Transmastoid Approach Research Articles

Drainage of middle cranial fossa epidural abscess through mastoidectomy: Our experience and review of the literature

Background: Otitis media (OM) can uncommonly lead to intracranial complications. Epidural abscesses represent a large proportion of cases; however, literature regarding the optimal surgical management of otogenic epidural abscesses is sparse. Favorably located epidural abscesses may be amenable to drainage through a transmastoid approach because the tegmen mastoideum lies immediately inferior to the middle cranial fossa (MCF). Case Description: We report 3 pediatric patients with OM complicated by epidural abscesses of the MCF. The ages ranged from 3 to 6 years old, with 2 females and 1 male. All 3 patients had acute mastoiditis with an abscess of the MCF ranging from 1.6 cm to 6.3 cm at the largest dimension. All patients underwent canal wall-up mastoidectomy with the evacuation of the MCF abscess through a small window, 0.7 × 0.7 cm or less, created in the tegmen mastoideum. All patients were successfully treated through this approach and had complete resolution of their infection on follow-up imaging. There were no postoperative temporal lobe encephaloceles. Conclusion: This is one of the few descriptions of the treatment of an otogenic epidural abscess of the MCF through a transmastoid approach. Collaboration with neurosurgery is vital because their familiarity with the intracranial space helped to guide the accurate direction of dissection. This highlights the importance of a multidisciplinary approach in the treatment of epidural intracranial abscess of the MCF through this approach. The risk of postoperative temporal lobe encephalocele was minimized due to the small tegmen defect size.

Intradural Repair of Temporal Bone Encephalocele and Cerebrospinal Fluid Leak: Results from a Single Institution

Abstract Background Lateral temporal bone encephaloceles incidence is increasing with obesity rates. Middle fossa (MF) craniotomy, transmastoid (TM), or combined MF + TM access can be used for repair. Methods Retrospective review of MF or MF + TM repair with an intradural graft. Sex, age, and body mass index (BMI) were collected. Pre/postoperative audiometric results were included. Postoperative complications were reported. Results A total of 49 patients (50 repairs) were included. In addition, 74% were women (p < 0.05). Ten patients had a history of chronic otitis media and surgery. Average BMI was 35.8, and average age was 59. Furthermore, 54% had multiple skull base defects; 18 (36%) patients had a MF approach. In total, 32 (64%) patients had a MF + TM approach for repair; 13 (40.1%) of these patients had a concurrent tympanoplasty. Hearing improved for 74%. Air conduction pure-tone average improved by an average of 5 dB (p 0.27). No differences in hearing outcomes were observed between the MF and MF + TM groups. Two patients (6%) had hearing decline. Eight complications were reported (1 (2%) skin infection, 4 (8%) recurrent/persistent cerebrospinal fluid [CSF] leaks requiring lumbar drain or shunt, and 3 (6%) episodes of aphasia or mental status change). Age >65 years was not associated with risk of postoperative complication. Conclusion Intradural repair of encephalocele and CSF leak is a safe and effective surgical approach. Intradural reinforcement along the entire MF floor is beneficial for multiple areas of dehiscence and thin dura. Complication rates including recurrent/persistent CSF leak and aphasia related to temporal lobe retraction were similar to previously published reports and not associated with older patient age. Hearing was stable or improved in 94% with no difference noted between MF and MF + TM repair.

Brain fungus: A case report of the journey from diagnosis to recovery

Brain fungus or temporal meningoencephalocele is a rare condition in otology. It results due to the defect in tegmen tympani or tegmen antri formed most commonly after mastoidectomy. As it could be a harbinger to serious complications like meningitis, hence it needs a prompt diagnosis and an urgent surgical intervention. we present a case of 27-year-old lady with a 2.4×1.2 cm sized defect in the tegmen tympani formed as a result of modified radical mastoidectomy which was managed surgically via trans mastoid approach and a complete closure was confirmed by HRCT scan after 6 months of surgery. we concluded the importance of early diagnosis and management of this disease along with a special emphasis over the surgical lessons learnt from our experience in this case.

