Peter J. Jannetta
Peter E. Sheptak and Peter J. Jannetta
✓ Total removal of huge acoustic neurinomas was carried out in 23 patients by means of a two-stage suboccipital transmeatal approach with microsurgical technique. There was no operative mortality. Good results were obtained in 18 (78%) of the patients who have returned to normal activities or full-time employment. Five patients (22%) have residual preoperative neurological deficits causing a reduced level of activity. All of these, except one, are able to care for themselves. None of the patients has had any further significant neurological deficit caused by the operative procedures. Anatomical integrity of the facial nerve was maintained in 17 patients (74%). Surgical technique, operative morbidity, and results are thoroughly discussed. The potential advantages of this technique are stressed.
Microsurgical excision and follow-up results
Laligam N. Sekhar and Peter J. Jannetta
✓ During the years 1974 through 1981, 22 patients with cerebellopontine angle meningiomas underwent surgery: 14 tumors were excised completely, and eight subtotally. A retromastoid approach was used in 19 cases and a subtemporal approach in three cases. There was no operative mortality and the quality of survival was good. Five patients suffered new cranial nerve deficits as a result of the operation. The average follow-up period was 5 years. One tumor thought to be completely removed has recurred, but has not required another operation so far. One subtotally excised tumor required reoperation. Computerized tomography and arteriography were important in preoperative evaluation. Good neuroanesthesia, the use of the surgical microscope and microtechnique, and an understanding of the pathological relationships were factors contributing to good results.
Daniel K. Resnick and Peter J. Jannetta
✓ A 37-year-old woman underwent microvascular decompression of the superior vestibular nerve for disabling positional vertigo. Immediately following the operation, she noted severe and spontaneous gagging and dysphagia. Multiple magnetic resonance images were obtained but failed to demonstrate a brainstem lesion and attempts at medical management failed. Two years later she underwent exploration of the posterior fossa. At the second operation, the vertebral artery as well as the posterior inferior cerebellar artery were noted to be compressing the vagus nerve. The vessels were mobilized and held away from the nerve with Teflon felt. The patient's symptoms resolved immediately after the second operation and she has remained symptom free. The authors hypothesize that at least one artery was shifted at the time of her first operation, or immediately thereafter, which resulted in vascular compression of the vagus nerve. To the authors' knowledge, this is the first reported case of a hyperactive gagging response treated with microvascular decompression. The case also illustrates the occurrence of a possibly iatrogenic neurovascular compression syndrome.
Aage R. Møller and Peter J. Jannetta
✓ A method is described for recording sound-evoked responses directly from the eighth nerve during operations in the cerebellopontine angle, particularly during microvascular decompression operations for cranial nerve dysfunction. This method provides important information to the surgeon during the operation that cannot be provided by recording brain-stem auditory evoked potentials (BAEP) using surface electrodes. By recording sound-evoked responses intracranially and recording BAEP with scalp electrodes, the risk of hearing loss in these operations is decreased.