Angiographic Features of Meningiomas Predicting Extent of Preoperative Embolization

Neurosurgery 95:1010–1025, 2024

Preoperative embolization is used as an endovascular adjunct to surgical resection of meningiomas. However, there is no standardized system to assess the efficacy or extent of embolization during the embolization procedure. We sought to establish a purely angiographic grading system to facilitate consistent reporting of the outcome of meningioma embolization and to characterize the anatomic and other features of meningiomas that predict the degree of devascularization achieved through preoperative embolization.

METHODS: We identified patients with meningiomas who underwent preoperative cerebral angiography and subsequent resection between 2015 and 2021. Demographic, clinical, and imaging data were collected in a research registry. We defined an angiographic devascularization grading scale as follows: grade 0 for no embolization, 1 for partial embolization, 2 for majority embolization, 3 for complete external carotid artery embolization, and 4 for complete embolization.

RESULTS: Eighty consecutive patients were included, 60 of whom underwent preoperative tumor embolization (20 underwent angiography with an intention to treat but ultimately not embolization). Embolized tumors were larger (59.0 vs 35.9 cc; P = .03). Gross total resection, length of stay, and complication rates did not differ among groups. The distribution of arterial feeders differed significantly across tumors in a location-specific manner. Both the tumor location and the identity of arterial feeders were predictive of the extent of embolization. Anterior midline meningiomas were associated with internal carotid (ophthalmic, ethmoidal) supply and lower devascularization grades (P = .03). Tumors fed by meningeal feeders (convexity, falcine, lateral sphenoid wing) were associated with higher devascularization grades (P < .01). The procedural complication rate for tumor embolization was 2.5%.

CONCLUSION: Angiographic outcomes can be graded to indicate the extent of tumor embolization. This system may facilitate consistency of reported angiographic results. In addition, arterial feeders vary in a manner predicted by tumor location, and these patterns correlate with typical degrees of devascularization achieved in those tumor locations.

A Review of Preoperative Embolization Effectiveness in Patients With Arteriovenous Malformations

Neurosurgery 94:129–139, 2024

Preoperative embolization of arteriovenous malformations (AVMs) remains controversial. This study sought to analyze the cost-effectiveness of preoperative embolization of AVMs.

METHODS: Patients who underwent AVM resection at a single institute (January 1, 2015—December 31, 2020) were analyzed. Patients with preoperative embolization (embolization cohort) were compared with those without preoperative embolization (nonembolization cohort). Cost-effectiveness score (CE) was the primary outcome of interest and was determined by dividing the total 1-year cost by effectiveness, which was derived from a validated preoperative to last follow-up change in the modified Rankin Scale utility score. A lower CE signifies a more cost-effective treatment strategy.

RESULTS: Of 188 patients, 88 (47%) underwent preoperative embolization. The mean (SD) total cost was higher in the embolization group than in the nonembolization group ($117 594 [$102 295] vs $84 348 [$82326]; P < .001). The mean (SD) CE was higher in the embolization cohort ($336476 [$1 303 842]) than in the nonembolization cohort ($100 237 [$246 255]; P < .001). Among patients with Spetzler-Martin (SM) grade I and II AVMs, the mean (SD) CE was higher in the embolization (n = 40) than in the nonembolization (n = 72) cohort ($164 950 [$348 286] vs $69 021 [$114 938]; P = .004). Among patients with SM grade III AVMs, the mean (SD) CE was lower in the embolization (n = 33) than in the nonembolization (n = 25) cohort ($151 577 [$219130] vs $189 195 [$446 335]; P = .006). The mean (SD) CE was not significantly different between cohorts among patients with higher-grade AVMs (embolization cohort [n = 3] vs nonembolization cohort [n = 15]: $503639 [$776 492] vs $2048 419 [$4 794 758]; P = .49). The mean CE for embolized SM grade III aneurysms was nonsignificant in the ruptured group; however, for the unruptured group, CE was significantly higher in the embolization cohort (n = 26; $160871 [$240 535]) relative to the nonembolization cohort (n = 15; $108152 [$166 446]) (P = .006).

CONCLUSION: Preoperative embolization was cost-effective for patients with SM grade III AVMs but not for patients with lower-grade AVMs.

Surgical complications and recurrence factors for asymptomatic meningiomas: a single‑center retrospective study

Acta Neurochirurgica (2023) 165:1345–1353

Observation is the first management option in asymptomatic meningiomas, but when an enlargement or mass effect is observed, surgery is indicated. This study is aimed at exploring risk factors for complications and recurrence after surgery for asymptomatic meningioma. We also examined the impact of preoperative tumor embolization, which is considered controversial.

Methods We retrospectively reviewed 109 patients with primary asymptomatic meningiomas surgically treated at our institute between April 2007 and March 2021. Patients who only had headaches as a nonspecific complaint were included in the asymptomatic group. Complications, time to recurrence, and Glasgow Outcome Scale (GOS) score were the endpoints of the study. Risk factors for complications and recurrence were explored. Moreover, the effect of the resection on nonspecific headaches was also explored.

Results The permanent postoperative complication rate related to the surgical procedure was 1.8%. Of the total, 107 patients (98.2%) with asymptomatic meningiomas who were surgically treated achieved a GOS score of 5 1 year after the operation. Preoperative headache was present in 31 patients and improved postoperatively in 21 patients. Multivariate analysis using the Cox proportional hazard model showed that preoperative tumor embolization with > 80% resolution of tumor staining (p < 0.001) was negatively related to recurrence, whereas age (p = 0.046) and Simpson grade IV resection (p = 0.041) were positively related to recurrence.

Conclusion Although surgery for asymptomatic meningiomas can, in many cases, be safe, it is not free of complications Thus, surgical intervention for asymptomatic meningiomas should be considered cautiously. However, more than half the patients with headaches showed improvement. Simpson grade IV resection cases should be assessed for recurrence, and preoperative tumor embolization might be effective in controlling recurrence.

Effects of Preoperative Embolization on Spetzler– Martin Grade I and II Arteriovenous Malformations

 

Neurosurgery 90:92–98, 2022

Cerebral arteriovenous malformations (AVMs) with low Spetzler–Martin grades (I and II) are associated with good neurological outcomes after microsurgical resection; however, the use of preoperative embolization for these lesions is controversial.

OBJECTIVE: To compare the neurological outcomes of preoperative embolization with no embolization in patients with low-grade AVMs.

METHODS: Patients with a Spetzler–Martin grade I or II AVM who underwent microsurgical resection during January 1, 1997, through December 31, 2019, were analyzed. Patients undergoing preoperative embolization were compared with patients not undergoing embolization. A propensity score was constructed from baseline characteristics and used to match intervention (embolization) and control (nonembolization) groups in a 1:1 ratio. The primary outcome was poor neurological status on last follow-up examination, defined as a modified Rankin Scale score >2 and a modified Rankin Scale score worse at follow-up than at the preoperative examination.

RESULTS: Of the 603 patients analyzed, 310 (51.4%) underwent preoperative embolization and 293 (48.6%) did not. Patients in the embolization cohort compared with those in the nonembolization cohort had a higher percentage of Spetzler–Martin grade II AVMs (71.6% vs 52.6%, P < .001) and a lower percentage of hemorrhage (41% vs 55%, P = .001). After propensity score matching, no differences were found between paired cohorts (each N = 203) for baseline characteristics with a significant reduction in absolute standardized mean differences. No significant differences were found in primary outcomes between treatment groups in the matched or unmatched cohorts.

CONCLUSION: Preoperative embolization of low-grade Spetzler–Martin AVMs is not associated with improved neurological outcomes after microsurgical resection.