A Case of Bilateral Idiopathic Temporal Cerebrospinal Fluid Leakage With Multiple Fistulas in the Middle and Posterior Cranial Fossae Closed Using the Transmastoid Approach

A Case of Bilateral Idiopathic Temporal Cerebrospinal Fluid Leakage With Multiple Fistulas in the Middle and Posterior Cranial Fossae Closed Using the Transmastoid Approach

Outcomes at 6 months after isolated or non-isolated surgery for temporal bone cerebrospinal fluid leak in adults: A STROBE analysis

AimThe main aim of this study was to evaluate 6-month closure success in surgery for isolated or non-isolated temporal bone osteomeningeal breach (OMB). Secondary objectives were to analyze complications of closure and correlations between success and breach, treatment and patient data. Material and methodThis was a single-center retrospective observational study of patients who underwent surgery for temporal bone OMB via a middle cranial fossa or transmastoid approach in a French university teaching hospital between 2007 and 2022, with follow-up of at least 6months. Patients with superior semicircular canal dehiscence were excluded. Study data comprised gender, age, body mass index, OMB etiology, mode of discovery, audiometric and radiological data, surgical technique, length of hospital stay and postoperative complications. The primary endpoint was absence of a cerebrospinal fluid leak on MRI at 6months. Fisher's exact test or Chi2 test were used for qualitative data and Student t-test for quantitative data. ResultsThe closure success rate was 87%: 81% (3 recurrences) in the middle cranial fossa group of 16 patients and 93% in the transmastoid group of 14 patients. Postoperative audiometry showed significant improvement (P=0.0016) for air conduction in the middle cranial fossa group. Five patients (17%) operated on via the middle cranial fossa approach and 1 (7%) operated on via the transmastoid approach had postoperative complications. OMB was in the tegmen mastoideum in 8 patients (29%), tegmen tympani in 7 (25%), tegmen antri in 4 (14%), tegmina antri and tympani in 3 (11%), antri and mastoideum in 1 (8%) and in the whole tegmen in 5 (18%). Eleven OMBs were lateral to the superior semicircular canal, 13 medial and 4 on either side. ConclusionThe transmastoid approach is indicated in case of associated middle-ear procedures, patients aged over 75years or OMB lateral to the superior semicircular canal. The middle cranial fossa approach is reserved for OMB located medial to the superior semicircular canal patients under 75years of age without associated ossicular procedures. For patients with OMB medial to the superior semicircular canal who require middle-ear surgery, a combined approach can be used.

Endoscopic transcanal facial nerve decompression in traumatic facial nerve palsy: A case series

Abstract Temporal bone fractures contribute to 7%–10% of patients suffering from facial nerve (FN) palsy.Traumatic facial paralysis is the most common cause of lower motor neuron facial paralysis, accounting for about 17% of its incidence. Temporal bone fractures contribute to 7%–10% of patients suffering from facial nerve (FN) palsy. The proximal tympanic segment of FN is most commonly affected in such cases. The classical microscopic surgeries for pathologies involving the FN, such as transmastoid approach, middle cranial fossa approach, and translabyrinthine approach, are associated with several disadvantages. The endoscopic transcanal approach is a minimally invasive surgery that can be used mostly for a lesion limited to the tympanic segment of the FN. It provides sufficient exposure for nerve decompression as compared to other approaches. Clear endoscopic vision of the tympanic cavity is also achieved, which is beneficial to ossicular chain reconstruction. Moreover, it causes minimal surgical trauma. Operating time and postoperative hospital stay are also reduced. This technique is cosmetically more acceptable to the patient. In this article, we report three cases of posttraumatic FN palsy where we performed endoscopic transcanal nerve decompression. It resulted in dramatic improvement of the facial palsy from House–Brackmann Grade IV or Grade V to Grade II immediately following surgery. The outcome of FN decompression through this approach was found to be comparable to conventional approach.

An algorithm for the surgical approach to spontaneous temporal bone CSF leak

ObjectiveTo suggest a comprehensive algorithm for the surgical approach for correcting of sources of temporal bone CSF leaks. MethodsA case series for patients operated in a single academic tertiary referral center between 2011 and 4.2022. Included in the study were 46 patients, 5 of whom had a bilateral problem, resulting in 51 pathologic temporal bones. The presentation was an active CSF leak (38 patients) or bacterial otogenic meningitis (8 patients). Follow up ranged from 8 months to 5 years. ResultsOf the 42 ears operated via the default middle fossa approach, 37 were successful (88 %) in controlling CSF leak. None had intracranial complications or sensorineural hearing loss. Location, number and size of the defects, hearing status, associated superior semicircular canal dehiscence, additional intra-temporal or intra-cranial pathologies may indicate a transmastoid approach. Of the six ears that had a canal wall up mastoidectomy as a primary procedure, one required revision due to ongoing CSF leak. Five revision cases and three primary cases were effectively sealed with a subtotal petrosectomy and obliteration. One was lost to follow-up. Hearing was reconstructed with bone-anchored hearing implants in 6 out of these 8 ears. ConclusionsThe middle fossa approach could be used as a default approach for sealing TD. There are a number of indications for transmastoid approaches in both primary and revision cases. Obliteration of the ear was used in all revision cases. The suggested algorithm can help in planning surgery for temporal bone CSF leaks or a history of otogenic meningitis.

