Cochlear Implantation in Neurofibromatosis Type 2-Related Schwannomatosis: Long-Term Hearing Outcomes.

OBJECTIVE: To evaluate long-term hearing outcomes following cochlear implantation in patients with neurofibromatosis type 2 and ipsilateral vestibular schwannoma. STUDY DESIGN: Retrospective study. SETTING: Tertiary general hospital. METHODS: Twenty-two patients undergoing cochlear implantation between 2004 and 2018 with at least 1 year of follow-up were included. Patients were categorized as "users" or "nonusers" of their cochlear implant (CI). For users, speech perception (disyllabic words) without lip-reading was assessed in quiet conditions 1-year postimplantation, and annually thereafter. CI users were classified into 2 groups on the basis of speech intelligibility (≥40% or <40%). Demographic data, treatment options, and tumor size were also recorded. RESULTS: One year after implantation, 16 (73%) patients used their CI daily. Twelve of these patients had a speech intelligibility ≥40% (mean: 74 ± 21.9%). Three had a Koos stage IV tumor. At the last visit (mean duration of follow-up: 6 ± 5 years), 12 of these 16 patients were still using their implant daily, and 6 had a speech intelligibility ≥40%. No predictive factors for good performance at 1 year or performance stability were identified. CONCLUSION: Neurofibromatosis type 2 is a complex disease profoundly affecting patient quality of life, and cochlear implantation should always be considered on a case-by-case basis. In some individuals, cochlear implantation can provide good speech intelligibility for extended periods, even posttreatment or in cases of large tumors.

Exploring Trauma Patterns and Contributing Factors With Slim Straight Electrode Array After Cochlear Implantation.

OBJECTIVE: To assess trauma patterns associated with the insertion of lateral wall electrode arrays. The study focused on 3 categories-scala tympani (ST), intermediate, and scala vestibuli (SV)-to identify traumatic patterns and contributing factors. STUDY DESIGN: Retrospective study. SETTING: Data from 106 cochlear implant recipients at a tertiary otologic center. METHODS: Demographic and surgical data were collected from recipients who underwent cochlear implantation manually and with RobOtol®. Measurements included cochlear dimensions, angular depth of insertion, and position of the first electrode. Three-dimensional reconstructions were used to analyze the electrode array location relative to the basilar membrane, categorized into ST, intermediate, and SV electrodes. Nontraumatic insertion was defined as all electrodes in the ST, while traumatic insertions had 1 or more electrodes in intermediate or SV locations. RESULTS: Out of 106 cases, 44% had nontraumatic and 56% had traumatic insertions. Demographic and surgical characteristics showed no association with traumatic insertions. A deeper position of the first electrode, relative to the round window, was associated with traumatic insertions (P = .03). Three trauma patterns were observed: distal (facing the apical electrodes), proximal (facing the middle electrodes around 180°), and distal/proximal. CONCLUSION: This study considers the intermediate position which could be associated with basilar membrane lesions. Risk zones for intracochlear trauma with lateral wall arrays were identified distally and proximally. Traumatic insertions were independently linked to deeper array placement. Future studies should explore whether gentler insertion, without insisting on further electrode array insertion depth, could reduce the trauma during cochlear implantation.

Auditory outcomes after scala vestibuli array insertion are similar to those after scala tympani insertion 1 year after cochlear implantation.

PURPOSE: In cochlear implantation, a scala vestibuli (SV) insertion of an electrode array is a rare occurrence and is reported to be linked to poor hearing outcomes. Using the same electrode array, the auditory performance of patients with a complete SV location was compared with that of patients having a complete scala tympani (ST) location 1 year after implantation. METHODS: Thirty-three patients were included in this retrospective case-control study (SV, n = 12; ST, n = 21). The matching criteria were electrode array type, age at implantation, and duration of severe or profound deafness. The array location was analyzed using 3D reconstruction of postoperative CT scans. Postoperative audiological evaluation of the implanted ear was performed using pure-tone audiometry, speech recognition of monosyllabic words in quiet, and words and sentences in noise. RESULTS: On the preoperative CT scan, six patients in the SV group presented with both round window (RW) and ST ossification, three with RW ossification alone, and three with no RW ossification. Auditory performance did not differ between SV and ST groups 1 year after cochlear implantation. Speech recognition of words was 49 ± 7.6% and 56 ± 5.0% in quiet and 75 ± 9.5% and 66 ± 6.0% in noise in SV and ST groups, respectively. CONCLUSION: ST insertion is the gold standard that allows the three cochlear scalae to preserve scalar cochlear integrity. However, 1 year after implantation, a planned or unexpected SV insertion is not detrimental to hearing outcomes, providing similar auditory performance in quiet and noise to ST insertion.

