Ommaya reservoir
Pronunciation: oh-MY-ah
An implanted ventricular access device consisting of a catheter and subcutaneous dome, used for CSF sampling and intrathecal drug delivery.
Full Definition
An Ommaya reservoir is a surgically implanted ventricular access system consisting of a silastic catheter placed in the lateral ventricle connected to a subcutaneous dome-shaped reservoir positioned under the scalp. Named after Pakistani-American neurosurgeon Ayub Ommaya, this device provides reliable access to the cerebrospinal fluid for repeated sampling, intrathecal chemotherapy administration, and CSF drainage. The reservoir can be accessed percutaneously through the scalp using a needle, eliminating the need for repeated lumbar punctures. Complications include infection, catheter malposition, and CSF leak, requiring careful patient selection and sterile technique during access.
Usage
Usage note: Capitalize as proper noun; specify purpose (chemotherapy, sampling) when documenting placement.
In Context
- "An Ommaya reservoir was placed for repeated intrathecal methotrexate administration." — neurosurgical operative report
- "CSF was aspirated from the Ommaya reservoir for cytological analysis." — oncology procedure note