Factors Affecting the Swallowing Dysfunction Following Oral Cancer Surgery.

OBJECTIVE: To investigate the factors affecting the postoperative swallowing dysfunction in patients who underwent oral cancer surgery. METHODS: Retrospective review of clinical records of 70 patients (50 males and 20 females) who underwent oral cancer surgeries from July 2007 to April 2015 were enrolled. Multiple regression analysis was performed using the Food Intake LEVEL Scale (FILS) at discharge as the objective variable and age, tumor size, resection of the tongue base, suprahyoid muscle resection, segmental mandibulectomy, neck dissection and radiation therapy as the explanatory variables in 70 patients. In addition, multiple regression analysis was performed between objective variables, which include maximum hyoid bone movement, laryngeal elevation delay time, pharyngeal constriction ratio (PCR), residue in the vallecular and pear-shaped depression (pyriform sinuses), and Penetration-Aspiration Scale score and one of the main factors representing the characteristics of each case as the explanatory variables, and age was treated as an adjustment factor in 23 patients. RESULTS: The FILS shows significant negative correlation by age and resection of the tongue base. In videofluoroscopic swallowing study, the maximum movement, PCR and residue in the vallecular are significantly correlated with factors demonstrating the characteristic for each case. CONCLUSION: It was suggested that in elderly patients, the presence of more than half of the tongue base resection, suprahyoid muscle resection and neck dissection cause severe dysphagia after surgery.

Swallowing dysfunction in myasthenia gravis patients examined with high-resolution manometry.

OBJECTIVE: To prospectively compare oropharyngeal swallowing dysfunction in myasthenia gravis (MG) patients presenting with difficulty in swallowing between the neutral and chin-down positions, based on the results of high-resolution manometry (HRM) examination. METHODS: We prospectively compared the HRM results of swallowing studies of seven MG patients showing difficulty in swallowing (neutral and chin-down positions) at the Department of Neurology of our institution during the period February-December 2018. The HRM assessment parameters were as follows: maximum swallowing pressure (SP) at the soft palate, meso­hypopharynx, and upper esophageal sphincter (UES), and the duration of relaxation pressure at the UES. These parameters were compared between the two positions and their correlations with the results of neurological evaluations, such as the Quantitative Myasthenia Gravis (QMG) score (total and neck muscles alone), and grip strength, were also analyzed. RESULTS: In comparison with the neutral position, in the chin-down position the maximum SP at the meso­hypopharynx was significantly increased (p < 0.05), the maximum SP at the UES was significantly decreased (p < 0.05), and the duration of relaxing SP at the UES was significantly increased (p < 0.05). Interestingly, there were no correlations between the SP at any location and the results of the neurological evaluations. CONCLUSIONS: The chin-down position appears useful for improving pharyngeal clearance in MG patients, by promoting increased SP at the meso­hypopharynx, relaxing SP at the UES, and increasing the duration of relaxation pressure at the UES.

Different types of dysphagia alleviated by the chin-down position.

OBJECTIVE: Retrospective videofluoroscopic swallowing study (VFSS) evaluations of pharyngeal swallowing were used to evaluate the types of dysphagia alleviated by the chin-down maneuver. MATERIALS AND METHODS: The study population consisted of 64 patients who underwent VFSS evaluations during neutral and chin-down maneuvers presenting specifically penetration or aspiration. The assessment of the VFSS movie clips of each maneuver was performed using parameters of the Modified Barium Swallow Impairment Profile (MBSImP) and the presence and degree of airway invasion(PDAI) by three blinded raters in the following five subcategorized groups, 1. patietns presenting penetration or aspiration during swallow 2. after swallow, patients of 3. head and neck, 4. digestive and 5. neuromuscular disorders, respectively. The scores registered for the two maneuvers were statistically compared. Additionally, we examined statistically which factors had the impact on the improvement of the PDAI using fisher's exact test. RESULTS: Compared with the neutral position, PDAI, pharyngeal constriction, anterior hyoid movement, pharyngeal constriction, laryngeal elevation, laryngeal closure, upper esophageal sphincter opening, initiation of the pharyngeal swallow, and pharyngeal clearance in pyriform sinus were significantly (p < 0.01-0.05) improved with the chin-down maneuver. In a subcategory comparison with group 1, 3 and 4, the PDAI improved significantly (p < 0.01) with the chin-down maneuver, in which laryngeal elevation and laryngeal closure had statistically the impact (p < 0.01-0.05) on improvement of PDAI. CONCLUSION: The chin-down maneuver was most effective in improving swallow function when the impairment included penetration and aspiration during swallow caused by inadequate laryngeal elevation and laryngeal closure.

