Enlarged Translabyrinthine Approach Research Articles

Otological Surgery of Acoustic Neuroma

Acoustic neuroma is the most common benign tumor in the internal auditory canal and cerebellopontine region． Its common clinical symptoms include unilateral sensorineural hearing loss, tinnitus and so on． Surgical resection is the predominant treatment of acoustic neuroma. The common approaches dominated by otologists include translabyrinthine approach, enlarged translabyrinthine approach, transotic approach, modified transotic approach, and middle cranial fossa approach; the approach dominated by neurosurgeons is retrosigmoid (suboccipital) approach.. For small tumors with intact hearing, it is recommended to choose the middle cranial fossa approach. Those with large tumors who wish to preserve their hearing can adopt the suboccipital retrosigmoid approach; those who do not consider retaining hearing and have medium or small acoustic neuromas can adopt the translabyrinthe approach or through the transotic approach. With the development of microsurgical technology and the wide application of intraoperative nerve monitoring equipment, the retention rate of facial/cochlear nerve function for surgery of small and medium-sized acoustic neuroma has been significantly improved. In the future, more patients with acoustic neuroma are expected to be completely cured on the basis of preserving facial/cochlear nerve function.

Simultaneous Treatment of Vestibular Schwannoma and Concurrent Middle Ear Disease Using the Enlarged Translabyrinthine Approach

Unilateral presentation of vestibular schwannoma with concurrent chronic middle ear disease or cholesteatoma is rare. We report a series of patients with ipsilateral chronic middle ear disease and vestibular schwannoma, which were simultaneously removed via the enlarged translabyrinthine approach. All tumors were near-totally removed, and middle ear disease was completely excised; there were no major postoperative complications such as cerebrospinal fluid leakage, cholesteatoma recurrence, or meningitis. If hearing preservation of the affected ear is not necessary, simultaneous surgical removal of both pathologies is more convenient than staged treatment. The enlarged translabyrinthine approach can achieve complete treatment with one corridor.

Facial Nerve Outcomes Following Total Excision of Vestibular Schwannoma by the Enlarged Translabyrinthine Approach.

To study the early and late facial nerve (FN) outcomes in different tumor classes in addition to determining the predictive factors for the same. A retrospective clinical study. A quaternary referral otology and skull base center. A retrospective study of 1983 cases of vestibular schwannomas (VSs) with preoperative normal FN function, undergoing total excision with anatomical preservation of the nerve by enlarged translabyrinthine approach (ETLA) were included. FN status was recorded postoperatively at day 1, at discharge, and at 1-year follow-up and were analyzed in different tumor sizes. At 1 year, 988 patients with House-Brackmann (H-B) grade I and II FN at day 1 after surgery, 958 (96.9%) maintained their status up-to 1 year. Of the 216 patients with H-B grade III at day 1 after surgery, 113 (52.3%) improved to H-B grade I and II. Similarly, of the 779 patients with H-B grade IV and VI FN function at day 1 after surgery, improvement to H-B III and H-B I and II were noted in 442 (56.7%) and 80 (10.3%) of patients, respectively. Intrameatal and extrameatal tumors upto 2 cm showed better recovery from H-B grade III to H-B I and II and from H-B grade IV and VI to H-B I and III when compared with extrameatal tumors >2 cm (p = 0.001). Tumors of smaller sizes have good immediate postoperative FN results and recover well at the end of 1 year while more than 3 cm have poor outcomes and recover poorly at the end of 1 year. When the VSs reaches more than 1 cm, the HB I and II outcomes drop significantly.

Decision making in dissection range of temporal bone: refinements to enlarged translabyrinthine approach.