Performance of Non-EPI DW MRI for Pediatric Cholesteatoma Follow-Up.

OBJECTIVE: To evaluate the accuracy, sensitivity, and specificity of nonecho planar (non-EPI) diffusion-weighted (DW) magnetic resonance imaging (MRI) to detect residual cholesteatoma in children. STUDY DESIGN: Retrospective study. SETTING: Tertiary comprehensive hospital. METHODS: Children operated on for a first-stage cholesteatoma procedure from 2010 to 2019 were included. MRIs were performed with non-EPI DW sequences. Initial reports were collected, indicating the presence or absence of hyperintensity suggestive of cholesteatoma. Three hundred twenty-three MRIs were correlated with the subsequent surgery (66%) or year-later MRI (21%), or were considered accurate if performed 5 years or more after the last surgery (13%). The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of each imaging procedure for the detection of cholesteatoma were calculated. RESULTS: Two hundred twenty-four children with mean age of 9 ± 4 years old presented with cholesteatoma. MRIs were performed 27 ± 24 months after surgery. Residual cholesteatoma was diagnosed in 35%. The sensitivity, specificity, PPV, and NPV of MRI were 62%, 86%, 74%, and 78%, respectively. Accuracy, sensitivity, and specificity increased significantly over time (multivariate analysis). The mean delay after last surgery was of 30 ± 2.0 months for accurate MRI (true positive or negative) versus 17 ± 2.0 months for nonaccurate (false positive or negative) MRIs (p < .001). CONCLUSION: However, long the delay after the last surgery, the sensitivity of non-EPI diffusion sequence MRI in children has limitations for the detection of residual cholesteatoma. Surveillance for residual cholesteatoma should incorporate findings at primary surgery, surgeon experience, a low threshold for second-look procedures, and routine imaging.

Spontaneous shrinkage of sporadic vestibular schwannomas: a clinical and radiological analysis.

OBJECTIVE: The natural history of sporadic vestibular schwannoma (VS) is unpredictable, as tumors may or may not grow and can even spontaneously regress. A spontaneous VS shrinkage MRI-based pattern has been proposed with either a scalloped tumor aspect in the cerebellopontine angle or the appearance of a CSF-filled space surrounding the intracanalicular (IC) tumor within an enlarged canal. The authors of this retrospective study aimed to describe the evolution of sporadic VSs with radiological signs of VS regression and to identify prognostic factors for tumor shrinkage. METHODS: All MRI scans obtained during patient follow-up were reviewed for extracanalicular (EC) and IC size and tumor characteristics. Volumetric measurements were performed on the first and last MRI scans. Shrinkage was considered to have occurred if the tumor size had decreased by ≥ 2 mm in its largest diameter and/or if the volume had decreased by ≥ 20%. Audiometric data were also collected. RESULTS: Among 512 patients under observation for sporadic VSs, 66 (13%) had at least one radiological sign of VS regression and 31 of these (6% overall) had confirmed tumor shrinkage. The mean follow-up was 4 ± 2.5 years. One radiological sign was present on initial MRI in 58% of patients and appeared during the follow-up period in the remaining 42%. Two groups were identified: 31 patients (47%) demonstrated progressive tumor regression during follow-up, and tumors in 35 patients (53%) remained stable once signs of regression were identified (assuming a stabilized regression). The prognostic factors for VS regression were as follows: EC VS extension (p = 0.02), cystic lesion (p = 0.002), and central necrosis (p = 0.02). The mean pure-tone average (PTA) was 43 ± 26.2 dB at the time of diagnosis and 53 ± 28.3 dB at the last visit (p < 0.0001). Among patients with an observed tumor shrinkage, ∆PTA was lower if the inner ear signal on the high-resolution T2-weighted image had improved (-3 ± 8.9 dB, n = 11) than if the inner ear signal had not improved (-10 ± 6.9 dB, n = 20) (p = 0.02) between the initial and last MRI scans. CONCLUSIONS: Spontaneous shrinkage of sporadic VSs could be suspected based on two radiological aspects that are indicative of VSs in progressive or stabilized regression and is an additional argument for the conservative management of these tumors. During follow-up, recovery from a reduced to a normal cochlear fluid MRI signal is a good indicator for hearing preservation.

