Microsurgical Removal of Petroclival Meningiomas

Abstract

This is a report of 33 consecutive cases of petroclival meningioma treated surgically at our institution over the last 10 years; there were 21 women and 12 men between the ages of 27 and 68 (mean age, 52). All patients were assessed by computed tomographic scans including coronal sections and bone algorithm studies; in most cases, digital subtraction angiography and magnetic resonance imaging were also done. The largest tumor diameter was between 2 and 3.5 cm in 14 cases, 3.5 to 6 cm in 15 cases, and over 6 cm in 4 cases. Dural attachment predominantly involved the clivus and apical petrous bone on one side only; in 14 cases, however, the tumor grew over the clivus midline or crossed the tentorial notch. Cranial nerve deficit was extant in all cases and was commensurate with tumor size. Cerebellar signs and somatic motor deficits were present in 60 and 30% of cases, respectively. The surgical approaches used were the retromastoid-retrosigmoid in 23 cases, subtemporal in 5 cases, and combined retromastoid subtemporal presigmoid in the remaining 5. Total removal was achieved in 26 cases (79%); incomplete removal occurred in 7 cases (21%). The extent of tumor removal and operative morbidity were not significantly related to tumor size. Brain stem indentation, arterial and cranial nerve encasement, and epidural invasion were the main factors that prevented total tumor removal and influenced operative morbidity. There was no intraoperative mortality, but three patients (9%) died perioperatively. In the postoperative period, most patients went through momentary neurological deterioration, chiefly due to new cranial nerve deficits. The average follow-up was 4.3 years in 27 patients; of these 17 were unchanged and 10 were improved. Before surgery, only 13 patients were self-sufficient; at long-term follow-up, another 6 had achieved independence. Our experience suggests that, even though real petroclival meningiomas still represent a formidable surgical challenge, such tumors can in most cases be removed completely with low attendant mortality and acceptable morbidity.

Petroclival meningiomas: Surgical management and common complications

“…Bricolo et al and Hakuba et al showed a rate of total removal and mortality respectively of: 79% and 9%; 75% and 12%. 9,14 Our rate of total removal was 87% with a rate of mortality of 13.3%. Probably our higher success rate of total resections was related to the higher number of fatal complications and morbidity.…”

“…The rate of cranial nerve deficits ranged from 31% to 100%. [14][15][16][17][18][19][20] The nerve most frequently damaged during surgery and of slowest recovery is cranial nerve VI. In our series, all patients had post-operative VI nerve palsy, although the palsy was transient in 7 patients.…”

The retrosigmoid approach to petroclival meningioma surgery

“…The most common complication reported is CN deficits. [1][2][3][4][5][6][7][8] In our series, although evoked potential monitoring was performed in all patients and the CN anatomy could be somewhat preserved, nine patients suffered from facial palsy, of whom six patients recovered to House-Brackmann Grade 2 after 3 months, and two patients with permanent facial palsy underwent hypoglossal-facial anastomosis with excellent results after 6 months.…”

“…In the mean follow-up of 4.3 years, no patient who underwent GTR experienced tumor recurrence (Figs. [2][3][4]. Of the 42 patients operated via the retrosigmoid approach who underwent a Simpson Grade III and IV resection, tumor regrowth was observed in three patients.…”

“…Despite the evolution in microsurgical techniques, as well as improvements in neuroimaging and neural electrophysiology monitoring, surgical morbidity and mortality are significant. [1][2][3][4][5][6][7][8] Several approaches have been applied to resect petroclival meningiomas, which include translabyrinthine, transcochlear, total petrosal, retrosigmoid, and subtemporal approaches. Transpetrosal and subtemporal approaches involve resection of the petrosal bone and retraction of the temporal lobe, and injury to the temporal lobe, and cranial nerves (CN) VII and VIII, is possible.…”