Comparing Approaches for Repair of Superior Semicircular Canal Dehiscence.

Compare outcomes for subjects who underwent middle cranial fossa (MCF) or transmastoid (TM) repair of superior semicircular canal dehiscence (SSCD). Retrospective cohort study. Quaternary-care, academic neurotology practice. Subjects who underwent MCF or TM repair of SSCD between December 1999 and April 2023 were identified. Main outcome measures included demographic data, length of surgery and hospital stay, clinical presentation, and audiometric testing. Ninety-three subjects (97 ears) who underwent surgery for SSCD met inclusion criteria: 58.8% (57) via MCF, 39.2% (38) via TM, and 2.0% (2) via TM + MCF. Median operative time was shorter for the TM (35) compared to the MCF (29) approach (118 vs 151 minutes, P < .001). Additionally, median hospital stays were shorter for TM (36) compared to the MCF (56) approach (15.3 vs 67.7 hours, P < .001). Overall, 92% (49/53) of MCF and 92% (33/36) of TM surgeries resulted in an improvement or resolution of one or more symptoms (P = .84). There was no significant preoperative to postoperative change in the median air conduction pure-tone average (PTA), air-bone gap, or word recognition score in both the MCF and TM groups (P > .05). Improvements of >10 dB in the pre- to postoperative absolute change in bone conduction PTA were noted in 3 subjects in the MCF group and 4 subjects in the TM group (P = .49). The TM approach for SSCD demonstrates shorter operative times and length of hospital stay. The TM and MCF approaches have comparable audiometric and clinical outcomes.

Superior semicircular canal dehiscence in relation with the superior petrosal sinus: our experience, surgical management and systematic review of literature.

Most of Superior Semicircular Canal Dehiscence (SSCD) are located in the apical region of the SSC. However, in a small number of cases, it may be situated in the medial wall, causing the SSC to contact with the superior petrosal sinus (SPS). The aim of this study is to describe four patients with SSCD involving the superior petrosal sinus (SSCD-SPS) and to perform a review of the literature. Observational retrospective study of patients diagnosed of SSCD-SPS in a tertiary referral center. A systematic review was made, identifying 7 articles in the literature. Clinical presentation, complementary test (pure-tone audiometry, PTA; vestibular evoked myogenic potential, VEMP; computed tomography, CT), therapeutic management and outcomes were reported. Four new cases of SSCD-SPS are reported, in three of them a transmastoid plugging was performed. 54 patients with SSCD-SPS (57 dehiscences) were reported in the literature. The most frequent symptoms were aural pressure (57.41%) and vertigo provoked by pressure/Valsalva (55.55%). Conductive hearing loss was the most common finding in PTA (47.37%). Abnormally low thresholds were observed in 59.46% of reported VEMP. Transmastoid approach was used in ten cases, middle fossa approach in four, round window reinforcement in one, and occlusion of the SPS using coils in two. Within SSCD, we have encountered a rare subtype characterized by its medial wall location in close proximity to the SPS. This subgroup needs special consideration as it has shown its own distinct characteristics. Regarding therapeutic management, we advocate a transmastoid approach.

