Giant Vestibular Schwannomas Research Articles

Results in the Surgical Treatment of Giant Acoustic Neuromas

Introduction and objectivesTo compare the results obtained in the resection of 21 giant vestibular schwannomas via retrosigmoid (RS) and combined retrosigmoid/translabyrinthine (RS/TL) approaches with respect to intra- and postoperative complications, facial nerve preservation and postsurgical sequelae. MethodsThis was a retrospective study of 21 patients who underwent a resection of a giant vestibular neuroma according to the Tos & Thomsen Scale (greater than or equal to 4cm) in a tertiary care centre in the period between 2000 and 2008. We present the most significant characteristics of the series studied and the analysis of the advantages and inconveniences of each approach. We also analyse the results regarding facial nerve function preservation. ResultsWe highlight the absence of mortality in the 21-patient group. There were no important intraoperative complications. Total resection of the lesion was achieved in the 87% of the cases, with facial nerve preservation of 73% using the combined RS/TL approach, in comparison to 40% using the RS. Facial nerve function after two years was acceptable or good in 67% (including those with heteronerve anastomosis). A global percentage of 14.3% of cerebrospinal liquid fistula was observed, as well as 9.5% of meningitis. ConclusionsThe results of the study demonstrate that the combined retrosigmoid translabyrinthine approach for giant schwannoma treatment offers increased facial nerve preservation and lower morbidity, constituting an important option in the treatment of this kind of tumours thanks to a multidisciplinary approach.

Resultados en el tratamiento quirúrgico de los neurinomas del acústico gigantes

Introduction and objectivesTo compare the results obtained in the resection of 21 giant vestibular schwannomas via retrosigmoid (RS) and combined retrosigmoid/translabyrinthine (RS/TL) approaches with respect to intra- and postoperative complications, facial nerve preservation and postsurgical sequelae. MethodsThis was a retrospective study of 21 patients who underwent a resection of a giant vestibular neuroma according to the Tos & Thomsen Scale (greater than or equal to 4 centimetres) in a tertiary care centre in the period between 2000 and 2008. We present the most significant characteristics of the series studied and the analysis of the advantages and inconveniences of each approach. We also analyse the results regarding facial nerve function preservation. ResultsWe highlight the absence of mortality in the 21-patient group. There were no important intraoperative complications. Total resection of the lesion was achieved in the 87% of the cases, with facial nerve preservation of 73% using the combined RS/TL approach, in comparison to 40% using the RS. Facial nerve function after two years was acceptable or good in 67% (including those with heteronerve anastomosis). A global percentage of 14.3% of cerebrospinal liquid fistula was observed, as well as 9.5% of meningitis. ConclusionsThe results of the study demonstrate that the combined retrosigmoid translabyrinthine approach for giant schwannoma treatment offers increased facial nerve preservation and lower morbidity, constituting an important option in the treatment of this kind of tumours thanks to a multidisciplinary approach.

Management of Large and Giant Vestibular Schwannomas

The study was conducted to analyze outcomes following surgical management of large and giant vestibular schwannomas and management options for residual disease. This retrospective case note study includes patients who had undergone microsurgical resection of sporadic, large, or giant vestibular schwannomas from 1986 to 2008. Tumors are classified as large if the largest extracanalicular diameter was 3.5 cm or greater and giant if 4.5 cm or greater. The study included 45 patients (33 large, 12 giant tumors), mean tumor size 4.1 cm. Total excision was achieved in 14 cases (31.1%), near-total in 26 (57.8%), and subtotal in 5 (11.1%). Facial nerve outcome was House-Brackmann Grade I/II in 25 cases (55.6%), III/IV in 16 (35.6%), and V/VI in 4 (8.9%). No recurrence has been detected in those undergoing a complete resection. No residual tumor growth been observed in 15 of 26 who underwent near-total resection (57.7%). Of 11 patients, 10 received further treatment as their residual tumors showed growth. In the subtotal excision group, one patient died, three have demonstrated no growth, and one residual tumor has grown slightly but not required intervention. Optimal management for patients with large or giant vestibular schwannomas has yet to be determined. Management decisions must balance long term function with tumor control.

Dural Landmark to Locate the Internal Auditory Canal in Large and Giant Vestibular Schwannomas: The Tübingen Line

In cases of large and giant vestibular schwannomas (VS), the visualization of the internal auditory canal (IAC) opening is difficult or impossible. To describe the Tübingen line and explore its relationships with the IAC as a landmark to help locate the IAC. Ten cadaveric heads were used in this study. Between 2004 and 2009, the senior author (M.T.) used the Tübingen line as a landmark to recognize the IAC in 300 consecutive patients with VS. To locate the Tübingen line, the initial step was to identify several vertical foldings of dura located around the area of the vestibular aqueduct. After this, foldings upward consistently reached a linear level where all of the foldings ended and the dura tightly adhered to the bony surface in a smooth, foldless shape. The Tübingen line was identified in all temporal bones studied and in all 300 patients operated on, with the exception of 2 cases (<1%). Removal of the bone just above the Tübingen line located the IAC in all temporal bone specimens studied. Similarly, the surgical cases showed that the Tübingen line helped locate the IAC in all patients. The Tübingen line is an easy, consistent, and safe method to locate the projection of the IAC along the posterior surface of the temporal bone.

