A Retrospective Evaluation of the Retrosigmoidal Approach for Petroclival Meningioma Surgery and Prognostic Factors Affecting Clinical Outcome

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.

Combined petrosal approach: a systematic review and meta-analysis of surgical complications

Transpetrosal approaches are known to be associated with a significant risk of complications, including CSF leak, facial palsy, hearing impairment, venous injury, and/or temporal lobe injury. We aimed to evaluate the morbidity of the standard combined petrosal approach (CPA), defined as a combination of the posterior (retrolabyrinthine) and the anterior petrosal approach. We performed a systematic review and meta-analysis of articles reporting on clinical series of patients operated on for petroclival meningiomas through CPA. Studies that used the terminology "combined petrosal approach" without matching the aforementioned definition were excluded as well as clinical series that included less than 5 patients. A total of 8 studies were included involving 160 patients. The pooled complication rates were 3% (95% CI, 0.5-5.6) for CSF leak, 8.6% (95% CI, 4.1-13.2%) for facial palsy, 8.2% (95% CI, 3.9-12.6%) for hearing impairment, 2.8% (95% CI, 0.9-6.5%) for venous complications, and finally 4.8% (95%, 1.2-8.4%) for temporal lobe injury. Contrary to the general belief, CPA is associated with an acceptable rate of complications, especially when compared to alternative approaches to the petroclival area. In view of the major advantages like shorter trajectory, multiple angles of surgical attack, and early tumor devascularization, CPA remains an important tool in the armamentarium of the skull base surgeon.

Correlation of Surgical Outcomes of Petroclival Meningiomas with Clinicoradiologic Parameters and Molecular and Chromosomal Alterations

OBJECTIVE

To identify clinical, radiologic, intraoperative, histopathologic, and molecular factors that might affect the surgical outcome of petroclival meningiomas.

METHODS

Medical records of 53 cases of petroclival meningiomas operated from 2003 to 2021 were reviewed for clinicoradiologic and molecular factors that were correlated with extent of resection.

RESULTS

Modified Dolenc-Kawase anterior transpetrous rhomboid (44, 83.0%) was the most commonly used approach, followed by retrosigmoid (2, 3.8%) and combined (7, 13.2%) approaches. Hypointense tumors on T2-weighted magnetic resonance imaging (odds ratio [OR] 5.85; 95% confidence interval [CI] 1.70-20.41) and presence of brainstem edema (OR 4.53; 95% CI 1.36-15.12) were found to be significant factors increasing the likelihood of subtotal resection (STR; P = 0.004 and P = 0.011, respectively). In the presence of both tumor T2 hypointensity and brainstem edema, there was a significant increase in the likelihood of STR (P = 0.001; OR 25; 95% CI 3.52-177.48). Of the 16 cases for which molecular analysis was performed, no specimen was found to have pTERT, AKT-1 E17K, and SMO L412F and W535L mutations. All (100%) the patients harboring H3K27me3 loss and/or hemizygous CDKN2A deletion had cavernous sinus extension compared with 62.5% of patients without H3K27me3 loss and 72.7% with hemizygous CDKN2A retention. Similarly, hemizygous CDKN2A deletion and H3K27me3 loss were associated with an increase in the rate of brainstem edema from 27.3% to 60% and 25% to 50%, respectively.

CONCLUSIONS

T2 hypointense tumor and brainstem edema on preoperative imaging are significant predictors of STR. H3K27me3 loss and hemizygous CDKN2A deletion may be associated with cavernous sinus extension, suggesting their role in tumor spread.

Surgical management of skull base meningiomas and vestibular schwannomas

PURPOSE OF REVIEW

The aim of this study is to discuss surgical management of meningiomas and schwannomas of skull base.

RECENT FINDINGS

Meningiomas and schwannomas are typically benign neoplasm with a good prognosis after surgery. Patients should be treated individually related to several features: size and localization of tumor and its proximity with deep critical neurovascular structures, neurological status, age and comorbidity. Also, the widespread use of neuroimaging and the progressive and constant aging of the populations inevitably result in the increase of detection rate of incidental (asymptomatic) neoplasm.Nowadays, there are still controversies about the correct management strategy.

SUMMARY

Surgery represents the gold standard treatment, with the objective of gross total resection; however, it is not always feasible due to localization, encasement of neuro-vascular structure, invasion of cranial nerve and brain parenchyma. Stereotactic radiosurgery and radiation therapy are important to achieve a satisfactory functional outcome and tumor control in case of residue or recurrence. A multidisciplinary approach is pivotal.

Increased MIB-1 Labeling Index Is Associated with Abducens Nerve Morbidity in Primary Sporadic Petroclival Meningioma Surgery: Beyond Location and Approach

Abducens nerve palsy is a severe dysfunction after petroclival meningioma (PC MNG) surgery. The objective of this investigation was to analyze abducens nerve outcomes in patients who underwent the retrosigmoid approach in relation to the MIB-1 index. Thirty-two patients with primary sporadic PC MNG were retrospectively analyzed. Mean follow-up was 28.0 months. Analysis of the MIB-1 index was performed to evaluate the abducens nerve outcome. An optimal MIB-1 index cut-off value (<4/≥4) in the association with postoperative CN VI palsy was determined by ROC analysis (AUC: 0.74, 95% CI: 0.57−0.92). A new-onset CN VI palsy was present in 7 cases (21.88%) and was significantly associated with an increased MIB-1 index (≥4%, p = 0.025) and a peritumoral edema in the brachium pontis (p = 0.047) which might be caused by the increased growth rate. Tumor volume, cavernous sinus infiltration, auditory canal invasion, and Simpson grading were not associated with new CN VI deficits. Six (85.7%) of the 7 patients with both an increased MIB-1 index (≥4%) and new abducens nerve palsy still had a CN VI deficit at the 12-month follow-up. A peritumoral edema caused by a highly proliferative PC MNG with an elevated MIB-1 index (≥4%) is associated with postoperative abducens nerve deficits.