Tandem cranial and spinal cerebrospinal fluid leaks presenting with otogenic tension pneumocephalus: illustrative case.

BACKGROUND: Cranial and spinal cerebrospinal fluid (CSF) leaks are associated with opposite CSF fluid dynamics. The differing pathophysiology between spontaneous cranial and spinal CSF leaks are, therefore, mutually exclusive in theory. OBSERVATIONS: A 66-year-old female presented with tension pneumocephalus. The patient underwent computed tomography (CT) scanning, which demonstrated left-sided tension pneumocephalus, with an expanding volume of air directly above a bony defect of the tegmen tympani and mastoideum. The patient underwent a left middle fossa craniotomy for repair of the tegmen CSF leak. In the week after discharge, she developed a recurrence of positional headaches and underwent head CT. Further magnetic resonance imaging of the brain and thoracic spine showed bilateral subdural hematomas and multiple meningeal diverticula. LESSONS: Cranial CSF leaks are caused by intracranial hypertension and are not associated with subdural hematomas. Clinicians should maintain a high index of suspicion for intracranial hypotension due to spinal CSF leak whenever "otogenic" pneumocephalus is found. Close postoperative follow-up and clinical monitoring for symptoms of intracranial hypotension in any patients who undergo repair of a tegmen defect for otogenic pneumocephalus is recommended.

Anatomic Assessment of the Limits of an Endoscopically Assisted Retrolabyrinthine Approach to the Internal Auditory Canal.

Objective Data regarding the surgical advantages and anatomic constraints of a hearing-preserving endoscopic-assisted retrolabyrinthine approach to the IAC are scarce. This study aimed to define the minimum amount of retrosigmoid dural exposure necessary for endoscopic exposure of the IAC and the surgical freedom of motion afforded by this approach. Methods Presigmoid retrolabyrinthine approaches were performed on fresh cadaveric heads. The IAC was exposed under endoscopic guidance. The retrosigmoid posterior fossa dura was decompressed until the fundus of the IAC was exposed. Surgical freedom of motion at the fundus was calculated after both retrolabyrinthine and translabyrinthine approaches. Results The IAC was entirely exposed in nine specimens with a median length of 12 mm (range: 10-13 mm). Complete IAC exposure could be achieved with 1 cm of retrosigmoid dural exposure in eight of nine mastoids. For the retrolabyrinthine approach, the median anterior-posterior surgical freedom was 13 degrees (range: 6-23 degrees) compared with 46 degrees (range: 36-53 degrees) for the translabyrinthine approach ( p = 0.014). For the retrolabyrinthine approach, the median superior-inferior surgical freedom was 40 degrees (range 33-46 degrees) compared with 47 degrees (range: 42-51 degrees) for the translabyrinthine approach ( p = 0.022). Conclusion Using endoscopic assistance, the retrolabyrinthine approach can expose the entire IAC. We recommend at least 1.5 cm of retrosigmoid posterior fossa dura exposure for this approach. Although this strategy provides significantly less instrument freedom of motion in both the horizontal and vertical axes than the translabyrinthine approach, it may be appropriate for carefully selected patients with intact hearing and small-to-medium sized tumors involving the IAC.

Clinical Significance of Middle Cerebellar Peduncle Ischemia After Translabyrinthine Vestibular Schwannoma Resection.

