Translabyrinthine Approach Research Articles

Key perspectives on Woven EndoBridge device for wide-necked bifurcation aneurysms, endoscopic endonasal clipping of intracranial aneurysms, retrosigmoid versus translabyrinthine approaches for acoustic neuromas, and impact of local intraoperative steroid administration on postoperative dysphagia following anterior cervical discectomy and fusion.

Key perspectives on Woven EndoBridge device for wide-necked bifurcation aneurysms, endoscopic endonasal clipping of intracranial aneurysms, retrosigmoid versus translabyrinthine approaches for acoustic neuromas, and impact of local intraoperative steroid administration on postoperative dysphagia following anterior cervical discectomy and fusion.

Tratamiento quirúrgico del schwannoma vestibular. Revisión de 420 casos

Introduction and objectivesVestibular schwannoma is the most frequent cerebellopontine angle tumor. The aim of our study is to reflect our experience in the surgical treatment of this tumor Material and methodsRetrospective study of 420 vestibular schwannomas operated in our hospital between 1994-2014. We include tumor size, preoperative hearing, surgical approaches, definitive facial and hearing functional results, and complications due to surgery. ResultsA total of 417 patients with 420 tumors were analyzed, 209 female (50.1%) and 208 male (49.9%). Mean age at diagnosis was 49.8±13.2 years. The majority of the tumors were resected through a translabyrinthine approach (80.2%). Total tumor removal was achieved in 411 tumors (98.3%), and anatomic preservation of facial nerve in 404 (96.2%). Definitive facial nerve outcome was House-Brackmann grade I and II in 69.9%, and was significantly better in tumors under 20mm. Surgical complications included cerebrospinal fluid leakage in 3 patients (0.7%) and retroauricular subcutaneous collection in 16 (3.8%), 5 cases of meningitis (1.2%), 4 patients with intracraneal bleeding (0.9%), and death in 3 patients (0.7%). ConclusionsSurgery is the treatment of choice for vestibular schwannoma in the majority of patients. In our experience, the complication rate is very low and tumor size is the main factor influencing postoperative facial nerve function.

Impact of Elevation of Temporal Lobe During Middle Fossa Acoustic Neuroma Surgery on Contralateral Speech Discrimination.

For middle fossa acoustic neuroma approach, retractors are needed to elevate the temporal lobe to be able to access the internal auditory meatus. The temporal lobe hosts the primary and secondary auditory fields. The question arises regarding whether this elevation affects the functionality of the auditory cortex. In patients, who underwent acoustic neuroma surgery, contralateral speech discrimination was tested pre- and postsurgery using different speech discrimination tests. Results of patients with a middle fossa approach were compared with patients with a translabyrinthine approach. No major differences between the translabyrinthine and the middle fossa approach could be detected. Elevation of the temporal lobe during middle fossa approach for acoustic neuroma surgery does not lead to short-term impaired contralateral speech discrimination compared with translabyrinthine approach.

Surgery for sporadic vestibular schwannoma. Part IV. Predictive factors influencing facial nerve function after surgery