Effect analysis of facial nerve decompression surgery in the treatment of Bell's palsy and Hunt syndrome

Objective:To summarize and analyze the effect of facial nerve decompression surgery for the treatment of Bell's palsy and Hunt syndrome. Methods:The clinical data of 65 patients with facial nerve palsy who underwent facial nerve decompression in our center from October 2015 to October 2022 were retrospectively analyzed, including 54 patients with Bell's palsy and 11 patients with Hunter syndrome. The degree of facial paralysis（HB grade） was evaluated before surgery, and ENoG, pure tone audiometry, temporal bone CT and other examinations were completed. All patients had facial palsy with HB grade V or above after conservative treatment for at least 1 month, and ENoG decreased by more than 90%. All patients underwent facial nerve decompression surgery through the transmastoid approach within 3 months after onset of symptoms. The recovery effect of facial nerve function after surgery in patients with Bell's palsy and Hunter syndrome was summarized and analyzed. In addition, 15 cases in group A（operated within 30-60 days after onset） and 50 cases in group B（operated within 61-90 days after onset） were grouped according to the course of the disease（the interval between onset of symptoms and surgery） to explore the effect of surgical timing on postoperative effect. Results:There was no significant difference between the two groups of patients with Chi-square test（P=0.54） in 42 patients（77.8%, 42/54） with Bell's palsy and 7 patients（63.6%, 7/11） in patients with Hunter syndrome who recovered to grade Ⅰ-Ⅱ. According to the course of the disease, 10 cases（66.7%, 10/15） in group A recovered to grade Ⅰ-Ⅱ after surgery. In group B, 39 patients（78.0%, 39/50） recovered to grade Ⅰ-Ⅱ after surgery, and there was no statistically significant difference between the two groups by Chi-square test（P=0.58）. Conclusion:Patients with Bell's palsy and Hunter syndrome can achieve good results after facial nerve decompression within 3 months of onset, and there is no significant difference in the surgical effect between the two types of patients.

Audiometric outcomes following surgery for spontaneous temporal bone cerebrospinal fluid leaks – A single institution study

PurposeTo assess the audiometric outcomes following surgical repair of spontaneous temporal bone cerebrospinal fluid otorrhea and compare different surgical approaches. Materials and methodsRetrospective review of adults (≥18 years old) who underwent repair of spontaneous CSF leak between 2011 and 2022. Audiometric outcomes were compared across the three surgical groups: transmastoid, middle cranial fossa and combined. ResultsThirty-nine patients (40 ears) met the inclusion criteria (71.8 % females; mean age 59.77 +/− 12.4). Forty-two percent underwent transmastoid, 12.5 % middle cranial fossa and 45 % transmastoid-middle cranial fossa. Four patients (10 %) had recurrence, 3 in the transmastoid group and 1 in the combined approach. The mean change in air-bone gap (ABG) for all patients (postoperative-preoperative) was −7.4 (paired t-test, p-value = 0.0003). The postoperative ABG was closed in 28 (70 %) ears (postoperative ABG ≤ 15). The mean change in pure tone average (PTA) for all patients (postoperative-preoperative) was −4.1 (paired t-test, p-value = 0.13). The mean change in word recognition scores (WRS) for all patients (postoperative-preoperative) was −3 (paired t-test, p-value = 0.35). On multivariable analysis (controlling for site and reconstruction material), there was no significant difference in ABG, PTA and WRS change between surgical groups. ConclusionsTransmastoid, middle cranial fossa and combined approaches are all effective in treatment of spontaneous CSF leaks and all showed mean decrease in post-operative ABG. Transmastoid approach showed the greatest decrease in ABG and PTA (although middle cranial fossa approach shows the greatest decrease, when excluding profound hearing loss in a patient with superior canal dehiscence). Further studies comparing audiometric outcomes are needed.

