Neuromapping olfactory stimulation using magnetoencephalography - visualizing smell, a proof-of-concept study.

Importance: Currently, clinical assessment of olfaction is largely reliant on subjective methods that require patient participation. The objective method for measuring olfaction, using electroencephalogram (EEG) readings, can be supplemented with the improved temporal resolution of magnetoencephalography (MEG) for olfactory measurement that can delineate cortical and peripheral olfactory loss. MEG provides high temporal and spatial resolution which can enhance our understanding of central olfactory processing compared to using EEG alone. Objective: To determine the feasibility of building an in-house portable olfactory stimulator paired with electrophysiological neuroimaging technique with MEG to assess olfaction in the clinical setting. Design setting and participants: This proof-of-concept study utilized a paired MEG-olfactometer paradigm to assess olfaction in three normosmic participants. We used a two-channel olfactory stimulator to deliver odorants according to a programmed stimulus-rest paradigm. Two synthetic odorants: 2% phenethyl alcohol (rose) and 0.5% amyl acetate (banana) were delivered in increasing increments of time followed by periods of rest. Cortical activity was measured via a 306-channel MEG system. Main outcomes and measures: Primary outcome measure was the relative spectral power for each frequency band, which was contrasted between rest and olfactory stimulation. Results: Compared to rest, olfactory stimulation produced a 40% increase in relative alpha power within the olfactory cortex bilaterally with both odorants. A 25%-30% increase in relative alpha power occurred in the left orbitofrontal cortex and precentral gyrus with phenethyl alcohol stimulation but not amyl acetate. Conclusion and relevance: In this proof-of-concept study, we demonstrate the feasibility of olfactory measurement via an olfactometer-MEG paradigm. We found that odorant-specific cortical signatures can be identified using this paradigm, setting the basis for further investigation of this system as a prognostic tool for olfactory loss.

Utility of Nasal Access Guides in Endoscopic Endonasal Skull Base Surgery: Assessment of Use during Cadaveric Dissection and Workflow Analysis in Surgery.

Background A nasal access guide (NAG) for endoscopic endonasal approaches (EEAs) to the skull-base has been developed and approved for clinical use but its utility has not been formally investigated. Objective The study aims to assess the effect of a NAG on endoscopic visualization during cadaveric dissection and to perform a workflow analysis with process-based performance measures in the operating room and their effect on clinical outcomes. Methods Skull-base course participants were observed during hands-on cadaveric dissection with and without NAG. Instances of endoscope withdrawal for lens cleaning and inadequate visualization due to lens soiling were tabulated. Participants completed a Likert-scale survey examining the NAG utility and provided an overall grading. Surgical workflow and process-based performance on patients undergoing EEA to the skull-base was analyzed. Passage of powered and dissecting instruments, removal of endoscopes for cleaning, and dislodgment or migration of the device were reviewed. Postoperative assessments included mucosal trauma and synechiae formation. Results Instances of endoscope soiling and manual cleaning were significantly reduced by 40% and 61% with the NAG during cadaveric dissection. The overall grading of the device was 2.75/3. Surgical workflow was observed in 35 patients. Average number of passes of endoscopes, instruments, and powered tools during a 10-minute observation period were 3,17, and 5 during the surgical approach, and 3, 18, and 1 during tumor dissection. Dislodgement of the device occurred in 25.7% and migration of the device in 2.8% of cases. Postoperative synechiae, exposed cartilage or septal perforation was not observed in follow up. Conclusion NAG can significantly reduce inadequate visualization during EEA to the skull-base and has the potential to reduce instances of nasal trauma. Participants assessed its overall utility as being "excellent."

Poor Outcome in Camel-Related Eye Trauma with Ruptured Globe.

PURPOSE: To report the poor visual outcome of ruptured globe caused by camel bites. OBSERVATIONS: A 48-year-old camel caregiver presented to the emergency department after being bitten by a camel in the left side of his face. Ophthalmic examination revealed a superior scleral wound from 9 to 2 o'clock, about 6 mm from the limbus extending to the equator with prolapse of uveal and vitreous tissues, an opaque cornea, total hyphema, diffuse subconjunctival hemorrhage, and a lower lid laceration involving the lid margin and the nasolacrimal duct. The patient has undergone surgical repairs of ruptured globe and lid laceration, followed by retinal detachment surgery. Following these surgical interventions, the patient preserved a light perception vision with flat retina. CONCLUSION: Camel-related injuries might primarily involve the ophthalmic structures, especially in camel bites. Camel-related eye trauma might lead to poor visual and anatomical outcomes which might not improve following surgical interventions.