The aim of the study was to describe the refinements to the classic enlarged translabyrinthine approach (ETLA) by modifying the bony dissection range of temporal bone and to analyze the main outcomes achieved in a series of vestibular schwannoma (VS) cases submitted to microsurgery by ETLA. This was a retrospective study of 382 patients who underwent VS surgical removal via ETLA between January 2001 and December 2012. Among those cases, 332 were via classic ETLA, while 28 cases were via ETLA with blind sac technique and middle ear eradication and 22 via transotic approach. Total tumor removal was achieved in 368 cases, whereas near total removal in 11 patients and subtotal in 3 patients. In cases of large VS (>3 cm) via classic ETLA, good short-term and long-term facial nerve function (HB I-II) was gained in 27.8 % (32/115) and 42.6 % (49/115) cases, respectively, meanwhile in VS operated via blind sac technique, good short-term (p = 0.048) and long-term (p = 0.044) facial nerve function was reached in 44.0 % (22/50) and 60.0 % (30/50) cases, respectively. Postoperative facial nerve function was proved to be better in modified ETLA group. CSF leakage occurred in 16 (4.2 %) patients via classic ETLA. In 115 cases of large VS (>3 cm), postoperative CSF leakage occurred in 10 (8.7 %) patients. Whereas in 50 cases via blind sac technique, none developed CSF leakage (p = 0.03). The incidence of CSF leakage was lower in modified ETLA group. Our refinements to classic ETLA by changing the temporal bone resection range provide a wide surgical field, well prevention of CSF leakage and preservation of facial nerve function in large VS.

The behavior of residual tumors and facial nerve outcomes after incomplete excision of vestibular schwannomas.

The authors evaluated the behavior of residual tumors and facial nerve outcomes after incomplete excision of vestibular schwannomas (VSs). The case records of all patients who underwent surgical treatment of VSs were analyzed. All patients in whom an incomplete excision had been performed were analyzed. Incomplete excision was defined as near-total resection (NTR), subtotal resection (STR), and partial resection (PR). Tumors in the NTR and STR categories were followed up with a wait-and-rescan approach, whereas the tumors in the PR category were subjected to a second-stage surgery and were excluded from this series. All patients included in the study underwent baseline MRI at the 3rd and 12th postoperative months, and repeat imaging was subsequently performed every year for 7-10 years postoperatively or as indicated clinically. Preoperative and postoperative facial function was noted. Of the 2368 patients who underwent surgery for VS, 111 patients who had incomplete excisions of VSs were included in the study. Of these patients, 73 (65.77%) had undergone NTR and 38 (34.23%) had undergone STR. Of the VSs, 62 (55.86%) were cystic and 44 (70.97%) of these cystic VSs underwent NTR. The residual tumor was left behind on the facial nerve alone in 62 patients (55.86%), on the facial nerve and vessels in 2 patients (1.80%), on the facial nerve and brainstem in 15 patients (13.51%), and on the brainstem alone in 25 patients (22.52%). In the 105 patients with normal preoperative facial nerve function, postoperative facial nerve function was House-Brackmann (HB) Grades I and II in 51 patients (48.57%), HB Grade III in 34 patients (32.38%), and HB Grades IV-VI in 20 patients (19.05%). Seven patients (6.3%) showed evidence of tumor regrowth on follow-up MRI. All 7 patients (100%) who showed evidence of tumor regrowth had undergone STR. No patient in the NTR group exhibited regrowth. The Kaplan-Meier plot demonstrated a 5-year tumor regrowth-free survival of 92%, with a mean disease-free interval of 140 months (95% CI 127-151 months). The follow-up period ranged from 12 to 156 months (mean 45.4 months). The authors' report and review of the literature show that there is undoubtedly merit for NTR and STR for preservation of the facial nerve. On the basis of this they propose an algorithm for the management of incomplete VS excisions. Patients who undergo incomplete excisions must be subjected to follow-up MRI for a period of at least 7-10 years. When compared with STR, NTR via an enlarged translabyrinthine approach has shown to have a lower rate of regrowth of residual tumor, while having almost the same result in terms of facial nerve function.