Enlarged Translabyrinthine Approach With Transapical Extension in the Management of Giant Vestibular Schwannomas

To describe and analyze the main outcomes achieved in a series of patients with sporadic vestibular schwannoma (VS) larger than 40 mm in extrameatal diameter, defined as giant VS, submitted to microsurgery by the enlarged translabyrinthine approach with transapical extension. Retrospective chart review. Tertiary referral center. A retrospective chart review was conducted on 2,133 patients who underwent surgery for VS from April 1987 to July 2009. One hundred ten cases of giant VS were elected for analysis. Extent of removal, residual or recurrent disease, facial nerve integrity during surgery, long-term facial nerve function, and postoperative complications. Total removal was accomplished in 91.8% of cases. In 5 patients (4.5%), total removal was accomplished in 2 stages. Near-total removal was performed in 7 patients (6.3%). The facial nerve was anatomically preserved in 76.4% of cases. Intraoperative facial nerve reconstruction was performed in 8 cases. Facial nerve function after 1 year of follow-up was House-Brackmann grades I to III in 75% of cases. There were no deaths in this series. Neurovascular life-threatening complications occurred in 2 patients. Cerebrospinal fluid leak was present in 1.8% of cases. Results indicate the enlarged translabyrinthine approach with transapical extension as an elective approach for removal of giant VS. The method permits achievement of a high rate of total removal with low incidence of complications.

Perioperative complications after translabyrinthine removal of large or giant vestibular schwannoma: Outcomes for 123 patients

Conclusion: Large vestibular schwannomas are benign but dangerous tumors. The translabyrinthine approach allows the surgeon to limit vital and functional complications due to the disease itself or to its surgical removal. Objective: Morbi-mortality study focused on large vestibular schwannoma surgically treated by translabyrinthine removal. Methods: This was a retrospective review of prospectively collected data in a series of 123 patients who underwent translabyrinthine removal of a large vestibular schwannoma (>4 cm in the cerebellopontine angle, stage IV). All surgical and medical complications and facial function were reviewed, with a 1-year follow-up. Results: Mortality during the first year was 0.8% (one case of infarct of the anterior inferior cerebellar artery, fatal after 8 months). In all, 4.9% of patients underwent a second surgery (for delayed hemorrhage or cerebrospinal fluid leak) during the first months after removal of a large vestibular schwannoma; 3.2% of patients experienced definitive neurologic complications (one death, one cerebellar disturbance, and two cases of 10th cranial nerve palsy).

Functional outcome after complete surgical removal of giant vestibular schwannomas

The authors evaluated the outcome of radical surgery in a consecutive series of patients with giant vestibular schwannomas (VSs). Fifty patients with VSs > 4.0 cm in maximal extrameatal diameter were included in this retrospective study (Group A). The group was compared with a matched group of 167 patients with VSs < 3.9 cm (Group B). In all cases the retrosigmoid approach was used. Outcome measures included completeness of tumor removal, facial nerve function, hearing, and the surgery-related complication rate. The mean tumor size in Group A was 4.4 cm and that in Group B was 2.3 cm. Total removal was achieved in all Group A patients and in 97.6% of Group B patients. The anatomical integrity of the facial nerve was preserved in 92% in Group A and in 98.8% in Group B. At last follow-up 75% of the patients with giant VSs had excellent or good facial nerve function, 19% had fair function, and 6% had poor function. In 33% of patients (3 cases) with good preoperative hearing level, it was preserved. Newly developed lower cranial nerve dysfunction occurred in 3 patients but proved to be temporary in 2 of them. A CSF leak developed in 6% of those who not previously undergone surgery. Compared with Group B, a significant difference was found only in the rates of the following parameters: excellent facial nerve function, useful and good hearing, lower cranial nerve dysfunction, and blood collection (p < 0.05). The perioperative mortality rate in both groups was 0%. In patients with a giant VS, total tumor removal can be achieved via the retrosigmoid approach with a 0% mortality rate and low morbidity rate, especially with regards to facial nerve function. In selected cases even hearing preservation is possible. Tumor size significantly correlates with postoperative outcome.