Monitoring Cochlear Nerve Action Potential for Hearing Preservation in Medium/Large Vestibular Schwannoma Surgery: Tips and Pitfalls.

The diagnosis of large vestibular schwannomas (VS) with retained useful hearing has become increasingly common. Preservation of facial nerve (FN) function has improved using intraoperative EMG monitoring, hearing preservation remains challenging, with the recent use of cochlear nerve action potential (CNAP) monitoring. This prospective longitudinal series of VS with useful hearing operated on using a retrosigmoid approach included 37 patients with a mean largest extrameatal VS. diameter of 25 ± 8.7 mm (81% of Koos stage 4). CNAP was detected in 51% of patients, while auditory brainstem responses (ABR) were present in 22%. Patients were divided into two groups based on the initial intraoperative CNAP status, whether it was present or absent. FN function was preserved (grade I-II) in 95% of cases at 6 months. Serviceable hearing (class A + B) was preserved in 16% of the cases, while 27% retained hearing with intelligibility (class A-C). Hearing with intelligibility (class A-C) was preserved in 42% of cases when CNAP could be monitored in the early stages of VS resection versus 11% when it was initially absent. Changes in both the approach to the cochlear nerve and VS resection are mandatory in preserving CNAP and improve the rate of hearing preservation.

Best Fit 3D Basilar Membrane Reconstruction to Routinely Assess the Scalar Position of the Electrode Array after Cochlear Implantation.

The scalar position of the electrode array is assumed to be associated with auditory performance after cochlear implantation. We propose a new method that can be routinely applied in clinical practice to assess the position of an electrode array. Ten basilar membrane templates were generated using micro-computed tomography (micro-CT), based on the dimensions of 100 cochleae. Five surgeons were blinded to determine the position of the electrode array in 30 cadaveric cochleae. The procedure consisted of selecting the appropriate template based on cochlear dimensions, merging the electrode array reconstruction with the template using four landmarks, determining the position of the array according to the template position, and comparing the results obtained to histology data. The time taken to analyze each implanted cochlea was approximately 12 min. We found that, according to histology, surgeons were in almost perfect agreement when determining an electrode translocated to the scala vestibuli with the perimodiolar MidScala array (Fleiss' kappa (κ) = 0.82), and in moderate agreement when using the lateral wall EVO array (κ = 0.42). Our data indicate that an adapted basilar membrane template can be used as a rapid and reproducible method to assess the position of the electrode array after cochlear implantation.

Candidacy for Cochlear Implantation in Prelingual Profoundly Deaf Adult Patients.

Cochlear implantation is usually not recommended for prelingual profoundly deaf adults, although some of these patients might benefit from it. This study aims to define the candidates for cochlear implantation in this population. This retrospective study reviewed 34 prelingual profoundly deaf patients who had received a cochlear implant at 32 ± 1.7 years old (16−55), with at least 1 year of follow-up. Speech perception and quality of life were assessed before and 3, 6, and 12 months after cochlear implantation, then every year thereafter. According to the word speech intelligibility in quiet (WSI) 1 year after implantation, two groups were identified: good performer (GP) with WSI ≥ 50% (n = 15), and poor performer (PP) with WSI ≤ 40% (n = 19). At the 1 year mark, mean WSI improved by 28 ± 4.6% (−20−100) (p < 0.0001). In GP, the intelligibility for words and sentences, communication and quality of life scales improved. In PP, the communication scale improved, but not auditory performance or quality of life. GP and PP differed pre-operatively in speech production, communication abilities, and WSI in best-aided conditions. In prelingual profoundly deaf adults, a dramatic auditory performance benefit could be expected after cochlear implantation if the patients have some degree of speech intelligibility in aided conditions and have developed oral communication and speech production.

