Lateral skull base surgery for glomus tumors: long-term control.

OBJECTIVE: The age of modern microsurgery has made resection of glomus tumors with extensive skull base involvement possible. Resection of extensive lesions is not without risk of major complication or new cranial nerve deficit. Because glomus tumors are rare and slow growing, data reflecting recurrence risk after resection using modern skull base techniques are lacking. These factors complicate the accurate definition of efficacy of surgical resection and its functional cost. The object of this review is to determine the current incidence of major complications, the surgical cranial nerve deficit, the long-term control rate, and the recurrence risk in patients undergoing surgical resection of glomus jugulare tumors. STUDY DESIGN: Retrospective case review. SETTING: Private practice tertiary referral center. PATIENTS AND INTERVENTIONS: One hundred seventy-six patients with glomus tumors underwent 182 lateral skull base resections between 1972 and 1998. MAIN OUTCOME MEASURES: Major complications, tumor recurrence, postoperative functional capacity, and factors affecting the incidence of each were assessed. RESULTS: Complete surgical control was achieved in 85% of cases. There were nine cases of recurrence, for a recurrent rate of 5.5% (9/164). Cerebrospinal fluid leakage occurred in 4.5% of cases with intracranial extension. New deficits for cranial nerves IX, X, XI, and XII occurred in 39%, 25%, 26%, and 21% of cases, respectively. Satisfactory functional recovery was achieved in an overwhelming majority of cases. The mortality rate was 2.7% (5/182). CONCLUSIONS: Surgical resection of glomus tumors is established as an effective technique with good functional outcomes and long-term control.

Comparison of postoperative headache after retrosigmoid approach: vestibular nerve section versus vestibular schwannoma resection.

OBJECTIVE: To evaluate intradural drilling as a mechanism for the development of postoperative headache after retrosigmoid craniectomy. STUDY DESIGN: A retrospective review of charts was performed on 565 retrosigmoid approaches to the cerebellopontine angle performed between January 1980 and January 1998. Patients treated with retrosigmoid vestibular nerve section without intradural drilling were compared with patients who underwent retrosigmoid removal of vestibular schwannomas in which intradural drilling was performed for exposure of the internal auditory canal. SETTING: Private practice tertiary referral center. PATIENTS: Consecutive patients undergoing retrosigmoid approach between January 1980 and January 1998 were reviewed. MAIN OUTCOME MEASURES: The presence of headache, duration of headache, and severity of headache were noted. RESULTS: In this large series, 54% of patients experienced headaches after vestibular schwannoma removal, and 5% of patients experienced headaches after vestibular nerve section (p < 0.01, chi-square). CONCLUSIONS: Postoperative headache is not a characteristic of retrosigmoid craniectomy in the absence of intradural drilling. Intradural drilling is a probable cause of headache after the retrosigmoid approach. Cranioplasty is not necessary to prevent a high incidence of postoperative headache after retrosigmoid approach.

Malignant glomus tumors.

OBJECTIVES/HYPOTHESIS: To ascertain the incidence of malignancy in a large glomus and skull base series and to compare the clinical course of such patients with those who do not have malignant skull base lesions. STUDY DESIGN: Retrospective review of all skull base surgery cases treated at the Otology Group between 1970 and 1995. RESULTS: In a series of 175 jugulotympanic glomus tumors, 9 cases (5.1%) were identified. The surgery required for their extirpation is more extensive than nonmalignant glomus tumors. Attendant deficits and mortality from these procedures are accordingly greater. Five-year survival in this limited population was 72%. Prolonged periods of survival are possible with distant metastases. CONCLUSIONS: This rate of malignancy should advocate against a watchful, waiting approach. Radiation therapy is not advocated as a primary modality for this type of tumor, as it may lead to recurrence/persistence with either subsequent malignant degeneration and metastases or local recurrence.

Temporal bone and lateral skull base malignancy: experience and results with 81 patients.

