Hydrocephalus in posterior fossa lesions: ventriculostomy and permanent shunt rates by diagnosis.

OBJECTIVES

The rate of ventriculostomy for acute hydrocephalus and progression to shunt-dependent chronic hydrocephalus in patients with posterior fossa lesions are not well known.

METHODS

We retrospectively reviewed 104 consecutive cases with posterior fossa lesions on admission to the University of Illinois Hospital from June 2002 to December 2005. We recorded the rate of ventriculostomy and permanent ventricular shunting, which were compared among etiologic groups, using chi-squared and Fisher's exact tests.

RESULTS

Overall, 35 patients had ventriculostomy for acute hydrocephalus and 16 had permanent shunting for shunt-dependent chronic hydrocephalus. Of those with primary posterior fossa intracranial hemorrhage (ICH) (42 cases), 19 (45%) required ventriculostomy, with five (26%) requiring subsequent permanent shunting; 13 patients had hematoma evacuation, with two having permanent shunting. Of those with cerebellar infarction (14 cases), four (29%) required ventriculostomy and one (25%) had a permanent shunt; two had a decompressive craniectomy. Of those with neoplasms (43 cases, 33 surgically resected), ten (23%) required ventriculostomy and nine (21%) required permanent shunting. In addition, two of the three cases with infectious processes required ventriculostomy and one required a permanent shunt. In-hospital mortality was 21% (9/42 cases) for patients with ICH, 14% (2/14 cases) for patients with infarction and 0% for all others.

DISCUSSION

Acute primary posterior fossa hemorrhage has the highest rate of ventriculostomy for acute hydrocephalus and highest inpatient mortality but a surprisingly low rate of permanent shunt-dependency. When hydrocephalus was caused by a neoplasm, there was a higher rate of permanent shunt placement.