Analysis of the outcome of 12 cases of facial nerve tumors

Objective:This study aims to provide a comprehensive summary of the pathogenesis, screening modalities, treatment strategies, repair modalities and preliminary results associated with facial nerve tumors. Methods:A retrospective analysis was conducted on the clinical data of 12 patients with facial nerve tumors who were admitted to our department between May 2018 and February 2023. The study population consisted of 5 males and 7 females, with ages ranging from 35 to 90 years. Clinical symptoms observed in these patients included facial nerve palsy, hearing loss, tinnitus, headache, and otalgia, etc. The severity of facial nerve dysfunction was assessed using the House-Brackmann（H-B） facial nerve function classification, with 3 cases classified as grade Ⅰ, 4 cases as grade Ⅲ, 2 cases as grade Ⅳ, and 3 cases as grade Ⅴ. There was a total of 11 patients who presented with hearing loss. Among these patients, 7 cases were diagnosed with conductive hearing loss, 2 cases with sensorineural hearing loss, and 2 cases with mixed hearing loss. The selection of the observation or surgical route for tumor localization was based on clinical symptoms, facial nerve function grading, and imaging examination results including temporal bone CT and enhanced MRI. Specifically, the location of the tumor was selected for observation or the best surgical route: 2 cases were followed up for observation, 1 case underwent biopsy, and 9 cases underwent tumor resection（7 cases of trans-mastoid approach, 2 cases of combined parotid-mastoidal approach）, concurrent repair of the facial nerve（4 cases of auricular nerve grafting, 3 cases of facial nerve diversion anastomosis, 2 cases of peroneal nerve grafting）. （4 cases of auricular nerve graft, 3 cases of facial nerve diversion anastomosis and 2 cases of peroneal nerve grafting）. Periodic postoperative evaluation of facial nerve function was conducted. Results:1-year follow-up was available. Intraoperatively, it was observed that 66.7%（6 out of 9） of the facial nerve tumors were present in multiple segments. Among these segments, the vertical segment had the highest proportion, accounting for 77.8%（7 out of 9）, followed by the labyrinthine segment/geniculate ganglion with 66.7%（6 out of 9） and the horizontal segment with 55.6%（5 out of 9）. Postoperative pathology confirmed 8 cases with nerve sheath meningioma, Ⅰ with seminal fibroma and 1 with hemangioma. Postoperative facial nerve function was graded as H-B grade I in one patient）, grade Ⅲ in three, grade Ⅳ in four, grade Ⅴ in 2, and grade Ⅵ in 2 patients. The auditory outcomes following surgery are as follows: 8 individuals experienced postoperative hearing loss, while 2 individuals demonstrated postoperative hearing preservation. Conclusion:In the case of patients presenting with facial nerve palsy as their initial symptom, it is imperative to consider the potential presence of a facial nerve tumor. To determine the appropriate course of action, it is necessary to ascertain the size and location of the tumors through imaging examinations. This information will aid in the decision making process regarding whether surgical intervention is warranted, and so, the most suitable approach. Additionally, the choice of repair method during the operation should be guided by the extent of facial nerve defect.

Opioid Prescribing Patterns Following Lateral Skull Base Spontaneous Cerebrospinal Fluid Leak Repair.

To characterize the opioid prescribing patterns for and requirements of patients undergoing repair of spontaneous cerebrospinal fluid (sCSF) leaks of the lateral skull base. Retrospective chart review. Tertiary referral center. Adults with lateral skull base sCSF leaks who underwent repairs between September 1, 2014, and December 31, 2020. Mean morphine milligram equivalents (MMEs) of opioids dispensed to inpatients and prescribed at discharge, additional pain control medications dispensed, and outpatient additional opioid requests were compared between groups. Of 78 patients included, 46 (59%) underwent repair via a transmastoid (TM), 6 (7.7%) via a middle cranial fossa (MCF), and 26 (33.3%) via a combined TM-MCF approach. Inpatients received a mean of 21.3, 31.4, and 37.6 MMEs per day during admission for the TM, MCF, and combined TM-MCF approaches, respectively ( p = 0.019, ηp 2 = 0.101). Upon discharge, nearly all patients (n = 74, 94.9%) received opioids; 27.3, 32.5, and 37.6 MMEs per day were prescribed after the TM, MCF, and TM-MCF approaches, respectively ( p = 0.015, ηp 2 = 0.093). Five (6.4%) patients requested additional outpatient pain medication, after which three were prescribed 36.7 MMEs per day. Patients with idiopathic intracranial hypertension required significantly more inpatient MMEs than those without (41.5 versus 25.2, p = 0.02, d = 0.689), as did patients with a history of headaches (39.6 versus 23.6, p = 0.042, d = 0.684). Patients undergoing sCSF leak repair via the MCF or TM-MCF approaches are prescribed more opioids postoperatively than patients undergoing the TM approach. Patients with a history of headaches or idiopathic intracranial hypertension might require more opioids postoperatively.

A new active bone-conduction implant: surgical experiences and audiological outcomes in patients with bilateral congenital microtia.

