Hearing preservation in solitary vestibular schwannoma surgery using the retrosigmoid approach

Hearing Preservation Surgery in Vestibular Schwannoma: The Hidden Truth

To compare the results of hearing preservation surgeries using different approaches — the enlarged middle cranial fossa approach and the retrosigmoid approach — and different classification systems, stressing the importance of preserving “normal hearing,” we performed a retrospective case review in a tertiary care medical center. The charts of 107 patients with vestibular schwannoma who underwent tumor resection were reviewed. Hearing preservation was reported according to 2 different classification systems: the modified Sanna classification and the classification of the American Academy of Otolaryngology—Head and Neck Surgery. The facial nerve results were graded according to the House-Brackmann scale. The hearing preservation rates differed markedly depending on the classification used. We conclude that hearing preservation in acoustic neuroma is a more difficult proposition than most surgeons appreciate, especially in terms of serviceable hearing.

Long-term Auditory Symptoms in Patients With Sporadic Vestibular Schwannoma: An International Cross-Sectional Study

BACKGROUND

There are limited data on the long-term auditory symptoms in patients with sporadic small- and medium-sized vestibular schwannoma (VS). The initial treatment strategy for VS is controversial.

OBJECTIVE

To characterize auditory symptoms in a large cohort of patients with VS.

METHODS

Patients with ≤3 cm VS who underwent primary microsurgery, gamma knife surgery, or observation between 1998 and 2008 at 2 independent hospitals were identified. Clinical data were extracted from existing VS databases. At a mean time of 7.7 years after initial treatment, patients were surveyed via mail with the use of the Hearing Handicap Inventory for Adults (HHIA) and the Tinnitus Handicap Inventory.

RESULTS

The response rate was 79%; a total of 539 respondents were analyzed. Overall, the hearing prognosis was poor, because more than 75% of all patients had nonserviceable hearing at the last clinical follow-up. Good baseline hearing proved to be a strong predictor for maintained serviceable hearing. Treatment modality was independently associated with both audiometric outcome and HHIA results. Active treatment with microsurgery or gamma knife surgery did not appear to be protective, because patients who were observed had the greatest probability of durable hearing. Patients in the surgical series had the greatest hearing loss. Tinnitus Handicap Inventory results were less predictable. The only predictors of tinnitus handicap were age and HHIA score.

CONCLUSION

The overall prognosis for hearing in sporadic VS is poor regardless of treatment strategy. Treatment modality was an independent predictor of hearing status; observation was associated with the highest rate of hearing preservation. .

Facial Nerve Outcome after Vestibular Schwannoma Resection: A Comparative Meta-Analysis of Endoscopic versus Open Retrosigmoid Approach

The minimal access retrosigmoid endoscopic approach to vestibular schwannoma (VS) resection has been used with promising results. However, it has not been compared with the standard open approach in the literature. We performed a meta-analysis review for all articles describing both approaches for VS from 1996 to 2011. We found 1861 articles. After review and discussion, we narrowed our study to 25 articles, 4 endoscopic and 21 open. The total number of patients was 3026 for open and 790 for endoscopic. The mean tumor sizes in the open and endoscopic series were 2.5 cm and 2.7 cm, respectively. Good facial nerve outcome was achieved in 67% of the open series patients and in 94% of the endoscopic series patients. Other outcomes in the open and endoscopic series were the following: gross total resection, 91% versus 97%; functional hearing, 22.6% versus 46%; wound infection, 1.3% versus 2.6%; and recurrence, 5.4% versus 2.2%. We acknowledge the limitations of our study, but we can state that the endoscopic approach is not inferior to the standard open approach. In expert hands the endoscopic approach can offer as good a result as the open, with potential benefits such as less pain and a shorter length of stay in the hospital. There is a need for more controlled studies for a definitive comparison.

Hearing Preservation Using the Middle Fossa Approach for the Treatment of Vestibular Schwannoma

BACKGROUND:

The incidence of small vestibular schwannomas in patients with serviceable hearing is increasing because of the widespread use of MRI. The middle fossa approach provides the patient with an opportunity for tumor removal with hearing preservation.

OBJECTIVE:

To determine the rate of hearing preservation and facial nerve outcomes after removal of a vestibular schwannoma with the use of the middle fossa approach.

METHODS:

A retrospective case review at a tertiary, academic medical center was performed identifying patients from 1998 through 2008 that underwent removal of a vestibular schwannoma by the middle fossa approach. Preoperative and postoperative audiograms were compared to determine hearing preservation rates. In addition, facial nerve outcomes at last follow-up were recorded.

