Audiologic Outcomes After Vestibulotomy in Patients With Congenital Absence of the Oval Window.

OBJECTIVE: To examine the clinical features and surgical outcomes in patients with congenital absence of the oval window (CAOW), and to investigate the potential factors that affect audiologic results. STUDY DESIGN: A retrospective chart review. SETTING: A tertiary academic center. PATIENTS AND INTERVENTION: A total of 17 ears among 16 patients were confirmed to have CAOW. Among them, 13 ears underwent vestibulotomy for hearing reconstruction. Clinical parameters associated with the hearing outcomes were analyzed. MAIN OUTCOME MEASURES: A mean air-bone gap (ABG) after 6-month and long-term follow-up was compared with preoperative measurements. RESULTS: Intraoperative findings showed that anomalies of the malleus or incus were observed in 11 ears (64.7%), stapes anomalies were present in all ears (100%), and facial nerve anomalies were present in 10 ears (58.8%). Because of unfavorable facial nerve anomalies, hearing reconstruction was aborted in four cases (23.5%). In the hearing reconstruction group, the mean ABG at 6 months postoperation was significantly reduced after compared with the preoperative value (44.0 ± 8.4 dB versus 58.8 ± 9.1 dB, p = 0.006). After dividing ears into a success subgroup (ABG ≤ 30 dB, seven ears) and non-success subgroup (ABG > 30 dB, six ears), the use of a drill during vestibulotomy was significantly related to a poor hearing outcome (100% versus 16.7%, p = 0.015). The long-term follow-up result (mean, 60 mo) revealed no deterioration compared with the 6-month postoperative result. Five ears (29.4%) underwent revision surgery, and three of them showed ABG improvements. No serious complications were reported. CONCLUSION: Vestibulotomy is an effective and safe option for hearing restoration in patients with CAOW, particularly when the use of a drill is not required. The long-term audiologic outcome is also reliable.

Deterioration of Hearing due to Hearing Aids.

Objectives: In the large population with sensorineural hearing loss, one of the main reasons for insufficient adoption rate of hearing aids (HA) has been the social concern that the devices may negatively affect remaining hearing ability. To date, there have been few studies with controversial results on the issue. This study examined the long-term effects of HA on standard audiometric changes in sensorineural hearing loss. Methods: The study retrospectively analyzed patients who had newly acquired unilateral HA between 2015 and 2017 and showed consistent use for five years. Demographics; medical comorbidities; audiometric data; questionnaire results of the Hearing Handicap Inventory for the Elderly (HHIE) and International Outcome Inventory for Hearing Aids (IOI-HA); history of noise exposure and previous HA use were examined. Results: Fifty-five patients used unilateral HA for a mean follow up period of 5.32 years. Thirty-one patients (56.4%) used HA on the right side. Audiometric data of the aided side did not show significant difference compared to the unaided side, in prefit pure-tone average of air conduction (AC) and word recognition score (WRS) (P= 0.73, 0.11, respectively), in fiveyear follow-up audiometry of AC and WRS (P=0.98, 0.07) or in the change from last to prefit audiometry of AC and WRS (P=0.58, 0.70). When comparing patients who showed 5dB or more deterioration of hearing on the aided side compared with the unaided side, 11 patients (20%) had worsened AC on the aided side and 23 (53.5%) presented with further deterioration of WRS on the aided side. There were no significant factors contributing to the difference in hearing deterioration in either group for AC or WRS. Conclusion: After long-term use of HA, there were no significant factors contributing to the hearing deterioration and, overall, the use of HA did not negatively affect residual hearing.

Long-term follow-up results of facial nerve schwannoma with good facial nerve function: a multicenter study.