OBJECTIVE: This study aimed to examine predictive factors and treatment outcome and to devise a staging method for malignant lateral skull base disease. STUDY DESIGN: The study design was a retrospective review of all lateral skull base surgery cases. SETTING: The study was conducted at a tertiary referral center. PATIENTS: Of 317 lateral skull base lesions, 81 patients were found to have malignant disease. Three groups were identified, and the data were analyzed according to the following: epithelial malignancies, 30 patients; malignancies of salivary gland origin, 23 patients; and malignancies of mesenchymal origin, 28 patients. The mean age was 48.5 years with a range of 5-83 years. There were 42 males and 39 females. Our mean follow-up time was 54 months with a range of 1-180 months. Forty-three patients were alive without evidence of recurrent disease, 6 were living with disease, 25 were dead of disease, 3 died of other causes, and 4 were lost to follow-up. INTERVENTIONS: All patients underwent surgery with curative intent. Forty-two received adjuvant radiation, and 8 received chemotherapy. MAIN OUTCOME MEASURES: Treatment failure, survival, cranial nerve deficits, complications, and predictive factors were analyzed. RESULTS: A 58% treatment success rate was observed. Epithelial and salivary malignancy had a poorer prognosis, and pain and facial nerve dysfunction at presentation carried a worse prognosis. CONCLUSIONS: Lateral skull base malignancy is a rare entity that continues to challenge cranial base surgeons. Cranial nerve deficits and complications are frequent. The success rate of treatment is dependent on histology and disease extent.

Facial nerve outcome in lateral skull base surgery for benign lesions.

OBJECTIVE: To statistically identify factors most important in affecting CN7 outcome in lateral skull base surgery for benign lesions. STUDY DESIGN: A retrospective review of 217 nonmalignancy lateral skull base procedures from 1970 to 1995 at the Otology Group in Nashville. METHODS: Charts were reviewed for epidemiology, histopathology, staging, type of CN7 mobilization (none, short, long, severance with reanastomosis, and resection), preoperative and postoperative CN7 function, surgery performed, and survival. RESULTS: Average House-Brackman (HB) scores for mobilizations were as follows: short, 1.65: long, 2.74: and grafting, 4.33. Factors found to affect outcome in a statistically significant fashion were preoperative HB score, staging, type of CN7 manipulation, and surgical approach. Meningiomas were found to have a worse outcome than glomus tumors. CONCLUSIONS: Complete resection of tumors should be performed with minimal manipulation of the facial nerve based on regional anatomy and tumor anatomy.

Vagal paraganglioma: a review of 46 patients treated during a 20-year period.

BACKGROUND: Vagal paragangliomas (VPs) arise from paraganglia associated with the vagus nerve. Approximately 200 cases have been reported in the medical literature. Because of their rarity, most information regarding these tumors has arisen from case reports and small clinical series. OBJECTIVE: To detail the clinicopathologic features of 46 patients with VP with an emphasis on the role of a multidisciplinary skull base team in both the successful extirpation and rehabilitation. DESIGN: Retrospective review of 46 patients with VP managed by a single skull base team. SETTING: An academic tertiary medical center. RESULTS: Forty-six patients were treated over a 20-year period (1978-1998). Ten (22%) demonstrated intracranial extension. There was a history of familial paragangliomas in 9 (20%) of the patients. The incidence of multicentric paragangliomas was 78% in patients with familial paragangliomas vs 23% in patients with nonfamilial paragangliomas. Management of this group of 46 patients consisted of surgery (n = 40), radiation therapy (n = 4), and observation (n = 2). The operative approach consisted of a transcervical excision often combined with a transtemporal or lateral skull base approach as dictated by the tumor extent. Postoperative cranial nerve deficits were common, and, as such, aggressive rehabilitation was a vital component in the management of these tumors. CONCLUSIONS: The management of VP and its associated cranial nerve deficits remains a difficult clinical problem. Options for treatment include surgical resection, radiation therapy, and, in selected cases, observation. Surgical extirpation requires a multidisciplinary skull base team to achieve complete tumor resection. Radiation therapy is reserved for elderly patients and patients at risk for bilateral cranial nerve deficits. Rehabilitation of cranial nerve deficits is an integral part of the management of VP.

Medical treatment of headache after suboccipital acoustic tumor removal.

OBJECTIVES: Suboccipital craniotomy is a frequently used surgical approach for removal of cerebellopontine angle (CPA) tumors. A frequently cited consequence, however, is the high incidence of postoperative headaches. Much has been written regarding prevention of these headaches, but little has been written of their treatment. The authors review their extensive experience in suboccipital tumor removal and the medical management of postoperative headache, highlighting the recent use of a regimen of divalproex sodium and verapamil. STUDY DESIGN: Retrospective chart review. METHODS: The charts of a consecutive series of patients having suboccipital craniotomies for CPA tumors were reviewed. Presence, duration, and severity of headache were noted. Medical treatments and their effectiveness were also noted. RESULTS: Between 1980 and 1997, 228 patients underwent suboccipital craniotomy for removal of CPA tumors. Of these patients, 124 (54.4%) complained of headache. For 62 (27.2%) the headaches persisted for more than a year after surgery. Twenty-nine patients (12.7%) received no relief from any medication. Ten of these patients received a regimen of divalproex sodium and verapamil, with all patients obtaining significant relief. CONCLUSION: Headache is a significant problem with the suboccipital approach for acoustic tumor removal. The majority of patients that complain of headache can be adequately treated with nonsteroidal anti-inflammatory drugs (NSAIDs). If pain is unrelieved by NSAIDs, treatment becomes problematic. The authors' early experience with divalproex sodium/verapamil is encouraging and deserves further investigation as a treatment for these refractory cases.

