Non-surgical management of acoustic neuromas

Watchful waiting is one of the options available in the management of acoustic neuromas and this article deals with 13 patients who were so managed. Non-operative management was advised because of age, poor general health, small size of tumour, only hearing ear, or in patients unwilling to undergo surgery for various reasons. This group was followed up at 6-12-monthly intervals and the follow-up period ranged from 1 to 18 years (mean 5.3 years). Ten patients had small tumours and only in 2 of these was increase in tumour size demonstrated on follow-up CT scan. In one this increase was later followed by regression. Two patients required partial removal of tumour because of increasing symptoms after 3 and 7 years of follow-up; one of them died on the twelfth post-operative day. There appears to be a small group of patients for whom delay is worth while rather than to subject all patients with acoustic neuroma to surgery from which full recovery cannot be guaranteed.     

Management of growing vestibular schwannomas

Conservative management of small vestibular schwannomas is frequently proposed as most tumours do not grow. Anyway, tumour growth is reported in 30–40 % of the cases, so that surgery is consequently generally proposed. We primarily observed 161 patients affected by unilateral vestibular schwannomas. All patients were examined by means of gadolinium-enhanced magnetic resonance imaging scans. Tumour growth was recorded in 58 cases (35.8 %) and these subjects set up the group of study. Twenty-two (37.9 %) patients were surgically treated; tumour was always completely removed, all patients had normal facial function after surgery and only one patient suffered from a major complication (cerebellar haematoma). Fourteen patients (24.1 %) were submitted to radiotherapy, while one patient was lost at follow-up and another one died because of other medical reasons. Finally, 20 (34.5 %) subjects continued to be observed for different reasons. The mean follow-up period after identification of growth was 6.1 years. Nine tumours continued to grow, nine tumours stopped growing, one tumour grew and then regressed in size and one tumour decreased. Sixty percent of patients with useful hearing at diagnosis preserved it during the entire observation period. In conclusion, most of VS do not grow; in case of tumour growth, a surgical procedure may be suggested and the outcomes are not negatively influenced by the delay of the procedure. But in some cases, patients can still follow the “wait and scan” policy. In fact, only less than half of the growing tumours continued to grow. Moreover, most of the patients continued to retain a useful hearing.     

Growth rate of acoustic neuromas

During the past 25 years the authors have diagnosed over 1,600 acoustic neuromas. In almost all of the cases surgery for the removal of the tumor was performed shortly after the diagnostic tests. However in 35 cases one or more follow-up imaging studies was performed since the patients refused surgery, or surgery was not performed because of the poor general condition of the patients or the small size of the lesion, particularly in individuals of advanced age. In the latter group there was a clear understanding that surgery would be performed if the follow-up study showed progression of the lesion. In this paper the authors review the evolution of the tumor in the 35 cases, try to establish the rate of growth in cases where the tumor became larger, and correlate tumor evolution to patient's age and clinical findings.     

Conservative management versus surgery for small vestibular schwannomas

A high rate of deterioration in hearing function and the loss of patient compliance during conservative management should be taken into account when considering hearing preservation strategies for patients with vestibular schwannoma (VS).To compare conservative management with surgery for solitary small VS.Among 693 patients followed up for VS between 1991 and 2002, 114 (16%) intracanalicular VSs (stage 1) and 302 (44%) VSs measuring <15 mm in the cerebellopontine angle (stage 2) were included in this study. Initially, surgery was performed in 305 (73%) cases (50 stage 1, 255 stage 2) and 111 (27%) were managed conservatively (64 stage 1, 54 stage 2) by means of annual MRI scans and audiometry. Conservative management was chosen in patients aged >60 years and in those who refused surgery. In this subgroup, the mean follow-up period was 33 months (range 6-111 months).In the conservative management group, 47% of VSs showed significant growth, 47% were stable and 6% showed regression. Seventeen patients (15%) were operated on secondarily for tumour growth and 1 (1%) was irradiated for tumour growth and because surgery was contraindicated. Deterioration of hearing function by > or =1 class was observed in 56% of cases, 34% of patients were initially in hearing class D and only 10% showed stable hearing function. Of the conservative management group, 17% were lost during follow-up. After surgery, grade 1 or 2 facial function was obtained in 86% of cases. Following hearing preservation attempts (n=137), 54% of patients were in hearing classes A-C.     

