Classification and Protection of Peritumoral Draining Veins of Parasagittal and Falcine Meningiomas

Efficacy and safety of a "radical" surgical strategy in the treatment of parasagittal sinus meningioma

Background

No standardized criteria for surgical resection of parasagittal sinus meningiomas (PSM) have been established, and different surgical strategies have been proposed. The aim of the present study was to investigate the efficacy and safety of a "radical" surgical strategy in the treatment of PSM.

Methods

The clinical histories, radiological findings, pathologic features, and surgical records of 53 patients with PSM admitted by the same surgical team using the "radical" surgical strategy were retrospectively analyzed between 2018 and 2023.

Results

Among the 53 PSM cases, 16 (30.2%) had a patent sinus proper, 28 (52.8%) had partial obstruction of the sinus proper, and 9 (17.0%) had complete obstruction of the sinus proper before the operation. During operation, Simpson grade I resection was performed in 34 (64.2%) cases and Simpson grade II in 19 (35.8%) cases. Postoperative pathologic examination suggested tumors of WHO grade I in 47 (88.7%) cases, WHO grade II in 4 (7.5%) cases, and WHO grade III in 2 (3.8%) cases. Postoperative complications primarily included a small amount of delayed intracerebral hemorrhage in 3 (5.7%) cases, exacerbation of cerebral edema in 3 (5.7%) cases, exacerbation of motor and sensory deficits in 4 (7.5%) cases, and intracranial infection in 2 (3.8%) cases. There were no cases of death or new-onset neurological dysfunction. Dizziness and headache symptoms improved to varying degrees, and a seizure-free status was achieved postoperatively. Excluding one case lost to follow-up, the average follow-up period was 33 months, and there were no cases of recurrence.

Conclusion

A "radical" strategy for the surgical management of PSM is effective, safe, and simple to perform, provided that the sagittal sinus is properly managed and its associated veins are protected.

Endoscopic Ipsilateral Interhemispheric Approach for Middle-Third Falcine Meningioma: A Case Report and Literature Review

Middle-third falcine meningiomas (FMs) are usually hidden deep under the eloquent cortex and abundant bridging veins, which represent the main hindrances to surgical access. The endoscopic approach has the advantages of wide visualization and free visual axis without areas of visual blindness, which allows for the resection of FMs with good visualization in a narrow space, especially in deep operations. Here, we report a case of a middle-third FM treated using the endoscopic ipsilateral interhemispheric approach. A 55-year-old female who had suffered a headache for 6 months without other remarkable symptoms was diagnosed with middle-third FM combined with imaging evaluation. According to the imaging performance and anatomical features, we scheduled the endoscopic ipsilateral interhemispheric approach to access and remove the tumor. Consequently, gross total tumor resection was achieved without surgery-related complications. After the surgery, the patient had an uneventful recovery and was discharged with no neurological deficit. During the 24-month follow-up, the patient's condition remained favorable, with no tumor recurrence. In our opinion, the endoscopic ipsilateral interhemispheric approach is a feasible surgical strategy for FMs, which deserves further exploration as a treatment option.

Utility of MRI in surgical planning for parasagittal meningiomas

BACKGROUND

Surgical resection is the standard treatment for parasagittal meningioma (PSM), but complete resection may be challenging due to superior sagittal sinus (SSS) involvement. The SSS may be partially or completely obstructed, and collateral veins are commonly present. Thus, knowing the status of the SSS in PSM cases prior to treatment is essential to a successful outcome. MRI is utilized prior to surgery in order to determine SSS status and to check for presence of collateral veins. The objective of this study is to evaluate the reliability of MRI in predicting both SSS involvement and presence of collateral veins in subsequent comparison to actual intra-operative findings, and to report on complications and outcomes.

METHODS

27 patients were retrospectively analyzed for this study. A blinded radiologist reviewed all pre-operative images, noting SSS status and collateral vein presence. Intraoperative findings were obtained from hospital records to similarly categorize SSS status and collateral vein presence.

RESULTS

Sensitivity of the MRI to SSS status was found to be 100% and specificity was 93%. However, sensitivity and specificity of MRI to collateral vein presence was only 40% and 78.6%, respectively. Complications were experienced by 22% of patients, the majority neurologic in nature.

CONCLUSION

MRI accurately predicted SSS occlusion status, but was less consistent in identification of collateral veins. These findings suggest MRI should be used with caution prior to PSM resection surgery particularly with regards to the presence of collateral veins which may complicate resection.

Risk factors influencing cerebral venous infarction after meningioma resection

BACKGROUND

Cerebral venous infarction (CVI) is a serious complication after meningioma resection. The risk factors of postoperative cerebral venous infarction after surgical resection of meningioma can be determined through large samples and this study can add evidence to the literature.

METHODS

The clinical and imaging data of 1127 patients with intracranial meningiomas who underwent resection in our hospital were retrospectively collected and analyzed. CVI was evaluated by postoperative imaging and clinical manifestations. Univariate and multivariate analyses were performed to identify risk factors associated with CVI.

RESULTS

Overall, 4.7% (53/1127) of patients experienced CVI after meningioma resection. Multivariate analysis revealed superficial meningioma, moderate to severe peritumoral edema, peritumoral critical vein and WHO grade II-III as independent predictors of a postoperative CVI. After timely intervention, the symptoms were clearly alleviated in one month, and the prognosis was good, but injury to key veins could cause irreversible neurological disorders.