ObjectiveTo analyze the impact of various clinical, radiological and perioperative factors that could influence the facial nerve intraoperative disruption risk (CNVII-IDR) and its long-term function (CNVII-LTF) after vestibular schwannoma (VS) surgery. Material and methodsThe study included 212 patients operated on for sporadic VS with no history of previous treatment for VS or CNVII palsy. The mean size of the tumor was 30mm. Gross (210) or near-total (2) resections were carried out using the retrosigmoid (210) or translabyrinthine (2) approach. Correlation studies and multivariate regression analysis (RA) were performed. ResultsIn correlation studies, the CNVII-IDR was increased by: headaches and cerebellar ataxia if one of them was the first symptom of the tumor (33% and 29%, respectively, p=0.008); preoperative hydrocephalus (40% vs. 9%, p=0.01), tumor size >3cm (18% vs. 5%, p<0.01), tumor volume >10cm3 (19% vs. 4%, p<0.01), right-sided location 15% vs. 6%, p=0.047), lateral “park-bench” position (19% vs. 5% for supine position, p<0.01) and the procedure order (16% for the first 106 procedures vs. 6% for the last 106 procedures, p<0.05). In RA the tumor volume (p=0.012), side of the tumor (p=0.028) and patient's position during surgery (p=0.016) independently affected the CNVII-IDR. The following factors correlated significantly with satisfactory CNVII-LTF (HB grades I–III): tumor stage <T4 (p=0.000), tumor size ≤3cm (p=0.000), tumor volume ≤10cm3 (p=0.001), and left-sided location (p=0.048). Additional factors correlated significantly with very good CNVII-LTF (HB grades I–II): anterior CNVII displacement (p=0.044), nimodipine use (p=0.016), the absence of postoperative complications (p=0.019), CNVII responsive on final intraoperative EMG stimulation (p=0.000) and supine position during surgery (p=0.018). However, an independent impact on very good CNVII-LTF proved to be the tumor size (p=0.0000), side (p=0.0175), and nimodipine use (p=0.0349). ConclusionsIn our series, the factors related to size and side of the tumor confirmed an independent impact on CNVII-IDR and CNVIILTF. The significance of patient positioning may reflect the impact of learning curve as only the first 91 patients were operated on using the lateral “park-bench” position. An independent impact on CNVII-LTF was exerted by the perioperative use of nimodipine.

Retrosigmoid Versus Translabyrinthine Approach for Acoustic Neuroma Resection: An Assessment of Complications and Payments in a Longitudinal Administrative Database.

ObjectRetrosigmoid (RS) and translabyrinthine (TL) surgery remain essential treatment approaches for symptomatic or enlarging acoustic neuromas (ANs). We compared nationwide complication rates and payments, independent of tumor characteristics, for these two strategies.MethodsWe identified 346 and 130 patients who underwent RS and TL approaches, respectively, for AN resection in the 2010-2012 MarketScan database, which characterizes primarily privately-insured patients from multiple institutions nationwide.ResultsAlthough we found no difference in 30-day general neurological or neurosurgical complication rates, in TL procedures there was a decreased risk for postoperative cranial nerve (CN) VII injury (20.2% vs 10.0%, CI 0.23–0.82), dysphagia (10.4% vs 3.1%, CI 0.10–0.78), and dysrhythmia (8.4% vs 2.3%, CI 0.08–0.86). Overall, there was no difference in surgical repair rates of CSF leak; however, intraoperative fat grafting was significantly higher in TL approaches (19.8% vs 60.2%, CI 3.95–9.43). In patients receiving grafts, there was a trend towards a higher repair rate after RS approach, while in those without grafts, there was a trend towards a higher repair rate after TL approach. Median total payments were $16,856 higher after RS approaches ($67,774 vs $50,918, p < 0.0001), without differences in physician or 90-day postoperative payments.Conclusions Using a nationwide longitudinal database, we observed that the TL, compared to RS, approach for AN resection experienced lower risks of CN VII injury, dysphagia, and dysrhythmia. There was no significant difference in CSF leak repair rates. The payments for RS procedures exceed payments for TL procedures by approximately $17,000. Data from additional years and non-private sources will further clarify these trends.

Diagnosis and treatment of cavernous hemangioma of the internal auditory canal.