Acoustic neuroma: outcome study

Three therapeutic modalities have been advocated in the management of acoustic neuromas: observation, surgery, and radiosurgery. Although surgery is still considered conventional treatment, at times the management can be controversial. The objectives of this article are to assess the results of each of these treatment modalities in a tertiary care acoustic neuroma referral setting. The methodology chosen was to group the patients along the initial intent to treat and then to see the results obtained. A total of 51 patients followed in the Skull Base Clinic of the McGill University Health Centre were included. The intent to treat was as follows: observation, 22 patients; surgery, 26 patients; and radiosurgery, 3 patients. The results showed that 50% of those followed by observation demonstrated growth and required surgery or radiotherapy. Surgical results, in terms of facial nerve outcome, varied with tumour size but also improved dramatically with the introduction of facial nerve monitoring and a multidisciplinary approach. In small and medium-size tumours (< 30 mm), intent to treat by observation or by surgery (with intraoperative monitoring) yielded similar results. The limitations of this study are discussed. In the future, a prospective multicentric study may help better in assessing the value of the various management options.     

Effectiveness of conservative management of acoustic neuromas

OBJECTIVE: The goal of this study was to assess the effectiveness of the conservative management in patients with acoustic neuroma (vestibular schwannoma). STUDY DESIGN: This retrospective study was performed in a university hospital. PATIENTS: Patients were selected for this wait-and-see policy on the basis of age, general condition, audiometric results, tumor size, and patient preference. The study group included 97 patients, 87 of whom had at least two neuroradiologic examinations. The mean age of this population was 63 years (29 to 89 years). The mean length of follow-up of this population was 31 months. Eighty-seven of these patients had at least two radiologic examinations (magnetic resonance imaging or computed tomography). The mean interval between the initial and follow-up radiologic examinations was 15 months. MAIN OUTCOME MEASURES: Tumor size was measured by use of two-dimensional data in all patients. The mean tumor size was 12 mm. The growth rate of the tumor was estimated by comparison of the results of the measurements from the initial and follow-up neuroradiologic examinations. RESULTS: Of the 97 patients studied, 6 patients required surgery and 6 required radiotherapy. Sixty patients (62%) were still being treated conservatively at the end of the study period. Three patients of 28 who were classified as candidates for hearing preservation surgery lost their candidacy during the observation period. The mean annual tumor growth rate was 1.52 mm/year. The tumor was stable in size in 36% of patients, regressed in 11% of patients, or grew in 53% of patients. The growth patterns of the acoustic neuroma fell into five categories: continuous growth in 15% of patients, negative growth in 5%, growth followed by negative growth in 40%, negative growth followed by growth in 20%, and no variation of tumor size in 20%. CONCLUSION: Conservative management of acoustic neuromas carries difficulties: long-term follow-up of the patients and unpredictability of the tumor growth pattern. A reliable and reproducible radiologic method for evaluating tumor size is of great importance.     

Management of acoustic neuromas in the elderly: retrospective study

The wide availability of gadolinium-enhanced magnetic resonance imaging (MRI-Gd) has led to the discovery of an increasing number of small and less symptomatic acoustic neuromas in elderly patients. We conducted a retrospective study in order to obtain data on outcomes and complications associated with different management strategies that would be useful in establishing a management guideline. We identified 44 patients aged 65 to 77 years with acoustic neuromas who had been managed with either surgery or simple observation with MRI-Gd imaging. Of the entire group, 36 patients had tumors larger than 1 cm, and they underwent surgery (most via the translabyrinthine approach). Complete removal of the tumor was achieved in 34 of these patients (94.4%). At the 1-year follow-up, grade VI facial nerve paralysis was evident in only two of 35 evaluable patients (5.7%). Postsurgical complications occurred in five patients (13.9%), including one death. The remaining eight patients had tumors 1 cm or smaller, and they were managed with periodic MRI-Gd scanning. At the 5-year follow-up, no tumor growth was seen in six of these patients. The other two patients exhibited a tumor growth rate of less than 2 mm per year. No patient in the observation group required surgical intervention.     

