Evaluating Mixed Reality as a Tool for Patient Education of Facial Fractures.

Background: Patients may be educated about facial fractures using two-dimensional computed tomography (2DCT); however, three-dimensional mixed reality (3DMR) goggles may improve patient education by delivering content in an immersive environment. Objective: To compare the effectiveness of 2DCT and 3DMR formats used for patient education on facial fractures, as measured by surveys. Methods: In this prospective, randomized, crossover study, video tutorials intended for facial fracture informed consent were created in 2DCT and 3DMR formats from a single CT data set of a zygomaticomaxillary complex (ZMC) fracture. Subjects were randomly assigned into two groups. Group 1 (n = 25) viewed the 2DCT tutorial, answered self-assessment and information recall surveys, viewed the 3DMR tutorial, repeated the prior surveys as well as a comparison survey. Group 2 (n = 25) followed the same sequence but viewed the 3DMR tutorial and then the 2DCT tutorial. Results: Participants (n = 50) had no differences in age (group 1-51.9 years/standard deviation [SD] 20.9; group 2-44.7 years/SD 17.6 years; p = 0.223), gender (group 1-10 male/15 female; group 2-11 male/14 female; p = 0.999), college education level (group 1-25 yes; group 2-25 yes; p = 0.844), or prior 2DCT or 3DMR experience (group 1-9 yes/16 no; group 2-13 yes/12 no; p = 0.393). The 3DMR format was preferred over 2DCT (p < 0.05), and it was reported to enhance understanding as compared to 2DCT (p < 0.05). No differences for information recall were noted (p = 0.753). Conclusion: In this study, participants preferred 3DMR goggles over 2DCT for a simulated ZMC fracture-informed consent.

Force Profiles of Single Ventricle Atrioventricular Leaflets in Response to Annular Dilation and Leaflet Tethering.

We sought to understand how leaflet forces change in response to annular dilation and leaflet tethering (LT) in single ventricle physiology. Explanted fetal bovine tricuspid valves were sutured onto image-derived annuli and ventricular mounts. Control valves (CON) were secured to a size-matched hypoplastic left heart syndrome (HLHS)-type annulus and compared to: (1) normal tricuspid valves secured to a size-matched saddle-shaped annulus, (2) HLHS-type annulus with LT, (3) HLHS-type annulus with annular dilation (dilation valves), or (4) a combined disease model with both dilation and tethering (disease valves). The specimens were tested in a systemic heart simulator at various single ventricle physiologies. Leaflet forces were measured using optical strain sensors sutured to each leaflet edge. Average force in the anterior leaflet was 43.2% lower in CON compared to normal tricuspid valves (P < 0.001). LT resulted in a 6.6% increase in average forces on the anterior leaflet (P = 0.04), 10.7% increase on the posterior leaflet (P = 0.03), and 14.1% increase on the septal leaflet (P < 0.001). In dilation valves, average septal leaflet forces increased relative to the CON by 42.2% (P = 0.01). In disease valves, average leaflet forces increased by 54.8% in the anterior leaflet (P < 0.001), 37.6% in the posterior leaflet (P = 0.03), and 79.9% in the septal leaflet (P < 0.001). The anterior leaflet experiences the highest forces in the normal tricuspid annulus under single ventricle physiology conditions. Annular dilation resulted in an increase in forces on the septal leaflet and LT resulted in an increase in forces across all 3 leaflets. Annular dilation and LT combined resulted in the largest increase in leaflet forces across all 3 leaflets.

Three-dimensional analysis of the human pharyngoesophageal sphincter.

OBJECTIVES: Dysfunction of the pharyngoesophageal segment (PES) is a common cause of oropharyngeal dysphagia. Surgical dilation of the PES uses cylindrical dilators that expand radially in a circular shape. Animal studies, however, suggest that the PES is kidney-shaped. The purpose of this investigation was to evaluate the 3D shape of the human PES with a novel casting method. METHODS: A platinum-cured liquid silicone polymer was infused under pressure into the upper aerodigestive tract of nine fresh human cadavers to construct 3D casts of the maximally distended PES. Cross-sectional and volumetric analysis were performed using computed tomography and serial sectioning of the models. Canonical variate analysis was used to identify the shape features that best distinguishes the PES from the cervical esophagus. RESULTS: The mean age of the cadavers was 77.9 (SD ± 10.6) years, with 67% women. Analysis of the casts confirms that the human PES possesses a kidney-shaped structure at maximal distention, which is discretely different from the adjacent esophagus (P < 0.001). The posterior body of the cricoid cartilage formed the anterior wall of the PES, which provided a rigid structure responsible for preservation of the kidney shape during distention. The diameter of the maximally distended PES at the cricopharyngeus was highly variable (range = 0.86-4.68 cm2 ; SD = 1.33 cm2 ). CONCLUSION: The data suggest that the human PES is not round and that targeted expansion at the level of the cricopharyngeus with an eccentrically shaped dilator may provide improved distention. LEVEL OF EVIDENCE: 4 Laryngoscope, 2019.

Micro-staining microbes: An alternative to traditional staining of microbiological specimens using microliter volumes of reagents.