Cavernous hemangioma of the internal auditory canal (IAC) is an extremely rare type of tumor, and only 50 cases have been reported in the literature prior to this study. The aim in this study was to describe the symptomatology, radiological features, and surgical outcomes for patients with cavernous hemangioma of the IAC and to discuss the diagnostic criteria and treatment strategy for the disease. The study included 6 patients with cavernous hemangioma of the IAC. All patients presented with sensorineural hearing loss and tinnitus, and 2 also suffered from vertigo. Five patients reported a history of facial symptoms with hemispasm or palsy: 3 had progressive facial weakness, 1 had a hemispasm, and 1 had a history of recovery from sudden facial paresis. All patients underwent CT and MRI to rule out intracanalicular vestibular schwannomas and facial nerve neuromas. Five patients had their tumors surgically removed, while 1 patient, who did not have facial problems, was followed up with a wait-and-scan approach. All patients had a presurgical diagnosis of cavernous hemangioma of the IAC, which was confirmed pathologically in the 5 patients who underwent surgical removal of the tumor. The translabyrinthine approach was used to remove the tumor in 4 patients, while the middle cranial fossa approach was used in the 1 patient who still had functional hearing. Tumors adhered to cranial nerves VII and/or VIII and were difficult to dissect from nerve sheaths during surgeries. Complete hearing loss occurred in all 5 patients. In 3 patients, the facial nerve could not be separated from the tumor, and primary end-to-end anastomosis was performed. Intact facial nerve preservation was achieved in 2 patients. Patients were followed up for at least 1 year after treatment, and MRI showed no evidence of tumor regrowth. All patients experienced some level of recovery in facial nerve function. Cavernous hemangioma of the IAC can be diagnosed preoperatively through analysis of clinical features and neuroimaging. Early surgical intervention may preserve the functional integrity of the facial nerve and provide a better outcome after nerve reconstruction. However, preservation of functional hearing may not be achieved, even with the retrosigmoid or middle cranial fossa approaches. The translabyrinthine approach seems to be the most appropriate approach overall, as the facial nerve can be easily located and reconstructed.

Surgery for sporadic vestibular schwannoma. Part III: Facial and auditory nerve function

ObjectiveThe aim of this analysis was to assess short-term and long-term outcomes with respect to the preservation of facial and auditory nerve function following surgery for sporadic vestibular schwannomas. Material and methodsThe study included 220 consecutive patients operated on with the retrosigmoid (217) or translabyrinthine (3) approach. The mean extrameatal diameter of the tumor was 30mm. In 217 patients, gross total resection was performed and near-total in 3. Before surgery, the facial nerve (CNVII) weakness was found in 18% of patients and only 20% had serviceable hearing. Intraoperative neurophysiological CNVII monitoring was routinely used (the last 211 procedures). Intraoperative monitoring of the cochlear nerve function was used when the preservation of hearing was attempted (45 procedures). ResultsThe rate of CNVII continuity loss during surgery was 11%, however, this decreased to 6% in the second half of the series. Facial nerve function deteriorated, in 88% of the patients shortly after surgery. However, it improved in 87% in follow-up. Delayed CNVII palsy was found in 5% of the patients and had a good prognosis in 88%. Final satisfactory CNVII function (CNVII-SF, HB grades I–III) was achieved in 76% of the patients when excluding the anastomosis results, and 87% when including them. In recent years, the rate of CNVII-SF has risen to 94%. Non-serviceable hearing was preserved in 49% of the patients, on whom it was attempted. ConclusionConsidering the size of the tumors and extent of the resections, the preservation of CNVII function is currently very high. A close surveillance of CNVII function evolution following surgery is mandatory, as 2/3 of the patients discharged with deep paresis will need different face reanimation procedures. The preservation of useful hearing is still problematic, especially in patients with large tumors.

The Prevalence of Cochlear Obliteration After Labyrinthectomy Using Magnetic Resonance Imaging and the Implications for Cochlear Implantation.

The aim of this study was to determine the prevalence of cochlear obliteration after labyrinthectomy. Retrospective review of medical records. Tertiary referral center. Sixty-five patients who had previously undergone resection of an acoustic neuroma through a translabyrinthine approach. The magnetic resonance studies were analyzed as part of the routine surveillance after tumor resection. To determine whether the cochlear lumen remained fluid filled. Sixty-five cochleas were examined. Forty-four cochleas were patent and, of the remaining 21, 9 were obliterated and 12 were partially obliterated. The average length of follow-up for the patent, partially obliterated, and obliterated cochlea groups was 47, 29, and 77 months, respectively. Obliteration of the cochlea, either partially or completely, occurs in approximately one-third of patients. Time elapsed after labyrinthectomy did not seem to be a predictor of cochlear obliteration.

Retrosigmoid Craniotomy for Auditory Brainstem Implantation in Adult Patients with Neurofibromatosis Type 2.

