Estimation of Nasal Airway Cross-sectional Area From Endoscopy Using Depth Maps: A Proof-of-Concept Study.

OBJECTIVE: Endoscopy is routinely used to diagnose obstructive airway diseases. Currently, endoscopy is only a visualization technique and does not allow quantification of airspace cross-sectional areas (CSAs). This pilot study tested the hypothesis that CSAs can be accurately estimated from depth maps created from virtual endoscopy videos. STUDY DESIGN: Cross-sectional. SETTING: Academic tertiary medical center. METHODS: Virtual endoscopy and depth map videos of the nasal cavity were digitally created based on anatomically accurate three-dimensional (3D) models built from computed tomography scans of 30 subjects. A software tool was developed to outline the airway perimeter and estimate the airspace CSA from the depth maps. Two otolaryngologists used the software tool to estimate the nasopharynx CSA and the nasal valve minimal CSA (mCSA) in the left and right nasal cavities. Model validation statistics were performed. RESULTS: Nasopharynx CSA had a median percent error of 3.7% to 4.6% when compared to the true values measured in the 3D models. Nasal valve mCSA had a median percent error of 22.7% to 33.6% relative to the true values. Raters successfully used the software tool to identify subjects with nasal valve stenosis (ie, mCSA < 0.20 cm2) with a sensitivity of 83.3%, specificity ≥ 90.7%, and classification accuracy ≥ 90.0%. Interrater and intrarater agreements were high. CONCLUSION: This study demonstrates that airway CSAs in 3D models can be accurately estimated from depth maps. The development of artificial intelligence algorithms to compute depth maps may soon allow the quantification of airspace CSAs from clinical endoscopies.

Preoperative n-BCA embolization in the resection of submandibular lymphatic malformations refractory to sclerotherapy treatment: A pilot case series.

OBJECTIVE: Lymphatic malformations in the submandibular neck pose unique challenges to treatment that elevate their risk of recurrence. This case series provides a review of five patients, previously treated with sclerotherapy or with a history of multiple infections, who were treated in a novel fashion: single-stage resection using preoperative n-butyl cyanoacrylate (n-BCA) glue embolization. METHODS: We performed a retrospective medical record review of five patients who underwent single-stage n-BCA embolization by Interventional Radiology followed by surgical resection by Otolaryngology, including a review of their symptoms, previous treatments, and post-treatment surveillance, with follow-up ranging from 4 to 24 months after the treatment of interest. RESULTS: All study subjects had unremarkable perioperative courses, and four patients did not demonstrate any evidence of disease recurrence or persistence during the follow-up period. One patient was found to have a small area of persistent disease on post-treatment imaging, but has remained symptom free. CONCLUSIONS: Treatment of submandibular lymphatic malformations with n-BCA embolization followed by surgical resection can be performed in a single stage. This case series demonstrates that this approach can yield durable relief of symptoms, even in patients whose lesions were refractory to previous treatments.

Epidemiology of Dizzy Patient Population in a Neurotology Clinic and Predictors of Peripheral Etiology.

OBJECTIVE: To compare the proportion of peripheral versus nonperipheral dizziness etiologies among all patients, inclusive of those presenting primarily or as referrals, to rank diagnoses in order of frequency, to determine whether or not age and sex predict diagnosis, and to determine which subgroups tended to undergo formal vestibular testing. STUDY DESIGN: Retrospective cohort. SETTING: Academic neurotology clinic. PATIENTS: Age greater than 18 neurotology clinic patients with the chief complaint of dizziness. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Age, sex, diagnosis, record of vestibular testing. RESULTS: Two thousand seventy-nine patients were assigned 2,468 diagnoses, of which 57.7 and 42.3% were of peripheral and nonperipheral etiologies, respectively. The most common diagnoses were Ménière's (23.0%), vestibular migraine (19.3%), benign paroxysmal positional vertigo (BPPV) (19.1%), and central origin, nonmigraine (16.4%). Peripheral diagnoses are more likely to be found in men than in women (odds ratio [OR] 1.59). Peripheral diagnoses were most likely to be found in the 60 to 69 age group (OR 3.82). There was not a significant difference in rate of vestibular testing between women and men. Among patients with two diagnoses, the most common combinations were vestibular migraine and BPPV then vestibular migraine and Ménière's. CONCLUSIONS: A large proportion of patients seen for the chief complaint of dizziness in the neurotology clinic were found not to have a peripheral etiology of their symptoms. These data challenge a prevalent dogma that the most common causes of dizziness are peripheral: BPPV, vestibular neuritis, and Ménière's disease. Age and sex are statistically significant predictors of peripheral etiology of dizziness.

Hair cell counts in a rat model of sound damage: Effects of tissue preparation & identification of regions of hair cell loss.

Exposure to intense sound can damage or kill cochlear hair cells (HC). This loss of input typically manifests as noise induced hearing loss, but it can also be involved in the initiation of other auditory disorders such as tinnitus or hyperacusis. In this study we quantify changes in HC number following exposure to one of four sound damage paradigms. We exposed adult, anesthetized Long-Evans rats to a unilateral 16 kHz pure tone that varied in intensity (114 dB or 118 dB) and duration (1, 2, or 4 h) and sacrificed animals 2-4 weeks later. We compared two different methods of tissue preparation, plastic embedding/sectioning and whole mount dissection, for quantifying hair cell loss as a function of frequency. We found that the two methods of tissue preparation produced largely comparable cochleograms, with whole mount dissections allowing a more rapid evaluation of hair cell number. Both inner and outer hair cell loss was observed throughout the length of the cochlea irrespective of sound damage paradigm. Inner HC loss was either equal to or greater than outer HC loss. Increasing the duration of sound exposures resulted in more severe HC loss, which included all HC lesions observed in an analogous shorter duration exposure.