Robotics, automation, active electrode arrays, and new devices for cochlear implantation: A contemporary review.

In the last two decades, cochlear implant surgery has evolved into a minimally invasive, hearing preservation surgical technique. The devices used during surgery have benefited from technological advances that have allowed modification and possible improvement of the surgical technique. Robotics has recently gained popularity in otology as an effective tool to overcome the surgeon's limitations such as tremor, drift and accurate force control feedback in laboratory testing. Cochlear implantation benefits from robotic assistance in several steps during the surgical procedure: (i) during the approach to the middle ear by automated mastoidectomy and posterior tympanotomy or through a tunnel from the postauricular skin to the middle ear (i.e. direct cochlear access); (ii) a minimally invasive cochleostomy by a robot-assisted drilling tool; (iii) alignment of the correct insertion axis on the basal cochlear turn; (iv) insertion of the electrode array with a motorized insertion tool. In recent years, the development of bone-attached parallel robots and image-guided surgical robotic systems has allowed the first successful cochlear implantation procedures in patients via a single hole drilled tunnel. Several other robotic systems, new materials, sensing technologies applied to the electrodes, and smart devices have been developed, tested in experimental models and finally some have been used in patients with the aim of reducing trauma in cochleostomy, and permitting slow and more accurate insertion of the electrodes. Despite the promising results in laboratory tests in terms of minimal invasiveness, reduced trauma and better hearing preservation, so far, no clinical benefits on residual hearing preservation or better speech performance have been demonstrated. Before these devices can become the standard approach for cochlear implantation, several points still need to be addressed, primarily cost and duration of the procedure. One can hope that improvement in the cost/benefit ratio will expand the technology to every cochlear implantation procedure. Laboratory research and clinical studies on patients should continue with the aim of making intracochlear implant insertion an atraumatic and reversible gesture for total preservation of the inner ear structure and physiology.

Atraumatic Insertion of a Cochlear Implant Pre-Curved Electrode Array by a Robot-Automated Alignment with the Coiling Direction of the Scala Tympani.

INTRODUCTION: Electrode array translocation is an unpredictable event with all types of arrays, even using a teleoperated robot in a clinical scenario. We aimed to compare the intracochlear trauma produced by the HiFocus™ Mid-Scala (MS) electrode array (Advanced Bionics, Valencia, CA, USA) using a teleoperated robot, with an automated robot connected to a navigation system to align the pre-curved tip of the electrode array with the coiling direction of the scala tympani (ST). METHODS: Fifteen freshly frozen temporal bones were implanted with the MS array using the RobOtol® (Collin, Bagneux, France). In the first group (n = 10), the robot was teleoperated to insert the electrode array into the basal turn of the ST under stereomicroscopic vision, and then the array was driven by a slow-speed hydraulic insertion technique with an estimated placement of the pre-curved electrode tip. In the second group (n = 5), 3 points were obtained from the preoperative cone-beam computed tomography: the 2 first defining the ST insertion axis of the basal turn and a third one at the center of the ST at 270°. They provided the information to the automated system (RobOtol® connected with a navigation system) to automatically align the electrode array with the ST insertion axis and to aim the pre-curved tip toward the subsequent coiling of the ST. After this, the electrode array was manually advanced. Finally, the cochleae were obtained and fixed in a crystal resin, and the position of each electrode was determined by a micro-grinding technique. RESULTS: In all cases, the electrode array was fully inserted into the cochlea and the depth of insertion was similar using both techniques. With the teleoperated robotic technique, translocations of the array were observed in 7/10 insertions (70%), but neither trauma nor array translocation occurred with automated robotic insertion. CONCLUSION: We have successfully tested an automated insertion system (robot + navigation) that could accurately align a pre-curved electrode array to the axis of the basal turn of the ST and its subsequent coiling, which reduced intracochlear insertion trauma and translocation.

