamine release from pheochromocytoma can be dangerous in patients with single ventricular circulation because it may elevate pulmonary resistance and thereby decrease cardiac output. Thorough preoperative examination is desirable.