Treatment of Large and Giant Residual and Recurrent Vestibular Schwannomas

Treatment of Large and Giant Residual and Recurrent Vestibular Schwannomas

Surgery for Large Vestibular Schwannomas in Developing Countries

Over a 10-year period from February 1998 to February 2008, 417 cases of large and giant vestibular schwannomas were operatively managed by the presenting author with a operative mortality of 1%(4 cases). A retrospective analysis of 100 consecutively operated cases was undertaken to compare clinical presentation and surgical outcome of giant tumor (size &gt; 4.5 cm) as opposed to tumors of smaller sizes (large: 2.5 to 4.5 cm, and small: &lt; 2.5 cm). While 25 patients in the study group had giant tumors, tumors were large in 72 and small in the remaining 3. Incidence of preoperative facial paresis, lower cranial nerve involvement, and hydrocephalus was significantly higher in the giant group. Except in five patients (two giant and three large), where only a subtotal removal was done, all the remaining had total excision of the lesion. While anatomical preservation of the seventh nerve could be achieved in 90% of large tumors, the rate was only 60% for the giant category. Mean hospital stay was 18 and 15 days for the giant and large groups, respectively.

Giant vestibular schwannomas: focusing on the differences between the solid and the cystic variants

In vestibular schwannomas (VS), the tumour size, as well as the size of the cystic component, have a considerable bearing on the outcome. This study addresses the differences between the cystic and solid variants of giant vestibular schwannomas. The study included 62 patients with giant VSs, of which 40 were solid and 22 were cystic (those in which cystic component greater or equal to 30% of the total tumour volume). The cystic tumour group was further divided into type A (31–60% volume of the cyst within tumour), type B (61–90% intra-tumoural cyst volume) and type C (more than 90% volume of the cyst). The clinicoradiological features, operative findings, histopathological characteristics and outcome of surgery of the two groups were compared. The mean duration of symptoms for the solid and cystic tumours were 21.1 and 26.2 months, respectively. However, six patients with cystic tumours showed recent and rapid neurological deterioration after a protracted existence. Papilloedema, lower cranial nerve involvement, facial paraesthesias and preoperative hydrocephalus were significantly more in cystic tumours. Total excision was achieved in 38 of the solid and 18 of the cystic tumours. VIIth nerve preservation was higher in the cystic lesions [solid 33/40 (82.5%), cystic 21/22 (95.4%)]. Myxoid degeneration, lobular growth patterns and cellular atypia were more prominent in the cystic variants. The giant vestibular schwannomas were associated with a higher incidence of cystic degeneration than has been reported for smaller tumours in literature. In cystic lesions, VIIth nerve preservation was higher due to early decompression of the lesion that facilitated in early identification of the VIIth nerve, except in patients with type C cystic tumour.

Commentary “Treatment of Large and Giant Residual and Recurrent Vestibular Schwannomas”

Commentary “Treatment of Large and Giant Residual and Recurrent Vestibular Schwannomas”

Transapical extension in difficult cerebellopontine angle tumors.

The transapical extension of the enlarged translabyrinthine approach is aimed at making the removal of certain tumors of the cerebellopontine angle simpler and with less morbidity. The extension is classified into 2 types--type I and type II--based on the extent of bone drilling around the internal auditory canal. Type I extension involves drilling for 300 degrees to 320 degrees around the canal and is indicated for large or giant vestibular schwannomas and vestibular schwannomas with significant extension anterior to the internal auditory canal. Type II extension entails complete removal of the bone around the canal for 360 degrees and is indicated for meningiomas of the posterior surface of the petrous bone extending anterior to the internal auditory canal. The extension allows better control over the anterior pole of the tumor, the displaced facial nerve, the prepontine cistern, and the venous vascularity of the cerebellopontine angle. The aim of this report is to present our experience with this extension.

Transapical extension in difficult cerebellopontine angle tumours: preliminary report.

Difficult cerebellopontine angle (CPA) tumours namely large/giant vestibular schwannomas, vestibular schwannomas with a significant anterior extension and meningiomas of the posterior surface of the petrous bone extending anterior to the internal auditory canal (IAC) have always posed a problem for the otoneurosurgeon. Modifications of the enlarged translabyrinthine approach (ETLA) specifically aimed at dealing with these tumours are not reported. The aim of this paper is to introduce the transapical extension of ETLA which involves increased circumferential drilling around the IAC beyond 270 degrees C. The extension allows enhanced surgical control over the tumour as well as the anterior aspect of the CPA including the prepontine cistern, the Vth and VIth cranial nerves. The extension is further classified into Type I and II depending upon the extent of drilling. Type I extension entails drilling around the IAC for 300-320 degrees and is indicated for large/giant vestibular schwannomas (large vestibular schwannoma extrameatal diameter 3-39 cm, giant vestibular schwannoma extrameatal diameter >or=4 cm) and vestibular schwannomas with significant anterior extension. Type II extension involves complete drilling around the canal for 360 degrees and is indicated for meningiomas of the posterior surface of the petrous bone extending anterior to the IAC.