Videofluoroscopic and manometric evaluation of pharyngeal and upper esophageal sphincter function during swallowing

Abstract

Background/aims: The purpose of this study was to determine important manometric metrics for the analysis of pharyngeal and upper esophageal sphincter (UES) function and to investigate the effect of viscosity and other confounding factors on manometric results.

Methods: Manometric studies were performed on 26 asymptomatic volunteers (12 men and 14 women; age, 19-81 years). The manometric protocol included 5 water swallows (5 mL), 5 barium swallows (5 mL) and 5 yogurt swallows (5 mL). Evaluation of high-resolution manometry parameters including basal pressure of the UES, mesopharyngeal contractile integral (mesopharyngeal CI, mmHg · cm · sec), CI of the hypopharynx and UES (hypopharyngeal CI), relaxation interval of UES, median intrabolus pressure and nadir pressure at UES was performed using MATLAB.

Results: Mesopharyngeal CIs for barium and yogurt swallows were significantly lower than those for water swallows (both P < 0.05). Hypopharyngeal CIs for water swallows were significantly lower than those for barium swallows (P = 0.004), and median bolus pressure at UES for barium swallows was significantly higher than that for water and yogurt swallows (both P < 0.05). Furthermore, hypopharyngeal CI and median intrabolus pressure at UES were significantly related to age for 3 swallows (all P < 0.01 and P < 0.05, respectively). A significant negative correlation was also noted between nadir pressure at UES and age for water and yogurt swallows (all P < 0.05).

Conclusions: Manometric measurement of the pharynx and UES varies with respect to viscosity. Moreover, age could be a confounding variable in the interpretation of pharyngeal manometry.

Keywords: Manometry, Deglutition, Esophageal sphincter, upper, Fluoroscopy, Pharynx.

Figure 1.

Isobaric contour image generated from binary manometric data. (A) Manoview image of water 5 mL swallow (B) Isobaric contour generated from MATLAB program. Mesopharyngeal contractile integral (CI) was calculated by amplitude X duration X length (mmHg · cm · sec) of muscular contraction ≥ 70 mmHg. CI of hypopharynx and upper esophageal sphincter (hypopharyngeal CI) was calculated in the same manner by amplitude X duration X length (mmHg · cm · sec) of muscular contraction ≥ 70 mmHg for 2 seconds after onset of deglutition.

Figure 2.

Isobaric and isoimpedance contour image within the upper esophageal sphincter (UES) during deglutitive relaxation. (A) Isobaric contour of the UES during deglutitive relaxation generated from MATLAB. Relaxation interval was defined as the duration of time from the onset at the point of departure from half the baseline to the offset at the return to half baseline pressure (indicated by dotted line) (B) Isobaric and isoimpedance contour during the UES relaxation interval. As the isoimpedance line gets closer to the starting point of UES contraction, the intervals between the lines become narrower and impedance increased. When relaxation comes to an end, low impedance lines change into lines with higher impedance, and the isoimpedance line changes its direction toward the right side of the image, not downward (orange arrow).

Figure 3.

Simultaneous evaluation of videofluoroscopic swallow evaluation (VFSE) and high-resolution manometry (HRM). (A) Seventh, 12th and 13–17th sensors were located on the same line of the soft palate, epiglottis and hypopharynx, respectively (B) About 1 second after swallowing, the food bolus began to be pushed to the back of the mouth by the tongue, and the HRM catheter was displaced upward and backward (C) About 1.7 seconds after swallowing, a large amount of food remnants was noticed under the epiglottis on VFSE, and increased pressure was detected by the sensor located on the mesopharynx. Next, increased pressure was detected by the 15th sensor located in the hypopharynx (D) Two seconds after swallowing, food remnants began to go through the hypopharynx and UES on VFSE and hypopharyngeal muscular contraction started on HRM (E) At 2.2 seconds after swallowing, a small amount of barium staining was noticed on the hypopharynx and UES contraction was found on HRM (F) 3 seconds after swallowing, barium staining on the hypopharynx was nearly gone on VFSE, and UES contraction almost stopped on HRM.

Figure 4.

Comparison of mesopharyngeal contractile integral (CI) for 3 swallows. Mesopharyngeal CIs for barium and yogurt swallows were significantly lower than those for water swallows.

Figure 5.

Comparison of hypopharyngeal contractile integral (CI) for 3 swallows. Hypopharyngeal CIs for water swallows were significantly lower than those for barium swallows.

Figure 6.

Comparison of median intrabolus pressure at upper esophageal sphincter (UES) for 3 swallows. Median intrabolus pressure at UES for barium swallows was significantly higher than that for water and yogurt swallows.

Figure 7.

Correlation between metrics for 3 swallows and age. (A) Correlation was significant between hypopharyngeal contractile integral (CI) and age for 3 swallows, (all P < 0.01, respectively) and (B) between median intrabolus pressure at UES and age for 3 swallows, (P = 0.010, P = 0.003 and P = 0.001, respectively) (C) Nadir pressure at upper esophageal sphincter was significantly related to age for water and yogurt swallows (all P < 0.05, respectively).