Microbial staining techniques are widely employed in clinical and academic laboratories for classifying and identifying microorganisms derived from clinical, food and environmental samples. Staining allows for the rapid visualization and determination of many morphological characteristics of microorganisms, used for their identification and classification. Over the past century, staining techniques such as the Gram stain, the Capsule stain, the Acid-fast stain and the Endospore stain, have seen few advances, and manual staining remains the gold standard. Typical instructions for these staining procedures recommend 'flooding' glass slides with milliliter volumes of dye, resulting in large volumes of hazardous waste. Here we present micro-staining, a simple alternative to flooding that utilizes microliter volumes of dye. Micro-staining minimizes the volume of waste generated, leads to significant cost savings for the laboratory, requires limited training, and produces results with equivalent quality to traditional stains.

Fabrication of Miniaturized Paper-Based Microfluidic Devices (MicroPADs).

Microfluidic paper-based analytical devices (microPADs) are emerging as cost-effective and portable platforms for point-of-care assays. A fundamental limitation of microPAD fabrication is the imprecise nature of most methods for patterning paper. The present work demonstrates that paper patterned via wax printing can be miniaturized by treating it with periodate to produce higher-resolution, high-fidelity microPADs. The optimal miniaturization parameters were determined by immersing microPADs in various concentrations of aqueous sodium periodate (NaIO4) for varying lengths of time. This treatment miniaturized microPADs by up to 80% in surface area, depending on the concentration of periodate and length of the reaction time. By immersing microPADs in 0.5-M NaIO4 for 48 hours, devices were miniaturized by 78% in surface area, and this treatment allowed for the fabrication of functional channels with widths as small as 301 µm and hydrophobic barriers with widths as small as 387 µm. The miniaturized devices were shown to be compatible with redox-based colorimetric assays and enzymatic reactions. This miniaturization technique provides a new option for fabricating sub-millimeter-sized features in paper-based fluidic devices without requiring specialized equipment and could enable new capabilities and applications for microPADs.

Analysis of Reported Balloon Malfunctions and Proposed Rescue Strategy for Malfunction during Airway Dilation.

Objective The rate of balloon dilator failure is unknown, and a rescue strategy for device malfunction has not been established. The purposes of this investigation were to determine the approximate number of balloon failures in the gastrointestinal tract and airway, evaluate the parameters required to rupture balloon dilators, and develop a rescue strategy to efficiently reestablish airway patency. Study Design Retrospective cohort and basic medical research. Setting Academic tertiary care medical center. Subjects and Methods The Manufacturer and User Facility Device Experience database was queried for adverse events associated with tracheal and esophageal dilators between January 1, 2014, and January 1, 2017. A bench-top model of airway stenosis was developed, and optimal conditions for the safe removal of a malfunctioning dilator were assessed (2, 4, 6 atm). Results There were 420 reported balloon malfunctions, including 104 cases with deflation/removal issues. The bench-top model determined that device rupture allowing for immediate removal occurs with needle puncture at balloon pressures ≥8 atm. Balloons inflated to 6 atm required a median of 17.5 seconds (range, 0-55.3) for removal, in comparison with 30.2 seconds (range, 7.1-87.5) at 2 atm ( P > .05). Conclusion Balloon dilator malfunction is a significant problem that practitioners must be prepared for. Pressure ≥8 atm (~33% overinflation) is required to consistently cause complete balloon dilator rupture via needle puncture. While counterintuitive, increasing the inflation pressure of a malfunctioning balloon (8-10 atm) may expedite rupture and safe removal. A rescue strategy for balloon malfunction is proposed.

Altered pharyngeal structure and dynamics among patients with cervical kyphosis.

OBJECTIVES/HYPOTHESIS: Deformities of the anterior cervical spine are an established cause of dysphagia. Whereas osteophytes and spinal fusion hardware have been reported to alter bolus flow and contribute to swallowing dysfunction, the relationship between abnormal spine curvature and swallowing dysfunction is not established. The purpose of this investigation was to evaluate the association between cervical kyphosis and objective measures of swallowing dysfunction on videofluoroscopy. STUDY DESIGN: Case-control study of patients presenting to tertiary dysphagia center. METHODS: All videofluoroscopic swallow studies (VFSS) performed at our institution, between August 1, 2014, and August 1, 2015, were retrospectively reviewed to identify patients with abnormal cervical kyphosis, according to Cobb and Jackson angle measurements. Patients with kyphosis were age- and gender-matched to persons without kyphosis. VFSS and demographic parameters were collected and compared between groups. RESULTS: Thirty-six patients with cervical kyphosis exceeding two standard deviations (SD) beyond established age-specific normal ranges were identified. The mean age of the entire cohort was 61.6 (SD ±19.1) years. Mean pharyngeal area was 3.34 cm2 greater in kyphosis patients compared to controls (95% confidence interval [CI]: 0.47-5.21 cm2 ; P = .0007). This was associated with increased hypopharyngeal transit time (0.57 seconds, 95% CI: 0.045-1.09 seconds, P = .034), and higher prevalence of penetration (P = .014). There was no significant difference in the pharyngeal constriction ratio (PCR), a surrogate measure of pharyngeal strength (P = .83). CONCLUSIONS: Patients with cervical spine kyphosis have a significantly dilated pharynx (P = .0007), elongated hypopharyngeal transit time (P = .034), and worsened penetration aspiration scores (P = .021). Absence of a difference in PCR suggests adequate compensation as a group. LEVEL OF EVIDENCE: 3b. Laryngoscope, 127:1832-1837, 2017.