Sonographic monitoring of ventricle enlargement in posthemorrhagic hydrocephalus

Abstract

Intraventricular hemorrhage often leads to obstructive hydrocephalus, necessitating placement of extraventricular drainage to prevent increasing intracranial pressure and subsequent herniation. For clamping and removal of the drainage, repeated CT scans are required to rule out recurrent hydrocephalus. We performed a prospective observational study on the use of transcranial duplex sonography to monitor changes in width of the lateral ventricles during clamping as an alternative to CT. Patients with hydrocephalus after intracranial or subarachnoid hemorrhage were monitored by transcranial duplex sonography (TDS). Serial examinations were carried out before and directly after placement of extraventricular or lumbar drainage as well as every 12 hours until 48 hours after removal of all drainages. Clinicians were blinded for all ultrasound results. Receiver operating characteristic analysis and calculation of the positive and negative predictive values was used to identify the optimal cutoff point in increased ventricle width that best predicted reopening of the drainage by the clinician. Ninety-two attempts to clamp either lumbar or extraventricular drainage were monitored in 37 patients during a 1-year period. A cutoff value for increase of ventricular width of 5.5 mm yielded high sensitivity (100%) and specificity (83%) in combination with a 100% negative predictive value for reopening of the drainage. TDS can be used to monitor ventricular width in experienced neurologic intensive care units. Because of its noninvasive character and suitability for bedside use, it offers a valuable alternative to repeated CT scans.