RESULTS:

Forty-six patients underwent a middle fossa craniotomy for the removal of a vestibular schwannoma. Of the 38 patients that had class A or class B hearing preoperatively, 24 (63.2%) retained class A or B hearing and 29 (76.3%) retained class A, B, or C hearing. When tumors were 10 mm or less in patients with class A or B preoperative hearing, 22 of 30 patients (73.3%) retained class A or B hearing. When the tumor size was greater than 10 mm in patients with class A or B preoperative hearing, 2 of 8 patients (25%) retained class A or B hearing. At most recent follow-up, 76.1% of patients had House-Brackmann grade I facial function, 13.0% had House-Brackmann grade II facial function, and 10.9% had House-Brackmann grade III facial function.

CONCLUSION:

Hearing preservation rates are excellent using the middle fossa approach, especially for smaller tumors. No patient experienced long-term facial nerve function worse than House-Brackmann grade III.

Change in hearing and tinnitus in conservatively managed vestibular schwannomas

OBJECTIVES

The aim of this study was to evaluate the change of hearing and tinnitus in a group of conservatively managed unilateral vestibular schwannomas (VS).

DESIGN

Retrospective case series review.

SETTING

Tertiary referral otoneurological and skull base surgery department.

PARTICIPANTS

Seventy patients affected by unilateral VS with at least two audiograms available were retrospectively evaluated.

MAIN OUTCOME MEASURES

Changes in pure tone average (PTA), speech discrimination score (SDS), and tinnitus were analyzed.

RESULTS

At diagnosis 16 patients (22.9%) had a PTA of 0 to 30 dB and 38 (54.4%) a PTA of 0 to 50 dB. At the end of the follow-up period, 9 patients (12.9%) had a PTA of 0 to 30 dB and 27 (38.7%) had a PTA of 0 to 50 dB, representing a hearing preservation rate of 56% and 70%, respectively. Of patients with both tonal and speech audiometry, 71.4% with class A hearing (PTA < 30 dB/SDS > 70%) maintained their initial hearing and 60% with class A or B hearing (PTA < 50 dB/SDS > 50%) maintained this useful hearing. Forty-two patients (60%) did not show a significant growth in their tumor over the period of observation. In this group of patients the mean PTA after a mean follow-up time of 40 months decreased from 44 dB HL to 50.8 dB HL, with a yearly rate of 2.47 dB HL. The chance of maintaining a PTA of 0 to 30 dB in this group of patients was 57.1% and a PTA of 0 to 50 dB was 81.4%.

CONCLUSIONS

In this group of patients affected by VS and managed conservatively with a mean follow-up of 33.3 months, the risk of losing eligibility for hearing preservation surgery was lower than 30%.

Hearing preservation in the resection of vestibular schwannomas: patterns of hearing preservation and patient-assessed hearing function

Object

No extant literature documents the analysis of patient perceptions of hearing as a corollary to objective audiometric measures in patients with vestibular schwannoma (VS), or acoustic neuroma. Therefore, using objective audiometric data and patient perceptions of hearing function as outlined on a questionnaire, the authors evaluated the hearing of patients who underwent VS resection.

Methods

This investigation involved a retrospective review of 176 patients who had undergone VS resections in which hearing preservation was a goal. Both pre- and postoperative audiometry, expressed as a speech discrimination score (SDS) and pure tone threshold average (PTA), were performed, and the results were analyzed. Intraoperative auditory brainstem responses were also recorded. Eighty-seven of the patients (49.4%) completed a postoperative questionnaire designed to assess hearing function in a variety of social and auditory situations. Multiple linear regression analyses were completed to compare available audiometric results with questionnaire responses for each patient.

Results

One hundred forty-two patients (80.7%) had PTA and SDS audiometric data pertaining to the surgically treated ear; 94 of these patients (66.2%) had measurable postoperative hearing, as defined by a PTA < 120 dB or SD > 0%. Eighty-seven patients (49.4%) completed the retrospective questionnaire, and 74 of them had complete audiometric data and thus were included in a comparative analysis. Questionnaire data showed major postoperative subjective hearing decrements, even among patients with the same pre- and postoperative objective audiometric hearing status. Moreover, the subscore reflecting hearing while exposed to background noise, or the “cocktail party effect,” characterized the most significant patient-perceived hearing deficit following VS resection.