Application of modified enlarged translabyrinthine approach in the removal of vestibular schwannoma

To describe and analyze the surgical outcomes of modified enlarged translabyrinthine approach(ETLA), which is combined with middle ear eradication and blind sac technique. A retrospective study was conducted on 28 patients who underwent surgery for vestibular schwannoma (VS) via modified ETLA from Jan. 2001 to Dec. 2012. The sizes of tumors were 25-52 mm[(38.2 ± 9.1) mm (X(-) ± s)]. Main outcomes measures included the rate of total removal, the rate of cerebral spinal fluid (CSF) leakage after surgery, complications, and intraoperative anatomical preservation of facial nerve and facial nerve function. Among the 28 patients who underwent modified ETLA, the rate of total removal was 100%. There was no death after surgery via modified ETLA. The rate of CSF leakage after surgery was 3.5% (1/28). The rate of intraoperative anatomical preservation of facial nerve was 89.3% (25/28).Short-term and long-term good facial nerve function rates were 25.0% (7/28) and 42.9% (12/28), respectively. Modified ETLA is suitable for VS>3 cm with extension to the anterior region of cerebellopontine angle, VS involve with labyrinth part of facial nerve, high jugular bulb, proposing sigmoid sinus and highly pneumatized temporal bone. This approach can provide a wide surgical field and well prevention of CSF leakage.

Salvage surgery of vestibular schwannoma after failed radiotherapy: The Gruppo Otologico experience and review of the literature

ObjectivesThe use of radiation therapy has largely widespread and becomes in many centers the preference modality of treatment for symptomatic patients who are old, medically unfit for surgical therapy, those who refuse surgery and in some recurrent or residual growing tumors.The risk of radiotherapy failure in the treatment of vestibular schwannoma might be underestimated in the literature. The purpose of this study is to show the Gruppo Otologico experience with salvage surgery to better understand the surgical outcomes and difficulties in treating vestibular schwannoma after failed radiotherapy. Study designRetrospective chart review of patients who required salvage surgery of vestibular schwannoma after failed radiotherapy. SettingsQuaternary referral otology and skull base center. ResultsBetween 1987 and 2010, 2500 cases of VS underwent surgical treatment at the Gruppo Otologico. Nineteen patients had received stereotactic radiation therapy before the surgical treatment. The interval time between radiotherapy and surgical salvage ranged from 1 to 10years.In all the cases decision of surgery was taken following an increase in tumor size with or without new onset of symptoms. Complete tumor removal was achieved in 86.6% of the cases through a transotic, transcochlear or enlarged translabyrinthine approach with trans-apical extension.Difficult dissection of the tumor was encountered in 93.3% the cases. The facial nerve was anatomically preserved in 93.3% but its function was worsened in 73.3% of patients after at least 6months of follow up. Malignant transformation of the vestibular schwannoma was encountered in one patient. ConclusionComplete surgical resection of VS is more difficult after radiotherapy with relatively poor facial nerve outcomes and nearly impossible hearing preservation.Patients who receive radiation therapy for the treatment of vestibular schwannoma should be made aware of its potential complications and risk of failure, especially in young patients and NF2 cases.

Rate of Recurrent Vestibular Schwannoma after Total Removal via Different Surgical Approaches

The objective of this study was to assess the differences in the recurrence rates of vestibular schwannoma (VS) after total tumor removal through enlarged translabyrinthine (ETL), retrosigmoid (RS), and middle cranial fossa (MCF) approaches. Our results were compared with previously published data, and literature reviews were done to identify the possible causes for the recurrence of VS. We performed a retrospective analysis of 2,400 cases of VS that underwent removal at the Gruppo Otologico, Piacenza, Italy, from 1983 until 2010. The minimum postoperative follow-up was 12 months. We also reviewed the previously published data on recurrence rates of VS after ETL, RS, and MCF approaches. Total tumor removal was achieved in 2,252 cases (93.8%). The recurrence rate was 0.05% for the ETL approach, 0.7% for the RS approach, and 1.8% for the MCF approach. Literature reviews of 3 previously published case series utilizing the translabyrinthine approach showed that none of the primary tumors were less than 2.0 cm in size. Recurrences were seen between 1 and 13 years after the initial surgery. The rate of VS recurrence after total removal is exceptionally low in experienced hands. Undetected microscopic deposits left on crucial points such as the facial nerve, the preserved cochlea nerve, or the fundus of the internal auditory canal could be possible causes for the recurrence. A definite advantage of an ETL approach is the excellent internal auditory canal exposure, resulting in an extremely low rate of VS recurrence. The patients should be followed up to 15 years with gadolinium-enhanced magnetic resonance imaging (with fat suppression sequence in ETL approach cases). Recurrent VS may exhibit a faster growth rate than primary VS.

