Bedside Sonographic Ventricular Monitoring Through a Sonolucent Cranial Implant for Weaning of External Ventricular Drain After Aneurysmal Subarachnoid Hemorrhage.

Abstract

Background and objectives: The development of sonolucent cranial implants has led to the possibility of sonographic visualization of intracranial structures. The use of ultrasound instead of computed tomography imaging for ventricular monitoring during external ventricular drain (EVD) weaning has not yet been described. This study aims to describe the feasibility of bedside sonographic ventricular monitoring for EVD weaning after aneurysmal subarachnoid hemorrhage and to report our preliminary clinical experience.

Methods: A 24-mm sonolucent cranial implant was incorporated in the bone flap after clipping of a ruptured aneurysm. Baseline sonographic measurements of ventricular size were obtained with the EVD set at 10 cm. After raising the EVD to 15 cm for 24 hours, a second sonographic assessment was performed. If ventricular size, intracranial pressure and the examination remained stable, the EVD was clamped. A third sonographic assessment was conducted 24 hours after clamping. If ventricular size, intracranial pressure, and the examination remained stable, the EVD was removed. A fourth sonographic assessment was performed 24 hours after removal, with 1 final assessment before discharge of the patient.

Results: A total of 6 patients underwent the placement of an EVD, surgical clipping, and sonographic weaning of the EVD. Adequate sonographic visualization of the ventricles for EVD weaning was obtained in all 6 patients. Sonographic increase in ventricular size, accompanied by clinical deterioration, was observed in 3 patients, leading to the decision to place a ventriculoperitoneal shunt. There were no instances of missed ventricular enlargement nor postoperative infection or need for revision within the mean follow-up period of 6 weeks.

Conclusion: Bedside sonographic ventricular monitoring through a sonolucent cranial implant represents a new and valid method for weaning of EVD after aneurysmal subarachnoid hemorrhage. Using ultrasound instead of computed tomography offers several advantages, including enhanced safety by avoiding intrahospital transport, reduced costs, and elimination of radiation exposure.