الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 198 |  |  |
| | | from | 198 | | |
Abstract
Parasagittal meningiomas (PSMs) are tumors arising at the convexity of the hemisphere, just off the midline and adjacent to the superior sagittal sinus (SSS), with no brain tissue between the tumor and the SSS.
Falcine meningiomas are tumors arising from the falx cerebri below the superior sagittal sinus (SSS) in the interhemispheric fissure; it is often bilateral and concealed by the overlying cortex.
They comprise approximately 19.5 to 45% of all intracranial meningiomas.
Most parasagittal (falcine) meningiomas are benign tumors that can be cured with surgical treatment. The goal of parasagittal meningioma surgery is to remove as much of the lesion as possible and preserve patency of the venous structure.
Nevertheless, despite the improvement in the diagnosis and topographic evaluation by CT scans and MR imaging, their intimate relationships with the superior sagittal sinus and bridging veins, may preclude their radical removal, making the management of these tumors a real challenge because of the relatively high mortality and morbidity due to injury to critical venous structures with consequent venous infarction. So the advantages of a radical resection should be weighed against the potential additional risks related to the opening of the sinus.
In our study we described the surgical strategy for parasagittal (falcine) meningioma in a prospective study conducted over 25 patients that aimed to evaluate the risk/benefit ratio in attempting radical removal of parasagittal (falcine) meningiomas involving the superior sagittal sinus.
The results of the neuroradiological work-up and, especially, of the venous study by MRV, significantly influences surgical strategy and making decisions which based on the location of the tumor along the SSS, degree of sinus involvement, and the collateral circulation.
Patients with meningioma involving the anterior third of the sinus underwent radical removal. Patients with meningioma that was involving the middle and posterior third of the sinus had a radical removal if the sinus was completely obliterated, the SSS was ligated at the proximal and distal ends of the involved sinus and then resected, allowing en bloc tumor removal with extreme care of collateral venous drainage and subtotal removal of tumors that are infiltrating but not obliterating the SSS, removing as much tumor as possible while preserving major cortical veins, and leaving tumor remnants that significantly involve the sinus. In this approach, the residual tumor can be followed closely with serial imaging, and in the event of subsequent growth can be treated with repeated surgery or radiosurgery.
The tumor removal was radical in 23 patients (92%) achieving Simpson GI and subtotal in 2 patients (8%) with partially occluded posterior third achieving Simpson GIV, both patients had stable disease with no tumor growth for the following 2 years of follow-up.
Overall, morbidity occurred in 3 patients (12%); transient neurological deterioration due to brain swelling occurred in patients with middle third SSS meningiomas removed through radical resection. All of these patients recovered from their complications within few days by corticosteroid and osmotic diuretic use.
Two patients (8%) died during the postoperative period, one secondary to postoperative brain swelling after radical resection of the tumor together with the portion of sinus involved and the other one died due to myocardial infarction.
The recurrence rate in the study overall was 5%, with a follow-up period for at least 24 months.
On the basis of our results, we conclude that if the sinus is obstructed, the portion of the sinus involved can be resected completely. If the sinus is partially occluded, less aggressive subtotal resections may be a reasonable choice and proved to be safe and very effective. In both situations, extreme care and preservation of bridging veins, which may offer important collateral drainage.
With our approach, good results are achieved and it is not necessary to reconstruct the sinus.