Otogenic Pneumocephalus After Tegmen Bone Reconstruction: A Case Report.

Pneumocephalus is usually induced by trauma, infections, tumors of the skull base, and surgical interventions. Spontaneous pneumocephalus occurs due to a defect in the temporal bone with no obvious cause. Few cases have been reported with spontaneous otogenic pneumocephalus. However, delayed postoperative pneumocephalus is rarely reported in the literature. Here, we present a case of otogenic pneumocephalus through Eustachian tube (ET) preceded by nose blowing 10 days after surgical treatment of meningoencephalocele of the right middle ear (ME) cleft and reconstruction of tegmen and dural defects. Pneumocephalus was provoked by decreased intracranial pressure (ICP) secondary to placement of lumbar drain, which caused direct communication between unsutured dural defect and the defective posterior wall of external auditory canal skin. A revision surgery of combined transmastoid/middle cranial fossa approach was performed for intracranial decompression followed by appropriate closure by suturing the dura, obliterating the ET and ME.

Cochlear implantation among patients with otosclerosis: a systematic review of clinical characteristics and outcomes.

PURPOSE: There have been considerable advancements in cochlear implants in different clinical scenarios; however, their use in patients with otosclerosis remains challenging. This review aimed to investigate the surgical and clinical outcomes of cochlear implantation in patients with otosclerosis. METHODS: An electronic literature search was performed using four main databases through February 2021 to identify original studies of cochlear implantation in patients with otosclerosis for inclusion in this systematic review. The study protocol was registered with the Prospectively Registered Systematic Reviews and Meta-analyses (reference number: CRD42021234753). RESULTS: A total of 23 studies including 3162 patients were enrolled. Of these patients, only 392 had otosclerosis and underwent cochlear implantation. The duration of deafness was reported in only eight studies, extending up to 50 years. Far-advanced otosclerosis was observed in 153 patients. A total of 56 patients used hearing aids. Stapedectomy and stapedotomy were performed in 118 and 63 patients, respectively. In three studies, the temporary success of stapedectomy and stapedotomy was 6 (43%) and 5 (71%) patients, respectively. Computed tomography was used as a preoperative assessment tool in most studies (n = 14, 60.9%). Incomplete implant insertion occurred in 17 patients, while facial nerve stimulation occurred in 36 patients after implantation. CONCLUSION: Cochlear implantation is a relatively safe modality that can provide promising audiological outcomes in patients with otosclerosis. However, several factors, including cochlear ossification, duration of deafness, and previous operations, can affect its outcomes. Further studies with a larger sample population are recommended.

Changes in the Area Adjacent to the Internal Receiver-Stimulator of Cochlear Implant: A Retrospective Study.

BACKGROUND: In some patients with cochlear implants, bony resorption at the internal receiver- stimulator site can be observed on postoperative computed tomography. Therefore, it is essential to elucidate the effects of the internal receiver-stimulator on the scalp and bony bed over time. OBJECTIVE: We aimed to evaluate how the internal receiver-stimulator of a cochlear implant device changed the thickness of the surrounding scalp and skull over time using computed tomography. METHODS: This retrospective study evaluated patients who underwent cochlear implantation and received two computed tomography scans postoperatively for different indications at a tertiary referral centre. The main outcomes were scalp thickness and bony bed depth. RESULTS: Fourteen ears were included in this study. There was very good inter-rater reliability among the two readers who evaluated the computed tomography of the included patients, with a Cronbach's alpha of 0.94. The mean scalp thickness over the internal receiver-stimulator was 6.02 (+/-2.4) mm in the first scan and decreased with no significant change to 5.62 mm (+/-1.64) in the second scan (p = 0.59, paired t-test). The mean depth of the bony bed increased significantly from 1.39 mm (+/-0.93) to 2.62 mm (+/-1.24) (p = 0.03). CONCLUSION: There was no change in the thickness of the scalp overlying the internal receiver-stimulator indicating that the scalp was more resistant than the bony skull to the tensile pressure exerted by the internal receiver-stimulator. In contrast, the bony bed depth of the internal receiver-stimulator increased over time. This can result in decreased internal receiver-stimulator protrusion and decreased risk of device displacement and migration.

Clinical Approaches To External Auditory Canal Hemangiomas: A Systematic Review.

