Three-dimensional analysis of the human pharyngoesophageal sphincter.
Fabrication of Miniaturized Paper-Based Microfluidic Devices (MicroPADs)
2019; 9: 7
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.
View details for DOI 10.1002/lary.28450
View details for PubMedID 31837160
Wax-Printed Fluidic Time Delays for Automating Multi-Step Assays in Paper-Based Microfluidic Devices (MicroPADs)
2019; 4 (1)
How to Shrink Paper Money: A Macroscopic Demonstration of the Malaprade Reaction
Journal of Chemical Education
2019; 96 (6): 1199-1204
Micro-Staining Microbes: An Alternative to Traditional Staining of Microbiological Specimens Using Microliter Volumes of Reagents
Journal of Microbiological Methods
2019; 164: 105654
Chronometric Quantitation of Analytes in Paper-Based Microfluidic Devices (MicroPADs) via Enzymatic Degradation of a Metastable Biomatrix
2019; 4 (3)
Paper miniaturization via periodate oxidation of cellulose
2018; 25 (6): 3211–17
Altered Pharyngeal Structure and Dynamics Among Patients With Cervical Kyphosis
WILEY. 2017: 1832–37
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.
View details for DOI 10.1038/s41598-018-37029-0
View details for Web of Science ID 000455346100007
View details for PubMedID 30626903
View details for PubMedCentralID PMC6327054
Frontal Sinus Fractures: A Surgical Management Paradigm
2017; 67 (1): 10-25
Effect of Vocal Fold Medialization on Dysphagia in Patients with Unilateral Vocal Fold Immobility
OTOLARYNGOLOGY-HEAD AND NECK SURGERY
2016; 155 (3): 454–57
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.Case-control study of patients presenting to tertiary dysphagia center.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.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).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.3b. Laryngoscope, 127:1832-1837, 2017.
View details for DOI 10.1002/lary.26417
View details for Web of Science ID 000406867800028
View details for PubMedID 27896816
The effect of vocal fold medialization (VFM) on vocal improvement in persons with unilateral vocal fold immobility (UVFI) is well established. The effect of VFM on the symptom of dysphagia is uncertain. The purpose of this study is to evaluate dysphagia symptoms in patients with UVFI pre- and post-VFM.Case series with chart review.Academic tertiary care medical center.The charts of 44 persons with UVFI who underwent VFM between June 1, 2013, and December 31, 2014, were abstracted from a prospectively maintained database at the University of California, Davis, Voice and Swallowing Center. Patient demographics, indications, and type of surgical procedure were recorded. Self-reported swallowing impairment was assessed with the validated 10-item Eating Assessment Tool (EAT-10) before and after surgery. A paired samples t test was used to compare pre- and postmedialization EAT-10 scores.Forty-four patients met criteria and underwent either vocal fold injection (73%) or thyroplasty (27%). Etiologies of vocal fold paralysis were iatrogenic (55%), idiopathic (29%), benign or malignant neoplastic (9%), traumatic (5%), or related to the late effects of radiation (2%). EAT-10 (mean ± SD) scores improved from 12.2 ± 11.1 to 7.7 ± 7.2 after medialization (P < .01) with a follow-up of 119 ± 65 days.Patients with UVFI suffer from dysphagia and report significant improvement in swallowing symptoms following VFM. The symptomatic improvement appears to be durable over time.
View details for DOI 10.1177/0194599816645765
View details for Web of Science ID 000383032800012
View details for PubMedID 27165683