Kevin X. Mckennan

A systematic approach to the surgical management of acoustic neuroma.

Contemporary otomicrosurgical techniques have made total removal of acoustic tumor with preservation of the seventh and sometimes the eighth cranial nerves possible. The four approaches currently used in acoustic tumor surgery are the middle cranial fossa, the translabyrinthine, the suboccipital, and the combined translabyrinthine‐suboccipital. This review examines the surgical results in the removal of more than 600 acoustic tumors and outlines a rationale for the choice of approach. Tumor size on computed tomographic scan and auditory reserve establish the parameters used in planning the surgical procedure. The translabyrinthine exposure is used most frequently followed by the combined translabyrinthine‐suboccipital. The middle fossa and suboccipital approaches are used when preservation of hearing is attempted. Total removal of tumor was accomplished in more than 99% of patients with a mortality rate of less than 1%. Anatomic preservation of the facial nerve, which is directly related to tumor size, was achieved in more than 80% of patients. Preservation of hearing is unlikely when the tumor is larger than 2 cm; anatomic preservation of the cochlear nerve was successful in 73% of hearing preservation procedures.

Endoscopic ‘second look’ mastoidoscopy to rule out residual epitympanic/mastoid cholesteatoma

Endoscopic mastoidoscopy is ideally suited for patients who have undergone an intact canal wall mastoidectomy for primary acquired cholesteatoma confined to the epitympanum and mastoid. The use of an endoscopic technique significantly decreases the morbidity of the second-look procedure. Visualization of the pertinent anatomy can be reliably, quickly, and safely accomplished.

Acoustic neuroma surgery: The results of hearing conservation surgery

Between the years of 1978 and 1986 attempts have been made to save the hearing in 47 patients with unilateral pathologically confirmed acoustic neuromas. The middle fossa approach has been used in 32 cases and the suboccipital approach in 15 cases. Our review demonstrates an advantage using the suboccipital approach to excise most of these tumors. The success rate is higher (47% vs. 31%) and complications fewer using the suboccipital route. Despite these findings the middle fossa approach may be preferable in selected tumors located laterally in the internal auditory canal.

Post-traumatic cholesteatoma

Cholesteatoma can develop as a late complication of fracture of the temporal bone. The otologist must be wary of it since the growth of the cholesteatoma resulting from a temporal bone fracture can be undetected for years allowing for invasive and extensive growth. Three illustrative cases are presented.

The changing characteristics of acoustic neuroma patients over the last 10 years

The first 100 patients in a series of 616 cerebellopontine angle tumors were compared to the most recent 100 patients. All of the first 100 patients were evaluated prior to the common use of CT or ABR. Recently, improved diagnostic studies have resulted in the discovery of significantly smaller tumors. The later group of patients was also found to have their symptoms for a shorter period of time and had better overall hearing at the time of diagnosis. Reductions in the rates of various complications were also observed. These trends are felt to be the direct result of improved audiologic and radiologic diagnostic studies. A heightened awareness of all otolaryngologists to seek the diagnosis of acoustic neuroma also improved early diagnosis.

Long-term results of labyrinthectomy

Ten years after labyrinthectomy, 38 patients responded to a questionnaire. There was a slight decline in relief of vertigo from 93% to 76%. Symptoms following the procedure are discussed. It is believed that the reason for the decline is secondary to the age of the patients, the occasional bilateral nature of Menieres disease, and possibly post‐surgical neuroma formation. The ramifications of this study are discussed with respect to hearing‐conservation procedures.

Persistent traumatic perilymph fistulas

Thirty‐four ears have been explored to rule out perilymph fistulas resulting from ear trauma. Eight ears (24%) were identified with a fistula, often persisting months (average 7.5 months) after the precipitating injury. Repair of fistulas, even if done relatively late, markedly reduces vestibular symptoms and may improve low and middle frequency sensorineural hearing. Complications from negative explorations are rare.

“Tissue welding” with the argon laser in middle ear surgery

Over the past 10 years the argon laser has been recognized as a valuable adjunct to middle ear surgery. It has been used to vaporize and cut tissue and to coagulate micro‐bleeding. It has been used by many other surgical specialties to “weld” adjacent tissues together. This welding process appears to have a limited but helpful role in middle ear surgery. A pilot study of 30 surgical cases in which argon laser “tissue welding” has been used are reported. The benefits, limitations, and possible future implications are discussed.

Meniere's syndrome : an atypical presentation of giant cell arteritis (temporal arteritis)

The authors discuss three patients with biopsyproven giant cell arteritis (GCA) who experienced significant auditory and vestibular symptoms. Two of the patients who presented with audiovestibular symptomatology died as a direct result of GCA affecting the vertebral arteries. Postmortem findings are reported.

Neurofibromatosis type 2: Report of a family and review of current evaluation and treatment

Significant advances during the past decade have greatly improved our understanding of neurofibromatosis type 2, a genetic disease which results in bilateral acoustic neuromas. The emergence of gadolinium-enhanced magnetic resonance imaging has allowed early detection of minute intracanalicular eighth-nerve tumors, less than 1 cm in diameter. Recombinant DNA studies have clarified the genetics that underlie neurofibromatosis type 2 and separate it from a variety of related conditions, such as von Recklinghausens neurofibromatosis. Early diagnosis and surgical removal of these tumors may offer the only hope of preserving hearing and facial nerve function. A report of the evaluation and treatment of a family with multiple affected individuals will exemplify these conclusions.