Ultrasound imaging for stereotactic evacuation of hypertension-associated intracerebral hematomas with aqua-stream and aspiration.

Stereotactic aqua-stream and aspiration (SASA) has been used for the evacuation of intracerebral hematomas. The authors have introduced ultrasound imaging (US) to monitor the evacuations of the hematoma during the surgical procedure. Hematomas were reproduced in an agar hematoma model which showed that if air collected in the hematoma cavity, it produced a strong artifact, and the hematoma could not be monitored. In the clinical trial, hematomas were visualized, and the surgical procedures were monitored in real time. The needle of the SASA and the air that collected in the hematoma cavity produced only weak artifacts, and the SASA water jet showed as a hyperechoic region on US, so that the procedure could be monitored in real time. In all cases, the average amount of evacuated hematoma exceeded 92%, as calculated from the preoperative and postoperative computed tomography images. The level of consciousness improved from a preoperative level of 1-20 (Japan Coma Scale) to 0-3 postoperatively. The addition of US monitoring to computed tomography guided stereotactic evacuation of hematomas with SASA enabled hypertension-associated intracranial hematomas to be evacuated more safely and more completely than has been achieved hitherto.