Acoustic neuroma surgery and tinnitus

The objectives of this study were to assess the effect that acoustic neuroma surgery has on tinnitus and to investigate possible predictors (tumour size and patients' ages at operation) as well as to ascertain if the overall quality of life in patients with acoustic neuromas is affected by their tinnitus. A questionnaire was sent to randomly selected patients post acoustic-neuroma surgery. This was based on the Glasgow Benefit Inventory and contained a standardised series of four functional gradings for tinnitus. In this study, 51 patients from a total of 68 returned the questionnaire, and there was a follow-up period of between 1 and 3 years following the acoustic neuroma surgery. The age at operation, size of the tumour and overall quality of life were correlated with the impact of surgery on tinnitus. Statistical analysis used the one-way analysis of variance, chi-square test, one-way analysis by ranks and Spearman Rank Correlations. Significance was accepted at the P<0.05 level. Overall, 30 (58.8%) of the patients had tinnitus preoperatively in comparison to 34 (66.6%) postoperatively. After surgery, tinnitus became better in 8 (16%) patients, 28 (55%) did not experience any change, and 15 (29%) became worse. Neither tumour size nor age at the time of the operation had a statistically significant association with the impact of surgery on tinnitus. There was no statistically significant association between changes in tinnitus status and changes in the quality of life following the operation ( P>0.05). A significant percentage of patients with acoustic neuromas, approximately 60%, suffer from tinnitus preoperatively, and this number may increase slightly postoperatively. It remains unpredictable which patients will improve, which will show no change and which will deteriorate as age and tumour size do not seem to be associated with the impact of surgery on tinnitus. The results also suggest that tinnitus may be of relatively minor importance in the overall quality of life of patients following acoustic neuroma surgery. However, candidates for surgery should be thoroughly informed about the possible effect of the operation on their tinnitus status.     

Management of acoustic neuromas in patients 65 years or older.

OBJECTIVE: To analyze an optimal management protocol for patients 65 years or older at the time of acoustic neuroma diagnosis. STUDY DESIGN: Retrospective case review. SETTING: Tertiary care hospital. PATIENTS: Two hundred sixteen patients with acoustic neuroma 65 years or older at time of diagnosis. INTERVENTION: Patients with smaller tumors (<2.5 cm) were followed with serial magnetic resonance imaging. If significant growth occurred, they were treated with surgery. Surgery was performed at initial diagnosis on patients with larger tumors or in selected patients for hearing preservation. Stereotactic radiotherapy was performed for poor surgical candidates and for patient choice. OUTCOME MEASURES: Measurement of acoustic neuroma growth and tabulation of complications. RESULTS: One hundred fourteen patients were initially managed by observation, 80 with surgery, and 3 with radiation therapy, with an average follow-up of 35.4 months. For patients in the observation group, average tumor growth was 1.2 mm/yr. Thirty-two patients required crossover to surgery or radiotherapy due to tumor growth (average growth, 4.1 versus 0.3 mm/yr for those remaining in the observation group). One of the patients in the observation group had a complication (0.9%). CONCLUSION: Management of acoustic neuromas in elderly patients can be based on size and "biological age" criteria. Surgical treatment can safely be reserved for the few patients who have significant tumor growth.     

Audiologic findings after stereotactic radiosurgery in nine cases of acoustic neurinomas.

Nine cases of acoustic neurinoma were treated by stereotactic radiosurgery between 1969 and 1974. The follow-up period can now be regarded as sufficiently long for a preliminary evaluation of the results. An arrest of growth or shrinkage of the tumour was observed in 8 of the 9 cases. In one case open surgery was performed 2 years after irradiation and histological examination showed regressive changes of the type expected after irradiation. Audiological examination revealed that in the majority of cases radiosurgery could be performed without causing serious damage to the hearing function. The average hearing loss present before treatment increased on average only 20.0 dB in the most successful 7 cases. None of the patients suffered facial nerve involvement. In small and medium-sized acoustic tumours this method offers a satisfactory therapeutic alternative worthy of consideration.     