Robot-Assisted Middle Ear Endoscopic Surgery: Preliminary Results on 37 Patients.

Background: Endoscopy during middle ear surgery is advantageous for better exploration of middle ear structures. However, using an endoscope has some weaknesses as surgical gestures are performed with one hand. This may trouble surgeons accustomed to using two-handed surgery, and may affect accuracy. A robot-based holder may combine the benefits from endoscopic exposure with a two-handed technique. The purpose of this study was to assess the safety and value of an endoscope held by a teleoperated system. Patients and Methods: A case series of 37 consecutive patients operated using endoscopic exposure with robot-based assistance was analyzed retrospectively. The RobOtol® system (Collin, France) was teleoperated as an endoscope holder in combination with a microscope. The following data were collected: patient characteristics, etiology, procedure type, complications, mean air and bone conduction thresholds, and speech performance at 3 months postoperatively. Patients had type I (myringoplasty), II (partial ossiculoplasty), and III (total ossiculoplasty) tympanoplasties in 15, 14, and 4 cases, respectively. Three patients had partial petrosectomies for cholesteatomas extending to the petrous apex. Finally, one case underwent resection of a tympanic paraganglioma. Ambulatory procedures were performed in 25 of the 37 patients (68%). Results: Complete healing with no perforation of the tympanic membrane was noted postoperatively in all patients. No complications relating to robotic manipulation occurred during surgery or postoperatively. The mean air conduction gain was 3.8 ± 12.6 dB for type I (n = 15), 7.9 ± 11.4 dB for type II (n = 14), and -0.9 ± 10.8 for type III tympanoplasties (n = 4), and the postoperative air-bone conduction gap was 13.8 ± 13.3 dB for type I, 19.7 ± 11.7 dB for type II and 31.6 ± 13.0 dB for type III tympanoplasty. They was no relapse of cholesteatoma or paraganglioma during the short follow-up period (<1 year). Conclusion: This study indicates that robot-assisted endoscopy is a safe and trustworthy tool for several categories of middle ear procedures. It combines the benefits of endoscopic exposure with a two-handed technique in middle ear surgery. It can be used as a standalone tool for pathology limited to the middle ear cleft or in combination with a microscope in lesions extending to the mastoid or petrous apex.

Restoration of High Frequency Auditory Perception After Robot-Assisted or Manual Cochlear Implantation in Profoundly Deaf Adults Improves Speech Recognition.

Background and Purpose: Robot-assisted cochlear implantation has recently been implemented in clinical practice; however, its effect on hearing outcomes is unknown. The aim of this preliminary study was to evaluate hearing performance 1 year post-implantation whether the electrode array was inserted manually or assisted by a robot. Methods: Forty-two profoundly deaf adults were implanted either manually (n = 21) or assisted by a robot (RobOtol®, Collin, Bagneux, France) with three different electrode array types. Participants were paired by age, and electrode array type. The scalar position of the electrode array in the cochlea was assessed by 3D reconstruction from the pre- and post-implantation computed tomography. Pure-tone audiometry and speech perception in silence (percentage of disyllabic words at 60 dB) were tested on the implanted ear 1 year post-implantation in free-field conditions. The pure-tone average was calculated at 250-500-750 Hz, 500-1,000-2,000-3,000 Hz, and 3,000-4,000-8,000 Hz for low, mid, and high frequencies, respectively. Results: One year after cochlear implantation, restoration of the high-frequency thresholds was associated with better speech perception in silence, but not with low or mid frequencies (p < 0.0001; Adjusted R 2 = 0.64, polynomial non-linear regression). Although array translocation was similar using either technique, the number of translocated electrodes was lower when the electrode arrays had been inserted with the assistance of the robot compared with manual insertion (p = 0.018; Fisher's exact test). Conclusion: The restoration of high-frequency thresholds (3,000-4,000-8,000 Hz) by cochlear implantation was associated with good speech perception in silence. The numbers of translocated electrodes were reduced after a robot-assisted insertion.

Analysis of forces during robot-assisted and manual manipulations of mobile and fixed footplate in temporal bone specimens.

