DISE-PAP: a method for troubleshooting residual AHI elevation despite positive pressure therapy.

None: Despite excellent positive airway pressure (PAP) adherence, a subset of patients with obstructive sleep apnea experience residual elevation of the apnea-hypopnea index (AHI). Drug-induced sleep endoscopy during PAP application provides an opportunity to examine the anatomic effect of PAP therapy on the upper airway and to troubleshoot refractory residual AHI elevation. We present a patient who demonstrated persistent moderate-severe AHI elevation during titration polysomnogram and subsequent data download reports despite numerous mask refits, chin strap, positional modifications, and multiple pressure and mode adjustments in both the clinic and sleep laboratory settings. Drug-induced sleep endoscopy was performed with the flexible endoscope passed through the PAP circuit into the upper airway. Jaw laxity and associated mandibular retrusion at sleep onset was found to result in a complete fixed tongue base obstruction that PAP therapy, delivered via the patient's oronasal interface, was unable to overcome. Various strategies to overcome these obstacles are discussed.

Obstructive sleep apnea and CPAP therapy alter distinct transcriptional programs in subcutaneous fat tissue.

Obstructive sleep apnea (OSA) has been linked to dysregulated metabolic states, and treatment of sleep apnea may improve these conditions. Subcutaneous adipose tissue is a readily samplable fat depot that plays an important role in regulating metabolism. However, neither the pathophysiologic consequences of OSA nor the effects of continuous positive airway pressure (CPAP) in altering this compartment's molecular pathways are understood. This study aimed to systematically identify subcutaneous adipose tissue transcriptional programs modulated in OSA and in response to its effective treatment with CPAP. Two subject groups were investigated: Study Group 1 was comprised of 10 OSA and 8 controls; Study Group 2 included 24 individuals with OSA studied at baseline and following CPAP. For each subject, genome-wide gene expression measurement of subcutaneous fat was performed. Differentially activated pathways elicited by OSA (Group 1) and in response to its treatment (Group 2) were determined using network and Gene Set Enrichment Analysis (GSEA). In Group 2, treatment of OSA with CPAP improved apnea-hypopnea index, daytime sleepiness, and blood pressure, but not anthropometric measures. In Group 1, GSEA revealed many up-regulated gene sets in OSA subjects, most of which were involved in immuno-inflammatory (e.g. interferon-γ signaling), transcription, and metabolic processes such as adipogenesis. Unexpectedly, CPAP therapy in Group 2 subjects was also associated with up-regulation of several immune pathways as well as cholesterol biosynthesis. Collectively, our findings demonstrate that OSA alters distinct inflammatory and metabolic programs in subcutaneous fat, but these transcriptional signatures are not reversed with short-term effective therapy.

Dysfunctional hypoglossal nerve stimulator after electrical cardioversion: A case series.

OBJECTIVES/HYPOTHESIS: Upper airway stimulation has demonstrated marked improvements in apnea-hypopnea index, oxygen desaturation index, and quality-of-life measures in patients with moderate to severe obstructive sleep apnea (OSA) who cannot tolerate continuous positive airway pressure. Cardiac arrhythmias are common in patients with OSA and can require electrical cardioversion. We describe the first four reported cases of hypoglossal nerve stimulator (HGNS) dysfunction after electrical cardioversion and illustrate our operative approach to device troubleshooting and repair. STUDY DESIGN: Retrospective case series. METHODS: A retrospective review of 201 HGNS implantations performed at two academic institutions revealed four cases of HGNS device dysfunction after electrical cardioversion requiring surgical revision. Preoperative and postoperative device performance metrics and electrical cardioversion specifications were retrospectively assessed and compiled for this case series. The senior authors (R.J.S., M.S.B.) detail operative planning and approach for HGNS implantable pulse generator (IPG) replacement. RESULTS: At least two patients with HGNS device dysfunction had received cardioversion via anterolateral electrode pad placement. Three patients had received multiple shocks. All four patients experienced a change in device functionality or complete cessation of functionality after electrocardioversion. Operatively, each patient required replacement of the IPG, with subsequent intraoperative interrogation revealing proper device functionality. CONCLUSION: Counseling for patients with HGNS undergoing external electrical cardioversion should include possible device damage and need for operative replacement. Anteroposterior electrode pad placement should be considered for patients with HGNS who require electrocardioversion. Operative replacement of an HGNS system damaged by electrocardioversion begins with IPG replacement and intraoperative device interrogation. LEVEL OF EVIDENCE: 4 Laryngoscope, 129:1949-1953, 2019.

Risk of Postoperative Complications in Patients with Obstructive Sleep Apnea following Skull Base Surgery.

