Drilling off the Petrosal Apex and Opening the Upper Wall of Meckel’s Cave Are the Key Elements of Good Outcomes in the Treatment of Trigeminal Neuralgia Secondary to Petrous Apex Meningioma

Abstract

Objective :The surgical management of trigeminal neuralgia (TN) caused by petrous apex meningioma (PAM) is still a challenge because of the lesion's deep location and the surrounding complex structures. The authors describe the intradural anterior transpetrosal approach (ATPA) and its effect on the treatment of TN secondary to PAM. Methods : A retrospective analysis of 15 patients with TN secondary to PAM who underwent surgery via the intradural ATPA was conducted. The key techniques, which included drilling off the petrosal apex (PA) and opening the upper wall of Meckel's cave (MC), are described in detail. Results : Total removal of the tumor and complete pain relief (Barrow Neurological Institute I) were achieved in all 15 patients without significant morbidity. Five patients developed new facial numbness postoperatively, which disappeared within three months after surgery. The postoperative magnetic resonance imaging showed temporal lobe swelling in three patients, but no clinical symptoms. One patient had cerebrospinal fluid leakage and was managed with bed rest and temporary lumbar drainage. One patient had an intracranial infection and was treated with antibiotics. By the last follow up, no patients had pain relapse or/ and tumor recurrence. It is worth noting that the vascular compression at the root of the trigeminal nerve was found in one patient during the operation. Conclusion : Our experience suggests that drilling off the PA and opening the upper wall of the MC are key elements for a good outcome of the treatment of TN secondary to PAM. The intradural ATPA has the advantages for both tumor resection and pain relief.

Anatomic Study of Petrous Bone and Its Surrounding Structures in the Extended Anterior Transpetrosal Approach

“…4,5 However, if the tumor is large in volume, such as if it extends to the IAC, beyond the anterior loop of the ICA, or to the sellar region, an extended intradural ATPA is needed, and epidural or intradural drilling of the petrous bone is performed to create further expansion. 14 Several anatomic research about petrous apex and petroclival region in transarcuate approach, endoscopic trans-nasal, and trans-oral approach 9,10,15 have been reported. Extended ATPA needs multidimensional anatomic information on petrous bone and its surrounding vascular and neural structures.…”

“…Introduced by Kawase, the ATPA is a relatively less aggressive skull base approach for exposing the petroclival area and has been used for PCM resection and basilar artery aneurysm clipping 4,5 . However, if the tumor is large in volume, such as if it extends to the IAC, beyond the anterior loop of the ICA, or to the sellar region, an extended intradural ATPA is needed, and epidural or intradural drilling of the petrous bone is performed to create further expansion 14 . Several anatomic research about petrous apex and petroclival region in transarcuate approach, endoscopic trans-nasal, and trans-oral approach 9,10,15 have been reported.…”