Objective To report our technique and experience using a retrosigmoid craniotomy approach for auditory brainstem implantation (ABI) placement in adult neurofibromatosis type 2 (NF2) patients. Design Retrospective case series. Setting Single-center study, Boston, Massachusetts, United States. Participants All NF2 patients who underwent evaluation at Massachusetts Eye and Ear Infirmary and surgery at Massachusetts General Hospital from 2009 to 2013 were reviewed. Six cases of retrosigmoid craniotomy for ABI surgery in five adult NF2 patients were identified. The clinical history, operative course, and outcomes in these patients were reviewed. Main Outcome Measures Postoperative complications and audiological outcomes. Results Indications for ABI surgery were profound hearing loss associated with growth or treatment of bilateral vestibular schwannomas. In all cases, a retrosigmoid craniotomy was performed for tumor resection and ABI placement without complication. Electrode placement was confirmed intraoperatively using electrical-evoked auditory brainstem responses. The ABI was activated in the awake patient 4 to 6 weeks postoperatively. Audiological testing was used to evaluate sound detection and speech perception with the ABI. There were no cases of cerebrospinal fluid leak. Conclusion Retrosigmoid craniotomy is a safe and effective means to provide access to the cochlear nucleus for ABI placement following tumor resection in the adult NF2 patient. Preliminary data indicate that this approach has few complications while offering benefits for hearing. The retrosigmoid craniotomy should be considered a reasonable alternative to the traditional translabyrinthine approach for placement of the ABI in deaf patients who are not candidates for the cochlear implant.

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.

Comparative Analysis of Transpetrosal Approaches to the Internal Acoustic Meatus Using Three-Dimensional Radio-Anatomical Models.

Background The transcrusal approach that involves partial removal of the labyrinth was recently described to approach lesions of the cerebellopontine angle. It carries the benefit of hearing preservation and was suggested to have equivalent exposure of the petroclival surface compared with the transcochlear/transotic approaches. The current study was designed to assess if the transcrusal approach could achieve as good access to the internal auditory meatus (IAM) as the more destructive translabyrinthine exposure. Methods Fifty disease-free high-resolution computed tomography scans of the temporal bone were reviewed. Surgical freedom, angle of attack, and angle of trajectory to the internal acoustic canal were measured in three-dimensional models. Results Surgical freedom and angles of attack showed steady increments with the progression of petrous bone resection from the retrolabyrinthine-transcrusal-translabyrinthine approaches. The angle of access to the IAM axis was dramatically reduced in the translabyrinthine approach compared with the transcrusal and retrolabyrinthine approaches (37.51 ± 5.7, 24.56 ± 4.6, and 3.17 ± 2.85 degrees, respectively; n = 50; average plus or minus standard deviation, p < 0.001). Conclusion Using this novel radio-anatomical system, we demonstrate the advantage of the translabyrinthine approach to the axis of the internal auditory canal. The transcrusal approach lags behind the translabyrinthine corridor and should be considered alongside the subtemporal and retrosigmoid approaches designed to spare hearing.

Auditory brainstem implantation: anatomy and approaches.

Auditory brainstem implantation at the cochlear nuclei used mainly for neurofibromatosis type 2 patients with bilateral loss of the cochlear nerves has more recently been extended to the inferior colliculus. To examine the microsurgical and endoscopic anatomy of the cochlear nuclei and inferior colliculus as seen through the translabyrinthine and retrosigmoid approaches used for cochlear nuclei and inferior collicular implantation. Ten cerebellopontine angles of formalin-fixed adult cadaveric heads were examined with the aid of the surgical microscope and endoscope. The ascending auditory pathways between the cochlear nuclei and inferior colliculi and above were examined by the fiber dissection technique. Both the translabyrinthine and retrosigmoid routes provide sufficient exposure for concurrent tumor removal and implantation at either the cochlear nuclei or inferior colliculus. The position of the inferior colliculus in the auditory pathways and its accessibility in the infratentorial supracerebellar exposure directed through either the translabyrinthine or retrosigmoid approach makes it an alternative site for electrode placement if the cochlear nuclei are not functionally or structurally suitable for implantation. Endoscopic assistance may aid the exposure and electrode placement at either site. The translabyrinthine or retrosigmoid approaches provide access to the cochlear nuclei for implantation and also to the inferior colliculus through the translabyrinthine or retrosigmoid infratentorial supracerebellar route. The endoscope may aid in exposing either site.