Surgical Results and Technical Refinements in Translabyrinthine Excision of Vestibular Schwannomas

Vestibular schwannomas (VSs) are the most common cerebellopontine angle tumors, accounting for 75% of all lesions in this location. To evaluate the results after removal of VS through the enlarged translabyrinthine approach, which is a widening of the classic translabyrinthine approach that gives larger access and provides more room to facilitate tumor removal and to minimize surgery-related morbidities. This was a retrospective study of 1865 patients who underwent VS excision through the enlarged translabyrinthine approach between 1987 and 2009. Mean age was 50.39 years. Mean tumor size was 1.8 cm. Median follow-up was 5.7 years. Total removal was achieved in 92.33% of cases; 143 patients had incomplete resection with evidence of regrowth in 8. In the 1742 previously untreated patients, anatomic preservation of facial nerve was achieved in 1661 cases (95.35%), and House-Brackmann grade I or II was reached in 1047 patients (59.87%). Facial nerve outcome was significantly better in tumors ≤ 20 mm. Surgical complications included cerebrospinal fluid leakage in 0.85%, meningitis in 0.10%, intracranial bleeding in 0.80%, non--VII/VIII cranial nerve palsy in 0.96%, cerebellar ataxia in 0.69%, and death in 0.10%. The technical modifications that evolved with increasing experience are described. The enlarged translabyrinthine approach is a safe and effective approach for the removal of VS. In our experience, the complication rate is very low and tumor size is still the main factor influencing postoperative facial nerve function with a cutoff point at around 20 mm.

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.

Cystic Vestibular Schwannoma

Review of postoperative morbidity and facial nerve outcomes of cystic vestibular schwannoma (CVS) patients compared with solid vestibular schwannoma (SVS) patients and a proposal for a new CVS classification system. Retrospective review. Tertiary care facility. Ninety-six patients with surgically treated CVS (1998-2008). Outcomes were assessed in a subpopulation of 57 patients with greater than or equal to 1-year follow-up compared with 57 SVS patients. Fifty-six CVS patients underwent the enlarged translabyrinthine approach with transapical extension (Type I), and 1 patient underwent a transcochlear/transzygomatic approach. Preoperative and postoperative (at least 1 yr) House-Brackmann facial nerve (HBFN) grade evaluation. Favorable HBFN grades (I-III) were observed in 46 (81%) CVS patients, and unfavorable HBFN grades (IV-VI) were seen in 11 (19%) CVS patients. Comparison of tumor size and 1-year HBFN grades showed significant, moderate to strong, Pearson correlation (0.38). Comparison of long-term facial nerve outcomes with a sample of 57 matched SVS patients showed no significant difference (p = 0.74). When the tumor was adherent to the facial nerve and a dissection plane could not be developed between the cyst wall and the nerve, only subtotal resection could offer the CVS patients a normal facial nerve outcome. In most CVS cases, complete resection should be foreseen. Central and thick-walled tumors can be removed in almost all cases. However, when peripheral thin-walled, adherent, cystic tumors are confronted and the cysts are medially or anteriorly located, we recommend subtotal resection, leaving portions of the cyst walls on neurovascular structures and on the facial nerve. This surgical strategy allows us to improve facial nerve outcomes and to reduce complications.