The jugulotympanic paragangliomas: 41 cases report

OBJECTIVE: The jugulotympanic paragangliomas (JTP) represents the most frequent tumour of the middle ear but also of the temporal bone, after the acoustic neurinoma. The management of these vascular tumours remains uncleared. The purpose of this study was to report our experience about JTP in the CHU of Grenoble. MATERIALS AND METHODS: Retrospective study of 41 patients, between 1973 and 1996. Six stages A, 8 stages B and 27 stages C are reported in whom 20 cases (49%) presented an intracranial extension (classification of Fisch). There were 2 familial cases with multiple localisations, in particular carotid. All the patients were divided in 3 groups: surgery or radiation therapy in first intention, surgery followed by radiation therapy. RESULTS: A total tumor removal without recurrence was achieved by surgery in more than 95% of the cases with 6 years follow-up but was associated with significant morbidity (major cranial nerve injury). We noticed one death by laryngospasme (C2Di2 tumour operated by infratemporal A approach). A stabilization of the tumour was obtained with radiotherapy in first intention in 75% of the cases (5 years follow-up) but with a risk of radionecrosis. A revision surgery was necessary in 3 cases. CONCLUSION: The comparaison of our different therapeutic management, surgery (23), radiation therapy (16) or combined (2), encourage us to perform a radical surgery whenever possible. Because of the slow rate of growth, the radiotherapy is indicated for older patients, at risk for surgery or extensive tumors. The objectives of the radiation therapy are to obtain a tumoral stabilization with improvement of the symptoms and low morbidity. The management of this rare pathology must be multidisciplinary. The recent discoveries on genes encoding three succinate dehydrogenase subunits (SDHD, SDHB et SDHC) will allow a genetic detection of asymptomatic case and will define the procedures for their management, coordinated by a national network PGL.NET. A retrospective study could also study the real incidence of familial paragangliomas.     

Conservative management versus surgery for small vestibular schwannomas

Conclusion

A high rate of deterioration in hearing function and the loss of patient compliance during conservative management should be taken into account when considering hearing preservation strategies for patients with vestibular schwannoma (VS).

Objective

To compare conservative management with surgery for solitary small VS.

Material and methods

Among 693 patients followed up for VS between 1991 and 2002, 114 (16%) intracanalicular VSs (stage 1) and 302 (44%) VSs measuring <15 mm in the cerebellopontine angle (stage 2) were included in this study. Initially, surgery was performed in 305 (73%) cases (50 stage 1, 255 stage 2) and 111 (27%) were managed conservatively (64 stage 1, 54 stage 2) by means of annual MRI scans and audiometry. Conservative management was chosen in patients aged >60 years and in those who refused surgery. In this subgroup, the mean follow-up period was 33 months (range 6–111 months).

Results

In the conservative management group, 47% of VSs showed significant growth, 47% were stable and 6% showed regression. Seventeen patients (15%) were operated on secondarily for tumour growth and 1 (1%) was irradiated for tumour growth and because surgery was contraindicated. Deterioration of hearing function by ≥1 class was observed in 56% of cases, 34% of patients were initially in hearing class D and only 10% showed stable hearing function. Of the conservative management group, 17% were lost during follow-up. After surgery, grade 1 or 2 facial function was obtained in 86% of cases. Following hearing preservation attempts (n=137), 54% of patients were in hearing classes A–C.     

Suboccipital surgery for acoustic neuroma

A retrospective study was performed on 106 consecutive patients with an acoustic neuroma who underwent suboccipital surgery for the first time between 1980 and 1992. Complete follow-up data were available for all the patients, including regular imaging up to 1 January 1994. Incomplete removal of the tumours was chosen in preference to radical surgery in a large proportion of the patients, to avoid the risk of postoperative morbidity. The recurrence rate in this series was 20%. Comparison of the results of suboccipital surgery to those obtained using other surgical approaches, while taking the tumour size into consideration, showed that better results can be obtained after total removal of the tumour without any additional risk to post-operative facial nerve function. The long-term results of subtotal removal using the suboccipital approach were disappointing. It is therefore necessary to review the indications for non-radical surgery in patients with an acoustic neuroma.     

