The initial treatment of hydrocephalus: an assessment of surgeons' preference between third ventriculostomy and shunt insertion.

Third ventriculostomy is an option for patients who have traditionally received a ventriculoperitoneal shunt. This study has been conducted to determine: 1. How common is third ventriculostomy as the initial treatment of hydrocephalus? 2. Does the frequency of third ventriculostomy vary among surgeons? 3. What factors influence surgeons' decision to choose third ventriculostomy? Surgeons completed a questionnaire addressing patient selection and technique factors. Nine case scenarios were reviewed by surgeons who were then asked to choose a ventriculoperitoneal shunt or a third ventriculostomy as the initial treatment. Forty-three responses were received. The proportion of new patients treated with third ventriculostomy varied widely (0%-100%, median 13%). This was not related to years in practice, type of training or presence of residents/fellows. Factors that increased the chance of a third ventriculostomy were triventricular hydrocephalus on CT/MR, isolated aqueduct stenosis, thin ballooned floor and tectal tumor. Factors that decreased the chance of a third ventriculostomy were dilated subarachnoid spaces, meningitis and head injury. The presence of myelomeningocele or age < 1 year were less likely to influence the choice of operation. Variation in the rate of third ventriculostomy as the first treatment for hydrocephalus is large. It is unlikely that this degree of variation can be explained by differences in patient populations. Further work to refine and disseminate the indications for third ventriculostomy is warranted.