PURPOSE: Facial nerve schwannomas (FNSs) are rare intracranial tumors, and the optimal management of these tumors remains unclear. We investigated the long-term follow-up results of FNS with good facial nerve function. METHODS: At nine medical centers in the Korean Facial Nerve Study Group, 43 patients undergoing observation periods longer than 12 months for FNS with good facial nerve function (House-Brackmann grade ≤ II) were enrolled, and clinical and radiographic data were obtained for these cases. RESULTS: The mean follow-up period was 63 months. In the majority of cases, tumors involved multiple segments (81.4%) and only eight cases were confined to a single site. There were no cases where the tumor was confined to the extratemporal region. Tumor size increased slightly, with an average estimated change of 0.48 mm/year. Twenty (46.5%) of 43 patients showed no change in tumor size. Seven patients (16.3%) showed worsening House-Brackmann (H-B) grade, of which two patients deteriorated from H-B grade I to II, four worsened to grade III, and one deteriorated to grade IV. The remaining 36 patients (83.7%) showed no change in facial nerve function. There was no difference in H-B grade according to tumor size at the time of diagnosis or change in tumor size. CONCLUSION: We conducted a large-scale observational study of FNS with good facial nerve function. Our study showed that many patients maintained facial nerve function during long-term follow-up. Conservative management with regular examination and imaging can be an appropriate option for managing FNS with good facial nerve function.

Changes in Listening Effort Through Pupil Response After Atresioplasty in Children With Congenital Aural Atresia.

OBJECTIVES: This study aimed to determine whether the improvement of hearing by surgical treatment alleviates cognitive demands through pupil response in patients with unilateral congenital aural atresia (CAA). DESIGN: A prospective study was performed on patients with unilateral CAA who were scheduled to undergo primary atresioplasty between November 2017 and May 2020. Pure-tone audiometry, auditory digit span test, Korean Speech Perception in Noise test, pupil measurement during speech tests, and questionnaires (Sound-Spatial-Qualities of Hearing Scale; subjective listening effort rating) were performed before and 6 months after surgery. RESULTS: Of 30 consecutive patients who initially enrolled, only 18 patients (12 males and 6 females) were included in the analysis. When the improvement of the air-bone gap and interaural difference of air conduction within 30 dB was defined as a successful hearing outcome, successful hearing improvement was achieved in 50% of the 18 patients. In pupil measurement, the success group had a significantly smaller mean pupil dilation response than the nonsuccess group at 0 and -3 dB signal to noise ratio (SNR) (all p < 0.01). In addition, significant differences were identified between the two groups for peak dilation and peak latency at all noise levels (all p < 0.01). When analyzing the change in pupil response before and after surgery, the difference in relative mean pupil dilation in the success group was significantly greater than that in the nonsuccess group at -3 dB SNR (p = 0.02). In addition, the success group showed a significantly greater change in peak latency than the nonsuccess group at the -3 dB SNR (p < 0.01). The difference in peak dilation tended to be greater in the success group than in the nonsuccess group, but the difference was not statistically significant. CONCLUSIONS: Patients with unilateral CAA who achieved surgically improved hearing had a smaller pupil dilation response than those who did not. These results suggest that successful hearing outcomes after surgery in patients with unilateral CAA may reduce the cognitive effort required to understand speech under difficult listening conditions.

Infiltrative fibrous lesion of the facial nerve mimicking a facial nerve tumor.

PURPOSE: To report three cases of facial nerve lesions that were clinically expected to be facial nerve tumors but showed fibrotic infiltration without any apparent signs of a specific tumor on histopathological findings. We also aimed to investigate the clinical characteristics of these cases. METHODS: Medical records of patients who underwent surgery for facial nerve lesions were reviewed. RESULTS: All three cases initially had House-Brackmann (HB) grade IV-V facial nerve palsy. On radiological imaging, schwannoma or glomus tumor originating from the facial nerve was suspected. All patients underwent complete surgical removal of the neoplasm followed by facial nerve reconstruction using the sural nerve. The lesions were histologically confirmed as infiltrative fibrous lesions without tumor cells. In two cases, facial nerve palsy improved to HB grade III by nine months post-surgery, and there were no signs of recurrence on follow-up MRI. The other case, after 1 year of follow-up, showed persistence of HB grade V facial nerve palsy without any evidence of recurrence. CONCLUSION: Fibrotic lesions of the facial nerve could mimic primary facial nerve tumors. Clinicians should consider this condition even when a facial nerve tumor is suspected.