Surgical Management of Jugular Foramen Meningiomas: A Series of 13 Cases and Review of the Literature

Primary meningiomas occurring within the jugular foramen are exceedingly rare lesions presumed to originate from arachnoid-lining cells situated within the jugular foramen. The objective of this study is to analyze the management and outcome in a series of 13 primary jugular foramen meningiomas collected at a single center. Retrospective study. Quaternary referral otology and skull base private center. Charts belonging to 13 consecutive patients with pathologically confirmed jugular foramen meningioma surgically treated between September 1991 and May 2005 were examined retrospectively. The follow-up of the series ranged from 12 to 120 (mean, 42.8 +/- 27.5) months. Four (28.5%) patients underwent single-stage tumor removal through the petro-occipital transigmoid (POTS) approach. In two patients with preoperative unserviceable hearing, a combined POTS-translabyrinthine approach was adopted. Two patients underwent a combined POTS-transotic approach because of massive erosion of the carotid canal. A modified transcochlear approach type D with posterior rerouting of the facial nerve and transection of the sigmoid sinus and jugular bulb was performed in two patients with a huge cerebellopontine angle tumor component with extension to the prepontine cistern together with massive involvement of the petrous bone and middle ear and encasement of the vertical and horizontal segments of the intrapetrous carotid artery. In one patient with evidence of a dominant sinus on the site of the tumor, a subtotal tumor removal via an enlarged translabyrinthine approach (ETLA) was planned to resect the intradural component of the tumor. Two patients in our series underwent a planned staged procedure on account of a huge tumor component in the neck. One of these patients underwent a first-stage infratemporal fossa approach type A to remove the tumor component in the neck; the second-stage intradural removal of the tumor was accomplished via an ETLA. The last patient underwent a first-stage modified transcochlear type D approach to remove the intradural tumor component followed by a second-stage transcervical procedure for removal of the extracranial component. Gross total tumor removal (Simpson grade I-II) was achieved in 11 (84.6%) cases. Subtotal removal of the tumor was accomplished in two patients. Good facial nerve function (grades I and II) was achieved in 46.1% of cases, whereas acceptable function (grade III) was achieved in the remaining cases 1 year after tumor removal. Hearing was preserved at the preoperative level in all four patients who underwent surgery via the POTS approach. After surgery, no patient recovered function of the preoperatively paralyzed lower cranial nerves. A new deficit of one or more of the lower cranial nerves was recorded in 61.5% of cases. Surgical resection is the treatment of choice for jugular foramen meningiomas. Among the various surgical techniques proposed for dealing with these lesions, we prefer the POTS approach alone or combined with the translabyrinthine or transotic approaches. Despite the advances in skull base surgery, new postoperative lower cranial nerve deficits still represent a challenge.

Simultaneous Cochlear Implantation and Translabyrinthine Removal of Vestibular Schwannoma in an Only Hearing Ear: Report of Two Cases (Neurofibromatosis Type 2 and Unilateral Vestibular Schwannoma)

The goal is to confirm the effectiveness of cochlear implantation performed at the time of surgery for tumor removal, using a translabyrinthine approach. This is a retrospective case review of two cases of vestibular schwannoma (VS) in the only hearing ear in which a cochlear implant (CI) was placed simultaneous to removal of VS through a modified enlarged translabyrinthine approach. The aim of the study is to confirm the effectiveness in terms of hearing rehabilitation. The study involved a tertiary referral center in a hospital setting. The study includes a report of two cases: a case of a Neurofibromatosis Type 2 (NF2) patient who received a MEDEL COMBI 40+ CI after a translabyrinthine surgery for removal of a large (4.0 cm) cystic VS; and a patient with a 1.2 cm VS in the only hearing ear who was submitted to the same strategy and operation, using a Nucleus 24 Contour CI. The whole strategy used in the two mentioned cases is outlined, including decision making, surgical interventions, and hearing rehabilitation programs. Surgical and audiometric outcome of two patients who underwent VS resection through a translabyrinthine approach and simultaneous cochlear implantation are shown. Postoperative results demonstrate that a CI could be successful after a translabyrinthine surgery for VS, with hearing performances similar to the best postlingual implanted deaf adults of other origin. The present cases demonstrate that cochlear implantation can be successful after a translabyrinthine approach for VS, regardless of the tumor size, the kind of patient (NF2, unilateral VS), and the type of implant. The results also are suggestive that cochlear implantation is more successful if done concurrent with surgery for tumor removal and before hearing is completely lost.

