INNV-11. THE RISK OF HEMORRHAGE ASSOCIATED WITH THROMBOCYTOPENIA IN PATIENTS UNDERGOING OMMAYA RESERVOIR PLACEMENT FOR INTRATHECAL CHEMOTHERAPY: A SINGLE INSTITUTION RETROSPECTIVE ANALYSIS

Abstract

Abstract PURPOSE Ommaya reservoirs are frequently inserted in patients requiring regular delivery of intrathecal medications. The incidence of intracranial hemorrhage following insertion ranges from 1–3% and is typically associated with thrombocytopenia. However, the exact platelet count at which it is considered safe to insert an Ommaya reservoir has not been previously reported. The purpose of this study is to investigate the nature of the relationship between thrombocytopenia and post-operative hemorrhage following insertion of Ommaya reservoirs for intrathecal chemotherapy. METHODS Consecutive patients requiring insertion of an Ommaya reservoir were enrolled in the study with no minimum platelet count as an exclusion criterion. Patients data were retrospectively reviewed with thrombocytopenia defined as platelet count < 100,000. All thrombocytopenic patients received at least one unit of intraoperative platelet transfusion. Post-operative incidence of hemorrhage, determined through CT scan, was compared between the thrombocytopenic group and normal platelet group. RESULTS 53 patients were enrolled within the study with 23 patients determined to be thrombocytopenic at the time of insertion. Thrombocytopenic patients were found to have 18.6 times the odds of post-operative bleeding when compared to patients with normal platelet counts (p< 0.001). However, no patient in the thrombocytopenic group had a clinically significant bleed, defined as being symptomatic or requiring intervention. CONCLUSIONS Although thrombocytopenia increases the risk of post-operative hemorrhage associated with Ommaya reservoir placement, there is no increase in clinically significant bleeding. With concurrent platelet transfusion and use of neuronavigation, Ommaya reservoir may be safely placed in thrombocytopenic patients.