OBJECTIVE: To assess clinical symptoms, signs, and radiographic evolution of middle cerebellar peduncle (MCP) diffusion restriction (DR) abnormalities following vestibular schwannoma (VS) resection. STUDY DESIGN: Retrospective chart and imaging review. SETTING: Tertiary-referral neurotology and neurosurgery practice. PATIENTS: All consecutive patients who underwent translabyrinthine VS resection over a 2-year period (August 2017-May 2019). INTERVENTION: Translabyrinthine craniotomy for VS resection. MAIN OUTCOME MEASURES: Magnetic resonance imaging (MRI) obtained on postoperative day 1 were reviewed for DR within the pons and cerebellum, with 3 months follow-up MRI to assess for evolution of these vascular changes. RESULTS: Of the 31 patients who met inclusion criteria, MRI demonstrated MCP DR consistent with acute ischemia in 29% (9/31). Of those, two showed corresponding T2 signal abnormalities on follow up MRI consistent with cerebrovascular accident (CVA) within the MCP. Both had severe gait ataxia and dysmetria requiring acute rehabilitation admission and significantly larger tumors (p = 0.02). The remaining seven were asymptomatic, and DR abnormality resolved without lasting radiographic changes. Brainstem compression was present in 100% of patients with postoperative MCP DR (mean MCP ipsilateral:contralateral ratio 0.59 ±â€Š0.19), and 68.1% of those without (mean MCP ratio 0.71 ±â€Š0.25), a difference that was not statistically significant (p = 0.14). In the two patients with CVA, MCP asymmetry persisted, whereas the asymmetry resolved in all others. CONCLUSIONS: Asymptomatic acute MCP ischemia discovered incidentally does not require intervention. However, when the ischemic area is large and patients are symptomatic, especially if an acute rehabilitation admission is required, surgeons should suspect true CVA.

Hypercoagulability in Vestibular Schwannoma Surgery.

OBJECTIVE: Patients with vestibular schwannoma who harbor a genetic predisposition for venous thromboembolism require special consideration when determining optimal therapeutic management. The primary objective of the current study was to provide recommendations on treatment of hypercoagulable patients with vestibular schwannoma through a case series and review of the literature. PATIENTS: Two patients who underwent resection of vestibular schwannomas. INTERVENTIONS: Surgical resection and diagnostic testing. MAIN OUTCOME MEASURES: Postoperative venous thromboses. RESULTS: One patient who underwent resection of vestibular schwannoma and suffered several postoperative thrombotic complications consistent with a clinical thrombophilia. One patient with known Factor V Leiden deficiency who underwent resection of vestibular schwannoma followed by postoperative chemoprophylaxis with a direct factor Xa inhibitor and experienced an uneventful postoperative course. CONCLUSIONS: In patients with a known propensity for venous thromboembolism, the skull base surgeon should consider nonsurgical management. If the patient undergoes surgical resection, we recommend careful effort to minimize trauma to the sigmoid sinus. In addition, the surgeon may consider retrosigmoid or middle fossa approaches. Best practice recommendations include the use of pneumatic compression devices, early ambulation, and consideration of postoperative prophylactic anticoagulation in patients with a known genetic predisposition.

Internal Auditory Canal Diverticula in Children: A Congenital Variant.

OBJECTIVES/HYPOTHESIS: Internal auditory diverticula in adults have been found to exist independent of otosclerosis, and in the presence of otosclerosis. We sought to determine the prevalence of internal auditory canal (IAC) diverticula in a pediatric cohort, to assess whether IAC diverticula are a risk factor for hearing loss, and the co-occurrence of otic capsule hypoattenuation. STUDY DESIGN: Retrospective review. METHODS: A single-site retrospective review of high-resolution temporal bones computed tomography (CT) scans including the presence and size of diverticula and hypoattenuation of the otic capsule. Demographic, imaging, and audiometric data were collected and descriptively analyzed. Bivariate analysis of collected variables was conducted. Comparisons between sides in unilateral cases were also performed. RESULTS: 16/600 (2.7%; 95% CI [2.0%, 3.4%]) were found to have IAC diverticula. Six were bilateral. Thirty-one patients (5.2%) were found to have hypoattenuation of the otic capsule. There were no coincident cases of IAC diverticulum and hypoattenuation of the otic capsule. There was no association between the presence of IAC diverticula and age (P = .13). In six patients with unilateral diverticula, pure tone average (P = .42), and word recognition (P = .27) scores were not significantly different when compared to the normal, contralateral side. CONCLUSIONS: The prevalence of IAC diverticula in children is lower than the prevalence in adults. IAC diverticula in children likely represent congenital variants of temporal bone anatomy. Similar to adult populations, there is evidence that IAC diverticula in children are likely not an independent risk factor for hearing loss. LEVEL OF EVIDENCE: 4 Laryngoscope, 131:E1683-E1687, 2021.

