Preoperative embolization versus no embolization for WHO grade I intracranial meningioma: a retrospective matched cohort study

Abstract

<jats:sec><jats:title>OBJECTIVE</jats:title><jats:p>The controversy continues over the clinical utility of preoperative embolization for reducing tumor vascularity of intracranial meningiomas prior to resection. Previous studies comparing embolization and nonembolization patients have not controlled for detailed tumor parameters before assessing outcomes.</jats:p></jats:sec><jats:sec><jats:title>METHODS</jats:title><jats:p>The authors reviewed the cases of all patients who underwent resection of a WHO grade I intracranial meningioma at their institution from 2008 to 2016. Propensity score matching was used to generate embolization and nonembolization cohorts of 52 patients each, and a retrospective review of clinical and radiological outcomes was performed.</jats:p></jats:sec><jats:sec><jats:title>RESULTS</jats:title><jats:p>In total, 52 consecutive patients who underwent embolization (mean follow-up 34.8 ± 31.5 months) were compared to 52 patients who did not undergo embolization (mean follow-up 32.8 ± 28.7 months; p = 0.63). Variables controlled for included patient age (p = 0.82), tumor laterality (p &gt; 0.99), tumor location (p &gt; 0.99), tumor diameter (p = 0.07), tumor invasion into a major dural sinus (p &gt; 0.99), and tumor encasement around the internal carotid artery or middle cerebral artery (p &gt; 0.99). The embolization and nonembolization cohorts did not differ in terms of estimated blood loss during surgery (660.4 ± 637.1 ml vs 509.2 ± 422.0 ml; p = 0.17), Simpson grade IV resection (32.7% vs 25.0%; p = 0.39), perioperative procedural complications (26.9% vs 19.2%; p = 0.35), development of permanent new neurological deficits (5.8% vs 7.7%; p = 0.70), or favorable modified Rankin Scale (mRS) score (a score of 0–2) at last follow-up (96.0% vs 92.3%; p = 0.43), respectively. When comparing the final mRS score to the preoperative mRS score, patients in the embolization group were more likely than patients in the nonembolization group to have an improvement in mRS score (50.0% vs 28.8%; p = 0.03).</jats:p></jats:sec><jats:sec><jats:title>CONCLUSIONS</jats:title><jats:p>After controlling for patient age, tumor size, tumor laterality, tumor location, tumor invasion into a major dural sinus, and tumor encasement of the internal carotid artery or middle cerebral artery, preoperative meningioma embolization intended to decrease tumor vascularity did not improve the surgical outcomes of patients with WHO grade I intracranial meningiomas, but it did lead to a greater chance of clinical improvement compared to patients not treated with embolization.</jats:p></jats:sec>

Clinical Outcomes and Complications of Preoperative Embolization for Intracranial Giant Meningioma Tumorectomy: A Retrospective, Observational, Matched Cohort Study

“…Our data showed that preoperative embolization could significantly reduce the rate of surgical complication and the possibilities of mRS decline, which were distinct from others (7,12). Sensory and motor function deficits were the majority of postsurgical complications and contribute to degrees of daily life disabilities, as shown in Tables 3 and 4.…”

“…Specifically, the maximum tumor diameter, which differs significantly between groups in the original unmatched dataset (p < 0.0001), reached a statistical intergroup balance after matching (p = 0.69). Such bias also exists in other studies (7,12), which may indicate surgeons' preferences to embolize potential risky meningiomas. The rationales of preoperative embolization include the reduction of intraoperative blood loss and softening of the tumor mass to ease surgical operation and reduce surgery duration.…”

“…It is noteworthy that most previous studies were conducted in a manner to enroll consecutive meningioma patients in their institute, without controlling possible patient- and tumor-related confounds ( 10 , 12 ). It may result in heterogeneity between groups and limits the interpretation of their results.…”

“…Przybylowski et al. firstly introduced retrospective cohort matching to control critical confounds between embolization and nonembolization groups to yield more convincing interpretation of comparisons ( 12 ). Their results indicated that preoperative embolization did not alter the surgical outcomes of patients but could lead to a greater chance of improving functional outcomes.…”

“…As only WHO grade I meningiomas, which are generally less aggressive and complicated than WHO grades II and III meningiomas, are enrolled in this study, that limits generalizability of interpretation. Furthermore, their results demonstrate that embolization is found to lead to a greater chance of clinical improvement ( 12 ).…”