The effect of a chin-down maneuver after esophagectomy on oropharyngeal swallowing pressure measured using high-resolution manometry.

OBJECTIVE: To elucidate the effects of a chin-down maneuver using high-resolution manometry (HRM) to measure pharyngeal swallowing pressure (SP) after esophagectomy. METHODS: We evaluated 9 of 16 patients who underwent esophagectomy featuring gastric tube reconstruction and three-field lymph node dissection (3FL) in our Department of Gastroenterological Surgery from September 2015 to June 2016. We compared all parameters of the neutral and chin-down positions using HRM to measure the maximum SP at the velopharynx, meso-hypopharynx, and upper esophageal sphincter (UES) and the duration of lowered SP at the UES, the distance from nostrils to the boundary between hypopharynx and UES and to derive SP and SP propagation curves at various distances from the nostrils. RESULTS: Compared to that at the neutral position, the maximum SP at the velopharynx was significantly lower in the chin-down position (p<0.05); however, SP at the meso-hypopharynx and UES did not differ significantly. The duration of lowered SP at the UES was significantly prolonged in the chin-down position and the distance from nostrils to the boundary between hypopharynx and UES was significantly shortened representing the elevation of the larynx, respectively (p<0.05, p<0.01). On the SP propagation curve for males, the times to SP peaks at 13, 16, 17, and 18cm from the nostrils were significantly prolonged (all p<0.05) in the chin-down position. CONCLUSION: Chin-down positioning after esophagectomy/3FL may improve bolus passage by prolonging the duration of lowered SP at the UES, possibly by enhancing laryngeal elevation.

Assessment of oropharyngeal swallowing dysfunction in myasthenia gravis patients presenting with difficulty in swallowing.

OBJECTIVE: To examine the correlation between the results of a clinical neurological evaluation and swallowing dysfunction in myasthenia gravis (MG) patients who presented with difficulty in swallowing and underwent videofluorographic (VF) and fiber-optic endoscopic (FE) evaluation. METHODS: The swallowing studies of 13MG patients with difficulty in swallowing seen at the Department of Neurology from June 2016 to April 2018 were reviewed. The assessment parameters on VF and FE examination were as follows: swallowing initiation, bolus stasis at the pyriform sinus (PS) and vallecula (VC), and the degree of aspiration. They were assessed using a 4 or 5-point scale. Associations between these parameters and the clinical neurological evaluation, which included the Myasthenia Gravis Foundation of America (MGFA) clinical classification, the MG Activities of Daily Living score, and a quantitative MG score, were statistically determined. RESULTS: No patients demonstrated aspiration. However, in patients MGFA IIb/IIIb disease, the Hydo's FEES scale and pharyngeal residue examined using VF were significantly (p<0.05) more severe than in patients classified with MGFA IIa/IIIa disease. None of the parameters evaluated with VF and FE correlated significantly with the clinical neurological evaluation except for the grip assessment. CONCLUSION: While not presenting with aspiration but with swallowing difficulty alone, patients classified with MGFA IIb/IIIb disease, regardless of clinical neurological evaluation, require care addressing the reduced pharyngeal clearance. Controlling the severity of the pharyngeal residue may be the key to preventing silent aspiration, especially in patients with MGFA IIb/IIIb disease.

Determining the Efficacy of the Chin-Down Maneuver Following Esophagectomy With Fiberoptic Endoscopic Evaluation of Swallowing.