Pleomorphic adenoma of the parotid gland: is long-term follow-up needed?

INTRODUCTION: Pleomorphic adenoma is a slow-growing benign salivary tumour most commonly arising in the parotid gland. Macroscopically it has a surrounding capsule from which it can be enucleated-often the treatment used in the past. These tumours do not have a true capsule but can press surrounding normal salivary gland, frequently having finger-like extensions into the normal tissues. Recurrence, or more accurately residual disease, is thought to be due to these small islands of tumour which can be left behind at surgery, in particular enucleation which is associated with high recurrence rate. The current, most common practice is the excision of these tumours through superficial parotidectomy and postoperative follow-up. However, is long-term follow-up necessary and does it reduce the morbidity from tumour recurrence? METHODS: We reviewed the charts of 182 patients who underwent parotid surgery operated upon by a single surgeon (RKM) between 1973 and 1999. We included only 58 cases of pleomorphic adenomas removed by superficial parotidectomy. We excluded cases that had follow-up of less than 12 months and cases which had previous surgery elsewhere. Adequate tumour excision and the integrity of the capsule were ascertained intra-operatively, and this was confirmed by postoperative histology. RESULTS: In our study we had 34 females, mean age of 58, and 24 males, mean age of 50. The average follow-up was 6 years with a range of 1-23 years. We had no permanent facial nerve dysfunction, and we recorded only one recurrence (1.7%). CONCLUSION: Provided adequate excision of the tumour with intact capsule and histological confirmation are achieved, long-term follow-up is unnecessary and can be replaced by patient education and self-examination.     

Conservative management of patients with small acoustic tumors

Of 432 patients referred for treatment of their cerebellopontine angle tumors, 53 with acoustic neuromas were managed initially without intervention but with adequate follow-up. Mean presenting tumor size in this subgroup of patients was 0.98 cm (range, 0.2 to 3.0 cm), and average growth rate was 0.16 cm per year. Twenty-one patients demonstrated tumor growth with a mean follow-up interval of 1.9 years. Of these 21 patients, 14 underwent microsurgical excision, 4 received radiation, 2 continued to be observed and 1 was lost to follow-up. The remaining 32 (60%) had no demonstrable growth with a mean follow-up of 2.13 years. Of these patients, 29 continue to be followed and 3 were lost to follow-up. Of the information evaluated, the only statistically significant relationship is with larger tumor size in elderly patients–most likely reflecting the propensity to opt for conservative treatment in elderly patients. Tumor growth rate was unrelated to presenting tumor size or patient age, which suggests that conservative treatment may be appropriate in selected patients.     

Hearing preservation in acoustic neuroma surgery

Hearing conservation in acoustic tumour surgery remains controversial. There have been few previous reports in the British literature. The senior author has managed 24 patients by retrosigmoid surgery with the intention of preserving hearing during the last 9 years. The clinical features, surgical technique and results are discussed with respect to pre-operative selection criteria, and post-operative quality of hearing. Hearing preservation has been achieved in 11 (78.6%) of 14 patients with small or intracanalicular tumours and a mean minimum auditory threshold of 35 dB and 70% speech discrimination, the majority (81.8%) above the 50 dB/50% level. Tumour filling the fundus of the internal auditory canal was found to be a significant adverse prognostic factor as regards successful hearing preservation. Tumour excision was complete in all patients. Nearly 90% of patients had normal facial function, and the remaining 10% grade II function. Associated morbidity was minimal. It is suggested that the potential for hearing conservation should be considered as a factor in the management of patients with small acoustic neuromas.     