Clinical outcome and prognostic factors in adenoid cystic carcinoma of the external auditory canal: proposal for a refined T-stage classification system.

PURPOSE: Although adenoid cystic carcinoma (ACC) of the external auditory canal (EAC) has a different pathophysiology from squamous cell carcinoma, the same staging system is used. The aim of this study was to propose a refined staging system, which is more suitable for ACC of the EAC. METHODS: A total of 25 patients who were diagnosed with ACC of the EAC were reviewed. The modified Pittsburgh staging system (mPSS) that is universally used for temporal bone malignancy was refined for ACC (rPSS). The limited (< 0.5 cm) lateral soft tissue involvement was classified as T1 and extensive (≥ 0.5 cm) lateral soft tissue involvement as T2. The disease-free survival rate (DFSR) was assessed in the patients who underwent surgical treatment according to two staging systems; mPSS and rPSS. RESULTS: When staging using mPSS, most patients (96.0%, n = 24) were classified as T4. However, when rPSS was used, T1, T2, T3, and T4 stage occupied 36.0% (n = 9), 40.0% (n = 10), 12.0% (n = 3), 12.0% (n = 3), respectively. There was no difference in DFSR according to the T stage using mPSS (p = 0.466). However, when rPSS was used, the DFSR showed significant correlation with the T stage (p = 0.032). CONCLUSIONS: Clinical T stage of mPSS was not sufficient to predict survival rate in ACC of the EAC, and we propose that the information on the lateral soft tissue involvement needs to be added to the existing staging system.

Taste Changes after Atresioplasty in Patients with Congenital Aural Atresia.

OBJECTIVE: We evaluated chorda tympani nerve (CTN) and postoperative taste dysfunction according to anomaly severity and intraoperative CTN status. STUDY DESIGN: Prospective observational study. SETTING: Tertiary referral center, Samsung medical center hospital. PATIENTS: Thirty-one patients who underwent atresioplasty by a single surgeon in a tertiary referral center were enrolled. INTERVENTIONS: Therapeutic surgery. MAIN OUTCOME MEASURES: Preoperative Schuknecht type and Jahrsdoerfer score and intraoperative CTN status were recorded, and a postoperative questionnaire was administered to evaluate taste function. RESULTS: A significant difference was found among intact, cut, and unidentified groups in terms of Schuknecht type ( p = 0.000) and Jahrsdoerfer score (9.28 ± 1.11, 8.80 ± 0.83, 8.10 ± 0.93, p = 0.028). CTN was observed in Schuknecht type B, and not in type C ( p = 0.000), and was more likely to be observed as Jahrsdoerfer score increased ( p = 0.012). Taste disturbance tended to last longer in adult patients than in children. A significant difference was observed in the incidence of taste change between cut and intact CTN groups ( p = 0.018). CONCLUSION: CTN was not identified during surgery in patients with Schuknecht type C anomalies, and there was no change in taste after surgery. Meanwhile, CTN was observed in all patients with Schuknecht type B anomalies, and CTN injury occurred in 41.67%. Therefore, CTN presence can be predicted by severity of anomaly, and patients with type B anomalies should be informed of the risk of CTN injury before surgery.

Associations between aided speech audiometry and subjective assessment of hearing aid outcomes.