OBJECTIVES: To clarify the reliability of fiberoptic endoscopic evaluation of swallowing (FEES) compared to videofluoroscopic swallowing studies (VFSSs). Second, we explored the effect of the chin-down maneuver in the presence or absence of vocal fold paralysis (VFP) using FEES in patients with 3-field lymphadenectomy (3FL) postesophagectomy. DESIGN: Retrospective data collection from FEES and VFSS. SETTING: Dysphagic clinics in the ear, nose, and throat department. PARTICIPANTS: Patients (N=15) underwent esophagectomy with 3FL at the Department of Gastroenterologic Surgery, during a period of 12 months. INTERVENTIONS: The patients underwent FEES and VFSS with neutral and chin-down maneuvers 2 weeks postoperatively. Two raters of speech pathology blindly scored aspiration, penetration, delayed initiation, and pharyngeal clearance in the pyriform sinus and vallecula, respectively, from recorded movie clips of both examinations, using the penetration aspiration scale (PAS) and modified Hyodo FEES rating scale. MAIN OUTCOME MEASURES: The intrarater and interrater correlation coefficients of each parameter examined with FEES. Statistical comparison of each parameter between FEES and VFSS and of each parameter evaluated using FEES between 2 maneuvers with or without VFP. RESULTS: The intrarater and interrater correlation coefficients of the PAS and pyriform sinus examined with FEES were both statistically consistent between the 2 raters. The PAS and pyriform sinus evaluated using FEES were significantly correlated with those evaluated in a VFSS (P<.05). The 2 parameters evaluated using FEES were significantly (P<.05) improved with the chin-down maneuver compared to the neutral maneuver, especially in VFP patients. CONCLUSION: FEES performed postesophagectomy with 3FL for evaluation of aspiration is as reliable statistically as VFSSs. The chin-down maneuver is especially useful for reducing the PAS score and pyriform sinus in VFP patients.

Effects of Chin-Down Maneuver on the Parameters of Swallowing Function After Esophagectomy With 3-Field Lymphadenectomy Examined by Videofluoroscopy.

OBJECTIVES: To determine the effect of the chin-down maneuver after esophagectomy with 3-field lymphadenectomy (3FL) on pharyngeal residue, upper esophageal sphincter (UES) opening, and laryngeal closure. DESIGN: Prospective data were collected from a pharyngeal videofluoroscopic swallowing study. SETTING: Dysphagia clinics. PARTICIPANTS: Patients selected according to the inclusion criteria (N=14; mean age, 65.9y) from a total of 43 patients who underwent esophagectomy with 3FL from May to December 2014 were enrolled. INTERVENTIONS: Videofluoroscopy was conducted in head-neutral and chin-down positions to measure the pharyngeal constriction ratio (PCR), amount of residue in the vallecula and pyriform sinus after the first swallow, UES opening diameter, duration of UES opening, and duration of laryngeal vestibule closure. MAIN OUTCOME MEASURES: The aforementioned parameters were compared statistically between the head-neutral and chin-down positions. RESULTS: In comparison with the neutral group, the PCR and residue in the pyriform sinus were significantly smaller in the chin-down group (P<.01). However, the residue in the vallecula did not differ significantly from that of the neutral group (P=.44). The UES opening diameter, duration of UES opening, and duration of laryngeal vestibule closure were all significantly larger in the chin-down group than in the neutral group (P<.05). CONCLUSIONS: This study demonstrates that use of the chin-down maneuver after esophagectomy with 3FL can help expedite swallowing by strengthening pharyngeal constriction, widening the UES, and enhancing laryngeal closure.

Effect of three different chin-down maneuvers on swallowing pressure in healthy young adults.

OBJECTIVES/HYPOTHESIS: To determine the effects of three different chin-down maneuvers on swallowing pressure (SP) in healthy young adults using high-resolution manometry (HRM). STUDY DESIGN: Repeated measures with subjects serving as their own controls. METHODS: Twenty-six healthy subjects (average age 26.4 [range 21-35] years) swallowed 5 mL of cold water to examine the maximum swallowing pressure (MSP) at the velopharynx, meso-hypopharynx, and upper esophageal sphincter (UES), and to determine the duration of lowered SP at the UES using HRM. The subjects swallowed in the neutral position as a control and in the following three chin-down positions: 1) head flexion (HF); 2) neck flexion (NF); and 3) combined head and neck flexion (HFNF). RESULTS: The MSP at the velopharynx and meso-hypopharynx did not significantly differ among the three chin-down positions. Upon swallowing in the NF posture, the MSP was significantly lower (P < 0.0001) at the UES, and the duration of the lowered SP at the UES was significantly prolonged (P = 0.0010) compared to the neutral position. In comparison, the duration of lowered SP at the UES was significantly (P = 0.0001) shorter in the HF position than in the neutral position. Moreover, the HFNF position significantly (P = 0.0276) lowered the MSP at the UES compared to the control position. CONCLUSION: In young healthy adults, NF maneuver resulted in significantly lower MSP and longer duration of the lowered swallowing pressure at the UES, which might assist bolus passage through the UES. LEVEL OF EVIDENCE: 3b.

Propagation Curve and Velocity of Swallowing Pressure in Healthy Young Adults.

