A Simple Endoscopic Technique for Measuring the Cross-Sectional Area of the Upper Airway in a Rabbit Model.

OBJECTIVE: Validate an accurate and reproducible method of measuring the cross-sectional area (CSA) of the upper airway. SUBJECTS AND METHODS: This is a prospective animal study done at a tertiary care medical treatment facility. Control images were obtained using endotracheal tubes of varying sizes. In vivo images were obtained from various timepoints of a concurrent study on subglottic stenosis. Using a 0° rod telescope, an instrument was placed at the level of interest, and a photo was obtained. Three independent and blinded raters then measured the CSA of the narrowest portion of the airway using open source image analysis software. RESULTS: Each blinded rater measured the CSA of 79 photos. The t testing to assess for accuracy showed no difference between measured and known CSAs of the control images ( P = .86), with an average error of 1.5% (SD = 5.5%). All intraclass correlation (ICC) values for intrarater agreement showed excellent agreement (ICC > .75). Interrater reliability among all raters in control (ICC = .975; 95% CI, .817-.995) and in vivo (ICC = .846;, 95% CI, .780-.896) images showed excellent agreement. CONCLUSIONS: We validate a simple, accurate, and reproducible method of measuring the CSA of the airway that can be used in a clinical or research setting.

Reproducing severe acute subglottic stenosis in a rabbit model.

OBJECTIVES: The objectives of this study were to develop an animal model with consistent, severe subglottic stenosis (SGS), and to develop the timeline needed for intervention to limit rabbit mortality. METHODS: Subglottic stenosis was created endoscopically using either a nylon or polypropylene brush in sixteen New Zealand White rabbits. The subglottic cross-sectional area was measured endoscopically using a right-angled probe and an open source image analysis software The cross-sectional areas of the stenotic and native airways were compared to calculate the subglottic stenosis percentage and Myer-Cotton grade classification. RESULTS: The average diameter of the native subglottis was 4.7 mm (SD 0.4). The mean subglottic stenosis percentage was 73% (SD 32) for all rabbits. The three rabbits injured with the nylon brush had 30, 52, and 76% stenosis. Nine of the 12 surviving rabbits (75%) injured with the polypropylene brush had a >86% subglottic stenosis. Four rabbits in the polypropylene brush cohort died from procedural complications. CONCLUSION: This study demonstrates a reliable model using a polypropylene brush to create severe acute subglottic stenosis. Cartilage exposure after creating the injury was associated with more severe stenosis. Mortality rate may have been reduced if endoscopic balloon dilation was performed electively seven days after injury, rather than emergently nine days after injury. LEVEL OF EVIDENCE: 4.

Association between Lateral Skull Base Thickness and Surgical Outcomes in Spontaneous CSF Otorrhea.

OBJECTIVES: (1) Correlate skull base thickness with perioperative outcomes for spontaneous cerebrospinal fluid (CSF) otorrhea. (2) Augment perioperative counseling of patients with abnormally thin skull bases. STUDY DESIGN: Case series with chart review. SETTING: Tertiary center. Patients with spontaneous CSF otorrhea have thin skull bases. This is associated with obesity and/or idiopathic intracranial hypertension. The influence of skull base thinning on perioperative outcomes is unknown. SUBJECTS AND METHODS: A retrospective review was conducted from 2004 to 2014. Forty-eight cases of spontaneous CSF otorrhea met the inclusion criteria of primary surgery by the senior authors: preoperative dedicated temporal bone computed tomography, absence of other leak etiologies, and follow-up >6 months. Patients were stratified into thin (<0.9 mm) and thick (>0.9 mm) groups based on computed tomography measures of their tegmen. Primary outcomes measures were as follows: postoperative meningitis, recurrent leak, second site leak (contralateral ear/anterior fossa), and permanent shunt placement. Hearing outcomes were not assessed in this study. RESULTS: Thirty and 15 patients composed the thin and thick groups, respectively. Both the incidence (P < .0001) and the rate (P = .005) of adverse outcomes were significantly higher in the thin group. Only 2 patients in the thick group experienced an adverse outcome. Eleven patients underwent multiple procedures for spontaneous leaks. The recurrence rate was 14.5%. All but 1 recurrence occurred in the thin group. CONCLUSIONS: An abnormally thin tegmen was significantly associated with adverse perioperative outcomes in cases of spontaneous CSF otorrhea. A thick skull base and the presence of an encephalocele may be protective against recurrence. The effect of untreated intracranial hypertension on the results is unknown.