Frailty as a Predictor of Postoperative Complications Following Skull Base Surgery.

OBJECTIVE/HYPOTHESIS: Frailty has emerged as a powerful risk stratification tool across surgical specialties; however, an analysis of the impact of frailty on outcomes following skull base surgery has not been published. The aim of this study was to assess the validity of the 5-factor modified frailty index (mFI-5) as a predictor of perioperative morbidity and mortality in patients undergoing skull base surgery. METHODS: A mFI-5 score was calculated for patients undergoing skull base surgeries using the National Surgical Quality Improvement Program (NSQIP) database from 2005 to 2018. Multivariate logistic regression analysis was used to evaluate the association of increasing frailty with complications in the 30-day postoperative period, with a subanalysis by operative location. RESULTS: A total of 17,912 patients who underwent skull base procedures were identified, with 45.5% of patients having a frailty score of one or greater; 44.9% were male and the mean age was 52.0 (±16.1 SD) years. Multivariable regression analysis revealed frailty to be an independent predictor of overall complications (odds ratio [OR]: 1.325, P < .001), life-threatening complications (OR: 1.428, P < .001), and mortality (OR: 1.453, P < .001). Higher frailty also correlated with increased length of stay. When procedures were stratified by operative location, frailty correlated significantly with overall complications for middle, posterior, and multiple-fossae operations but not the anterior fossa. CONCLUSIONS: Frailty demonstrates a significant and stepwise association with life-threatening postoperative morbidity, mortality, and length of stay following skull base surgeries. mFI-5 is an objective and easily calculable measure of preoperative risk, which may facilitate perioperative planning and counseling regarding outcomes prior to surgery. LEVEL OF EVIDENCE: 3 Laryngoscope, 131:1977-1984, 2021.

Sleep-disordered breathing in cystic fibrosis.

Sleep-disordered breathing (SBD) is an under recognized comorbidity in the cystic fibrosis (CF) population across the lifespan. Nocturnal hypoxemia, obstructive sleep apnea, and nocturnal hypoventilation are respiratory abnormalities that occur commonly during sleep in patients with lung disease, and have deleterious consequences to the quality of life in people with CF. Effective screening for these abnormalities is needed to allow for timely initiation of treatment, which has been reported to be efficacious. Lack of treatment leads to worsened pulmonary, cardiovascular, and metabolic outcomes in patients. In this review, we give an overview of SBD for the CF clinician, including prevalence, treatment, and suggestions for future research. We strongly encourage the CF community to incorporate evaluation for SBD in CF clinical care so that outcomes for the subset of the CF patients with comorbid SBD improve.

Lateral nasal wall flap for endoscopic reconstruction of the skull base: anatomical study and clinical series.

BACKGROUND: The lateral nasal wall (LNW) flap provides vascularized endonasal reconstruction primarily in revision surgery. Although the harvesting technique and reconstructive surface have been reported, the arterial supply to the LNW flap and its clinical implications is not well defined. This study presents anatomical dissections to clarify the vascular supply to this flap, and the associated clinical outcomes from this reconstructive technique. METHODS: The course and branching pattern of the sphenopalatine artery (SPA) to the LNW were studied in 6 vascular latex-injected heads (11 LNW flaps total). Patients undergoing an LNW flap since 2008 were identified and the underlying pathology, indication, flap viability, and clinical outcomes were retrospectively analyzed. RESULTS: The inferior turbinate artery arises from the LNW artery and divides into 2 branches at the most posterior aspect of the inferior turbinate bone. A smaller-caliber superficial branch travels anteriorly and branches to the LNW. A larger dominant branch travels into the inferior meatus and tangentially supplies the nasal floor. Twenty-four patients with sellar or posterior cranial fossa (PCF) defects were reconstructed with an LNW flap. Postoperative contrast enhancement of the LWN flap was identified in 95.5% of cases. Postoperative cerebrospinal fluid (CSF) leaks were identified in 6 cases. CONCLUSION: Blood supply to the nasal floor by the dominant inferior meatus branch is more robust than the supply to the anterior LNW by the superficial arterial branch. The LNW flap is the preferred vascularized reconstructive option to the PCF and sella in the absence of a nasoseptal flap (NSF).

Endoscopic Visualization of the True Maxillary Ostium Following Uncinectomy.

