Surgical Management of Medial Sphenoid Wing Meningioma and Factors Affecting its Prognosis

Abstract

This study included 20 patients with Medial Sphenoid Wing meningiomas operated in the period between October 2011 to April 2015 in the neurosurgery departments. The highest incidence of these tumors was found in the 5th and 6th decades of life and were more common in females than males in ratio of 1.85/1. Visual deterioration was the most common clinical manifestation followed by Headache. Less common clinical manifestations were; seizures, diplopia, proptosis, unilateral motor weakness. MRI & CT scan were mandatory for proper diagnosis and visualization of these meningiomas and their relation to the neurovascular structures allowing planning of the best approach and follow up of the patients. CT scan was superior to MRI in delineating the bony anatomy and the pathological reaction in the skull such as hyperostosis and bony erosion. MRI was the diagnostic modality of choice in this study, it was helpful in delineating the relationship of the tumor to the neurovascular structures and it was very helpful in delineating the exact anatomical location of the tumor and its extent into different compartments. Preoperative angiography & MRA are important in delineating the position and the state of the neighboring vessels. The average tumor size was significantly small 4.2 cm due to the proximity to the optic nerve. All cases operated by Extended Pterional approach to avoid or minimize the use of self-retaining retractors in addition to early extradural tumor devascularization. 160 MSWM Simpson grading system was used to assess the degree of tumor removal. Total removal was defined as Simpson grades (I or II). Subtotal removal was defined as Simpson grades (III or IV). Total removal was achieved in 8 patients (40%), and subtotal removal in 12 patients (60%), patients with subtotal excision still having a good chance of a good outcome due to the slow growth of these skull base meningiomas especially with the adjuvant use of the radiosurgery provided by gamma knife and linear accelerator. The use of microsurgical techniques considerably widens the possibilities for total surgical excision with decompression of the vital neurovascular structures. There were statistically significant relations between the tumor size, vascular encasement, cavernous sinus invasion and orbital invasion to extent of tumor removal while there were no significant relation between the locations, the Histopathological types to the extent of tumor removal. Pathological examinations revealed: Meningiothelial type constituted 7 patients 35% of cases and Transitional type was found in 13 cases (65%), All of WHO grade I. Visual acuity improved in (61.1%) out of 18 cases with preoperative deterioration and one of them showed marked improvement post-operative. Seven patients (38.9%) out of 18 cases with preoperative deterioration shows no post-operative changes. There was significant relation between the degree of preoperative visual acuity and the rate of visual improvement, with better rates of improvement reported among those with good preoperative visual conditions. And there was significant relation between the visual outcome and the duration of visual complaint, patients with visual complaint less than one year had better visual outcome. 161 Summary CSF leakage, ocular nerves palsy, brain swelling, wound infection, DVT, intracerebral hematomas and hemiparesis were the complications encountered post-operatively in the patients. No patients died after surgery. Karnofsky scale was used to evaluate the functional outcome. The median preoperative Karnofsky scale was 80, which improved to 90 postoperatively.