Conclusions

The authors' analysis of a patient-perceived hearing questionnaire showed that hearing during exposure to background noise, or the cocktail party effect, represents a significant postoperative hearing deficit and that patient perception of this deficit has a strong relation with audiometric data. Furthermore, questionnaire responses revealed a significant disparity between subjective hearing function and standard audiometrics such that even with similar levels of audiometric data, subjective measures of hearing, especially the cocktail party effect, decreased postoperatively. The authors posit that the incorporation of patient-perceived hearing function evaluation along with standard audiometry is an illustrative means of identifying subjective hearing deficits after VS resection and may ultimately aid in specific and subsequent treatment for these patients.

Functional outcomes in retrosigmoid approach microsurgery and gamma knife stereotactic radiosurgery in vestibular schwannoma

Although vestibular schewannomas (VSs) are relatively rare as compared to other intracranial tumors, growing attention is required to achieve better outcomes with less morbidities among patients. In this retrospective study, we compared functional outcomes of retrosigmoid approach microsurgery (RSAMS) and gamma knife stereotactic radiosurgery (GKSRS) in VSs patients with serviceable hearing. Forty-six patients in inclusion criteria, who underwent RSAMS (n = 15) or GKSRS (n = 31) between January 2004 and June 2009 were reviewed. We evaluated symptoms at initial presentation, pre- and posttreatment pure-tone audiometry, speech discrimination score, tumor size, pre- and posttreatment assessments of facial nerve function, and pre- and posttreatment tinnitus, dizziness and facial paresthesia in vestibular schwannoma patients, who were treated with RSAMS or GKSRS. Hearing disturbance was the most common presenting symptom in both the groups. The hearing preservation rates in the RSAMS and GKSRS patients were 7% (1/15) and 45% (14/31), respectively. Two RSAMS patients and one GKSRS patient developed new facial neuropathy, defined as a temporary or permanent decline in House-Brackmann facial nerve grade. Tumor recurrence was observed in one RSAMS patient, whereas tumor size increase was observed in one GKSRS patient (3%). Tinnitus score was decreased after the treatment in both the groups. The results imply that GKSRS for vestibular schwannoma can possibly preserve hearing preservation with proper indication and treatment planning.

Decision analysis of treatment options for vestibular schwannoma

Object

Widespread use of MR imaging has contributed to the more frequent diagnosis of vestibular schwannomas (VSs). These tumors represent 10% of primary adult intracranial neoplasms, and if they are symptomatic, they usually present with hearing loss and tinnitus. Currently, there are 3 treatment options for quality of life (QOL): wait and scan, microsurgery, and radiosurgery. In this paper, the authors' purpose is to determine which treatment modality yields the highest QOL at 5- and 10-year follow-up, considering the likelihood of recurrence and various complications.

Methods

The MEDLINE, Embase, and Cochrane online databases were searched for English-language articles published between 1990 and June 2008, containing key words relating to VS. Data were pooled to calculate the prevalence of treatment complications, tumor recurrence, and QOL with various complications. For parameters in which incidence varied with time of follow-up, the authors used meta-regression to determine the mean prevalence rates at a specified length of follow-up. A decision-analytical model was constructed to compare 5- and 10-year outcomes for a patient with a unilateral tumor and partially intact hearing. The 3 treatment options, wait and scan, microsurgery, and radiosurgery, were compared.

Results

After screening more than 2500 abstracts, the authors ultimately included 113 articles in this analysis. Recurrence, complication rates, and onset of complication varied with the treatment chosen. The relative QOL at the 5-year follow-up was 0.898 of normal for wait and scan, 0.953 for microsurgery, and 0.97 for radiosurgery. These differences are significant (p < 0.0052). Data were too scarce at the 10-year follow-up to calculate significant differences between the microsurgery and radiosurgery strategies.

Conclusions

At 5 years, patients treated with radiosurgery have an overall better QOL than those treated with either microsurgery or those investigated further with serial imaging. The authors found that the complications associated with wait-and-scan and microsurgery treatment strategies negatively impacted patient lives more than the complications from radiosurgery. One limitation of this study is that the 10-year follow-up data were too limited to analyze, and more studies are needed to determine if the authors' results are still consistent at 10 years.

