Safe maximal resection of primary cavernous sinus meningiomas via a minimal anterior and posterior combined transpetrosal approach.

OBJECTIVE Meningiomas arising from the cavernous sinus (CS) continue to be a significant technical challenge, and resection continues to carry a relatively higher risk of neurological morbidity in patients with these lesions because of the tumor's proximity to neurovascular structures. The authors report the surgical outcomes of 9 patients with primary CS meningiomas (CSMs) that were surgically treated using a minimal anterior and posterior combined (MAPC) transpetrosal approach, and they emphasize the usefulness of the approach. METHODS This retrospective study included 9 patients who underwent surgery for CSM treatment between 2015 and 2016 via the MAPC transpetrosal approach. Two patients were men and 7 were women, with a mean age of 58.5 years (39-72 years). Five patients (55.5%) had undergone previous treatment. The surgical technique consisted of a temporo-occipito-suboccipital craniotomy and exposure of the posterolateral part of the CS via the presigmoidal MAPC approach. After opening Meckel's cave and identifying the 3rd-5th cranial nerves in the prepontine cistern, Parkinson's triangle and supratrochlear triangles were opened. Finally, the tumor occupying the posterolateral part of the CS was removed. RESULTS All lesions were safely and maximally removed, with preservation of external ocular movements and preoperative Karnofsky Performance Scale scores. The mean extent of resection was 77.0% (range 58.7%-95.4%). Six patients underwent adjuvant therapy in the form of stereotactic radiosurgery (SRS) or stereotactic radiotherapy (SRT) during the follow-up period; none of these patients experienced recurrence. CONCLUSION The authors conclude that the MAPC transpetrosal approach could be superior to other approaches for CSMs, as it provides direct visual access to the posterolateral portion of the CS. In their experience, this approach is an alternative and better option for safe maximal resection of CSMs.

Purely endoscopic subtemporal keyhole anterior transpetrosal approach to access the petrous apex region: surgical techniques and early results.

OBJECTIVE: The anterior transpetrosal approach using a microscope to provide wider access to the petrous apex region has been described for radical resection of lesions of the middle and posterior skull base. The microscopic anterior transpetrosal approach (mATPA) requires a wide craniotomy and meticulous epidural procedures to minimize temporal lobe retraction. Recently, the clinical application of transcranial endoscopic keyhole approaches for minimally invasive surgery has been steadily expanding. In this study, the details of the purely endoscopic subtemporal keyhole ATPA (eATPA) for petrous apex lesions are described and its initial results are reported. METHODS: Between May 2022 and May 2023, the authors performed eATPA in 10 patients with petrous apex lesions, of which 6 were meningiomas, 3 were trigeminal schwannomas, and 1 was epidermoid cyst. The surgical procedure of the purely eATPA is as follows. After a small temporal craniotomy, the endoscopic procedure is started. The anterior rim of the petrous bone and Meckel's cave are exposed via an intradural subtemporal approach. The lesion is removed with additional drilling of Kawase's triangle, cutting the superior petrosal sinus, opening Meckel's cave, and cutting the tentorium. The authors also compared the outcomes of mATPA versus eATPA for consecutive cases of petrous apex lesions. RESULTS: Gross-total resection was achieved in 8 of the 10 patients. The average operative time was 4 hours 13 minutes. There were 3 cases of transient abducens nerve palsy and 1 case of trochlear nerve palsy in the postoperative period. No new-onset motor deficits or CSF leakage was noted in any of these patients. Only 1 patient exhibited postoperative asymptomatic temporal lobe edema. The Karnofsky Performance Scale (KPS) scores remained unchanged or improved for all patients postoperatively. Compared with mATPA, eATPA achieved a similar extent of resection and comparable postoperative KPS scores with a significantly shorter mean operative time, much smaller temporal craniotomy, and thus less mean blood loss during surgery with lower rates of new-onset temporal lobe edema in the postoperative period. CONCLUSIONS: An eATPA allows a direct route to access Meckel's cave and posterior cranial fossa lesions similar to conventional mATPA, with shortening the operative time and reducing the risk of postoperative temporal lobe edema. This eATPA is considered one of the new surgical techniques that can be expected to develop in the future.

Contralateral Minimum Anterior and Posterior Combined Petrosal Approach for Retrochiasmatic Craniopharyngiomas: An Alternative Technique.

Retrochiasmatic craniopharyngiomas (RC) are a challenge for the neurosurgeon to treat surgically, restrained by their location in the interpeduncular fossa, surrounded by vital neurovascular structures, narrow corridor and poor visibility. Many approaches are possible and elucidated in the literature, which the surgeon chooses, based on multiple factors, such as the size of tumor, calcification, laterality, preoperative neurological deficits and the endocrine function status, recurrence, postradiotherapy status, or significant superior and/or posterior extension. 1 2 We describe a contralateral minimum anterior and posterior (CL-MAPC) petrosal approach for a case of recurrent RC, in a 37-year-old female patient operated before using a pterional approach, now presented with left homonymous hemianopia and panhypopituitarism ( Fig. 1 ). We preferred a contralateral approach to protect the ipsilateral optic tract (OT) from retraction injury, which formed an obstacle to the tumor from ipsilateral side. Apart from various benefits described by the author previously for RC, using MAPC petrosal approach, the CL-MAPC offers a safe corridor, protecting the ipsilateral OT, visualization of tumor origin usually posterior to chiasm, wider corridor if PCoM could be sacrificed, as it was done in this case, and pituitary stalk identification, with a probability of its functional preservation, unlike a necessity of pituitary transposition in EEA, though the endocrine outcome is poor after a radical resection irrespective of the approach chosen. 1 3 4 There was complete excision of the tumor with preservation of visual function postoperatively. We recommend the use of CL-MAPC as an alternative to EEA in some specific indications when the tumor is large, calcified, obscuring OT on the ipsilateral side and with significant lateral extension, which may be limiting factors in EEA ( Fig. 2 ). The link to the video can be found at: https://youtu.be/gWCJmh4_evs .

Sympathetic Plexus Schwannoma of Carotid Canal: 2 Cases with Surgical Technique and Review of Literature.

Carotid sympathetic plexus schwannomas are rare, and only 3 cases have been reported to the best of our knowledge. We report the fourth and fifth cases and define its origin on the basis of the exact division of the plexus from which the tumor arises. The surgical approach and technique in each variety and the postoperative outcome are also described. The relationship of partial Horner syndrome with the sympathetic plexus schwannoma of the internal carotid artery is discussed in detail.