Neuro-Oncology, 2017, Vol. 19(suppl6), pp.vi132-vi132
Preoperative embolization of radiographically suspected meningiomas is often performed to facilitate subsequent tumor resection. Its effects on the post-operative course have not been studied in detail and randomized trials are lacking. To gain insight into the role of tumor embolization, we conducted a retrospective study in all patients undergoing resection of an intracranial meningioma at the University Hospital Zurich 2000-2013 with a post-operative follow-up of at least 3 months (N=741). Patients were reviewed for the inclusion of pre-operative embolization in the management strategy. Annotations included demographics, radiographic, surgical, histological and hematological parameters, cardiovascular risk factors, pre- and postoperative neurological function and genome-wide methylation-based classification. Binary regression and Cox proportional hazards models were applied to determine factors associated with outcome. Pre-operative embolization was performed in 337 patients (42%). The decision for embolization was associated with larger tumor size and presence of peritumoral edema. On multivariate analyses controlling for established prognostic factors, pre-operative embolization was associated with inferior post-operative neurological outcome (odds ratio [OR] 1.85, 95% confidence interval [CI] 1.30-2.63), whereas gross total resection was associated with better neurological outcome (OR 0.59, 95% CI 0.39-0.87). Cardiovascular events after surgery comprised mostly deep vein thrombosis (N=39) and pulmonary embolisms (N=64). There were also associations with embolization (OR 2.38, 95% CI 1.37-4.00) and female gender (OR 2.18, 95% CI 1.17-4.08). Recurrence-free survival (RFS) of embolized patients was less favorable among patients with WHO grade II or grade III meningiomas (median RFS: 4.3 versus 7.0 years, multivariate hazard ratio [HR] 1.92, 95% CI 0.97-3.79, p=0.062) or in patients with intermediate or malignant gene methylation subtype meningiomas (median RFS: 2.0 versus 8.2 years, multivariate HR 8.66, 95% CI 3.00-25.05, p〈0.001). Pre-operative meningioma embolization may cause adverse surgical outcomes. Randomized trials to determine benefit-risk ratios are warranted to clarify the role of pre-operative embolization for meningioma surgery.
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