Hypofractionated Robotic Stereotactic Radiosurgery for Vagal Paragangliomas: A Novel Treatment Strategy for Cranial Nerve Preservation.

OBJECTIVE: To provide the first description of hypofractionated stereotactic radiosurgery (SRS) and evaluate tumor control and safety for vagal paragangliomas (VPs), which begin at the skull base but often have significant extracranial extension. STUDY DESIGN: Retrospective chart review. SETTING: Tertiary-referral neurotology and neurosurgery practice. SUBJECTS AND METHODS: Five VPs in 4 patients (all male, ages 15-56 years) underwent SRS between 2010 and 2018. Outcome measures included tumor dimensions on serial imaging, cranial nerve function, and radiation side effects. RESULTS: CyberKnife hypofractionated SRS was performed. The prescription dose was 24 or 27 Gy (maximum dose 33.4 Gy; range, 29.3-35.5 Gy) delivered in 3 equal fractions. The mean isodose line was 79% (range, 76%-82%). Four VPs were treated primarily, and 1 tumor underwent SRS to treat regrowth 2 years after microsurgical subtotal resection via the modified infratemporal fossa approach. The treatment volume ranged from 8.81 to 86.3 cm3 (mean, 35.7 cm3). All demonstrated stable size (n = 3) or regression (n = 2) at last follow-up, 63 to 85 months after SRS (mean, 76 months). One patient had stable premorbid vocal fold paralysis from a prior ipsilateral glomus jugulare tumor resection. All others demonstrated normal vagal function following SRS. Treatment-related side effects, including dysgeusia (n = 1), mucositis (n = 1), and neck soft-tissue edema (n = 2), were self-limited. CONCLUSIONS: Hypofractionated SRS appears to be both safe and effective for treating VPs, including large-volume and predominantly extracranial tumors, while preserving vagal function. SRS should be considered as a cranial nerve preservation option, especially in settings of contralateral lower cranial nerve deficits or in those with multiple paragangliomas risking both vagal nerves.

Temporal bone resection for lateral skull-base malignancies.

INTRODUCTION: Malignancies involving the temporal bone are increasingly common and require specialized multi-disciplinary care. Given this complex location, involvement of the lateral skull base and local neurovascular structures is common. In this review we discuss general principles for temporal bone resection, as well as alternative and complementary surgical approaches that should be considered in the management of patients with temporal bone cancer. METHODS: A comprehensive review on literature pertaining to temporal bone resection was performed. RESULTS: The primary surgical strategy for malignancies of the temporal bone is temporal bone resection. This may be limited to the ear canal and tympanic membrane (lateral temporal bone resection) or may include the otic capsule and its contents (subtotal temporal bone resection), and/or the petrous apex (total temporal bone resection). Management of adjacent neurovascular structures including the facial nerve, the carotid artery, and the jugular bulb/sigmoid sinus should be considered during surgical planning. Finally, adjunctive procedures such as parotidectomy and neck dissection may be required based on tumor stage. CONCLUSIONS: Temporal bone resection is an important technique in the treatment of lateral skull-base malignancies. This strategy should be incorporated into a multi-disciplinary approach to cancer.

Congenital Cholesteatoma of the Sphenoid, Occipital, and Temporal Bones: 54-Year Follow Up.