Bilateral acoustic neuromas

This article reviews 12 patients with bilateral acoustic neuromas. The sex incidence was equal and the mean age at diagnosis was 26.2 years. The family history was positive in nine of the patients. Five patients have had incomplete surgical removal of acoustic neuromas on both sides. Two of them are completely deaf and the other three have severe sensorineural hearing loss in one ear and no hearing in the other ear. In five patients the tumour on one side has been operated on and the other side is being observed with at least short-term preservation of good hearing. The remaining two patients died of intra-cranial complications, one of them post-operatively. Four patients developed facial palsy immediately following surgery and one developed facial weakness 6 months after surgery. Guidelines are discussed for the care of these patients including the timing of surgery and alternative treatment options (observation, radio-surgery adn chemotherapy). This is essentially a group of young individuals who have had multiple operations for bilateral acoustic tumours and associated manifestations and for whom the disease and the sequelae of treatment can be tragic.     

Contralateral auditory brainstem response abnormalities in acoustic neuroma

Contralateral Auditory Brainstem Response (ABR) findings in a series of 79 patients with unilateral acoustic neuroma are presented. Sixty-four patients (81 per cent) had a normal contralateral ABR, thirteen (16.4 per cent) had latency abnormalities contralaterally and in two patients (2.6 per cent) no consistent responses could be recorded despite good hearing. Abnormalities in the contralateral ABR were analysed and five patients had abnormal III-V interwave intervals, in seven patients the I-III intervals were abnormal and in one patient, only the fifth wave was present and of abnormal latency. The tumour size was assessed by computed axial tomography (CT) and the relationship between tumour size and contralateral ABR findings established. Large tumours (greater than 2.5 cm.) were associated with contralateral ABR abnormalities in 25.6 per cent of the patients, medium tumours (1.0-2.5 cm.) with ABR abnormalities in 14 per cent and there were no abnormalities in the small group (intracanalicular). The implications for interpretation of ABR recordings contralateral to an acoustic neuroma are discussed in relation to brainstem compression and its effect on the wave generator sites.     

The natural history of untreated vestibular schwannomas. Is there a role for conservative management?

OBJECTIVE: The aim of this study was to investigate the natural history and outcome following the conservative management of a group of patients with unilateral vestibular schwannomas. METHODS: 72 patients with a radiological diagnosis of unilateral vestibular schwannoma were managed conservatively because of poor general health, advanced age, patient preference, small tumour size, minimal symptoms, or tumour in the only/better hearing ear. All patients underwent serial magnetic resonance imaging for assessment of tumour growth, according to American Academy of Otolaryngology-Head & Neck Surgery guidelines (1995). The mean duration of follow-up was 37.8 months (range 12-194 months). Patients were deemed to have failed conservative management if there was evidence of continuous or rapid radiological tumour growth, and/or increasing symptoms or signs. RESULTS: The mean tumour growth rate was 1.16 mm/year (range -0.75 to 9.65 mm/year). Approximately 83% of tumours grew at less than 2 mm/year. Significant tumour growth (total growth > 1 mm) was seen in 36.4%, no or insignificant growth (0-1 mm) in 50%, and negative growth (< 0 mm) in 13.6% of tumours. The growth rate of cerebellopontine angle (CPA) tumours (1.4 mm/year) was significantly greater than that of tumours limited to the internal auditory canal (IAC) (0.2 mm/year) (p = 0.001). Failure of conservative management, in which active treatment was required, occurred in 15.3%. The outcome of these patients appeared to be as favourable as those who underwent primary treatment, without a period of conservative management. The growth rate of tumours in patients who failed conservative management (4.2 mm/year) was significantly greater than that in patients who did not fail (0.5 mm/year) (p < 0.01). No factors predictive of tumour growth were identified. Deterioration of mean pure tone average (0.5, 1, 2, 3 kHz) and speech discrimination scores occurred regardless of whether radiological tumour growth was demonstrated or not. CONCLUSIONS: The majority of vestibular schwannomas are slow growing, although, CPA tumours appear to grow faster than IAC tumours. Deterioration of auditory function occurs even in the absence of tumour growth. Although most Otolaryngologists and Neurosurgeons would agree that the treatment of choice for the majority of vestibular schwannomas is microsurgery, there remains a small group of patients in whom a conservative management approach may be a desirable alternative.