The Ommaya device is commonly used during intraventricular therapy. However, the superiority of intraventricular or intralumbar therapies for intrathecal administration is disputable. Here, we report the case of a 63-year-old woman who received intraventricular chemotherapy for breast cancer with progression and leptomeningeal metastases. We describe external ventricular port device implantation to establish a modified intraventricular route to replace the traditional Ommaya device.