OBJECTIVE: To provide long-term follow up of a unique patient with history of massive petrous apex congenital cholesteatoma. PATIENT: 75-year-old man who presented at age 18 with left Gradenigo-like syndrome. INTERVENTION: Staged left radical mastoidectomy and open transsphenoidal marsupialization. Followed with routine in-office cholesteatoma debridement. MAIN OUTCOME MEASURES: Bony erosion on computed tomography (CT), monitoring for new symptoms. RESULTS: Interval development of sensorineural component of hearing loss due to cochlear fistulization. Very slow skull base bony erosion continues without neck destabilization. No new or recurrent cranial neuropathies have developed. CONCLUSIONS: Marsupialized cholesteatoma may be followed with routine debridement and interval imaging for monitoring over many decades.

The Size of Internal Auditory Canal Diverticula Is Unrelated to Degree of Hearing Loss.

OBJECTIVES: To explore the relationship between hearing loss and the internal auditory canal (IAC) diverticula. To determine whether diverticula exist within or medial to the otic capsule and the prevalence in a control population. METHODS: Retrospective review of adult patients with radiologic evidence of an IAC diverticulum, no evidence of otosclerosis, and audiometric testing. Analyzed degree of hearing loss and width, length, height, and volume of diverticulum. Hounsfield unit (HU) measurements lateral and medial to the diverticulum. RESULTS: Pure tone average (PTA), air-bone gap, and WRS (word recognition score) did not correlate with length, width, height, and volume of the diverticula. In patients with a unilateral diverticulum, there was no difference in mean PTA or WRS when comparing the diverticulum and nondiverticulum sides. Mean HU lateral to the diverticulum (2104 HU) was found to be significantly higher than medial to the diverticulum (1818 HU). There is a 5.6% prevalence of IAC diverticula in patients who underwent high-resolution computed tomography (CT) scans for chronic sinusitis (control group). CONCLUSION: These data support the notion that hearing loss in this population is a product of sampling bias. The size of IAC diverticula does not correlate with the degree of hearing loss, and there is no statistically significant association between sensorineural hearing loss (SNHL) and the presence of an IAC diverticulum. IAC diverticula may exist medial to, rather than within, the otic capsule given the significant difference in mean HUs medial and lateral to the diverticula. LEVEL OF EVIDENCE: 4 Laryngoscope, 130:1011-1015, 2020.

Postoperative Opioid Use and Pain Management Following Otologic and Neurotologic Surgery.

OBJECTIVES: The topic of prescription opioid overuse remains a growing concern in the United States. Our objective is to provide insight into pain perception and opioid use based on a patient cohort undergoing common otologic and neurotologic surgeries. STUDY DESIGN: Prospective observational study with patient questionnaire. SETTING: Single academic medical center. SUBJECTS AND METHODS: Adult patients undergoing otologic and neurotologic procedures by two fellowship trained neurotologists between June and November of 2018 were included in this study. During first postoperative follow-up, participants completed a questionnaire assessing perceived postoperative pain and its impact on quality of life, pain management techniques, and extent of prescription opioid use. RESULTS: A total of 47 patients met inclusion and exclusion criteria. The median pain score was 3 out of 10 (Interquartile Range [IQR] = 2-6) with no significant gender differences (P = .92). Patients were prescribed a median of 15.0 (IQR = 10.0-15.0) tablets of opioid pain medication postoperatively, but only used a median of 4.0 (IQR = 1.0-11.5) tablets at the time of first follow-up. Measured quality of life areas included sleep, physical activity, work, and mood. Sleep was most commonly affected, with 69.4% of patients noting disturbances. CONCLUSIONS: This study suggests that practitioners may over-estimate the need for opioid pain medication following otologic and neurotologic surgery. It also demonstrates the need for ongoing patient education regarding opioid risks, alternatives, and measures to prevent diversion.

Rhabdomyolysis in a Morbidly Obese Patient After Oral Cavity Free Flap Reconstruction.

