Combined Microscopic and Endoscopic Surgery for Pineal Region Meningiomas Using the Occipital-Parietal Transtentorial Approach

Falcotentorial Meningiomas: Insights from Surgical Strategies and Clinical Outcomes

Background: Falcotentorial meningiomas are exceptionally uncommon tumors, presenting a challenge for neurosurgeons due to their close proximity to vital structures. Gross total resection represents the standard of treatment for these tumors. However, care must be taken when surgically approaching these lesions, since damaging neurovascular structures may cause unacceptable morbidity. Selecting the optimal surgical approach for each tumor is of paramount importance when treating these patients. Methods: The authors reviewed medical records to identify all patients with falcotentorial meningiomas who underwent resection at the University Hospital of Freiburg between January 2001 and December 2021. Clinical and imaging data, surgical management, and clinical outcomes were analyzed. Results: Falcotentorial meningiomas occurred in 0.7% (15 of 2124 patients) of patients with intracranial meningiomas. Of these 15 patients, 8 were female and 7 male. The occipital interhemispheric approach was used in nine patients, the supracerebellar infratentorial approach in five patients, and the retrosigmoidal approach in one patient. Three patients developed visual field deficits after surgical resection. Incomplete resection was significantly associated with tumor progression (p < 0.05). Conclusions: Individualized surgical strategies, guided by preoperative imaging and classification systems, play a crucial role in optimizing patient care. Among the available approaches, the occipital interhemispheric and supracerebellar infratentorial approaches are frequently employed and considered among the safest options for these tumors.

Surgical Treatment of Falcotentorial Meningioma: An Illustrative Case Report and Literature Review

Falcotentorial meningiomas are rare tumors, representing only 2-3% of all intracranial meningiomas. These tumors can grow rapidly, leading to severe neurological complications. They grow at the junction of the tentorium cerebelli and the falx cerebri, in close proximity to the great vein of Galen. The surgical approach depends on several factors, such as the tumor's size, the patency of the straight sinus, and its location, either above or below the tentorium. Complete removal of the tumor in this area is difficult due to its deep location near major neurovascular structures. Various surgical approaches can be employed to remove these tumors, and the decision on which approach to use should be based on its advantages and disadvantages.

Optimal therapeutic strategies for pineal region lesions

Background

The removal of pineal region lesions are challenging, and therapeutic strategies for their removal remain controversial. The current study was conducted to identify the characteristics and the optimal therapeutic strategies for pineal region lesions.

Methods

This retrospective study reviewed the treatments of 101 patients with pineal region lesions, and different characteristics and therapeutic strategies were observed.

Results

There were no statistical differences in the total resection ratio, complications, and prognosis outcomes between the hydrocephalus group and non-hydrocephalus group, except patients in the hydrocephalus group were younger and pediatric patients had an increased level of intracranial infections. Treatments of lesions and hydrocephalus secondary to pineal region lesions were two integral parts to therapeutic strategies. For the management of lesions, germinoma or non-germinoma were diagnosed preoperatively, and resection or diagnostic radiation were chosen to deal with pineal region lesions. Endoscopic-assisted surgery provided a higher total resection rate. For the management of hydrocephalus, endoscopic third ventriculostomy (ETV) had the better therapeutic effect. Additionally, cerebrospinal fluid (CSF) diversion before radiotherapy or resection did not improve prognosis outcome, but it was necessary for patients with severe hydrocephalus. Logistical regression analysis indicated that age, lesion size, reoperation ratio, and intracranial complications were predictors of prognosis outcome.

Conclusion

More attention should be paid to intracranial infections in pediatric patients with hydrocephalus secondary to pineal region lesions, and CSF diversion before radiotherapy or resection did not promote prognosis outcome, but it was necessary for patients with severe hydrocephalus. Age, lesion size, reoperation ratio, and intracranial complications may be the predictors of prognosis outcome. Most importantly, the surgical algorithm for pineal region lesions which was based on preoperatively diagnosis (non-germinoma and germinoma) is useful, especially for developing countries.

Endoscopic Occipital Transtentorial Approach for Supracerebellar Lesions

The occipital transtentorial approach (OTA), which is often applied for superior cerebellar lesions, has an inevitable risk of homonymous hemianopsia due to the retraction of the occipital lobe. The endoscopic approach provides increased visibility of the surgical field due to the wide-angled panoramic view and is minimally invasive in approaching deep brain lesions compared to the conventional microscopic approach. However, little is known regarding endoscopic OTA for the removal of cerebellar lesions. We experienced a case of a hemangioblastoma in the paramedian superior surface of the cerebellum that was successfully treated with endoscopic OTA combined with gravity retraction while avoiding postoperative visual dysfunction. A 48-year-old woman was diagnosed with a hemangioblastoma in the superior surface of the cerebellum. She underwent tumor removal with endoscopic OTA combined with gravity retraction of the occipital lobe instead of using brain retractors. The narrower space was sufficient for surgical manipulation with a panoramic view obtained by endoscopy. The simultaneous observation of the lesion with both an endoscope and a microscope revealed the superiority of infratentorial visualization with an endoscope. Gross total removal was achieved with no postoperative complications, including visual dysfunction. Endoscopic OTA may reduce the risk of postoperative visual dysfunction because of its minimally invasive nature, which is enhanced when combined with gravity retraction. Additionally, the panoramic view of the endoscope allows favorable visualization of an infratentorial lesion, which is otherwise hidden partly by the tentorium. The use of endoscopy is compatible with OTA, and endoscopic OTA could be an option for superior cerebellar lesions for avoiding visual dysfunction.

Combined supracerebellar infratentorial and right occipital interhemispheric approach to falcotentorial junction meningioma: A case report

Background

Falcotentorial meningioma is a rare tumor of pineal region, arising from the dural folds where the tentorium and falx meet. Due to the deep location and near closeness to significant neurovascular structures, gross-total tumor resection in this area can be complicated. Pineal meningiomas can be resected using a variety of approaches; however, all these approaches are associated with a significant risk of postoperative complications.

Case Description

A 50-year-old female patient who presented with several headaches and visual field defect and diagnosed with pineal region tumor is discussed in the case report. Patient was successfully managed surgically by combined supracerebellar infratentorial and right occipital interhemispheric approach. Cerebrospinal fluid circulation was restored after surgery and neurological defects were regressed.

Conclusion

Our case shows that it is possible to completely remove giant falcotentorial meningiomas with minimal brain retraction, preserve the straight sinus and vein of Galen, and prevent neurological impairments by combining two approaches.