Mapping clinical outcomes expectations to treatment decisions: an application to vestibular schwannoma management

OBJECTIVE

Complex medical decision making obligates tradeoff assessments among treatment outcomes expectations, but an accessible tool to perform the necessary analysis is conspicuously absent. We aimed to demonstrate methodology and feasibility of adapting conjoint analysis for mapping clinical outcomes expectations to treatment decisions in vestibular schwannoma (VS) management.

STUDY DESIGN

Prospective.

SETTINGS

Tertiary medical center and US-based otologists/neurotologists.

SUBJECTS

Treatment preference profiles among VS stakeholders-61 younger and 74 older prospective patients, 61 observation patients, and 60 surgeons-were assessed for the synthetic VS case scenario of a 10-mm tumor in association with useful hearing and normal facial function.

MAIN OUTCOME MEASURE

Treatment attribute utility.

METHODS

Conjoint analysis attribute levels were set in accordance to the results of a meta-analysis. Forty-five case series were disaggregated to formulate microsurgery facial nerve and hearing preservation outcomes expectations models. Attribute utilities were computed and mapped to the realistic treatment choices of translabyrinthine craniotomy, middle fossa craniotomy, and gamma knife radiosurgery.

RESULTS

Among the treatment attributes of likelihoods of causing deafness, temporary facial weakness for 2 months, and incurable cancer within 20 years, and recovery time, permanent deafness was less important to tumor surgeons, and temporary facial weakness was more important to tumor surgeons and observation patients (Wilcoxon rank-sum, p < 0.001). Inverse mapping of preference profiles to realistic treatment choices showed all study cohorts were inclined to choose gamma knife radiosurgery.

CONCLUSION

Mapping clinical outcomes expectations to treatment decisions for a synthetic clinical scenario revealed inhomogeneous drivers of choice selection among study cohorts. Medical decision engines that analyze personal preferences of outcomes expectations for VS and many other diseases may be developed to promote shared decision making among health care stakeholders and transparency in the informed consent process.

Hearing preservation in surgery for large vestibular schwannomas

OBJECT

Hearing preservation remains a challenging problem in vestibular schwannoma (VS) surgery. The ability to preserve hearing in patients with large tumors is subject to particular difficulty. In this study, the authors focus on hearing preservation in patients harboring large VSs.

METHODS

A total of 344 consecutive patients underwent surgical removal of VSs over the past 9 years. Of these 344 cases, 195 VSs were > 20 mm in maximum cisternal diameter. Of the 195 cases, hearing preservation surgery was attempted for 54 patients who had a Class A, B, C, or D preoperative hearing level; that is, a pure tone average <or= 60 dB and speech discrimination score >or= 50% according to the Sanna/Fukushima classification. The tumors were classified as moderately large (21-30 mm based on the largest extrameatal diameter), large (31-40 mm), and giant (>or= 41 mm) according to the international criteria. The authors categorized patients with Class A, B, C, D, or E hearing (pure tone average <or= 80 dB and speech discrimination score >or= 40%) as having preserved hearing postoperatively.

RESULTS

Forty-one tumors (75.9%) were totally removed and 13 (24.1%) had near-total removal. Of the 54 patients, 29 maintained their hearing postoperatively; the overall hearing preservation rate was 53.7%. Analysis based on the preoperative hearing level showed that hearing was preserved in 14 (77.8%) of 18 cases for Class A; in 8 (47.1%) of 17 cases for Class B; in 4 (57.1%) of 7 cases for Class C; and in 3 (25.0%) of 12 cases for Class D. In addition, according to the analysis based on the tumor size, 20 (52.6%) of 38 patients with moderately large tumors retained their hearing, as did 5 (50.0%) of 10 patients with large tumors and 4 (66.7%) of 6 patients with giant tumors. Complications included 2 cases of bacterial meningitis that were cured by intravenous injection of antibiotics, 3 cases of subcutaneous CSF leakage that resolved without any surgical repair, and 1 case of temporary abducent nerve palsy. There were no deaths in this series.

CONCLUSIONS

The results indicate that successful hearing preservation surgery in large VSs is possible with meticulous technique and attention to adhesions between the tumor and the cochlear nerves.

Hearing preservation and facial nerve function after microsurgery for intracanalicular vestibular schwannomas: comparison of middle fossa and retrosigmoid approaches

PURPOSE

Therapeutic options for vestibular schwannomas (VS) include microsurgery, stereotactic radiosurgery and conservative management. Early treatment of intracanalicular vestibular schwannomas (IVS) may be advisable because their spontaneous course will show hearing loss in most cases. Advanced microsurgical techniques and continuous intraoperative monitoring of cranial nerves may allow hearing preservation (HP) without facial nerve damage. However, there are still controversies about the definition of hearing preservation, and the best surgical approach that should be used.