OBJECTIVES: To examine the frequency in which angled endoscopes are necessary to visualize the true maxillary ostium (TMO) following uncinectomy and prior to maxillary antrostomy. Additionally, to identify preoperative computed tomography (CT) measures that predict need for an angled endoscope to visualize the TMO. STUDY DESIGN: Retrospective study. SETTING: Tertiary academic hospital. PATIENTS AND METHODS: Patients who underwent endoscopic sinus surgery (ESS) between December of 2017 and August of 2018 were retrospectively identified. Cases were reviewed if they were primary ESS cases for chronic rhinosinusitis without polyposis and if they were at least 18 years of age. RESULTS: Sixty-three maxillary antrostomies were reviewed (82.5% were from bilateral cases). Thirty-five cases (55.6%) required an angled endoscope in order to visualize the TMO. Of the preoperative CT measures examined, a smaller sphenoid keel-caudal septum-nasolacrimal duct (SK-CS-NL) angle was significantly associated with need for an angled endoscope intraoperatively to visualize the TMO (17.1° SD ± 3.2 vs 15.0° SD ± 2.9; P = .010). CONCLUSION: Angled endoscopes are likely required in the majority of maxillary antrostomies to visualize the TMO. This is important to recognize in order to prevent iatrogenic recirculation. The SK-CS-NL angle may help to identify cases preoperatively which require an angled endoscope to identify the TMO during surgery.

Perioperative Management of Total Laryngectomy Patients: A Survey of American Head and Neck Society Surgeons.

OBJECTIVES: Standards of care for total laryngectomy (TL) patients in the postoperative period have not been established. Perioperative care remains highly variable and perhaps primarily anecdotally based. The aim of this study was to survey members of the American Head and Neck Society to capture management practices in the perioperative care of TL patients. METHODS: In this survey study, an electronic survey was distributed to the international attending physician body of the American Head and Neck Society. Forty-five-question electronic surveys were distributed. A total of 777 members were invited to respond, of whom 177 (22.8%) fully completed the survey. The survey elicited information on management preferences in the perioperative care of TL patients. Differences in management on the basis of irradiation status and pharyngeal repair (primary closure vs regional or free flap reconstruction) were ascertained. Main outcomes and measures were time to initiate oral feeding, perioperative antibiotic selection and duration, and estimated pharyngocutaneous fistula rates. These measures were stratified by patient type. RESULTS: Most respondents completed head and neck fellowships (77.0%) and practice at academic tertiary centers (72.3%). Ampicillin/sulbactam was the most preferred perioperative antibiotic (43.2%-49.1% depending on patient type), followed by cefazolin and metronidazole in combination (32.0%-33.7%) and then clindamycin (10.8%-12.6%). Compared with nonirradiated patients, irradiated patients were significantly more likely to have longer durations of antibiotics ( P < .05), longer postoperative times to initiate oral feeding ( P < .05), and higher estimated fistula rates ( P < .05). Additionally, in nonirradiated patients, flap-repaired patients (vs primary repair) were significantly more likely to have longer durations of antibiotics (odds ratio, 1.29; 95% confidence interval, 1.13-1.48) and postoperative times to initiate oral feeding (odds ratio, 2.24; 95% confidence interval, 1.76-2.84). CONCLUSIONS: Perioperative management of TL patients is highly variable. Management of antibiotics and oral feeding are significantly affected by irradiation status and scope of pharyngeal repair. Further studies are needed to standardize perioperative care for this unique patient population.

Laryngeal distribution of recurrent respiratory papillomatosis in a previously untreated cohort.

OBJECTIVES/HYPOTHESIS: To describe the distribution of recurrent respiratory papillomatosis (RRP) lesions across 21 laryngeal anatomic regions in previously untreated patients at initial presentation to provide insight regarding the natural history of RRP. STUDY DESIGN: Multi-institutional, retrospective case series. METHODS: Initial laryngoscopic examination videos of 83 previously untreated patients with adult-onset RRP were reviewed. Papilloma locations were recorded using a 21-region laryngeal schematic. Multivariate analyses by anatomic subsite were conducted for the entire population and for subgroups stratified by sex, age, and proton pump inhibitor (PPI) usage. Heat maps were generated, hierarchically color coding the anatomic distribution of disease. RESULTS: In this cohort, RRP was most likely to occur on the true vocal folds (TVFs) and anterior commissure (P < .0001, odds ratio [OR]: 7.02); within the TVFs, the membranous vocal folds (MVFs) were most likely to be affected (P < .0001, OR: 3.56). The cohort was predominantly male (80.7%); males had a higher average number of affected sites (P = .005) and were more likely to have lesions in any laryngeal subsite (P < .0001, OR: 2.88,) compared to females. PPI users were more likely than nonusers to have disease in any laryngeal subsite (P = .0037, OR: 1.62), particularly in the posterior and subglottic regions (P = .0061, OR: 2.53). Age was not correlated with lesion prevalence or distribution. CONCLUSIONS: In untreated patients presenting to three laryngology clinics, the MVFs were most likely to be affected by RRP. Males had more anatomic sites affected by papilloma than females. The influence of PPI use on RRP distribution warrants further investigation. LEVEL OF EVIDENCE: 4. Laryngoscope, 128:138-143, 2018.

