Introduction: Skull-base location represents 20-30% of all intracranial meningiomas, being considered as a challenging region in terms of clinical symptoms, surgical accessibility, and complete resection achievement. Peritumoral edema may represent an important prognostic variable, which also has been attributed to surgical retraction.

Methods: A retrospective clinical records review of patients who underwent first-time surgical resection of meningioma (WHO grade 1) at Johns Hopkins Hospital between 2003 and 2015. DICOMS files from brain MRIs were analyzed with OSirix software. Volume measurements of the lesion and peritumoral brain edema were based on manual delineation assisted by a region-growing tool (Roi editor).

Results: 118 out of 1276 patients diagnosed with a single meningioma (WHO grade 1) were selected with location at the skull-base anterior midline and middle fossa, solely located in the olfactory groove (20.33%), planum sphenoidale (24.57%) and sellar region (39.83%). Median age was 54.66 years (IQR 47.25-63.48%), with a 73% of women. After the procedure, patients exhibit symptomatic recovery of seizures (68,42%), headaches (64,06%) and visual disturbances (41,52%). Besides, pre-operative tumor volume was 10.10 cm3 (IQR 3.77-28.40), achieving a median resection of 97.14%. Pre-operative, post-operative, 3-months follow-up and last follow-up (26.5 months) MRI showed peritumoral edema median volumes of 0.53 cm3 (IQR 0.00-29.72), 11.07 cm3 (IQR 2.31-37.65), 1.73 cm3 (IQR 0.00-5.46), and 1.23 cm3 (IQR 0.00-5.04) respectively. Brain retraction was performed for 66 (55.93%) patients. There were no significant differences among groups with and without retraction in regards to clinical outcomes and post-operative edema (p=0,050).

Conclusions: Following peritumoral brain edema volume through time may be a good strategy to assess recovery in patients; nonetheless, in this study, no statistical significance was not found for variables that may be associated with it. Further research using encephalomalacia volumetric measurements may be useful to address patients’ outcomes when retracting vs. non-retraction of the brain.

Patient Care: By addressing the clinical outcomes advantages and disadvantages of brain retraction during a resection of skull base lesions.

Learning Objectives: To characterize the pre- and post-operative clinical features of patients who underwent Meningioma’s resection. To measure peritumoral edema volumes based on pre-operative, post-operative, 3-months’ follow-up and last follow-up MRI. To identify significant clinical and neuroimaging differences among patients who require brain retraction, or not, during the procedure.

References: Chaichana et al.