[Case report of a saccular aneurysm of the thoracic aorta in childhood].

A five-year-old boy with a large saccular aneurysm of the thoracic descending aorta extending rightward in the mediastinum underwent operation. Through a left thoracotomy descending aorta was clamped during partial femoro-femoral bypass and a examination of somatosensory evoked potential of the spinal cord. Placing a vertical incision on the aorta, a orifice of the aneurysm was closed with a xenograft pericardial patch. The aneurysm was left untouched. Nine months after operation the aneurysm was not recognized on chest X-ray and computed tomography. Etiology was unknown.