Objectives Obstructive sleep apnea (OSA) presents several challenges in skull base surgery, including increased intracranial pressure, worsened OSA with nasal packing, and avoidance of positive airway pressure (PAP) therapy postoperatively. The objective of this study was to examine the risk of postoperative complications in a skull base population with OSA in which PAP therapy is withheld. Study Design Retrospective cohort study. Setting Tertiary care hospital. Subjects and Methods Medical records of 414 adult patients undergoing anterior skull base procedures between January 1, 2014, and January 7, 2017, were retrospectively reviewed. Revision surgeries, skull base infections, sinus surgery, and orbital cases were excluded. Results Fifty-four (13.0%) patients with a diagnosis of OSA were identified. While the known patients with OSA were more likely to require postoperative supplemental oxygen (odds ratio [OR], 4.29; 95% confidence interval [CI], 2.38-7.75; P < .001), there was no increased risk of serious respiratory events or cerebrospinal fluid leak (CSF). To address the likely underdiagnosis of OSA in this cohort, subgroup analyses were performed of patients at high risk for OSA (body mass index >30 kg/m2 and hypertension) and demonstrated an increased risk of serious respiratory events (OR, 4.41; 95% CI, 1.24-15.7; P = .034) and CSF leak (13.6% vs 4.7%; P = .018). Conclusions Skull base patients with known OSA can be successfully managed with diligent care in the perioperative period when PAP therapy is withheld. However, OSA is likely underdiagnosed in the skull base population, and patients at high risk for undiagnosed OSA may be at the greatest risk for respiratory complications and CSF leak. Increased presurgical awareness and implementation of a perioperative management algorithm is needed.

Positive airway pressure adherence and mask interface in the setting of sinonasal symptoms.

OBJECTIVES/HYPOTHESIS: Despite reports of lower positive pressure adherence rates with oronasal masks, patients with sinonasal problems are often prescribed this interface over a nasal interface. The aim of this study was to characterize the relationship between mask type and therapy adherence in the setting of sinonasal symptoms. STUDY DESIGN: Retrospective case series with chart review. METHODS: We reviewed 328 patients who underwent positive pressure titration between January 2012 and May 2015. Follow-up adherence data were available for 218 patients (66.5%). Multivariate analysis examined whether patients with sinonasal symptoms have improved adherence with oronasal masks compared to nasal or nasal pillow interfaces. RESULTS: At a median follow-up of 95 days, positive pressure adherence in patients with sinonasal symptoms was highest with the nasal pillow interface. When compared with oronasal interfaces, the odds of adequate therapy adherence were >5 times greater with nasal pillow interfaces (odds ratio [OR] = 5.20, 95% confidence interval [CI] = 1.61-16.80, P = .006) and >3 times greater with nasal interfaces (OR = 3.67, 95% CI = 1.20-11.26, P = .02) in these symptomatic patients. CONCLUSIONS: The presence of nasal problems does not predict the need for an oronasal mask. Positive pressure adherence rates are higher with nasal and nasal pillow interfaces compared to oronasal masks, even in patients with sinonasal complaints. LEVEL OF EVIDENCE: 4. Laryngoscope, 127:2418-2422, 2017.

Suggested excisional margins for cutaneous malignant lesions based on Mohs micrographic surgery.

IMPORTANCE: Surgical excision of skin cancer is a common treatment, yet the proper surgical margin remains unclear. This study reviews data on lesions and their margins as defined by Mohs micrographic surgery. OBJECTIVE: To review margins as defined by Mohs micrographic surgery. DESIGN: Retrospective review of data from patients with skin cancer. SETTING: Academic medical center. PARTICIPANTS: All patients with nonmelanoma skin cancer. MAIN OUTCOME AND MEASURE: Size and final defect size were compared to calculate the margins needed. All lesions were categorized based on histologic characteristics. RESULTS: A total of 495 lesions were reviewed. All tumors and defects had precise measurements. The mean margins for low-risk basal cell carcinomas, high-risk basal cell carcinomas, low-risk squamous cell carcinomas, and high-risk squamous cell carcinomas were 2.4 mm, 3.7 mm, 2.6 mm, and 5.3 mm, respectively. Statistical differences in surgical margins were found between all low- and high-risk cancer types. Established high-risk zones (H-zone) for basal cell carcinoma and squamous cell carcinoma were not associated with larger margins. Margins required to excise completely 95% of all the low-risk basal cell carcinomas, high-risk basal cell carcinomas, low-risk squamous cell carcinomas, and high-risk squamous cell carcinomas, were 4.75 mm, 8 mm, 5 mm, and 13.25 mm, respectively. CONCLUSIONS AND RELEVANCE: Differences are noted between low- and high-risk cutaneous lesions. When primary excision instead of Mohs micrographic surgery is the only option, the aforementioned margins may be considered guidelines. The relevance of this study is to guide future management and margins for primary excision. LEVEL OF EVIDENCE: 3.