The effects of concurrent chemoradiation therapy to the base of tongue in a preclinical model.

OBJECTIVES/HYPOTHESIS: To develop a clinically relevant model of oropharyngeal concurrent chemoradiation therapy (CCRT) in order to quantify the effects of CCRT on tongue function and structure. CCRT for advanced oropharyngeal cancer commonly leads to tongue base dysfunction and dysphagia. However, no preclinical models currently exist to study the pathophysiology of CCRT-related morbidity, thereby inhibiting the development of targeted therapeutics. STUDY DESIGN: Animal model. METHODS: Twenty-one male Sprague-Dawley rats were randomized into three groups: 2 week (2W), 5 month (5M), and control (C). The 2W and 5M animals received cisplatin, 5-fluorouracil, and five fractions of 7 Gy to the tongue base; the C animals received no intervention. In vivo tongue strength and displacement, as well as hyoglossus muscle collagen content, were assessed. Analyses were conducted 2 weeks or 5 months following completion of CCRT in the 2W and 5M groups, respectively. RESULTS: Peak tetanic and twitch tongue forces were significantly reduced in both 2W and 5M animals compared to controls (tetanic: P = .0041, P = .0089, respectively; twitch: P = .0201, P = .0020, respectively). Twitch half-decay time was prolonged in 2W animals compared to controls (P = .0247). Tongue displacement was significantly reduced across all testing parameters in 5M animals compared to both the C and 2W groups. No differences in collagen content were observed between experimental groups. CONCLUSIONS: The current study is the first to describe a preclinical model of CCRT to the head and neck with an emphasis on clinical relevance. Tongue strength decreased at 2 weeks and 5 months post-CCRT. Tongue displacement increased only at 5 months post-CCRT. Fibrosis was not detected, implicating alternative causative factors for these findings. LEVEL OF EVIDENCE: NA Laryngoscope, 1783-1790, 2018.

Evolution in Visualization for Sinus and Skull Base Surgery: From Headlight to Endoscope.

Rhinoscopy became a formal field of study in the mid-nineteenth century as improvements in nasal specula were made and the potent vasoconstrictive effects of cocaine on the intranasal tissues were discovered. Since then, a multitude of advances in visualization and illumination have been made. The advent of the Storz-Hopkins endoscope in the mid-twentieth century represents a culmination of efforts spanning nearly 2 centuries, and illumination has evolved concomitantly. The future of endoscopic sinus surgery may integrate developing technologies, such as 3-dimensional endoscopy, augmented reality navigation systems, and robotic endoscope holders.

Efficacy of Perioperative Lumbar Drainage following Endonasal Endoscopic Cerebrospinal Fluid Leak Repair.

Objective Perioperative lumbar drain (LD) use in the setting of endoscopic cerebrospinal fluid (CSF) leak repair is a well-established practice. However, recent data suggest that LDs may not provide significant benefit and may thus confer unnecessary risk. To examine this, we conducted a meta-analysis to investigate the effect of LDs on postoperative CSF leak recurrence following endoscopic repair of CSF rhinorrhea. Data Sources A comprehensive search was performed with the following databases: Ovid MEDLINE (1947 to November 2015), EMBASE (1974 to November 2015), Cochrane Review, and PubMed (1990 to November 2015). Review Method A meta-analysis was performed according to PRISMA guidelines. Results A total of 1314 nonduplicate studies were identified in our search. Twelve articles comprising 508 cases met inclusion criteria. Overall, use of LDs was not associated with significantly lower postoperative CSF leak recurrence rates following endoscopic repair of CSF rhinorrhea (odds ratio: 0.89, 95% confidence interval: 0.40-1.95) as compared with cases performed without LDs. Subgroup analysis of only CSF leaks associated with anterior skull base resections (6 studies, 153 cases) also demonstrated that lumbar drainage did not significantly affect rates of successful repair (odds ratio: 2.67, 95% confidence interval: 0.64-11.10). Conclusions There is insufficient evidence to support that adjunctive lumbar drainage significantly reduces postoperative CSF leak recurrence in patients undergoing endoscopic CSF leak repair. Subgroup analysis examining only those patients whose CSF leaks were associated with anterior skull base resections demonstrated similar results. More level 1 and 2 studies are needed to further investigate the efficacy of LDs, particularly in the setting of patients at high risk for CSF leak recurrence.

