Microsurgical Treatment For Meningioma Of Falcotentorinal Junction

Objective:Meningiomas arising from the falcotentorial junction are extremely rare. To investigate the clinical features, neuroimaging presentations, and results of surgical treatment of meningiomas of the falcotentorial junction, the senior author has treated seven consecutive patients with falcotentorial meningiomas during the past 7 years.Methods:Between Feb 2000 and Oct 2007, 7 patients with falcotentorial meningiomas were surgically treated. All seven cases are women; they range in age from 46 to 64 years, the mean age of 54.6 years. Preoperative examinations included head Computerized tomography(CT) and enhanced CT, Magnetic resonance(MR) imaging and Gd-DTPA enhanced MR imaging,MR venography in all patients, digital subtraction angiography(DSA) in 2. Based on MRI and MRV, We classified the direction of tumor extension into the four types. 6 patients were operated on via occipital (the medial surface of the occipital lobe), transtentorial approach, one via combined supra/infratentorial transsinus approach. All patients were followed-up with clinical examination and MRI and Gd- DTPA enhanced MRI studies 3 months, 6 months and 1 year after surgery, to determine the extent of tumor resection, a residual or recurrent. Follow-up 1-8 years.Results:According to Asari classification, in seven patients, the anterior type was seen in four, the inferior type in one patients and the posterior type in two. The anterior in 4, the inferior in 1 and the posterior (involve transverse sinus) in 1 was operated on via occipital, transtentorial approach, the inferior (involve transverse sinus, straight sinus, sinus confluens) in 1 patient via combined supra/infratentorial transsinus approach. Based on preoperative MRV examinations, all the great veins of Galen and 5 the straight sinus were occluded or severely stenosed in our seven patients. We have resected the great vein of Galen in 3 patients with good collateral venous channels after intraoperative verification of functional occlusion and blood flow diversion from the galenic venous system. They experienced a good outcome after deep venous resection. The other four cases did not show collateral circulation, the Galen's veins have been preserved. Resection of compromised parts of the straight sinus has been performed. Straight sinus not completely occluded of the other two has been saved. Resection rate according to Simpson's scale was grade 1 in 3. A grade 2 resection was achieved in 4.Histopathological subtypes of the WHO classification, all seven cases of meningioma grade I. The meningioma was of the fibroblastc subtype in 3 patients, epithelial in 3 patients, syneytial cell in 1 patient.Temporary conscious disturbance occurred postoperatively in 1 patient. There have been not permanent surgical morbidity. The postoperative KPS score was 90. None of tumor recurred during follow-up 1-8 years.Conclusions: The approach to meningioma of falcotentorinal meningioma should be customized to the dural origin and extent of the tumor as illustrated from preoperative MRI. In this series, the occlusion of deep veins did not significantly influence outcome.