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.

Perioperative complications in acoustic neuroma (vestibular schwannoma) surgery.

Retrospective study and review of the complications other than those related to the facial nerve and hearing, encountered in acoustic neuroma surgery. Also, an evaluation of hospital stay and its relation with various factors. Retrospective case review. Tertiary neurotologic and skull base referral center. A series of 707 patients who underwent surgical removal of acoustic neuroma from April 1987 to December 2001. The surgical approaches used were the enlarged translabyrinthine approach, the enlarged middle fossa approach, and the retrosigmoid approach. In a small number of cases, the operations were performed through other approaches. The duration of hospital stay and appearance of complications in the perioperative period along with their management. Results related to the facial nerve and hearing were not considered in this study. The most frequent complication was abdominal subcutaneous hematoma (site of fat harvest), which occurred in 23 patients (3.2%). Cerebrospinal fluid leak was present in 20 patients (2.8%), 15 of whom needed revision surgery. Other complications included VIth cranial nerve dysfunction in 12 cases (1.68%), subdural hematoma in 3 cases (0.4%), cerebellopontine angle hematoma in 4 cases (0.6%), cerebellar edema in 2 cases (0.28%), brainstem hematoma in 1 case (0.14%), transitory aphasia in 1 case (0.14%), and lower cranial nerve dysfunction in 1 case (0.14%). Mortality occurred in only one case (0.14%). Medical complications seldom occurred. The postoperative hospital stay ranged from 2 to 36 days, with an average of 6.4 days. The overall hospital stay diminished over time from 10.2 days in 1987 to 1990, to 4.9 days in 2001. There was a significant relation between hospital stay and tumor size, approach used, and presence/absence of complications. Perioperative complications in acoustic neuroma surgery do exist, but this study demonstrated how low the incidence is. The authors believe that the low percentage of complications is mainly attributable to the majority of operations being carried out in specialized clinics, where they are considered routine operations. They believe that following individualized approaches, depending on tumor size and on the preoperative function of the cranial nerves, is the proper way to reach a significant reduction in complications while maintaining a high percentage of total tumor removal. The results of this study, considered as a basis of comparison with other studies, will certainly be useful in preoperative patient counseling.

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.

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.

Enlarged Translabyrinthine Approach로 치료한 재발성 청신경종양 1예

Enlarged Translabyrinthine Approach로 치료한 재발성 청신경종양 1예

Surgical exposure in translabyrinthine approaches—an anatomical study

Objective: Translabyrinthine approach (TLA) is a procedure of choice for the removal of vestibular schwannomas in cases of profound hearing loss. There is a lack of anatomic studies reviewing the surgical anatomy of the cerebellopontine angle (CPA) as seen in the classical and enlarged TLAs. Methods: Seven formalin-preserved cadavers were dissected. Structures, visualized in the CPA through the TLA, were scored according to the degree of their exposure (1, structure not seen; 2, partial exposure; 3, full exposure). Results: The acousticofacial bundle, anterior inferior cerebellar artery and flocculus had the highest scores in both types of surgery. However, the fifth, ninth, and tenth cranial nerves, prepontine cistern, pons, superior cerebellar artery, and posterior inferior cerebellar artery had higher scores, i.e. better exposure, in the enlarged TLA than in the classical TLA. Conclusion: These findings suggest that the enlarged TLA be preferred in cases of larger tumors extending to either jugular foramen or middle fossa whereas the indications of the classical TLA should be limited to vestibular neurectomy and removal of smaller tumors.

The enlarged translabyrinthine approach for removal of large vestibular schwannomas

This study was carried out to validate the enlarged translabyrinthine approach for the surgical management of large vestibular schwannomas. A retrospective review of the charts of 53 patients with large tumours removed via the enlarged translabyrinthine approach at the Gruppo Otologico, Piacenza, Italy, during the last five years was carried out. The ability to control large tumours and the achievement of total removal with low morbidity and very few complications, demonstrate that tumour size does not influence the use of the enlarged translabyrinthine approach for managing large tumours.