PURPOSE: To evaluate the forces involved in different manipulations, manual or robot-assisted, applied to the ossicular chain, on normal temporal bones and on an anatomical model of otosclerosis. METHODS: Thirteen cadaveric temporal bones, with mobile footplates or with footplates that were fixed using hydroxyapatite cement, were manipulated, manually or using a robotic arm (RobOtol®). "Short contact" of a mobile footplate was the weakest interaction on the incus. "Long contact" was the same manipulation held for 10 s. "Mobilization" was the smallest visualized movement of the mobile footplate, or the movement necessary to regain mobility of the fixed footplate. A six-axis force sensor (Nano17, ATI) measured the maximal peak of forces, summation of forces applied, and yank. RESULTS: Maximal forces during short (~4 mN) and long contact (~15 mN) were similar for manual and robot-assisted manipulations. For manual manipulation, yank measured during long contact was twice as high compared to robot-assisted manipulation: 6 ± 2.4 (n = 5) and 3 ± 1.3 mN/s (n = 5), respectively (mean ± SD, p < 0.02). For mobilization of the mobile footplate, maximal forces during mobilization were similar during manual and robot-assisted manipulations, respectively: 12 ± 2.5 (n = 6) and 19 ± 7.6 mN (n = 7). Compared with mobilization of a mobile footplate, mobilization of a fixed footplate required ~ 60 and ~ 27 times higher maximal forces for manual and robot-assisted manipulations, respectively: 724 ± 366.4 and 507 ± 283.2 mN. Yank was twice as high during manual manipulation compared to robot-assisted manipulation (p < 0.05). CONCLUSION: Robot-assisted manipulation of the ossicular chain was reliable. Our anatomical model of otosclerosis was successfully developed requiring higher forces for stapes mobilization.

Robot-based assistance in middle ear surgery and cochlear implantation: first clinical report.

PURPOSE: Middle ear surgery may benefit from robot-based assistance to hold micro-instruments or an endoscope. However, the surgical gesture performed by one hand may perturb surgeons accustomed to two-handed surgery. A robot-based holder may combine the benefits from endoscopic exposure and a two-handed technique. Furthermore, tremor suppression and accurate tool control might help the surgeon during critical surgical steps. The goal of this work was to study the safety of an otological robot-based assistant under clinical conditions in a limited series of patients. METHODS: The RobOtol system has been used as an endoscope or a micro instrument holder for this series. Eleven cases were operated on with the robot as an endoscope holder for chronic otitis. Twenty-one cases were operated on with the robot as a micro-instrument holder for otosclerosis (9 cases), transtympanic tube placement (2 cases), or cochlear implantation (10 cases). RESULTS: No complications related to the robot manipulation occurred during surgery nor in postoperative. In the chronic otitis group, all perforations were sealed and 3-month postoperative pure-tone average air-bone gap (PTA ABG) was 15 ± 2.6 dB. In the otosclerosis group, 1-month post-op PTA ABG was 10 ± 1 dB. For cochlear implantation cases, a scala tympani insertion, a vestibular scala translocation occurred and a full scala vestibuli insertion was observed in 7, 2 and 1 case, respectively. CONCLUSION: The RobOtol system has reached the clinical stage. It could be used safely and with accurate control as an endoscope holder or a micro instrument holder in 32 cases.

Robot-assisted Cochlear Implant Electrode Array Insertion in Adults: A Comparative Study With Manual Insertion.

OBJECTIVE: To describe the first cochlear array insertions using a robot-assisted technique, with different types of straight or precurved electrode arrays, compared with arrays manually inserted into the cochlea. STUDY DESIGN: Retrospective review. SETTING: Tertiary otologic center. PATIENTS: Twenty cochlear implantations in the robot-assisted group and 40 in the manually inserted group. INTERVENTIONS: Cochlear implantations using a robot-assisted technique (RobOtol) with straight (eight Cochlear CI522/622, and eight Advanced Bionics Hifocus Slim J) or precurved (four Advanced Bionics Hifocus Mid-Scala) matched to manual cochlear implantations. Three-dimensional reconstruction images of the basilar membrane and the electrode array were obtained from pre- and postimplantation computed tomography. MAIN OUTCOME MEASURES: Rate and localization of scalar translocations. RESULTS: For straight electrode arrays, scalar translocations occurred in 19% (3/16) of the robot-assisted group and 31% (10/32) of the manually inserted group. Considering the number of translocated electrodes, this was lower in the robot-assisted group (7%) than in the manually inserted group (16%) (p < 0.0001, χ2 test). For precurved electrode arrays, scalar translocations occurred in 50% (2/4) of the robot-assisted group and 38% (3/8) of the manually inserted group. CONCLUSION: This study showed a safe and reliable insertion of different electrode array types with a robot-assisted technique, with a less traumatic robotic insertion of straight electrode arrays when compared with manual insertion.