OBJECTIVE: This study aimed to analyse outcomes with hearing aid (HA) use and to determine whether common audiological tests, including pure-tone audiometry or word recognition test, correlate with HA wearers' subjective benefit. DESIGN: A retrospective chart review. STUDY SAMPLE: A total of 129 patients who adopted new HAs between January 2011 and December 2018 were enrolled. Outcome measures including pure tone thresholds, word recognition score (WRS), and self-reported questionnaires were obtained 1, 4, and 12 months post fit. RESULTS: The mean aided threshold and WRS at each post-fit visit significantly improved from the unaided condition. Self-reported outcomes confirmed by the Hearing Handicap Inventory for the Elderly (HHIE) scores significantly improved compared to the unaided condition at 1- and 4-month follow-up. Results of the regression analysis indicated that the aided WRS score is a significant factor at all post-fit visits that explains less than 10% of the variance in HHIE scores. CONCLUSIONS: Aided WRS is the factor most associated with subjectively reported HA outcomes, both in the short- and long term. Therefore, aided WRS should be considered as a useful tool for evaluating HA benefits, even after the prolonged use of HAs.

Acoustic Reflex After Surgical Repair in Patients with Congenital Aural Atresia.

BACKGROUND: This study aimed to examine the plasticity of nerves indirectly by acoustic reflex after surgical repair of unilateral congenital aural atresia. METHODS: This study is a retrospective study including 80 patients who had undergone surgical repairs of congenital aural atresia before 18 years old and for whom acoustic reflex testing was performed postoperatively. Several variables correlated with acoustic reflex were analyzed to find factors affecting the presence of acoustic reflex. RESULTS: Among 80 patients, 44 were positive for acoustic reflex. As a result of multivariate analysis, good postoperative hearing (P = .017), younger age at surgery (P = .028), and the longer time interval between surgery and acoustic reflex test (P = .040) were revealed as factors affecting the acoustic reflex. CONCLUSION: Acoustic reflex was present in 55% of surgically managed patients with congenital aural atresia. The results of this study imply that the reflex arc of acoustic reflex may be restored after proper surgical reconstruction and prolonged use of reconstructed ear in patients with unilateral congenital aural atresia.

Mucosal Melanoma of Eustachian Tube: A Case Report.

Mucosal melanoma originating from the eustachian tube is very rare, and only 15 cases were reported so far. In this study, we report a case of mucosal melanoma from the eustachian tube which was surgically managed, followed by chemoradiotherapy. A 53-year-old man presented with a history of recurrent idiopathic hemotympanum and a dark red mass in the nasopharynx protruding from the eustachian tube orifice. Under an impression of mucosal melanoma from the eustachian tube, en-bloc surgical removal was performed using the infratemporal fossa approach type C combined with a transnasal endoscopic approach followed by postoperative chemoradiotherapy. However, the disease progressed to lung metastasis, and the patient died of the disease at 13 months postoperatively. The presenting case showed a poor progression despite a margin-free surgical resection followed by chemoradiotherapy. Additional trial of new treatment options is necessary to improve the poor prognosis.

Factors Affecting the Extrusion Rate and Complications After Ventilation Tube Insertion: A Multicenter Registry Study on the Effectiveness of Ventilation Tube Insertion in Pediatric Patients With Chronic Otitis Media With Effusion-Part II.

OBJECTIVES: The impacts of ventilation tube (VT) type and effusion composition on the VT extrusion rate and complications in children with otitis media remain unclear. This part II study evaluated the factors affecting the extrusion rate, recurrence rate, and complications of VT insertion. METHODS: A prospective study was conducted between June 2014 and December 2016 (the EVENT study [analysis of the effectiveness of ventilation tube insertion in pediatric patients with chronic otitis media]), with follow-up data collected until the end of 2017. Patients aged <15 years diagnosed with otitis media with effusion who received VT insertion were recruited at 15 tertiary hospitals. The primary outcomes were time to extrusion of VT, time to effusion recurrence, and complications. RESULTS: Data from 401 patients were analyzed. After excluding the. RESULTS: of long-lasting tubes (Paparella type II and T-tubes), silicone tubes (Paparella type I) exhibited a significantly longer extended time to extrusion (mean, 400 days) than titanium tubes (collar-button-type 1.0 mm: mean, 312 days; P<0.001). VT material (hazard ratio [HR], 2.117, 95% confidence interval [CI], 1.254-3.572; P=0.005), age (HR, 3.949; 95% CI, 1.239-12.590; P=0.02), and effusion composition (P=0.005) were significantly associated with the time to recurrence of middle ear effusion. Ears with purulent (mean, 567 days) and glue-like (mean, 588 days) effusions exhibited a shorter time to recurrence than ears with serous (mean, 846 days) or mucoid (mean, 925 days) effusions. The revision VT rates during follow-up were 3.5%, 15.5%, 10.4%, and 38.9% in ears with serous, mucoid, glue-like, and purulent effusions, respectively (P<0.001). The revision surgery rates were higher among patients aged <7 years than among those aged ≥7 years. CONCLUSION: Silicone tubes (Paparella type I) were less prone to early extrusion than titanium 1.0 mm tubes. VT type, patient age, and effusion composition affected the time to recurrence of effusion.