METHODS

In this study, we reviewed the main data from the recent literature on IVS surgery and compared hearing, facial function and complication rates after the retrosigmoid (RS) and middle fossa (MF) approaches, respectively.

RESULTS

The results showed that the average HP rate after IVS surgery ranged from 58% (RS) to 62% (MF). HP varied widely depending on the audiometric criteria that were used for definition of serviceable hearing. There was a trend to show that the MF approach offered a better quality of postoperative hearing (not statistically significant), whereas the RS approach offered a better facial nerve preservation and fewer complications (not statistically significant).

CONCLUSIONS

We believe that the timing of treatment in the course of the disease and selection between radiosurgical versus microsurgical procedure are key issues in the management of IVS. Preservation of hearing and good facial nerve function in surgery for VS is a reasonable goal for many patients with intracanalicular tumors and serviceable hearing. Once open surgery has been decided, selection of the approach mainly depends on individual anatomical considerations and experience of the surgeon.

Enlarged translabyrinthine approach for the management of large and giant acoustic neuromas: a report of 175 consecutive cases

The translabyrinthine approach was once considered inadequate for the removal of acoustic neuromas (ANs), but that theory has few proponents today. Over the years, the translabyrinthine approach has been modified into the enlarged translabyrinthine approach, with experience and technical refinements leading to a wider access. Between April 1987 and December 2001, the Gruppo Otologico of Piacenza-Rome was able to remove 175 ANs 3 cm or larger in size from the cerebellopontine angle by adopting this modified surgical technique. These tumors represented 24.7% of all 707 ANs for which surgery was performed during the same period of time. Among the 175 cases, there was only 1 death. The incidence of complications was very low and was comparable to results previously published in the literature. Consequently, the hospital stay was short, with a mean of 7.3 days (5.1 days in the last 45 cases). The preoperative ipsilateral hearing was already compromised in 119 of the 175 cases (68%; class C/D according to the Committee on Hearing and Equilibrium of the American Academy of Otolaryngology-Head and Neck Surgery, 1995). From our results, we can conclude that the use of the enlarged translabyrinthine approach in AN surgery is not dependent on tumor size. On the contrary, the advantages of a low rate of morbidity and a short hospital stay are ample proof that this is the best approach for the removal of large ANs.

Change in Hearing Handicap after Translabyrinthine Vestibular Schwannoma Excision

OBJECTIVE

To evaluate the change in hearing handicap after translabyrinthine vestibular schwannoma excision.

STUDY DESIGN

Prospective administration of the Hearing Handicap Inventory preoperatively and at 3 and 12 months postoperatively.

SETTING

A tertiary referral neurootology clinic.

PATIENTS

A total of 119 consecutive patients who had vestibular schwannomas excised between May 1998 and July 2002 and who had completed Hearing Handicap Inventories preoperatively and at 3 and 12 months postoperatively.

INTERVENTIONS

Translabyrinthine excision of a unilateral sporadic vestibular schwannoma; pre- and postoperative hearing therapy and rehabilitation.

MAIN OUTCOME MEASURES

Hearing Handicap Inventory scores.

RESULTS

Sixty-one percent of patients showed no change in their hearing handicap between preoperative and 3-month postoperative measures. Fifty-eight percent showed no change between preoperative and 12-month postoperative measures. Twenty-five percent of patients had a worsening in their hearing handicap when comparing preoperative and 12-month postoperative scores, and these patients were those with a better hearing class preoperatively. Seventeen percent of patients showed an improvement in their hearing handicap over this same time period, and the reasons for this remain unclear. Neither age nor tumor size had an effect on change in hearing handicap.

CONCLUSIONS

The findings of the current study can be used during preoperative patient counseling. In particular, the clinician is now able to take an informed and positive stance about the hearing handicap to be expected postoperatively.

Hearing preservation and facial nerve function in vestibular schwannoma surgery

The objective of this study was the assessment of hearing preservation in vestibular schwannoma surgery. This study reports a prospective cohort of 40 patients with clinically useful hearing from a consecutive series of 191 patients with unilateral vestibular schwannoma. The patients were managed in a tertiary centre by a combined team of Neurosurgeon, Otologist and Neuro-monitoring Scientist via a neuro-oto-surgical-retrosigmoid approach. Pure tone speech audiometry was conducted preoperatively and 6 months to 9 years following surgery. Using the AA0-HNS classification, useful hearing, i.e. grades A, B and C, was preserved in 47.5% of patients. Thirty-eight per cent achieved grade A or B. Using appropriate surgical and monitoring techniques, it is possible to preserve useful hearing in approximately 50% of patients following removal of a vestibular schwannoma via the retro-sigmoid approach.