Improving facial nerve outcome and hearing preservation by different degrees of vestibular schwannoma resection guided by intraoperative facial nerve electromyography.

BACKGROUND: Facial nerve (FN) outcome has been improved by deciding upon the degree of vestibular schwannoma (VS) resection guided by intraoperative facial nerve monitoring (IOFM). This study aimed to evaluate hearing and FN outcomes following IOFM-guided VS removal through a retrosigmoid approach (RS). METHODS: Between January 2015 and August 2017, 77 patients undergoing VS resection through RS, regardless of their preoperative hearing or tumor size, were included in this monocentric retrospective study. Total or near-/subtotal resection was decided intraoperatively according to IOFM. Partial resection was planned preoperatively. Pre- and postoperative FN function (House-Brackmann) and hearing level (AAO-HNS and Gardner-Robertson (GR) scales) were reported. Predictive factors for hearing preservation were analyzed according to a score developed to take into account pre-/postoperative hearing evolution. RESULTS: The mean extrameatal diameter was 17 ± 8.5 mm. VS resection was total, near-/subtotal, and partial in 71%, 21%, and 8% of cases, respectively. Postoperative grade I and II FN function was achieved in 91% of patients. Serviceable (A+B or GR I+II) hearing and hearing with intelligibility (A+B+C or GR I-III) were preserved in 30% and 43% of cases, respectively. In multivariate analysis, preoperative synchronized auditory brainstem responses (ABR) were the only predictive factor (p = 0.006) imparting a five times greater chance of hearing preservation. CONCLUSION: IOFM-guided VS excision through RS, whatever the VS size and hearing level, achieved a high rate of good postoperative FN function together with significant hearing preservation, and it should be used if hearing with some intelligibility is still present preoperatively, even in large VS.

Multimodal strategy for the management of sphenoid osteoradionecrosis: Preliminary results.

OBJECTIVE: Osteoradionecrosis (ORN) of the sphenoid is a rare but potentially lethal complication that can occur after irradiation of nasopharyngeal and clival malignancies. The objective of this study was to describe a multimodal treatment strategy tailored to the clinical signs and to the radiological extent of the disease, and to report on its preliminary results. METHODS: Retrospective monocentric study at a tertiary skull base center. Patients treated for a sphenoid ORN from January 2014 to August 2018 were identified and charts were retrospectively reviewed for demographics, histologic tumor type, previous treatments of the tumor, clinical signs at presentation, radiological data, treatment, and outcomes. Sphenoid ORN was treated by a combination of medical therapy, endovascular treatment, and/or surgery. The use of each of these therapeutic modalities was based on the extent of ORN and on the presenting signs. RESULTS: Seven patients were included: four patients underwent endovascular treatment with occlusion of the internal carotid artery, five patients underwent surgical debridement, and covering of the exposed bone by a local flap, seven patients received antibiotics (in combination with pentoxyphilline, tocopherol, and clodronate in one case). Three patients died after progression of the ORN. The global survival rate was 57% (4/7) with a mean follow-up of 24 months. In one case, ORN was treated successfully by medical treatment only, with a combination of antibiotics, pentoxyphilline, tocopherol, and clodronate. CONCLUSION: This retrospective study describes the results of a management strategy adapted to the extent of the disease in sphenoid ORN and based on medical therapy only, or on a combination of medical therapy, interventional radiology, and/or surgery. LEVEL OF EVIDENCE: 4.