Intractable middle ear effusion in EGPA patients might cause permanent hearing loss: a case-control study.

BACKGROUND: Ear, nose, and throat involvement are common in eosinophilic granulomatosis with polyangiitis (EGPA). Among otologic manifestation, middle ear effusion (MEE) is less recognized but a problematic condition as it may progress to hearing impairment when left untreated. This study aimed to evaluate the characteristics, risk factors and clinical outcomes of MEE in EGPA patients. METHODS: This is a case-control study of patients who were diagnosed and treated for EGPA from January 1995 to November 2018. Patients with ear symptoms (ear fullness, ear discharge, tinnitus or hearing loss) were assessed by otologists and were included in the case group (n = 23) if clinically relevant. The other patients without MEE were included in the control group (n = 52). Risk of MEE was calculated using the Cox proportional-hazard model. RESULTS: During median follow-up of 9.9 years, 23 (30.7%) out of 75 patients had MEE. In MEE group, 12 (52.2%) patients had hearing loss; conductive type in 10 (10/12, 83.3%) and mixed type in two (2/12, 16.7%). In multivariable regression analysis, major organ involvement at diagnosis (adjusted hazard ratio [aHR] 65.4; 95% confidence interval [CI], 1.50-2838.39; P = 0.030] , early onset of ear symptom after systemic therapy (< 6 months) (aHR 40.0; 95% CI, 1.35-1183.43; P = 0.033) and continuing the maintenance steroid without cessation (aHR 8.59; 95% CI, 1.13-65.42; P = 0.038) were independently associated with a risk of MEE. To control MEE, 16 (69.6%) patients had to increase maintenance steroid dose and 9 (39.1%) patients experienced recurrent MEE whenever maintenance dose was tapered. CONCLUSIONS: MEE is a common but frequently neglected condition in EGPA which is often intractable. The maintenance steroid dose should be adequately adjusted to control MEE and to prevent from progressive hearing loss. Novel biologic agents possibly have a role in controlling MEE in EGPA.

Automatic Prediction of Conductive Hearing Loss Using Video Pneumatic Otoscopy and Deep Learning Algorithm.