Post-operative rhabdomyolysis is a rare but life-threatening condition. Less than ten cases have been described in the otolaryngic literature and, to our knowledge, no reports exist in the setting of oral reconstructive free tissue transfer. Case report presentation. We discuss the clinical course that lead to the diagnosis of rhabdomyolysis with special consideration to simultaneous microvascular anastomosis. Serial lab values were closely followed to prevent kidney injury while preventing flap congestion. Excessive fluid resuscitation in free flap reconstruction has been associated with increased post-operative complications and flap failure. We present a cautionary case to highlight the need for early diagnosis of rhabdomyolysis, a condition that may become more prevalent in the head and neck population as obesity, the main risk factor, continues to increase worldwide.

Histopathologic Characteristics of Internal Auditory Canal Diverticula.

HYPOTHESIS: We hypothesize that internal auditory canal (IAC) diverticula occur independent of otosclerosis as demonstrated by temporal bone histopathology. BACKGROUND: Diverticula at the anterior-inferior aspect of the IAC have been described histologically in the setting of cavitary otosclerosis. Recent radiographic studies show the prevalence of IAC diverticula that is higher than what can be accounted for by cavitary otosclerosis alone. METHODS: We examined hematoxylin and eosin temporal bone histopathology slides with otosclerosis involving the IAC. We also examined bones from normal hearing subjects with normal histologic findings. Temporal bones were included if donors were more than 18 years of age at time of death and adequate horizontal cuts were available to evaluate the area of interest. RESULTS: IAC diverticula were found in 33 of 47 (70%) temporal bones with IAC otosclerosis and in 5 of 20 (25%) normal temporal bones. The difference in mean pure tone averages (PTA) in the normal temporal bones with (PTA 7.3 ±â€Š7) and without (PTA 8 ±â€Š2) diverticula was not statistically significant (p = 0.86). CONCLUSION: IAC diverticula which have been previously demonstrated to occur in the setting of cavitary otosclerosis can also occur independent from otosclerosis. Subjects with diverticula but without other temporal bone pathology have normal hearing thresholds.

Hypertrophic Pachymeningitis of the Internal Auditory Canal: A Rare Case of Unilateral Sudden Sensorineural Hearing Loss.

OBJECTIVES: To describe and increase awareness of a rare cause of unilateral sudden sensorineural hearing loss. METHODS: Case report and literature review. RESULTS: We present a 66-year-old female who suffered left-sided sudden sensorineural hearing loss and dizziness. Diagnostic magnetic resonance imaging (MRI) did not reveal masses or lesions along the eighth cranial nerve or in the inner ear. Upon eventual referral to neurotology clinic, hypertrophic pachymeningitis of her left internal auditory canal and adjacent middle and posterior fossa dura were identified. The ensuing laboratory workup for autoimmune and infectious etiology revealed mild elevation of ACE 93 (9-67) but otherwise normal results. CONCLUSIONS: Idiopathic hypertrophic pachymeningitis is a diagnosis of exclusion. Neoplastic, infectious, and autoimmune causes must be ruled out. The prevailing treatment for this condition is high-dose corticosteroids. This entity should be considered when evaluating MRI scans obtained in the setting of sudden sensorineural hearing loss.

Petrous Apex Pneumatization: Influence on Postoperative Cerebellopontine Angle Tumor Cerebrospinal Fluid Fistula.

OBJECTIVE: Multiple investigators have sought to identify risk factors for cerebrospinal fluid (CSF) leak following cerebellopontine angle (CPA) tumor resection. We evaluated whether pneumatization of the petrous apex (PA) is a risk factor for CSF fistula. METHOD: We conducted a retrospective chart review at 2 major tertiary academic institutions undergoing CPA tumor resection and analyzed their respective head or temporal computed tomography (CT) scans if available. RESULTS: A total of 91 cases were identified; 51 (64%) demonstrated PA pneumatization, and a total of 17 CSF leaks were identified. We discovered higher rates of CSF leak (25.0% vs 13.7%; P = .273) and CSF rhinorrhea (15.0% vs 5.9%; P = .174) in patients with PA pneumatization compared to those without PA pneumatization. CONCLUSIONS: Isolated PA pneumatization may be a risk factor and communication pathway for CSF fistula. Further studies will need to be broadened across multiple institutions to draw any additional and stronger conclusions.