OBJECTIVES: Hemangioma is a common soft tissue tumor that can be categorized mainly into cavernous, capillary, and venous subtypes. It usually develops in the head and neck and rarely in the external auditory canal (EAC). METHODS: A systematic review of patients with capillary hemangioma of the EAC was performed. A computerized systematic search was conducted in PubMed, Scopus, and Web of Science to extract relevant studies for a qualitative review. RESULTS: A total of 38 patients were included in the systematic review, and half of them were men. Hearing loss was the most common presenting feature (n = 19; 50%), followed by aural fullness (n = 15; 39.4%). Cavernous hemangioma was the predominant type (n = 22, 57.8%). Endaural and transcanal surgical approaches were the most frequent, with ten (26.3%) and nine (23.6%) cases, respectively. Most of the patients (n = 31; 81.5%) had no recurrence. CONCLUSIONS: Hemangioma of the EAC may not be uncommon as healthcare professionals may expect. Hearing loss, aural fullness, and tinnitus are possible symptoms, but many patients remain asymptomatic. Surgical excision is the main effective management option, and complete resolution is the most prevalent outcome. Computed tomography assists in the diagnosis, but histopathological examination after resection is mandatory for the definitive diagnosis.

A novel cochlear measurement that predicts inner-ear malformation.

The A-value used in cochlear duct length (CDL) estimation does not take malformed cochleae into consideration. The objective was to determine the A-value reported in the literature, to assess the accuracy of the A-value measurement and to evaluate a novel cochlear measurement in distinguishing malformed cochlea. High resolution Computer Tomography images in the oblique coronal plane/cochlear view of 74 human temporal bones were analyzed. The A-value and novel C-value measurement were evaluated as predictors of inner ear malformation type. The proximity of the facial nerve to the basal turn was evaluated subjectively. 26 publications report on the A-value; but they do not distinguish normal vs. malformed cochleae. The A-values of the normal cochleae compared to the cochleae with cochlear hypoplasia, incomplete partition (IP) type I, -type II, and -type III were significantly different. The A-value does not predict the C-value. The C-values of the normal cochleae compared to the cochleae with IP type I and IP type III were significantly different. The proximity of the facial nerve to the basal turn did not relate to the type of malformation. The A-value is different in normal vs. malformed cochleae. The novel C-value could be used to predict malformed anatomy, although it does not distinguish all malformation types.

Shape of the Cochlear Basal Turn: An Indicator for an Optimal Electrode-to-Modiolus Proximity With Precurved Electrode Type.

OBJECTIVE: The objective of this study was to determine the shape of cochlear basal turn through basic cochlear parameters measurement. The secondary aim was to overlay an image of the precurved electrode array on top of the three-dimensional (3D) image of the cochlea to determine which shape of the cochlear basal turn gives optimal electrode-to-modiolus proximity. MATERIALS AND METHODS: Computed tomography (CT) preoperative image-data sets of 117 ears were made available for the measurements of cochlear parameters retrospectively. Three-dimensional slicer was used in the visualization and measurement of cochlear parameters from both 3D and 2D (2-dimensional) images of the inner ear. Cochlear parameters including basal turn diameter (A), width of the basal turn (B), and cochlear height (H) were measured from the appropriate planes. B/A ratio was made to investigate which ratios correspond to round and elliptical shape of the cochlear basal turn. RESULTS: The cochlear size as measured by A value ranged between 7.4 mm and 10 mm. The B value and the cochlear height (H) showed a weak positive linear relation with A value. The ratio between the B and A values anything above or below 0.75 could be an indicator for a more round- or elliptical shaped cochlear basal turn, respectively. One sized/shaped commercially available precurved electrode array would not offer a tight electrode-to-modiolus in the cochlea that has an elliptical shaped basal turn as identified by the B/A ratio of <0.75. CONCLUSION: Accurate measurement of cochlear parameters adds value to the overall understanding of the cochlear geometry before a cochlear implantation procedure. The shape of cochlear basal turn could have clinical implications when comes to electrode-to-modiolus proximity.

Evaluation of computed tomography parameters in patients with facial nerve stimulation post-cochlear implantation.

PURPOSE: To compare the preoperative computed tomography (CT) parameters, including the thickness and density of the bone separating the upper basal turn of the cochlea (UBTC) and the labyrinthine segment of the facial nerve (LSFN), in patients with and without facial nerve stimulation (FNS) in post-cochlear implants (CI). METHODS: A retrospective case review of 1700 CI recipients in a tertiary referral center between January 2010 and January 2020 was performed; out of the 35 recipients who were found to have FNS, 29 were included in the study. The control group comprised the same number of randomly selected patients. CT parameters of the patients were measured independently by three fellowship-trained neuro-otologists blinded to the postoperative status of the patients. Thickness in axial and coronal views and density of the bone separating the UBTC and the LSFN were measured. RESULT: There was satisfactory agreement between the readings of the three reviewers. The distances (in mm) between the UBTC and LSFN obtained from the coronal (0.43 ± 0.24 vs. 0.63 ± 0.2) and axial (0.42 ± 0.25 vs. 0.6 ± 0.18) views were statistically lower in the FNS group (p = 0.001 and 0.005, respectively). The density (in HU) of the bony partition was also statistically lower in the FNS group (1038 ± 821 vs. 1409 ± 519; p = 0.029). CONCLUSION: Patients who experienced FNS postoperatively had significantly lower distance and bone density between the UBTC and the LSFN. This finding can help surgeons in preoperative planning in an attempt to decrease the occurrence of FNS.