The objective of this study is to construct a propagation curve and determine propagation velocities in young healthy adults examined using a 2.64-mm-diameter high-resolution manometry catheter with 36 circumferential sensors; to explore data reproducibility; and to determine whether the swallowing pressure (SP) propagation velocity correlated with bolus volume. Repeated measures with subjects serving as their own controls. Thirty healthy subjects (average age 25.3 years) swallowed saliva and 2, 5, and 10 mL of cold water to determine the maximum SP from the soft palate to the cervical esophagus. The SP propagation curve was obtained by plotting the duration to reach each SP peak. The SP propagation velocity was calculated for each region. These parameters were examined according to bolus size and gender. The intra-class correlation coefficient for estimating the SP propagation curves was >0.61 (i.e., highly consistent). The propagation velocity was maximal at the meso-hypopharynx and minimal at the UES and cervical esophagus. The SP propagation curve was very reproducible within any subject. Neither the water volume (with the exception of 2 and 5 mL) nor gender exerted any apparent effect on velocity in any region. However, the velocity was quite variable at the cervical esophagus.

Swallowing pressure and pressure profiles in young healthy adults.

OBJECTIVES/HYPOTHESIS: To measure the swallowing pressure (SP) of normal subjects using a 2.64-mm-diameter high-resolution manometry (HRM) catheter with 36 circumferential sensors. STUDY DESIGN: Repeated measures with subjects serving as controls. METHODS: Thirty healthy subjects swallowed water at different temperatures and volumes to examine the maximum SP at the velopharynx, meso-hypopharynx, upper esophageal sphincter (UES), and cervical esophagus, and the duration of lowered pressure at the UES. RESULTS: The maximum SP at any location was unaffected by the volume of water, whereas the maximum SP at the UES and cervical esophagus was affected by the temperature. The duration of lowered SP at the UES was significantly prolonged with 10 versus 2 mL of cold water. The pressure curve in males had two peaks (at the velopharynx and UES), whereas that of females had a single peak at the UES. CONCLUSIONS: Our data obtained with 2.64-mm HRM demonstrated that as the bolus volume is increased, the duration of lowered SP at the UES is prolonged. The higher maximum SP at the velopharynx in males versus females suggests that there may be a gender difference in pressure at the velopharynx that has not been described previously. This implies that it is necessary to take gender differences into consideration when evaluating the etiology of swallowing dysfunction by examining the SP and SP curve. Moreover, the thinner catheter is less invasive and may contribute to obtaining more physiological measurements.

Dynamics and regulation of lysine-acetylation during one-cell stage mouse embryos.

Previous studies show that treatment of zygotes with trichostatin A (TSA), a histone deacetylase inhibitor (HDACi), impacts the subsequent development to a blastocyst as well as full-term development. To reveal the dynamics of protein acetylation, with and without TSA treatment during one-cell stage, we examined oocytes and zygotes by immunofluorescence and Western Blot analyses using anti-acetylated lysine and acetylated α-tubulin antibodies. In unfertilized oocytes, lysine acetylation level was extremely low over all but faintly detected in the spindle. Once oocyte activation occurs, a dramatic increase of lysine acetylation signal was observed mostly in the pronuclei and a fiber-like structure, the so called midbody, suggesting activation coupled up-regulation of lysine acetylation presumably in histones and α-tubulin. TSA treatment resulted in significantly more hyperacetylation not only in the midbody structure and pronuclei but also in the whole cytoplasm. Consistently, Western Blot analysis revealed that acetylation of proteins about 53 kDa and 11 kDa in size, corresponding to α-tubulin and histone H4 sizes respectively, were increased mainly after oocyte activation and exclusively enhanced by TSA treatment in zygotes. To confirm this behavior of acetylated nonhistone proteins, acetylated α-tubulin was examined and found to be faintly detected in the spindle of MII oocytes but later in whole in the cell of zygotes including the midbody, which was enhanced by TSA treatment. To elucidate the mechanism underlying up-regulation of lysine acetylation following oocyte activation, we assayed the HDAC activity, and found significant reduction of HDAC activity from MII to zygotic stages. Taken together, our data indicate that HDACs play an important role in maintaining low acetylated status in a MII oocyte. However, once an oocyte has been activated, histone and nonhistone proteins including α-tubulin are hyperacetylated partly due to a reduction of HDAC activity. TSA treatment of zygotes enhances their acetylation, which could affect subsequent embryonic development.