Frontotemporal epidural approach to trigeminal neurinomas

Three patients with aneurysms of the internal carotid artery (ICA) situated in the cavernous sinus (CS), and four patients with traumatic carotid-cavernous fistulas (CCF's) were treated by direct surgical approach. Two aneurysms were clipped, whereas the third (a giant aneurysm) was resected and the wall of the ICA reconstructed using interrupted sutures. In two CCF's, the shunt was excluded during reconstruction of the ICA wall by suturing. In the remaining two patients with CCF's, the shunt was excluded by clipping. The CS was attacked directly using a combination of three different techniques: the pterional, the subtemporal, and the petrosal approach. The ICA in its whole course through the CS, as well as the third through the sixth cranial nerves, were exposed. No special measures, such as hypotension, hypothermia, extracorporeal circulation and cardiac arrest, or dehydration, were taken during surgery. The aim of the direct approach to the CS was to exclude the aneurysm and/or the CCF and preserve the ICA patency. In all seven cases operated on, the lesions were excluded without inflicting any additional damage to the third through sixth cranial nerves, and in five cases carotid patency was preserved.

A consecutive series of 14 patients with trigeminal schwannoma managed surgically at the Neurological Institute of New York since 1970 is reported. Nine women and five men (mean age 40 years) were diagnosed following a mean symptom duration of 33 months. Abnormalities of trigeminal nerve function were present in 11 patients on admission examination. Facial pain was a prominent feature in eight patients. Two patients, both with schwannomas arising from the trigeminal root, presented initially with typical trigeminal neuralgia. Additional cranial nerve palsies or cerebellar or pyramidal tract signs were noted in eight patients. The surgical approach to these tumors depends on their anatomical location. Four patients had tumors confined to the middle fossa, three patients had tumors limited to the posterior fossa, and seven patients had both supratentorial and infratentorial components of their tumors. Twenty operative procedures were performed on these patients, resulting in complete extirpation in six patients, nearly complete removal in seven patients, and partial removal in one patient. Adherence of the tumor to the lateral wall of the cavernous sinus or the brain stem precluded total removal. There was one postoperative death. In the immediate postoperative period, abnormalities of cranial nerves controlling the extraocular muscles were common. In general, these deficits were transient; however, some permanent loss of trigeminal nerve function occurred in nine patients. Two patients required tarsorrhaphy for neurotropic keratitis, and two patients underwent cerebrospinal fluid (CSF) shunting procedures for hydrocephalus or for a persistent CSF leak. The follow-up period ranged from 4 to 177 months (mean 47 months). The clinical features, anatomical considerations, and surgical approach to these rare tumors are discussed. A clinical review of 106 additional cases of trigeminal schwannoma, reported in the English literature since 1935, is also presented.

In the past, neurosurgeons have been reluctant to operate on tumors involving the cavernous sinus because of the possibility of bleeding from the venous plexus or injury to the internal carotid artery (ICA) or the third, fourth, or sixth cranial nerves. The authors describe techniques for a more aggressive surgical approach to neoplasms in this area that are either benign or locally confined malignant lesions. During the last 2 years, seven tumors involving the cavernous sinus have been resected: six totally and one subtotally. The preoperative evaluation included axial and coronal computerized tomography, cerebral angiography, and a balloon-occlusion test of the ICA. Intraoperative monitoring of the third, fourth, sixth, and seventh cranial nerves was used to assist in locating the nerves and in avoiding injury to them. The first major step in the operative procedure was to obtain proximal control of the ICA at the petrous apex and distal control in the supraclinoid segment. The cavernous sinus was then opened by a lateral, superior, or inferior approach for tumor resection. Temporary clipping and suture of the ICA was necessary in one patient. None of the patients died or suffered a stroke postoperatively. Permanent trigeminal nerve injury occurred in three patients; in two, this was the result of tumor invasion. One patient suffered temporary paralysis of the third, fourth, and sixth cranial nerves, and in another the sixth cranial nerve was temporarily paralyzed. Preoperative cranial nerve deficits were improved postoperatively in three patients. Radiation therapy was administered postoperatively to four patients. These seven patients have been followed for 6 to 18 months to date and none has shown evidence of recurrence of the intracavernous tumor.