Management of nonacoustic cranial nerve neuromata.

OBJECTIVE: This study aimed to review the authors' experience with diagnosis and management of nonacoustic neuroma of the cerebellopontine angle and skull base. In addition, management strategies for each type of tumor are suggested. STUDY DESIGN: A retrospective review of the charts of patients at the authors' institutions who underwent surgery for neuroma of the fifth through twelfth cranial nerves, between the years 1980-1996, was undertaken. Presenting symptoms, diagnostic techniques, and treatment are discussed for each type of lesion. PATIENTS: Four individuals with trigeminal neuroma, 1 individual with abducens neuroma, 40 individuals with facial neuroma, 3 individuals with glossopharyngeal neuroma, 21 individuals with vagal neuroma, 1 individual with accessory neuroma, and 4 individuals with hypoglossal neuroma participated. INTERVENTIONS: Surgical resection versus observation was examined. MAIN OUTCOME MEASURES: Freedom from recurrence or complication was measured. RESULTS: Surgical resection achieved in all patients, aside from the patient with abducens neuroma who is being observed, was measured. CONCLUSIONS: The preoperative diagnosis of nonacoustic lower cranial nerve neuroma is fairly common at the authors' institutions. Each type of neuroma requires its own tailored surgical approach once a decision has been made to resect the tumor.

Meningiomas intrinsic to the geniculate ganglion.

OBJECTIVE: To present the clinical, surgical and histopathological manifestations of meningioma intrinsic to the geniculate ganglion. STUDY DESIGN: Retrospective study of outcome. SETTING: Three private tertiary and one university (otology/neurotology) referral centers. PATIENTS: Six patients with cranial nerve VII paresis underwent magnetic resonance imaging and/or high-resolution computed tomography for subsequently histologically proven intrinsic meningioma of the geniculate ganglion. An additional six cases were identified in the literature. Most patients were female and ranged in age from 5 to 40 years. INTERVENTION: Total tumor removal via middle fossa and mastoid exposures followed by cable graft VII-VII neuroanastomosis. MAIN OUTCOME MEASURE: Meningioma can occur intrinsic to the geniculate ganglion and produces gradual VIIth nerve paresis as its first symptom. Other sites of predilection may occur extrinsically within the temporal bone or along intracranial venous sinuses at sites of arachnoid villi. RESULTS: Hearing was maintained in each patient, and postoperative House-Brackmann grade III-V facial nerve function was achieved. CONCLUSIONS: Intrinsic meningiomas of the geniculate ganglion rarely occur. However, this entity should be included in the differential diagnosis of a slowly progressive VIIth nerve paresis, especially in young females. Surgical removal and cable graft VII-VII neuroanastomosis is the treatment of choice. Long-term follow-up should be maintained because of the potential for von Recklinghausen's disease.

Brain herniation into the middle ear and mastoid: concepts in diagnosis and surgical management.

OBJECTIVE: To review the occurrence characteristics of and clinical repair experience with brain herniation in to the middle ear and mastoid from 1970-1995. STUDY DESIGN: Retrospective chart/case review. SETTING: Private Otology/Neurotology referral practice. PATIENTS: Thirty-five patients with temporal bone brain herniation diagnosed and treated from 1970-1995. INTERVENTION: Diagnosis confirmed by CT and/or MRI. Treatment was surgical. MAIN OUTCOME MEASURES: Success of surgical repair of the problem in a large experience with follow-up of up to 180 months (mean, 48.7 months). RESULTS: Diagnosis is most effectively made by both (computed tomography (CT) and magnetic resonance imaging (MRI). In this series diagnosis was accurate in 89% with MRI. Primary repair was successful in all but three patients, two of whom required a second repair. One was unreconstructable. CONCLUSIONS: Temporal bone encephaloceles occur after ear surgery and in chronic otitis media. Prompt and effective surgical repair is successful and integral to complication avoidance.

Management of acoustic neuroma in the elderly population.