OBJECTIVES: Diseases of the middle ear can interfere with normal sound transmission, which results in conductive hearing loss. Since video pneumatic otoscopy (VPO) findings reveal not only the presence of middle ear effusions but also dynamic movements of the tympanic membrane and part of the ossicles, analyzing VPO images was expected to be useful in predicting the presence of middle ear transmission problems. Using a convolutional neural network (CNN), a deep neural network implementing computer vision, this preliminary study aimed to create a deep learning model that detects the presence of an air-bone gap, conductive component of hearing loss, by analyzing VPO findings. DESIGN: The medical records of adult patients who underwent VPO tests and pure-tone audiometry (PTA) on the same day were reviewed for enrollment. Conductive hearing loss was defined as an average air-bone gap of more than 10 dB at 0.5, 1, 2, and 4 kHz on PTA. Two significant images from the original VPO videos, at the most medial position on positive pressure and the most laterally displaced position on negative pressure, were used for the analysis. Applying multi-column CNN architectures with individual backbones of pretrained CNN versions, the performance of each model was evaluated and compared for Inception-v3, VGG-16 or ResNet-50. The diagnostic accuracy predicting the presence of conductive component of hearing loss of the selected deep learning algorithm used was compared with experienced otologists. RESULTS: The conductive hearing loss group consisted of 57 cases (mean air-bone gap = 25 ± 8 dB): 21 ears with effusion, 14 ears with malleus-incus fixation, 15 ears with stapes fixation including otosclerosis, one ear with a loose incus-stapes joint, 3 cases with adhesive otitis media, and 3 ears with middle ear masses including congenital cholesteatoma. The control group consisted of 76 cases with normal hearing thresholds without air-bone gaps. A total of 1130 original images including repeated measurements were obtained for the analysis. Of the various network architectures designed, the best was to feed each of the images into the individual backbones of Inception-v3 (three-column architecture) and concatenate the feature maps after the last convolutional layer from each column. In the selected model, the average performance of 10-fold cross-validation in predicting conductive hearing loss was 0.972 mean areas under the curve (mAUC), 91.6% sensitivity, 96.0% specificity, 94.4% positive predictive value, 93.9% negative predictive value, and 94.1% accuracy, which was superior to that of experienced otologists, whose performance had 0.773 mAUC and 79.0% accuracy on average. The algorithm detected over 85% of cases with stapes fixations or ossicular chain problems other than malleus-incus fixations. Visualization of the region of interest in the deep learning model revealed that the algorithm made decisions generally based on findings in the malleus and nearby tympanic membrane. CONCLUSIONS: In this preliminary study, the deep learning algorithm created to analyze VPO images successfully detected the presence of conductive hearing losses caused by middle ear effusion, ossicular fixation, otosclerosis, and adhesive otitis media. Interpretation of VPO using the deep learning algorithm showed promise as a diagnostic tool to differentiate conductive hearing loss from sensorineural hearing loss, which would be especially useful for patients with poor cooperation.

The effect of charge-balanced transcutaneous electrical nerve stimulation on rodent facial nerve regeneration.

This study aimed to investigate the effect of charge-balanced transcutaneous electrical nerve stimulation (cb-TENS) in accelerating recovery of the facial function and nerve regeneration after facial nerve (FN) section in a rat model. The main trunk of the left FN was divided and immediately sutured just distal to the stylomastoid foramen in 66 Sprague-Dawley rats. The control group had no electrical stimulus. The other two groups received cb-TENS at 20 Hz (20 Hz group) or 40 Hz (40 Hz group). Cb-TENS was administered daily for seven days and then twice a week for three weeks thereafter. To assess the recovery of facial function, whisker movement was monitored for four weeks. Histopathological evaluation of nerve regeneration was performed using transmission electron microscopy (TEM) and confocal microscopy with immunofluorescence (IF) staining. In addition, the levels of various molecular biological markers that affect nerve regeneration were analyzed. Whisker movement in the cb-TENS groups showed faster and better recovery than the control group. The 40 Hz group showed significantly better movement at the first week after injury (p < 0.0125). In histopathological analyses using TEM, nerve axons and Schwann cells, which were destroyed immediately after the injury, recovered in all groups over time. However, the regeneration of the myelin sheath was remarkably rapid and thicker in the 20 Hz and 40 Hz groups than in the control group. Image analysis using IF staining showed that the expression levels of S100B and NF200 increased over time in all groups. Specifically, the expression of NF200 in the 20 Hz and 40 Hz groups increased markedly compared to the control group. The real-time polymerase chain reaction was performed on ten representative neurotrophic factors, and the levels of IL-1ß and IL-6 were significantly higher in the 20 and 40 Hz groups than in the control group (p < 0.015). Cb-TENS facilitated and accelerated FN recovery in the rat model, as it significantly reduced the recovery time for the whisker movement. The histopathological study and analysis of neurotrophic factors supported the role of cb-TENS in the enhanced regeneration of the FN.

