Indications for intracranial reservoirs: a six-year study

For patients with intracranial recurrent cysts, reservoir placement can offer symptomatic control at relatively low risk, allowing repeated outpatient aspiration. Predicting which patients will require repeated drainage is not always straightforward. The aim of this study was to examine a series of patients treated with reservoir system placement, and examine the factors that may be relevant to repeated drainage and morbidity.

We retrospectively reviewed all adult patients who had intracranial reservoir placement between 2005 and 2011 at a single neurosurgical centre. Information was gathered on the indications for placement, demographics, diagnosis, imaging, disease characteristics, complications and clinical outcome.

Forty-one adult patients had reservoir placement over the 6-year period, of which 31 had cystic lesions, 4 had hydrocephalus, and 6 were for intrathecal therapy. Of the 31 cystic lesions, 14 were high-grade gliomas, 6 craniopharyngiomas, 4 low-grade gliomas, 5 cystic metastases, 1 acoustic neuroma, and 1 arachnoid cyst. The 30 patients with malignant disease had 1-6 postoperative aspirations at a median of 290 days after surgery. In patients with hydrocephalus the reservoir was not used postoperatively. Eighty-three per cent of patients with cystic lesions who had recurrent aspirations (26/36) resulted in clinical improvement. For the three categories of cystic lesions with the most number of aspirations; 100% showed clinical improvement in low-grade lesions, 68.4% in high-grade lesions, and 66.7% in craniopharyngiomas. Four patients experienced complications, including reservoir malfunction (2), infection (1), and misplacement (1).

Intracranial reservoirs provide significant clinical improvement when used for recurrent aspiration in patients with cystic tumours. In particular, it is clear that ommaya reservoirs are of significant advantage in high-grade lesions, where the majority of patients undergo recurrent aspirations with clinical improvement.