Incidence and Risk Factors for Sigmoid Venous Thrombosis Following CPA Tumor Resection.

OBJECTIVE: Our primary aim was to determine the incidence of sigmoid venous thrombosis (SVT) and determine risks factors and sequelae of SVT following cerebellopontine angle tumor resection. STUDY DESIGN: Retrospective cohort study. SETTING: Academic tertiary care hospital. PATIENTS: Patients over 18 years of age who underwent resection of cerebellopontine angle meningioma or vestibular schwannoma from January 2005 to April 2016 who had postoperative magnetic resonance imaging. INTERVENTION(S): Diagnostic. MAIN OUTCOME MEASURE(S): Incidence of postoperative sigmoid venous thrombosis (SVT) from official radiology reports was compared with retrospective imaging review by our institutional neuroradiologists. Data collected included age, length of stay, body mass index, surgical approach, and postoperative complications. RESULTS: A total of 127 patients were identified. Official radiology reads significantly underreported the incidence of postoperative SVT compared with retrospective review by our institutional neuroradiologist for patients who underwent routine postoperative imaging (n = 4 [3.1%] versus n = 22 [17.3%]; p < 0.001). There was a statistical trend toward increased risk for thrombosis in patients undergoing translabyrinthine and staged resection that did not reach significance (p = 0.068). Cerebrospinal fluid (CSF) leak incidence in patients with thrombosis was significantly increased (n = 9 [37.5%] versus n = 13 [12.6%]; p = 0.007). When controlling for approach, the presence of thrombus was associated with a more then three-fold increase in odds of CSF leak (OR = 3.28, 95% CI: 1.12-9.48, p = 0.030). There was no correlation between SVT and age (p = 0.788), body mass index (p = 0.686), length of stay (p = 0.733), preoperative tumor size (p = 0.555), or increased postoperative ICP (p = 0.645). Only one patient was symptomatic from sigmoid thrombosis compared with 21 who were not. CONCLUSION: Incidence of SVT is significantly underreported and may predispose patients to increase risk for CSF leak. Staged and translabyrinthine approaches demonstrate an increased trend toward thrombosis risk. Our findings suggest it may not be necessary to treat asymptomatic SVT.

Bilateral pyriform sinus parathyroid adenomas.

Parathyroid glands undergo a variable descent during embryologic development and can be found anywhere in the neck from the level of the mandible to the mediastinum. To the best of our knowledge, we present the first report of a patient who was found to have bilateral parathyroid adenomas in her pyriform sinuses. A middle-aged woman with renal failure and secondary hyperparathyroidism presented with dysphagia and was found to have bilateral pyriform sinus masses on endoscopy. We performed direct laryngoscopy and surgical excision of these masses, and they were found to be parathyroid adenomas. Her dysphagia improved postoperatively, and she continues to be followed by her endocrinologist, who manages her secondary hyperparathyroidism medically. The differential diagnosis for hypopharyngeal masses is wide and should include parathyroid adenomas, even in patients with bilateral masses.

Effect of Piecemeal vs En Bloc Approaches to the Lateral Temporal Bone on Survival Outcomes.