Management of facial nerve schwannoma: when is the timing for surgery.

PURPOSE: Although the estimated prevalence is extremely low, facial nerve schwannoma (FNS) is the most common primary tumor of the facial nerve (FN). In the present study, the outcome of surgical management in 18 patients with FNS was analyzed and an appropriate time for surgery was proposed. MATERIALS AND METHODS: A total of 18 patients with FNS who underwent surgical management by a single surgeon from 1999 to 2018 were retrospectively analyzed. RESULTS: Among the 18 patients, five had no facial paralysis before surgery. Near-total removal was performed in three cases, and two cases were managed with decompression. In 13 cases with various degree of preoperative facial palsy, nerve continuity was lost during surgery. FN was reconstructed using cable graft in ten cases, direct anastomosis in one case, and facial-hypoglossal nerve transfer in one case. Facial reanimation surgery without FN reconstruction was performed in one case due to a long-standing facial paralysis before surgery. Preoperative House-Brackmann (H-B) grade in all patients was significantly worse as tumor size increased. The correlation was not observed between the duration and severity of preoperative facial palsy. Analysis of 12 patients who underwent FN reconstruction revealed that all patients with good preoperative facial function (H-B grade II-III) recovered to H-B grade III after surgery (7/7, 100%). However, patients with poor preoperative facial function (H-B grade IV or worse) had only a 40% (2/5) chance of improving to grade III after surgery. Preoperative tumor size and duration of facial palsy did not affect postoperative final facial function. CONCLUSION: We suggest that H-B grade III facial palsy is the best time for surgical intervention, regardless of the tumor size or duration of facial palsy.

Occult parotid involvement in early-stage squamous cell carcinoma of the external auditory canal.

BACKGROUND: The importance of elective parotidectomy in early-stage squamous cell carcinoma (SCC) of the external auditory canal (EAC) is not well established. METHODS: A retrospective study of 43 patients with early-stage SCC of the EAC who underwent parotidectomy in conjunction with lateral temporal bone resection at three centers. RESULTS: Overall occult parotid involvement (OPI) rate in early-stage SCC of the EAC was 13.9% (6/43). When considering both the anteroposterior position and the bony-cartilaginous position, patients with SCC in both the anterior wall and cartilaginous portion exhibited significantly higher OPI than other locations (37.5% vs. 0%, p = 0.001), with an increase in the OPI predictive value. CONCLUSION: SCC located in either the anterior wall of the EAC or the cartilaginous portion of the EAC or both simultaneously showed a high prevalence of OPI, and elective parotidectomy should be considered in those patients.

Growth of vestibular schwannoma: long-term follow-up study using survival analysis.

BACKGROUND: A vestibular schwannoma (VS) is a benign nerve sheath tumor derived from the vestibular nerves. The growth rate of VS during long-term follow-up has not yet been fully evaluated. We aimed to investigate the growth rate of newly diagnosed VS and the related predictive factors for tumor growth. METHODS: A retrospective review was performed using VS patients who underwent at least two magnetic resonance imaging (MRI) scans before tumor growth was observed. Tumor growth was defined as a size increase of more than 2 mm in the longest diameter of the tumor. To assess the growth rate of VS and related factors, we assessed tumor growth using survival analysis. Survival analysis to assess the growth rate and Cox regression analysis were performed to find related factors. RESULTS: The study included 118 patients. The mean age of patients was 57.0 ± 12.9 years. During the observation period, the 5-year cumulative growth incidence rate was 41.3% by survival analysis. Extrameatal tumor location and hearing loss were found to be associated with an increased hazard ratio (HR) for tumor growth. CONCLUSION: After long-term observation of VS, 41.3% of VS patients presented cumulative growth incidence rate in the first 5 years after diagnosis. Extrameatal tumor location and hearing changes were related to subsequent tumor growth.