Complications of surgery for sporadic vestibular schwannoma.

OBJECTIVES: We sought to investigate the postoperative complications of vestibular schwannoma excision and determine their significant clinical predictors. STUDY DESIGN: Cross-sectional. SETTING: California Hospital Inpatient Discharge Datasets 1997-2011. SUBJECTS AND METHODS: Data for vestibular schwannoma excisions performed in California were extracted using the ICD-9-CM code "04.01 excision of acoustic neuroma." Demographics, principal payer, state of residence, comorbidities, as well as hospital case volume were examined as possible predictors. Postoperative complications and patient disposition were examined as outcome variables. Comorbidities and complications were identified using ICD-9-CM diagnoses and procedures codes. RESULTS: Overall, 6553 cases were examined. Comorbidities were present in 2539 (38.7%) patients. Postoperative complications occurred in 1846 (28.2%) patients; 1714 (26.2%) neurological and 337 (5.1%) medical complications. Patients' admission ended with death or further care (ie, skilled nursing facilities) in 260 (4.0%) cases. Mortality rate was 0.2%. No significant changes were observed over time. Multivariate analysis revealed that the odds of neurological complications were greater in the 2007-2011 period (OR = 1.51; 95% CI, 1.12-2.04), in patients with comorbidities (OR = 1.48; 95% CI, 1.16-1.88), and in hospitals with low case volume (OR = 1.69; 95% CI. 1.31-2.18). The odds of medical complications were also greater in the 2007-2011 period (OR = 1.69; 95%, CI 1.02-2.80). Female gender, non-Caucasian ethnicity, presence of comorbidities, and low hospital case volume were associated with greater odds of patients requiring further care. CONCLUSION: Comorbidities and low hospital case volume were major risk factors for complications. No significant changes in rates of complications from vestibular schwannoma surgery were observed over the 15-year period.

Trends in demographics, charges, and outcomes of patients undergoing excision of sporadic vestibular schwannoma.

OBJECTIVE: To assess demographics, charges, and outcome measures by temporal and volume analysis in the treatment of vestibular schwannoma. DESIGN: Cross-sectional analysis. SETTING, SUBJECTS, AND METHODS: The California Hospital Inpatient Discharge Databases from 1996 to 2010. RESULTS: A total of 6545 cases from 1996 to 2010 were identified. Of these, 86.2% occurred at high-volume centers (HVCs), and the number of annual cases decreased by 28.5%. Patients presenting for surgery were increasingly younger, non-Caucasian, and likely to have comorbidities. Total charges significantly increased over time (P < .001), with the median total charge in 2006-2010 being $91,338 compared with $38,607.92 in 1996-2000 after adjusting for inflation. Routine discharges (home or residence) were more likely at HVCs (odds ratio [OR] 5.48, P < .001) and less likely if patients had Medicaid (Medi-Cal; OR 0.51, P = .002) or Medicare (OR 0.55, P = .022), were 65 years or older (OR 0.56, P = .025), or had comorbidities (OR 0.54, P < .001). Shorter hospital stays were more likely at HVCs (OR 3.77, P < .001) and less likely if patients had Medicaid (OR 0.36, P < .001) or comorbidities (OR 0.61, P < .001). Lesser total charges were more likely at HVCs (OR 2.12, P = .002) and less likely if patients had comorbidities (OR 0.70, P < .001). Mortality was less likely at HVCs (OR 0.10, P = .011). CONCLUSION: The profile of patients undergoing vestibular neuroma excision is changing. Surgical volume is decreasing, suggesting a trend toward more conservative management or stereotactic radiation. Patients are best served at HVCs, where routine discharges, shorter length of stay, decreased mortality, and lower total charges are more likely.