Surgical Outcomes of Cerebellopontine angle Tumors in 50 Cases.

To report our experience with a large series of surgical procedures for removal of cerebellopontine angle (CPA) tumors using different approaches. This was a retrospective analysis of 50 patients (mean age, 49 years) with CPA tumors (predominantly acoustic neuroma) who underwent surgical removal using appropriate techniques (principally a translabyrinthine approach) during a 4-year period. One death occurred during this study. There were nine cases (18%) of cerebrospinal fluid leak, and five patients (10%) were diagnosed as having bacterial meningitis. Complete gross tumor removal was not achieved in four patients (8%). Facial nerve function as measured by the House Brackmann system was recorded in all patients 1 year following surgery: 32% had a score of 1 or 2; 26% had a score of 3 or 4; and 8% had a score of 5 or 6. Other complications included four cases of wound infection. The translabyrinthine approach was predominantly used in our series of CPA tumors, and complication rates were comparable with other large case series.

Cavernous Hemangiomas of the Internal Auditory Canal and Cerebellopontine Angle

To review the clinical presentation, differential diagnosis, management strategy, and outcomes after microsurgical resection of cavernous hemangiomas (CHs) arising primarily within the internal auditory canal (IAC) and cerebellopontine angle (CPA). Twelve patients (10 men; aged 18-66 yr) were included from 1982 to 2012 from one of two tertiary academic referral centers. All patients underwent preoperative imaging evaluation and subsequent microsurgical resection. American Academy of Otolaryngology-Head and Neck Surgery hearing class, facial nerve function, and tumor control. The most common presenting symptoms were ipsilateral sensorineural hearing loss, nonpulsatile tinnitus, and vertigo. Three presented with facial paresis, 10 had lost serviceable hearing preoperatively. All lesions demonstrated heterogeneous enhancement with gadolinium and hyperintense signal on T2-weighted imaging. The median tumor diameter was 8 mm; eight CHs were confined to the IAC, whereas four involved the CPA. Tumors were accessed via a translabyrinthine approach in eight cases, retrosigmoid craniotomy in three cases, and a middle cranial fossa approach in one case. Ten patients received gross total resection, whereas two underwent subtotal removal. Neither patient with serviceable preoperative hearing retained useful hearing after resection. Eight of the nine patients with normal preoperative facial nerve function retained House-Brackmann grade 1 function after surgery. One patient had residual tumor treated with postoperative stereotactic radiosurgery. Primary CHs of the IAC and CPA are rare and present clinically and radiographically similar to vestibular schwannoma. Microsurgical resection provides excellent facial nerve outcomes and tumor control for most patients; however, the majority of individuals will acquire non-serviceable hearing either from disease or as a result of treatment.

Clinical features of vestibular schwannomas in patients who experience hearing improvement after surgery.

Postoperative improvements in hearing in patients with vestibular schwannoma are extremely rare. We reviewed nine cases retrospectively to investigate the clinical features of these cases. Hearing improvement was defined as an improvement in hearing class according to American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS) criteria. The nine patients comprised five men and four women with a mean age of 40.4 years. Of the nine tumors, three were solid and six cystic; mean tumor size was 29.7 mm. Mean pure tone average (PTA) and mean speech discrimination scores (SDS) were 47.5 dB and 22.8%, respectively, preoperatively and 29.6 dB and 83.9%, respectively, postoperatively. AAO-HNS class distribution was class B:1 and D:8, preoperatively, and class A: 5 and B:4, postoperatively. A lateral suboccipital retrosigmoid approach with a lateral (park bench) position was used in all nine patients. Clinical features of these vestibular schwannomas included (1) large cystic tumors, (2) sudden onset hearing loss, (3) the presence of a valley shape in the middle-pitch area on preoperative audiograms, (4) almost intact preoperative inner ear function, (5) a low SDS relative to PTA preoperatively, (6) surgical treatment via a lateral suboccipital approach within 6 months of the most recent exacerbation of hearing loss, (7) observation of I waves in preoperative, intraoperative, and postoperative auditory brainstem response (ABR) recordings, and (8) postoperative improvement in mainly the middle-pitch range and SDS. For surgical treatment of vestibular schwannomas with the above clinical features, a translabyrinthine approach and cochlear nerve section (unless the I wave on the intraoperative ABR trace disappears) should be avoided, regardless of the patient's preoperative hearing level, if a surgeon hopes to maximize the chances of preserving or improving hearing.

