Intraventricular Medication with or without Ventricular Shunt for Leptomeningeal Metastases with Different Intracranial Pressure: A Single-Center, Large-Scale Retrospective Study.

Objective: To evaluate the efficacy and prognosis of intraventricular medication (IVM) administered via the reservoir of Ommaya or ventricular shunt (VS) system to control leptomeningeal metastases, with or without VS based on intracranial pressure, in combination with postoperative systemic therapy.

Methods: Between April 2021 and December 2022, 125 patients with leptomeningeal metastases were managed in our department who underwent Ommaya reservoir placement and/or VS and subsequently received IVM postoperatively. The extent of symptom amelioration and survival, as well as the determinants influencing prognosis, were evaluated. The 3-, 6-month, and 1-year survival rates and mOS of the patients were calculated by the Kaplan‒Meier method, and survival and prognostic analyses were performed using the log-rank test, one-way analysis of variance, and the Cox proportional hazards model.

Results: Symptoms were significantly alleviated among the 113 leptomeningeal metastases with intracranial hypertension who underwent VS placement. The median survival time of 112（89.6%）cases who received medication regularly was 9.0 months, and significantly prolonged by 2-4 months compared with that of other studies not involving IVM in the literature. Cox multifactorial analysis revealed that postoperative administration of IVM and the number of IVM times independently influenced the efficacy of leptomeningeal metastases treatment.

Conclusions: For leptomeningeal metastases, VS not only significantly alleviates symptoms caused by intracranial hypertension but also avoids sudden death for those with severe intracranial hypertension. However, VS placement only does not improve overall survival. IVMs controls effectively leptomeningeal metastases, significantly prolongs survival, enhances quality of life.