Analysis of Approaches in the Microsurgical Treatment of 102 Cases of Petroclival Meningioma in a Single Center

Comparison of the efficacy in improving trigeminal neuralgia in petroclival meningioma between microsurgery and radiosurgery: a meta-analysis

The purpose of this study was to systematically review studies in the literature to assess the superiority between microsurgery and radiosurgery regarding the efficacy in improving petroclival meningioma (PCM)-related trigeminal neuralgia (TN). PubMed, Embase, Web of Science, and Cochrane clinical trial databases were systematically searched from the inception until December 08, 2022. The overall proportion of patients with improved TN after treatment in all six included studies was 56% (95% confidence interval [CI], 35-76.9%). Higgins I2 statistics showed significant heterogeneity (I2 = 90%). Subgroup analysis showed that the proportion of improved TN was higher in the microsurgery group than that in the radiosurgery group (89%; 95% CI, 81-96.5% vs. 37%, 95% CI, 22-52.7%, respectively, p < 0.01). Subgroup analysis (for studies that documented the number of posttreatment Barrow Neurological Institute scores 1 and 2) revealed that the proportion of pain-free without medication after treatment was higher in the microsurgery group than that in the radiosurgery group (90.7%; 95% CI, 81-99.7% vs. 34.5%, 95% CI, 21.3-47.7.7%, respectively, p < 0.01). Based on the results of this meta-analysis, we concluded that microsurgery is superior to radiosurgery in controlling PCM-related TN.

Quantitative Anatomical Comparison of Surgical Approaches to Meckel's Cave

BACKGROUND

Meckel's cave is a challenging surgical target due to its deep location and proximity to vital neurovascular structures. Surgeons have developed various microsurgical transcranial approaches (MTAs) to access it, but there is no consensus on the best method. Newer endoscopic approaches have also emerged. This study seeks to quantitatively compare these surgical approaches to Meckel's cave, offering insights into surgical volumes and exposure areas.

METHODS

Fifteen surgical approaches were performed bilaterally in six specimens, including the pterional approach (PTA), fronto-temporal-orbito-zygomatic approach (FTOZA), subtemporal approach (STA), Kawase approach (KWA), retrosigmoid approach (RSA), retrosigmoid approach with suprameatal extension (RSAS), endoscopic endonasal transpterygoid approach (EETPA), inferolateral transorbital approach (ILTEA) and superior eyelid approach (SEYA). All the MTAs were performed both with 10 mm and 15 mm of brain retraction, to consider different percentages of surface exposure. A dedicated navigation system was used to quantify the surgical working volumes and exposure of different areas of Meckel's cave (ApproachViewer, part of GTx-Eyes II, University Health Network, Toronto, Canada). Microsurgical transcranial approaches were quantified with two different degrees of brain retraction (10 mm and 15 mm). Statistical analysis was performed using a mixed linear model with bootstrap resampling.

RESULTS

The RSAS with 15 mm of retraction offered the maximum exposure of the trigeminal stem (TS). If compared to the KWA, the RSA exposed more of the TS (69% vs. 46%; p = 0.01). The EETPA and ILTEA exposed the Gasserian ganglion (GG) mainly in the anteromedial portion, but with a significant 20% gain in exposure provided by the EETPA compared to ILTEA (42% vs. 22%; p = 0.06). The STA with 15 mm of retraction offered the maximum exposure of the GG, with a significant gain in exposure compared to the STA with 10 mm of retraction (50% vs. 35%; p = 0.03). The medial part of the three trigeminal branches was mainly exposed by the EETPA, particularly for the ophthalmic (66%) and maxillary (83%) nerves. The EETPA offered the maximum exposure of the medial part of the mandibular nerve, with a significant gain in exposure compared to the ILTEA (42% vs. 11%; p = 0.01) and the SEY (42% vs. 2%; p = 0.01). The FTOZA offered the maximum exposure of the lateral part of the ophthalmic nerve, with a significant gain of 67% (p = 0.03) and 48% (p = 0.04) in exposure compared to the PTA and STA, respectively. The STA with 15 mm of retraction offered the maximum exposure of the lateral part of the maxillary nerve, with a significant gain in exposure compared to the STA with 10 mm of retraction (58% vs. 45%; p = 0.04). The STA with 15 mm of retraction provided a significant exposure gain of 23% for the lateral part of the mandibular nerve compared to FTOZA with 15 mm of retraction (p = 0.03).

CONCLUSIONS

The endoscopic approaches, through the endonasal and transorbital routes, can provide adequate exposure of Meckel's cave, especially for its more medial portions, bypassing the impediment of major neurovascular structures and significant brain retraction. As far as the most lateral portion of Meckel's cave, MTA approaches still seem to be the gold standard in obtaining optimal exposure and adequate surgical volumes.

Surgical Treatment and Clinical Outcomes of Petroclival Meningiomas: A Single-Center Experience of 107 Patients

Objective

This study aimed to establish optimal surgical strategies via reviewing the clinical outcomes of various surgical approaches for the pertroclival meningiomas (PCMs).

Methods

This retrospective study enrolled 107 patients with PCMs at the authors’ institution from year 2010 to 2020. Patient demographics, the clinical characteristics, various operative approaches, major morbidity, post-operative cranial nerve deficits and tumor progression or recurrence were analyzed.

Results

The subtemporal transtentorial approach (STA), the Kawase approach (KA), the retrosigmoid approach (RSA) and the anterior sigmoid approach (ASA), namely the posterior petrosal approach (PPA) were adopted for 17 cases, 22 cases, 31 cases and 34 cases respectively. Total or subtotal resection was achieved in 96 cases (89.7%). The incidence of new-onset and aggravated cranial nerve dysfunction were 13.1% (14/107) and 10.4% (15/144), respectively. Furthermore, 14 cases suffered from intracranial infection, 9 cases had cerebrospinal fluid leakage, and 3 cases sustained intracranial hematoma (1 case underwent second operation). The mean preoperative and postoperative Karnofsky Performance Status (KPS) score was 80 (range 60-100) and 78.6 (range 0-100), but this was not statistically significant (P>0.05). After a mean follow-up of 5.1 years (range 0.3- 10.6 years), tumor progression or recurrence was confirmed in 23 cases. Two cases died from postoperative complications.

Conclusions

For the treatment of PCMs, it is still a challenge to achieve total resection. With elaborate surgical plans and advanced microsurgical skills, most patients with PCMs can be rendered tumor resection with satisfactory extent and functional preservation, despite transient neurological deterioration during early postoperative periods.