First-generation bone bridges (BBs) have demonstrated favorable safety and audiological benefits in patients with conductive hearing loss. However, studies on the effects of second-generation BBs are limited, especially among children. In this study, we aimed to explore the surgical and audiological effects of second-generation BBs in patients with bilateral congenital microtia. This single-center prospective study included nine Mandarin-speaking patients with bilateral microtia. All the patients underwent BCI Generation 602 (BCI602; MED-EL, Innsbruck, Austria) implant surgery between September 2021 and June 2023. Audiological and sound localization tests were performed under unaided and BB-aided conditions. The transmastoid and retrosigmoid sinus approaches were implemented in three and six patients, respectively. No patient underwent preoperative planning, lifts were unnecessary, and no sigmoid sinus or dural compression occurred. The mean function gain at 0.5-4.0kHz was 28.06 ± 4.55-dB HL. The word recognition scores improved significantly in quiet under the BB aided condition. Signal-to-noise ratio reduction by 10.56 ± 2.30dB improved the speech reception threshold in noise. Patients fitted with a unilateral BB demonstrated inferior sound source localization after the initial activation. Second-generation BBs are safe and effective for patients with bilateral congenital microtia and may be suitable for children with mastoid hypoplasia without preoperative three-dimensional reconstruction.

Transmastoid Surgery for Superior Canal Dehiscence: Prospective Longitudinal Objective and Patient-Reported Audiovestibular Outcomes.

We assess symptom control, reversal and stability of objective third-window indicators, and hearing and balance function after transmastoid superior canal dehiscence plugging. To do this, we combine patient self-assessment questionnaires with auditory and vestibular test data collected at a preoperative and multiple postoperative visits. Prospective cohort study. Tertiary referral center. Patients who underwent transmastoid plugging for superior canal dehiscence from 2012 to 2020. Plugging of the superior semicircular canal using the transmastoid approach. Patients were evaluated preoperatively, 3-month postoperative, and at yearly follow-ups (up to 8 yr postoperative). Self-assessment questionnaires included Autophony Index, Dizziness Handicap Inventory, Tinnitus Handicap Inventory, and Hearing Handicap Inventory. Objective tests included audiometry, cervical vestibular evoked myogenic potential, ocular vestibular evoked myogenic potential, and video head impulse test. There was a statistically significant improvement in Autophony Index and Hearing Handicap Inventory total scores from the preoperative evaluation to 1 year postoperative. Dizziness Handicap Inventory and Tinnitus Handicap Inventory total scores also improved but statistically insignificant. Cervical and ocular vestibular evoked myogenic potential amplitudes and low-frequency air-bone gap showed statically significant reversal of the third-window effect preoperative versus 1 year postoperative. Video head impulse test of the superior semicircular canal revealed cases of pathological function preoperative with postoperative recovery. Results were stable over time. Superior canal dehiscence repair resolves symptoms of autophony and improves hearing disability. Objective third-window indicators reverse and show long-term stability. Auditory and vestibular function is preserved postoperative, even superior semicircular canal function may be normal. Data suggest that surgical outcomes should not be evaluated until 1 year postoperative.

An anatomical study of the sigmoid sinus artery: Application to the transmastoid approach

An anatomical study of the sigmoid sinus artery: Application to the transmastoid approach

Hydroxyapatite Use in Repair of Lateral Skull Base CSF Leaks Via Transmastoid Approach: When Does It Work?

The objective of this study is to evaluate the efficacy and outcomes of using a transmastoid approach with hydroxyapatite cement to repair lateral skull base cerebrospinal fluid (CSF) leaks. Retrospective cohort study. Tertiary-level care hospital. Surgical patients 18 years or older between 2013 and 2022 with spontaneous CSF leak. Trans-mastoid approach for skull base repair using hydroxyapatite cement. Failure rate of repair; location and size of defect, patient demographic factors. Of the 60 total defects (55 patients, 5 bilateral repairs) that underwent CSF leak repair using hydroxyapatite cement, the success rate was 91.66% (55 successful repairs). The average defect size in unsuccessful repairs was 1.15 cm compared with 0.71 cm for successful repairs. In addition, 80% (4/5) of the failed repairs were in the tegmen tympani region. Higher failure rate was noted in women (3/5) and in former smokers (4/5). Average time to recurrent symptoms was 1.75 years in the failed repair cohort. Of the patients with failed repairs, 4/5 were prescribed acetazolamide before their second procedure with successful second repair. In addition, five patients experienced postoperative headaches, three (5.4%) of whom required placement of VP shunts to relieve increased intracranial pressure. Two patients (3.6%) had complications of either infection or hearing loss. Transmastoid approach utilizing hydroxyapatite is a successful approach for CSF leak repair, with a low complication and failure rate. Women, prior smoking history, and larger defects in the tegmen tympani region may need alternative materials or approach for repair. Long follow-up is warranted as recurrence of symptoms might be delayed. In cases of benign intracranial hypertension, adjuvant treatment with either acetazolamide or VP shunt placement may prevent failures.