CONCLUSIONS

Intraoperative protection of veins is the primary way to prevent CVI. The present study identified several significant and independent risk factors for postoperative venous infarction, thereby enabling the identification of high-risk patients who require special attention during clinical and surgical management.

Venous anatomy of the infratentorial compartment

Approximately 7%-12% of all intracranial meningiomas are located in the posterior fossa (PF), a region which contains-among many other critical neurovascular structures-numerous major veins and sinuses draining blood away from the PF structures. There is a growing body of evidence indicating that venous sacrifice or injury during surgery are linked to serious postoperative complications-which may lead to significant morbidity and mortality. Thus, it is of paramount importance that clinicians charged with the preoperative, surgical, and postoperative care of patients undergoing treatment for meningioma are familiar with the general anatomy of the PF veins, as well as their structural nuances and drainage variations. The present chapter surveys the relevant anatomy in a manner that aims to be useful for an interdisciplinary team of clinicians and concludes with a discussion of emerging imaging technologies that may assist them in their clinical decision-making.

Is Falcine Meningioma a Diffuse Disease of the Falx? Case Series and Analysis of a "Grade Zero" Resection

BACKGROUND

Falcine meningiomas have unique characteristics including their high rates of recurrence, association with high grade pathology, increased male prevalence, and potential for diffuse involvement of the falx.

OBJECTIVE

To address these issues in a substantial series of falcine meningiomas and report on the impact of extent of resection for this distinct meningioma entity.

METHODS

Retrospective analysis of characteristics and outcomes of 59 falcine meningioma patients who underwent surgery with the senior author. A "Grade Zero" category was used when an additional resection margin of 2 to 3 cm from the tumor insertion was achieved.

RESULTS

For de novo falcine meningiomas, gross total resection (GTR) was associated with significantly decreased recurrence incidence compared with subtotal resection (P ≤ .0001). For recurrent falcine meningiomas, median progression-free survival (PFS) was significantly improved for GTR cases (37 mo vs 12 mo; P = .017, hazard ratio (HR) .243 (.077-.774)). "Grade Zero" resection demonstrated excellent durability for both de novo and recurrent cases, and PFS was significantly improved with "Grade Zero" resection for recurrent cases (P = .003, HR 1.544 (1.156-2.062)). The PFS benefit of "Grade Zero" resection did not achieve statistical significance over Simpson grade 1 during the limited follow-up period (mean 2.8 yr) for these groups.

CONCLUSION

The recurrence of falcine meningiomas is related to the diffuse presence of tumor between the leaflets of the falx. Increased extent of resection including, when possible, a clear margin of falx surrounding the tumor base was associated with the best long-term outcomes in our series, particularly for recurrent tumors.

Classification of Peritumoral Veins in Convexity and Parasagittal Meningiomas and Its Significance in Preventing Cerebral Venous Infarction

OBJECTIVE

The medium (2-4 cm) convexity located closer to the sinus and parasagittal meningiomas (Sindou type I-Ⅲ) without obvious invasion of the superior sagittal sinus are considered simple to operate on. However, the tumors are often accompanied by the cortical bridging vein. Because of lack of collateral vein circulation in cortical areas, the damage of peritumoral veins will subsequently lead to venous infarction. To avoid the serious complications caused by intraoperative injury of peritumoral veins, it is necessary to define the classification of the progression of peritumoral veins and tumors to guide surgical safety.

METHODS

The clinical information of 57 patients with convexity and parasagittal meningiomas was collected and retrospectively analyzed. All patients underwent preoperative magnetic resonance imaging and magnetic resonance venography scanning to observe the imaging characteristics of peritumoral veins and preoperative evaluation. The actual relationship between the tumor and peritumoral vein was observed intraoperatively. Postoperative computed tomography and magnetic resonance imaging were used to determine tumor resection and the presence of venous infarction.

RESULTS

According to preoperative magnetic resonance venography and intraoperative findings, we divided the peritumoral veins into 3 types: type A (n = 33, 57.9%), the vein surrounds the tumor; type B (n = 15, 26.3%), the vein is located on the ventral side of the tumor; and type C (n = 9, 15.8%), the vein is located on the dorsal side of the tumor. Peritumoral vein injury occurred in 6 cases followed by serious complications. Treatments were as follows: 4 cases underwent decompression and 2 cases were treated conservatively. The prognosis Glasgow Outcome Scale (GOS) scores were as follows: 3 cases were score 5 for injury of posterior frontal vein or middle frontal vein, 2 cases were score 3 for injury of the central vein, 1 case was score 1 for death due to injury of the central vein. All cases were followed up for 6 months.

CONCLUSIONS

Attention should be paid to the peritumoral vein of special meningiomas. Injured vein in the medial third of superior sagittal sinus carries a high rate of postoperative morbidity. Understanding the type of peritumoral veins preoperatively can be used as a guide in determining the corresponding protective strategy during surgery, which can significantly decrease postoperative disability and improve quality of life.

Parasagittal meningiomas

Parasagittal meningiomas are defined as meningiomas that grow into at least one wall of the superior sagittal sinus. Long- and short-term morbidity is, in addition to cortical function, related to management of venous structures and flow. Clinical management needs to address the extent of removal in the sinus wall and to address relations to the adjacent cortex, which is highly eloquent in the Rolandic and calcarine areas.