OBJECTIVE: Ongoing controversy regarding the optimal treatment of acoustic neuromas in the elderly population has prompted us to examine the our experience in order to arrive at a treatment algorithm. STUDY DESIGN: Retrospective case review. SETTING: Tertiary referral center. PATIENTS: The records of 48 elderly patients ranging from age 70 to 90 years with acoustic tumors were reviewed. INTERVENTIONS: In 34 cases, tumor size was followed through serial imaging for a mean 28.5 months (range 5-108 months). Eight of these patients subsequently required surgery for significant tumor growth. An additional 12 patients were managed surgically from the time of diagnosis. MAIN OUTCOME MEASURE: The natural history of acoustic neuromas in the elderly population. RESULTS: The mean tumor growth rate for the watched group was 0.29 cm/y. Fifteen patients demonstrated no growth whereas accelerated growth was noted in eight cases. Ten patients with tumors confined to the internal auditory canal demonstrated an average growth rate of only 0.06 cm/y over a mean interval of 38 months. For the surgically treated group, the mean tumor size at the time of resection was 2.8 cm. Resection was described as complete in 17 cases and near-total in three cases. Perioperative complication rates and facial nerve results were comparable to our figures for all age groups. There was one perioperative death. CONCLUSIONS: Elderly patients with small acoustic neuromas should be offered a trial of observation. When significant tumor growth, size, or neurologic deterioration are demonstrated, early surgical intervention is required to avoid complications associated with the removal of larger tumors.

Lateral skull base surgery: the otology group experience.

Lateral skull base surgery has remained the surgical frontier of new developments in the treatment of lesions heretofore difficult to access. Examination of surgical results stimulates technical innovation and provides an intervention risk-benefit ratio assessment for particular lesions useful in management planning. With this in mind, we report the updated collective experience with lateral skull base surgery at the Otology Group over the past 20 years. Two hundred ninety-eight patients underwent surgical intervention for lateral skull base lesions. In 81 patients these lesions were malignant; in 217, benign. Of the benign lesions, 165 were glomus tumors: 139 glomus jugulare, 19 glomus vagale, and 7 glomus tympanicum. The remainder comprised 21 menigniomas, 14 neuromas, two neurofibromas, and a small group of much rarer entities. The philosophy of surgical approach, results, and follow-up are discussed.

Pediatric neurotologic skull base surgery.

The objectives of neurotologic skull base surgery are complete resection of the lesion and high-grade function following surgery. There is a perception that these goals are more difficult to achieve in children than in adults. Skull base disease in children and adolescents is rare. Of the 292 skull base tumors treated from 1970 to 1995 by The Otology Group in Nashville, 15 were in patients 21 years of age or younger, with only 5 patients under 10 years old. In this retrospective study, the authors review these 15 cases and compare them to their adult series. The pathology encountered in the 15 young patients with skull base tumors included 8 glomus lesions and 4 schwannomas. In these patients, 13 tumors occurred sporadically, and 2 tumors were related to neurofibromatosis type 2. Advanced-stage disease and malignancy were prevalent in this younger patient group. All patients underwent excision of their skull base tumor, with one procedure considered a subtotal resection. As compared with an adult glomus tumor series, postoperative cranial nerve function and complication rates were generally worse in the young glomus patients. However, postoperative function and complications were consistent with the extensive procedures required for the treatment of advanced disease. Despite the advances that have been made in imaging and treatment modalities, this study illustrates the need for more timely diagnosis in younger patients with skull base tumors.

Mutational spectrum in the neurofibromatosis type 2 gene in sporadic and familial schwannomas.

Using a heteroduplex approach and direct sequencing, we have completed the screening of approximately 88% of the neurofibromatosis type 2 (NF2)-coding sequence of DNA extracted from 33 schwannomas from NF2 patients and from 29 patients with sporadic schwannomas. The extensive screening has resulted in the identification of 33 unique mutations. Similarly to other human genes, we have shown that the CpG sites are more highly mutable in the NF2 gene. The frequency, distribution, and types of mutations were shown to differ between the sporadic and familial tumors. The majority of the mutations resulted in protein truncation and were consistent with more severe phenotype, however three missense mutations were identified during this study and were all associated with milder manifestations of the disease.

Stapedectomy in profound cochlear loss.

Stapedectomy can be used in certain patients with profound sensorineural hearing loss and stapes fixation to improve hearing to a level at which a hearing aid may be effective. This study reviews the outcomes of 11 patients with profound cochlear loss secondary to otosclerosis who underwent stapes surgery performed by the senior author (M.E.G.) over a 25-year period. Postoperative hearing aid usage was effective in 9 of 11 patients. Preoperatively, these patients derived no benefits from hearing aids. Stapedectomy may be of immense value in patients with the proper history and profound cochlear loss.