Novel radiographic measurement algorithm demonstrating a link between obesity and lateral skull base attenuation.

OBJECTIVES: (1) To describe a validated algorithm for measuring tegmen thickness on computed tomography scans. (2) To compare the tegmen thickness in 3 groups: patients with spontaneous cerebrospinal fluid (CSF) leaks, obese controls, and nonobese controls. STUDY DESIGN: Retrospective review. SETTING: Patients with spontaneous CSF otorrhea often have highly attenuated tegmen plates. This is associated with obesity and/or idiopathic intracranial hypertension (IIH). No evidence exists, however, that objectively links obesity and/or IIH with skull base attenuation. SUBJECTS AND METHODS: This was a retrospective review from 2004 to the present. Patients with spontaneous CSF otorrhea and matched obese (body mass index [BMI] >30 kg/m(2)) and nonobese (BMI <30 kg/m(2)) controls were selected. Tegmen thickness was measured radiographically. Interrater validity was assessed. RESULTS: Ninety-eight patients were measured: 37 in the CSF group (BMI, 36.6 kg/m(2)), 30 in the obese group (BMI, 34.6 kg/m(2)), and 31 in the nonobese group (BMI, 24.2 kg/m(2)). The CSF group had a significantly thinner tegmen compared to both the obese control (P < .01) and nonobese control (P = .0004) groups. Obese controls had a thinner tegmen than nonobese controls (P < .00001). A significant inverse correlation was detected between skull base thickness and BMI. Signs/symptoms of IIH were most commonly found in the CSF group. Good to very good strength of agreement was detected for measures between raters. CONCLUSION: This is the first study to (1) quantify lateral skull base thickness and (2) significantly correlate obesity with lateral skull base attenuation. Patients who are obese with spontaneous CSF leaks have greater attenuation of their skull base than matched obese controls. This finding supports theories that an additional process, possibly congenital, has a pathoetiological role in skull base dehiscence.

Initial symptoms in patients with HPV-positive and HPV-negative oropharyngeal cancer.

IMPORTANCE This study addresses the most common initial symptoms of oropharyngeal squamous cell carcinoma (OPSCC) and investigates differences between human papillomavirus (HPV)­positive vs HPV-negative tumors. OBJECTIVES To analyze the most common initial symptoms in patients with OPSCC and to determine if any differences in initial symptoms occur between HPV-positive and HPV-negative tumors. DESIGN, SETTING, AND PATIENTS Retrospective single-institution review of medical records of previously untreated patients with OPSCC diagnosed from January 1, 2008, toMay 20, 2013, who were evaluated by 1 physician (the senior author, T.A.D.) at the Medical University of South Carolina. MAIN OUTCOMES AND MEASURES We determined the most common initial symptoms of OPSCC and analyzed differences between HPV-positive and HPV-negative tumors. RESULTS Neck mass (in 39 patients [44%]) and sore throat (in 29 patients [33%]) comprised the most common initial symptoms in OPSCC. Patients who were HPV-positive were more likely to initially notice a neck mass than HPV-negative patients (51% vs 18%; P = .02), whereas HPV-negative patients were more likely to notice sore throat (53%vs 28%; P = .09), dysphagia (41% vs 10%; P = .05), or odynophagia (24%vs 6%; P = .04). CONCLUSIONS AND RELEVANCE This study provides preliminary evidence supporting neck mass and sore throat as the initial symptoms of patients with OPSCC. Patients who were HPV-positive more commonly complained of a neck mass as the initial symptom, whereas HPV-negative patients more commonly had symptoms related to the primary tumor site, including sore throat, dysphagia, and/or odynophagia.