Optimal Volume of the Residual Tumor to Predict Long-term Tumor Control Using Stereotactic Radiosurgery after Facial Nerve-preserving Surgery for Vestibular Schwannomas.

BACKGROUND: Intended subtotal resection (STR) followed by adjuvant gamma knife radiosurgery (GKRS) has emerged as an effective treatment option for facial nerve (FN) preservation in vestibular schwannomas (VSs). This study aimed to identify the optimal cut-off volume of residual VS to predict favorable outcomes in terms of both tumor control and FN preservation. METHODS: This retrospective study assessed the patients who underwent adjuvant GKRS for residual VS after microsurgery. A total of 68 patients who had been followed up for ≥ 24 months after GKRS were included. Tumor progression was defined as an increase in tumor volume (TV) of ≥ 20%. House-Brackmann grades I and II were considered to indicate good FN function. RESULTS: The median residual TV was 2.5 cm³ (range: 0.3-27.4). The median follow-up period after the first adjuvant GKRS was 64 months (range: 25.7-152.4). Eight (12%) patients showed tumor progression. In multivariate analyses, residual TV was associated with tumor progression (P = 0.003; hazard ratio [HR], 1.229; 95% confidence interval [CI], 1.075-1.405). A residual TV of 6.4 cm³ was identified as the cut-off volume for showing the greatest difference in progression-free survival (PFS). The 5-year PFS rates in the group with residual TVs of < 6.4 cm³ (54 patients) and that with residual TVs of ≥ 6.4 cm³ (14 patients) were 93.3% and 69.3%, respectively (P = 0.014). A good FN outcome was achieved in 57 (84%) patients. Residual TV was not associated with good FN function during the immediate postoperative period (P = 0.695; odds ratio [OR], 1.024; 95% CI, 0.908-1.156) or at the last follow-up (P = 0.755; OR, 0.980; 95% CI, 0.866-1.110). CONCLUSION: In this study, residual TV was associated with tumor progression in VS after adjuvant GKRS following STR. As preservation of FN function is not correlated with the extent of resection, optimal volume reduction is imperative to achieve long-term tumor control. Our findings will help surgeons predict the prognosis of residual VS after FN-preserving surgery.

Comparison between retrosigmoid and translabyrinthine approaches for large vestibular schwannoma: focus on cerebellar injury and morbidities.

This study aimed to compare the surgical outcomes and morbidities of retrosigmoid and translabyrinthine approaches for large vestibular schwannoma (VS), with a focus on cerebellar injury and morbidities. Eighty-six consecutive patients with large VS, with a maximal extrameatal diameter > 3.0 cm, were reviewed between August 2010 and September 2018. The surgical outcomes, operating time, volume change of perioperative cerebellar edema, and inpatient rehabilitation related to cerebellar morbidities were compared between the two approaches. In total, 53 and 33 patients underwent the retrosigmoid and translabyrinthine approaches, respectively. The median follow-up time was 34.5 months. Surgical outcomes, including the extent of resection, tumor recurrence, and facial nerve preservation, showed no significant differences between the two groups. Patients who underwent the retrosigmoid approach showed a marginal trend for postoperative lower cranial nerve (LCN) dysfunction (P = 0.068). Although the approaching procedure time was longer in the translabyrinthine group, the tumor resection time was significantly longer in the retrosigmoid group (P = 0.001). The median change in the volume of the perioperative cerebellar edema was significantly larger in the retrosigmoid group (P < 0.001) and significantly related to the retrosigmoid approach, solid VS, and tumor resection time. Most cerebellar and LCN deficits were transient; however, the patients in the retrosigmoid group underwent inpatient rehabilitation more than those in the translabyrinthine group (P = 0.018). Both surgical approaches show equivalent surgical outcomes. Notably, the translabyrinthine approach for large VS has advantages in that it reduces cerebellar injury and related morbidities.