Slow-flow phenomena in magnetic resonance imaging of the jugular bulb masquerading as skull base neoplasms.

Enhancement in the region of the jugular foramen on magnetic resonance imaging (MRI) is highly sensitive to the presence of a skull base neoplasm. Unfortunately, this imaging method lacks the specificity to be the sole criterion in the diagnosis of a lesion of the jugular foramen. Although well described in the radiological literature, the phenomenon of gadolinium enhancement of the relatively static blood in the jugular system continues to be erroneously diagnosed as glomus jugulare tumor. Instances of this phenomenon present in patients referred to our practice for surgical opinions before radiation therapy and/or definitive resection will be presented. The purpose of this communication is to bring this potential treatment pitfall to the attention of the neurotology community. Treatment planning for lesions of the lateral skull base cannot singularly be based on MRI findings but requires a healthy skepticism satisfied only by more complete evaluation.

Hearing conservation in surgery for glomus jugulare tumors.

The most common ground on which surgery for glomus jugulare (GJ) tumors is criticized is the perceived risk of functional incapacity that attends possible cranial nerve (CN) loss. It is aggregate lower CN loss that is most often highlighted as particularly disabling to the quality of postsurgical survival. The documented success of both conservation surgery and operative rehabilitation of phonopharyngeal surgical deficits has, however, neutralized much of this criticism. The issue of hearing conservation (HC) in neurotologic skull base surgery, on the other hand, has not been well documented toward this end. The presence of a GJ neoplasm need not reflexly nor technically forfeit preexisting hearing. HC is, admittedly, a subordinate priority to total tumor removal, successful distal control of the internal carotid artery, and even facial nerve integrity. Yet, in appropriately selected patients, existing operative technology permits hearing preservation, a noteworthy addition to the high-grade functional outcome we have come to reasonably expect of conservation surgery. Hearing salvage further serves to define the concept of neurotologic skull base surgery. Hearing preservation in 122 GJ tumor patients is reviewed. Intuitively, as for acoustic tumor, HC appears tumor size related. Selection criteria for conservation surgery and its operative technique are detailed. Outcome is appropriately scored. The radiation therapy literature on this subject will be assiduously scrutinized for comparison.

A surgical solution for the difficult chronic ear.

We all encounter them: difficult chronic ears that seem to confound management efforts and that constitute an unrelenting imposition to the patient. Typically these ears have undergone multiple surgeries and are chronically infected. Such cases are commonly associated with residual or recurrent cholesteatoma. Those rare ears that temporarily respond to therapy promptly recur once treatment is withdrawn. Even the most aggressive nonsurgical protocols fail these patients, who exhibit lifelong social and professional incapacity. They seem to ultimately defy resolution. The purpose of this article is to present a surgical solution to the difficult chronic ear dilemma that emphasizes disease control. Treatment outcome is reviewed in 541 cases. Management pitfalls are analyzed with follow-up, in some cases 20 years.

Endolymphatic system shunting: a long-term profile of the Denver Inner Ear Shunt.

Endolymphatic system surgery for Meniere's disease, particularly endolymphatic shunting, remains controversial. In 1988, we presented our findings on the efficacy of the Denver Inner Ear Shunt in 100 patients. These data were accumulated in the short term. The purpose of this article is to review the long-term results of our endolymphatic shunt procedure, highlighting the population of Denver Inner Ear Shunt recipients. Results were analyzed according to both 1972 and 1985 AAO-HNS criteria. We seek corroboration or refutation of our preliminary conclusion that (a) endolymphatic shunt surgery has little efficacy and that (b) the Denver valve does not appear to offer any advantage in this regard.

Ossiculoplasty using the black hydroxylapatite hybrid ossicular replacement prostheses.

The problems of ossicular reconstruction in chronic ear surgery have led to the development of new ossicular replacement prostheses. Improvements in biocompatibility and design led to the development of hydroxylapatite hybrid (HaH) ossicular replacement prostheses. The senior author's (M.E.G.) experience with the Black HaH prostheses is reviewed. Sixty cases are grouped by procedure and prosthesis (19 TORPs and 41 PORPs) with a minimum follow-up of 1 year. Audiometric data are analyzed to determine the success rate in air-bone gap closure. Complication and extrusion rates are reviewed. These results are compared against those obtained using other prostheses using similar criteria, and this report serves as a follow-up on a previous paper on this subject by the senior author.