Is it worthwhile to attempt hearing preservation in larger acoustic neuromas?

OBJECTIVE

To determine the hearing outcome in patients undergoing surgery via the retrosigmoid approach for acoustic neuromas with a substantial component in the cerebellopontine angle.

STUDY DESIGN

Retrospective case review.

SETTING

Tertiary referral center.

PATIENTS

The medical records of all patients undergoing acoustic neuroma removal via the retrosigmoid approach at a tertiary referral center were retrospectively reviewed. Sixty-four patients with both cerebellopontine angle component >or=15 mm and preoperative audiometry of class A or B (American Academy of Otolaryngology-Head and Neck Surgery) were identified.

MAIN OUTCOME MEASURES

Postoperative average pure tone threshold and word recognition scores, categorized according to the classification of the American Academy of Otolaryngology-Head and Neck Surgery, were used to assess hearing outcome.

RESULTS

Overall, only 6.3% (4 of 63) retained good hearing (class A or B) postoperatively. Hearing preservation rate in the smallest (15- to 19-mm) group was 17.6% (3 of 17), which was better than that for the larger groups. No successful hearing preservation was achieved in tumors with >or=25 mm cerebellopontine angle component (0 of 23).

CONCLUSIONS

Surgeon and patient alike would always choose a hearing preservation technique if there was no potential for increased morbidity in making the attempt. When compared with the non-hearing preservation translabyrinthine approach, the retrosigmoid approach had a higher incidence of persistent headache. In addition, efforts to conserve the auditory nerve prolong operating time, increase the incidence of postoperative vestibular dysfunction, and carry a slightly higher risk of tumor recurrence. Nevertheless, even though the probability of success is disappointingly small, when excellent hearing is present we favor offering the option of a hearing conservation attempt when the patient has been well informed of the pros and cons of the endeavor. Factors weighing against undertaking this effort include larger cerebellopontine angle component (>or=25 mm), deep involvement of the fundus, wide erosion of the porus, and marginal residual hearing.

[Is hearing preservation feasible with the retrosigmoid approach?]

The main advantages of the retrosigmoid approach are fast and good visualization of the brainstem structures and the possibility to remove tumors of all sizes. Hearing preservation, although possible, is not always achieved. The aim of this study is to present our experience with the retrosigmoid approach for acoustic neuroma resection, emphasizing our hearing results. The notes of 56 cases of acoustic neuroma removed through a the retrosigmoid approach were reviewed. Tumor size ranged from 8 to 50 mm (mean 24 mm). Considering patients with preoperative serviceable hearing, postoperative serviceable and measurable hearing was achieved in 13.3% and 26.7% of cases respectively. No tumor recurrence occurred in our series. The retrosigmoid approach is a reliable surgical procedure for most vestibular schwannoma. However, hearing preservation results may be unsatisfactory and show wide differences depending on selection criteria and the hearing terminology used. Concerns about hearing preservation should not be the deciding factor for using this approach.

Retrosigmoid approach for small and medium-sized acoustic neuromas

OBJECTIVE

Clinical study of the keyhole acoustic neuroma retrosigmoid approach for facial nerve and hearing preservation.

STUDY DESIGN

This was a prospective case review from October 1993 to December 1998 in a referral hospital care unit.

PATIENTS

A total of 119 consecutive patients with a tumor size of <25 mm in the cerebellopontine angle corrected by a retrosigmoid approach were included in the study.

INTERVENTIONS

Standard audiometric and imaging assessments, complete tumor removal by using endoscopy-assisted control, and nerve monitoring.

MAIN OUTCOME MEASURES

House-Brackmann facial nerve grade and hearing level by the American Academy of Otolaryngology-Head and Neck Surgery classification.

RESULTS

Grades I and II facial nerve function was obtained in 96% of cases, measurable hearing was preserved in 49% of cases, and 30% of cases achieved serviceable hearing.

CONCLUSION

The retrosigmoid approach is a safe and reliable approach in random patients with small and medium-sized acoustic neuromas.