Iatrogenic inner ear dehiscence associated with lateral skull base surgery: a systematic analysis of drilling injuries and their causal factors.

Drilling injuries of the inner ear are an underreported complication of lateral skull base (LSB) surgery. Inner ear breaches can cause hearing loss, vestibular dysfunction, and third window phenomenon. This study aims to elucidate primary factors causing iatrogenic inner ear dehiscences (IED) in 9 patients who presented to a tertiary care center with postoperative symptoms of IED following LSB surgery for vestibular schwannoma, endolymphatic sac tumor, Meniere's disease, paraganglioma jugulare, and vagal schwannoma. Utilizing 3D Slicer image processing software, geometric and volumetric analysis was applied to both preoperative and postoperative imaging to identify causal factors iatrogenic inner ear breaches. Segmentation analyses, craniotomy analyses, and drilling trajectory analyses were performed. Cases of retrosigmoid approaches for vestibular schwannoma resection were compared to matched controls. Excessive lateral drilling and breach of a single inner ear structure occurred in 3 cases undergoing transjugular (n=2) and transmastoid (n=1) approaches. Inadequate drilling trajectory breaching ≥1 inner ear structure occurred in 6 cases undergoing retrosigmoid (n=4), transmastoid (n=1), and middle cranial fossa approaches (n=1). In retrosigmoid approaches the 2-cm visualization window and craniotomy limits did not provide drilling angles to the entire tumor without causing IED in comparison to matched controls. Inappropriate drill depth, errant lateral drilling, inadequate drill trajectory, or a combination of these led to iatrogenic IED. Image-based segmentation, individualized 3D anatomical model generation, and geometric and volumetric analyses can optimize operative plans and possibly reduce inner ear breaches from lateral skull base surgery.

Long-term outcomes of facial nerve decompression by transmastoid versus middle cranial fossa approach for traumatic facial paralysis

ObjectivesTo evaluate and compare the long-term results of patients who underwent facial nerve decompression surgery with either transmastoid-supralabyrinthine (TMSL) or combined transmastoid- middle cranial fossa (MCF) approach for traumatic facial nerve paralysis. Materials and methodsThis is a single-center retrospective case-control study. The medical records of traumatic facial paralysis patients with House Brackmann (HB) Grade 6 who underwent facial nerve decompression surgery at via either TMSL or MCF approach between January 2011 and December 2017 were reviewed. The patients who had otic capsule involvement and total sensorineural hearing loss, therefore underwent translabyrinthine facial nerve decompression, and the patients follow-up period has not yet reached four years were excluded from the study. Postoperative HB score and hearing status were compared. ResultsEleven patients were operated with MCF approach (group 1), while 9 patients with TMSL approach (group 2). Average age of patients was 20.04 + 15.2 (range:4–47) years. Three (15 %) patients were female, while 17 (85 %) was male. Geniculate ganglion (90 %) was the most affected segment of the facial nerve. Facial nerve edema was observed in all cases, while intraneural hematoma were encountered in 4 (20 %) cases. Statistically significant improvement in median HB scores were reached in both groups, and no significant difference was observed in post-operative HB scores between both techniques. No significant difference in median AC 0,5–4 khZ and BC 0,5–3 kHz thresholds was observed between both techniques. ConclusionEven middle fossa approach is the best surgical technique to explore geniculate ganglion and labyrinthine segment of facial nerve, the functional results of transmastoid supralabrynthine approach, which is not needed craniotomy with low complication rate are as successful as middle fossa approach in selected patients.

Superior semicircular dehiscence syndrome

Disorders of the equilibrium have a variety of etiologies and are common reasons for medical consultations. A thorough diagnostic workup is mandatory. A dehiscent superior semicircular canal may be a rare, but characteristic situation which is responsible for specific symptoms and clinical findings. Typical are sound and/or pressure induced vertigo, autophonia, pulsatile tinnitus, hyperacusis and aural fullness. High resolution CT-scan of the temporal bone reveals a missing bony cover over the superior semicircular canal such causing a third "mobile window". Besides patients' counselling plugging and/or resurfacing via a transmastoid or transtemporal approach may be therapeutic options.