Schwannome du nerf facial : rapport de 16 cas

But de la presentation To describe the characteristics, diagnosis, management and outcomes of facial nerve schwannomas (FNSs). Materiel et methodes Patients whose outpatient diagnosis was facial nerve tumor and whose intraoperative identification was FNS between 2002 and 2012 were studied. Preoperative data (audiologic data, facial nerve [FN] function, and patient symptoms, tumor location on imaging data), intraoperative data (total versus subtotal resection, and FN status), and postoperative data (audiologic data, FN function, and recurrence) were collected. Resultats Surgical removal was performed in 16 patients whose FNS were confirmed histologically and 5 patients decided on follow-up. Facial paralysis and hearing loss presented commonly. The FNS involved mostly the geniculate segment, following internal auditory canal. 16 patients were operated on, of them 14 total resection, and 2 subtotal resection. The translabyrinthine approach was performed in 9 cases, the middle fossa approach was performed in 5 cases of which 1 combined with transmastoid approach, and the TM approach was performed in 2 cases. One-stage facial nerve repair was performed in 11 cases, of them 5 facial-hypoglossal nerve anastomosis and 6 sural nerve graft. These patients showed better facial function (mainly HB grades III–IV). Partial removal kept the facial function at grade II. Conclusion The symptoms of FNS are related to its location, the patients complained mainly facial paralysis and hearing loss. MRI is indispensable for the differential diagnosis, subtotal removal may be a better choice for VS-like FNS. One-stage facial repair can give a good FN outcome.

Rerouting technique of the facial nerve in the procedure of removal of jugular foramen tumors: Outcomes and indications

But de la presentation To analyze retrospectively the functional outcome of the facial nerve after different nerve rerouting techniques in the procedure of removal of jugular foramen tumors, and to discuss their indications. Materiel et methodes From 2004 to 2013, 47 patients with jugular foramen tumor were operated on, in which 40 were totally, six near-totally and 1 partially resected. The pathologies consisted of 35 jugular paragangliomas, six schwannomas, 4 chordomas, one synovial sarcoma, and one ossifying myxoid tumor. According to the location and extension of the tumors, infra-temporal fossa type A (IFTA) approach was carried out in 23 cases, infra-temporal fossa combined translabyrinthine approach in 10 cases, petro-occipital trans-sigmoid approach (POTS) in 14 cases. The total rerouting of the facial nerve was done in 14 cases, partial rerouting in 12 cases, and no rerouting in 21 cases. Resultats These patients were followed up for 1-10 years. The facial nerve function after one year was HB I-II in 28 cases, HB III-IV in 17 cases, and HB V-VI in two cases. The facial nerve function after three years was HB I-II in 35 cases and HB III-IV in eight cases. The facial nerve function was deteriorated in 18 cases, improved in two cases, and unchanged in 27 cases. Conclusion The intraoperative facial nerve injury is a common complication in the surgery of jugular foramen tumors. The nature, size, location of tumors, preoperative facial function, surgical approach and intraoperative nerve management could affect the prognosis of facial nerve function. Partial or no rerouting of the facial nerve could be used in the procedure of removal of jugular foramen tumors in order to obtain better facial function. The tumors, those posterior and inferior to the labyrinth, could be removed via IFTA with partial or no rerouting of the facial nerve or POTS.

