Impact of long-term nasal airflow deprivation on sinonasal structures and chronic rhinosinusitis in total laryngectomy patients.

Objective: Total laryngectomy (TL) patients are good models in which to evaluate the effects of nasal airflow cessation on the sinonasal tract. Here, we evaluated changes in sinonasal structures and association with sinus opacification in the computed tomography (CT) images 3 years post-TL. Methods: Patients who underwent TL from 2005 to 2017 in a teaching academic center were reviewed retrospectively. Patients with a final follow-up CT taken less than 3 years after TL, tracheoesophageal puncture, inadequate CT image, or history of sinonasal surgery were excluded. The control group included patients who underwent a partial laryngectomy or hypopharyngectomy without requiring a tracheotomy for more than a month. Altogether, 45 TL patients and 38 controls were selected. The volume of all four paranasal sinuses, inferior turbinate soft tissue volume (ITSTV), maxillary sinus natural ostium (MSNO) mucosal width, and Lund-Mackay scores (LMS) were measured on preoperative and postoperative CT scans. Results: The mean duration between surgery and the final CT scan was 6.3 ± 2.4 and 5.5 ± 2.3 years for the TL and control groups, respectively. Neither group showed significant changes in the four paranasal sinuses' volume or MSNO mucosa width. The ITSTV decreased significantly, from 4.6 ± 1.3 to 2.8 ± 1.1 mL (p < .001), in the TL group, regardless of the presence of nasal septal deviation, showing ITSTV reduction on both concave and convex sides. By contrast, the control group showed no significant changes in ITSTV. Postoperative LMS changes in both groups were insignificant. The number of patients with LMS aggravation or alleviation was the same in both groups, regardless of preoperative sinus opacification. Conclusions: Paranasal sinus structures and sinus opacification are not affected significantly by nasal airflow cessation; however, the inferior turbinate mucosa is affected by long-term discontinuation of nasal airflow. Level of Evidence: 4 (case-control study).

The Impact of National Health Insurance Coverage on Compliance With Positive Airway Pressure Therapy in Patients With Obstructive Sleep Apnea.

OBJECTIVES: Compliance with positive airway pressure (PAP) in patients with obstructive sleep apnea (OSA) directly affects its treatment efficacy. Since July 2018, polysomnography and PAP therapy have been covered by the National Health Insurance (NHI), which has reduced the price barrier and promoted PAP therapy in Korea. This study aimed to compare changes in PAP compliance before and after NHI implementation. METHODS: This study is a retrospective analysis in a tertiary hospital setting in Korea. From 2011 to 2019, patients with OSA (apnea-hypopnea index ≥5) treated using a PAP device for ≥1 month were included. They were classified as belonging to the pre-insurance (PI) group (having started PAP before July 2018) or the NHI group (having received a PAP reimbursement by the NHI service). We collected and analyzed medical records and PAP use information for between-group comparisons of compliance. We defined compliance as the percentage of usage days, the percentage of days with usage for ≥4 night hours, and average daily usage hours. RESULTS: We included 146 and 100 patients in the PI and NHI groups, respectively. Automatic PAP mode and NHI were independent predictors of compliance B at the 3- and 9-month follow-up points. The NHI group showed significantly higher compliance A at 3, but not 9 months. For compliance B, the NHI group showed significantly higher compliance than the PI group at 1 month and 3 months, but not at 9 months. Compared with the PI group, the NHI group showed significantly higher compliance C only at 3 months. CONCLUSION: The NHI has positively affected PAP therapy in patients with OSA. Insurance policy may affect compliance within the first 3 months of PAP therapy.

Insects perceive local sex ratio in the absence of tactile or visual sex-specific cues.

Numerous studies have demonstrated adaptive behavioral responses of males and females to changes in operational sex ratio (the ratio of potentially receptive males to receptive females; OSR), and theory often assumes that animals have perfect instantaneous knowledge about the OSR. However, the role of sensory mechanisms in monitoring the local sex ratio by animals and whether animals can perceive local sex ratio in a manner consistent with model assumptions have not been well addressed. Here, we show that mating water striders Gerris gracilicornis respond to local sex ratio even when visual and physical contact with other individuals were experimentally prohibited. Our study shows that insects are able to estimate local population's sex ratio and adjust their behavior based on nonvisual cues perceived at a distance or released to the habitat. Hence, the frequent theoretical assumption that individuals have knowledge about their local sex ratio regardless of their direct behavioral interactions may be an acceptable approximation of reality.