Deep hypothermic circulatory arrest for hemiarch replacement in a pediatric patient with moyamoya disease

Moyamoya disease is a chronic cerebrovascular occlusive disease, occurring predominantly in young populations, that causes cerebral ischemia and hemorrhage. Patients with moyamoya disease are at high risk of neurological complications during cardiac surgery because of perioperative hemodynamic changes. However, there is no established evidence on temperature management during cardiopulmonary bypass. Previous reports described normothermia or mild to moderate hypothermia during cardiopulmonary bypass in patients with moyamoya disease; however, surgical conditions, such as not having enough space to clamp the aorta or a clean surgical field, sometimes force us to use deep hypothermic circuratory arrest. We report a successful case of a pediatric patient with moyamoya disease who underwent deep hypothermic circulatory arrest (18 °C) for hemiarch replacement without neurological complications. Deep hypothermia may be an alternative technique for achieving cerebral protection in the context of moyamoya disease.