Systematic Review of Postcochlear Implant Electrode Migration: What Is Known?

BACKGROUND AND OBJECTIVES: Electrode migration after cochlear implantation (CI) is a rare complication that accounts for 1to 15% of all revision surgery. This study is a systematic review of the literature for investigating the knowledge and approaches to the incidence of electrode migration after CI. METHODS: A systematic electronic search of the literature was carried out using PubMed, Cochrane, Virtual Health Library, Scopus and Web of Science (ISI). All original articles that reported electrode migration after CI surgery were included. The Newcastle-Ottawa Scale and CARE checklist were utilized for the assessment of the risk of bias. Descriptive data analysis was performed using SPSS software. RESULTS: A total of 26 studies including 4,316 patients were included. Out of them, 289 patients had electrode migration following CI. To diagnose electrode migration, traditional computed tomography scan was used in 13 studies, while cone-beam computed tomography was applied in three studies. In addition, electrode migration was detected during intraoperative exploration in eight studies. The most common presenting symptom was change in sound/poor performance (n = 43) followed by pain sensation (n = 15) and facial nerve stimulation (n = 10). Cholesteatoma was the most common associated pathology (n = 10) followed by infection (n = 9) and ossification of the basal turn of the cochlea (n = 8). CONCLUSION: Electrode migration is a major complication of CI and could be more common than previously thought. As it may occur with or without clinical complaints, long-term follow-up through routine radiological scanning is recommended. Further studies are warranted to identify the underlying mechanism of electrode extrusion and the appropriate fixation method.

Direct measurement of cochlear parameters for automatic calculation of the cochlear duct length.

BACKGROUND: Cochlear morphology and cochlear duct length (CDL) play important roles in the selection of appropriate electrodes. Cochlear parameters such as diameter (A value) and width (B value) are used as inputs for calculating the CDL. Current measurements of these parameters are inefficient and time consuming. Recently developed otological planning software (OTOPLAN) allows surgeons to directly measure these parameters and then automatically calculate the CDL. OBJECTIVES: The primary objective was to validate this new software for measuring the cochlear parameters and CDL. The secondary aim was to investigate the correlation between each cochlear parameter with the calculated CDL. DESIGN: Retrospective. SETTINGS: Ear specialist hospital. PATIENTS AND METHODS: The measurement of cochlear diameter (A value) was chosen as the validation parameter. To do this, the A value was measured by a neurotologist on the new OTOPLAN planning software and was validated to the one measured on the currently used DICOM viewer. Upon the validation of the OTOPLAN software, the other two cochlear parameters, namely width (B value) and height (H value) were measured, and CDL was automatically calculated. Finally, the correlation of all parameters with the CDL was statistically analyzed. MAIN OUTCOME MEASURES: Validation of OTOPLAN and CDL estimation. SAMPLE SIZE: 88 ears. RESULTS: There was no significant difference between the A-value measured on the DICOM viewing software and that on the new planning software by the two independent neurotologists (P=.27). Both A-and B-values showed a high positive correlation to the CDL. However, the B-value showed a stronger correlation to the CDL than the A-value (r=0.63 for A, and r=0.96 for B). CONCLUSION: The direct measurement of cochlea parameters and automatic calculation of the CDL could improve the efficiency of clinical workflow and make otology surgeons more independent. Moreover, the cochlear width (B) has a strong correlation to the CDL. Thus, we suggest using the combination of A and B to accurately estimate the CDL rather than using only one. LIMITATIONS: Single center and small sample size. CONFLICT OF INTEREST: None. No relationship with manufacturers.

Diagnostic approaches to and management options for patulous eustachian tube.

OBJECTIVES: To systematically review the literature and to summarize all evidence related to the diagnosis and management of patulous eustachian tube. METHODS: The present study was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. RESULTS: Overall, 59 articles were retrieved and included in the analysis. Studies investigating treatments enrolled 1279 patients collectively, with follow-up duration varying from few days and up to 2 years. Eight studies reported medical treatments with intranasal saline instillation as the most frequently studied option. Other studies reported various surgical treatments varying from simple tympanostomy to invasive procedures targeting the orifice of the ET or the anatomical features surrounding it. In addition, 10 studies including 367 subjects investigated different diagnostic methods. CONCLUSION: Currently, there is a wide spectrum of diagnostic and therapeutic interventions with minimal clinical efficacy, a persistent lack of systematic guidelines, and several gaps in previous research endeavours.