Objectives Lateral temporal bone resection (LTBR) has traditionally been performed en bloc in accordance with oncologic principles. Occasionally, this is not possible due to a low tegmen or lateralized vasculature. We sought to determine if outcomes of piecemeal and en bloc LTBR are comparable. Study Design Retrospective review. Setting Two academic medical centers. Subjects and Methods Multi-institutional retrospective cohort study. Current Procedural Terminology codes were used to identify patients with T1 to T3 squamous cell carcinoma of the external auditory canal (EAC) who underwent LTBR from 2005 to 2015. Kaplan-Meier curves were constructed to compare total survival between the 2 treatment approaches. Pairwise comparisons were performed using χ2 and Fisher exact tests (significance at P = .05), as appropriate. Results Twenty-five patients were identified. Ten patients underwent en bloc LTBR; 15 underwent piecemeal LTBR. Median follow-up time was 11 months (range, 1-60 months). There was not a significant difference in overall survival between en bloc (38.9 months; 95% confidence interval [CI], 22.7-55.2) compared to piecemeal (37.5 months; 95% CI, 21.1-53.9) procedures ( P = .519). Estimates of disease-free survival also did not reveal statistically significant differences: estimated mean disease-free survival was 48.1 months (95% CI, 33.7-62.6) in en bloc patients and 32.5 months (95% CI, 17.1-47.8) in piecemeal patients ( P = .246). Conclusion These data suggest that piecemeal resection can be considered for cases of squamous cell carcinoma involving the external auditory canal where anatomic constraints preclude a safe en bloc resection. Larger studies or studies with a longer follow-up time may provide improved insight into survival comparisons.

Obesity Does Not Increase Operative Time in Otologic Surgery: An Analysis of 5125 Cases.

OBJECTIVES: A large shoulder can impact otologic surgical access. The physical obstruction of a large shoulder may force the surgeon to adjust his or her posture or hand position. We sought to assess the effect of body mass index (BMI) on operative time in tympanoplasties and tympanomastoidectomies. STUDY DESIGN: Cross-sectional analysis. SETTING: National surgical quality improvement program dataset (NSQIP) 2011 to 2014. PATIENTS: Current procedural terminology (CPT) codes were used to identify patients undergoing tympanoplasties and tympanomastoidectomies. INTERVENTIONS: Otologic surgery as indicated by CPT code. MAIN OUTCOME MEASURES: Targeted variables included height, weight, and operative time. BMI was stratified to assess a range of body compositions (<25, 25-30, >30-35, >35-40, >40). Categorical variables were compared using χ tests and continuous variables were compared using Kruskal-Wallis tests. Correlation between operative time and BMI was assessed using Spearman's rho. A generalized linear model was used to analyze the variables affecting operative time. Surgical complications were assessed in binary logistic regression using the enter method. Two-tailed significance was set at α = 0.05. RESULTS: Two surgical groups were identified: tympanoplasty (n = 3,508) and tympanomastoidectomy (n = 1,617). There was not a significant difference in mean operative time across the BMI subgroups for either surgical group (p = 0.617, 0.859, respectively). Multivariate analyses showed no significant difference in operative times based on BMI classification. CONCLUSIONS: The body habitus of obese patients may force the otologic surgeon to adapt, but obese patients do not have a statistically significant longer mean operative time for tympanoplasties and tympanomastoidectomies than patients with a lower BMI.

Endoscopically Assisted Drilling, Exposure of the Fundus through a Presigmoid Retrolabyrinthine Approach: A Cadaveric Feasibility Study.

The presigmoid retrolabyrinthine approach to the cerebellopontine angle is traditionally described to not provide access to the internal auditory canal (IAC). We aimed to evaluate the extent of the IAC that could be exposed with endoscopically assisted drilling and to measure the percentage of the IAC that could be visualized with the microscope and various endoscopes after drilling had been completed. Presigmoid retrolabyrinthine approaches were performed bilaterally on 4 fresh cadaveric heads. We performed endoscopically assisted drilling to expose the fundus of the IAC, which resulted in exposure of the entire IAC in 8 of 8 temporal bone specimens. The microscope afforded a mean view of 83% (n = 8) of the IAC. The 0°, 30°, 45°, and 70° endoscope each afforded a view of 100% of the IAC in 8 of 8 temporal bone specimens. In conclusion, endoscopic drilling of the IAC of can provide an extradural means of exposing the entire length of the IAC while preserving the labyrinth.