Surgical Approaches to Cerebellopontine Angle: A 17‐Year Experience of Our Skull Base Team

Objectives: We give an overview of the current state of cerebellopontine angle (CPA) surgery, based on the recent evidence, and describe our center’s experience in surgical approaches to these lesions. Methods: Retrospective review of cases who underwent surgery for CPA lesions at our hospital during the past 17 years (1996-2013), with focus on the description of the currently most used technique-extended retrosigmoid. We also conducted a brief review of the literature on CPA surgery, comparing the different approaches, their indications and complications. Results: During this period, 203 patients underwent surgery for CPA. The most frequent indication was vestibular schwannoma (84.7%). Other indications were meningiomas (8.4%), epidermoids (1%), vestibular neurectomies (1.5%), arteriovenous malformations (1%), anterior inferior cerebellar artery–posterior inferior cerebellar artery aneurysms (1%), trigeminal microscopic decompression (0.5%), and other more rare tumors (2%). The most used approach was extended retrosigmoid (71.9%), followed by the translabyrinthine (26.1%) and middle fossa approach (2%). Until 2004, the most used approach was the translabyrinthine; after 2004, the most used was the extended retrosigmoid. Conclusions: Currently, the preferred surgical approach used by our team is the extended retrosigmoid, because it allows a complete exposition of sigmoid sinus from the transverse sinus to the jugular bulb, enhances CPA vision, avoids cerebellar retraction, and is a simple way to get a wide route to the CPA. It also allows good functional outcomes (hearing and facial nerve preservation) in most cases. However, indications for approaches depend on the size of the lesion, its location and the quality of preoperative hearing, as well as a necessary familiarity with all approaches.

Hydrophilic Hydroxyapatite Cement Cranioplasty: Preventing Cerebrospinal Fluid Leaks and Wound Complications in Translabyrinthine Acoustic Neuroma Surgery

Objectives: (1) Examine the efficacy of quick-setting, hydrophilic formulation of hydroxyapatite cement (HAC) used in cranioplasty for the prevention of cerebrospinal fluid (CSF) leaks and long-term wound complications following translabyrinthine acoustic neuroma (TLAN) surgery. (2) Review evolution of HAC cranioplasty. Methods: Retrospective case review from 2006 to 2013 in atertiary referral center. Consecutive patients undergoing translabyrinthine approach for acoustic neuroma tumors were operated on by the senior author. Intervention: Therapeutic: Cranioplasty combining a medial abdominal fat graft with hydrophilic hydroxyapatite cement filling the mastoid. Main outcome measures: Incidence of cerebrospinal fluid (CSF) leaks and any wound complications. Results: Forty-four patients met inclusion criteria. There were no CSF leaks or other wound complications in this series. Conclusions: Hydrophilic HAC appears to be safe and efficacious for cranioplasty following translabyrinthine acoustic neuroma surgery.

Facial nerve preservation surgery for koos grade 3 and 4 vestibular schwannomas.

Facial nerve preservation surgery for large vestibular schwannomas is a novel strategy for maintaining normal nerve function by allowing residual tumor adherent to this nerve or root-entry zone. To report, in a retrospective study, outcomes for large Koos grade 3 and 4 vestibular schwannomas. After surgical treatment for vestibular schwannomas in 52 patients (2004-2013), outcomes included extent of resection, postoperative hearing, and facial nerve function. Extent of resection defined as gross total, near total, or subtotal were 7 (39%), 3 (17%), and 8 (44%) in 18 patients after retrosigmoid approaches, respectively, and 10 (29.5%), 9 (26.5%), and 15 (44%) for 34 patients after translabyrinthine approaches, respectively. Hearing was preserved in 1 (20%) of 5 gross total, 0 of 2 near-total, and 1 (33%) of 3 subtotal resections. Good long-term facial nerve function (House-Brackmann grades of I and II) was achieved in 16 of 17 gross total (94%), 11 of 12 near-total (92%), and 21 of 23 subtotal (91%) resections. Long-term tumor control was 100% for gross total, 92% for near-total, and 83% for subtotal resections. Postoperative radiation therapy was delivered to 9 subtotal resection patients and 1 near-total resection patient. Follow-up averaged 33 months. Our findings support facial nerve preservation surgery in becoming the new standard for acoustic neuroma treatment. Maximizing resection and close postoperative radiographic follow-up enable early identification of tumors that will progress to radiosurgical treatment. This sequential approach can lead to combined optimal facial nerve function and effective tumor control rates.