Volume 131, Issue 6, Pages 1725-1733 (December 2006) Transient Lower Esophageal Sphincter Relaxations and Reflux: Mechanistic Analysis Using Concurrent Fluoroscopy and High-Resolution Manometry  John E. Pandolfino, Qing G. Zhang, Sudip K. Ghosh, Alexander Han, Christopher Boniquit, Peter J. Kahrilas  Gastroenterology  Volume 131, Issue 6, Pages 1725-1733 (December 2006) DOI: 10.1053/j.gastro.2006.09.009 Copyright © 2006 AGA Institute Terms and Conditions

Figure 1 (A) Isocontour manometric plots of the EGJ during a tLESR. The pressure scale is color-coded with the high-pressure magnitudes represented by the red regions and the low-pressure magnitudes represented by blue. The exact pressure at any point on this spatial-temporal grid can be ascertained using either the isobaric contour tool or the point-and-click smart mouse tool of the ManoView software. The positions of the SCJ and proximal esophageal endoclip are superimposed on the isocontour plots as magenta lines illustrating the temporal relationship between esophageal shortening, EGJ relaxation, and common cavity formation. (B) Spatial pressure variation plots of the same pressure data illustrated in panel A. Each vertical line depicts the axial pressure profile spanning from the pharynx to the stomach with successive lines showing 0.2-s time increments. Note that a common cavity is generated during the relaxation period, indicated by an abrupt intraesophageal pressure increase. Again, the magenta lines indicate endoclip positions. Gastroenterology 2006 131, 1725-1733DOI: (10.1053/j.gastro.2006.09.009) Copyright © 2006 AGA Institute Terms and Conditions

Figure 2 Example of manometric evidence of flow confirmed with simultaneous high-resolution impedance during a tLESR. Manometric data are converted into spatial pressure variation plots (bottom) and are plotted along the same time-line with simultaneous isocontour impedance data (top). The impedance color scale is on the right. During the prolonged tLESR there is intermittent transit of liquid through the EGJ highlighted by a sudden decrease in impedance along each 1-cm segment of the EGJ into the esophagus (blue color). During this 7-second time frame there is manometric evidence of flow (pressure equalization gradient from high [gastric] to low [esophagus]) at the exact instance that liquid is moving through the EGJ into the proximal esophagus (orange shading on the spatial pressure variation plot). Note the sequential increase in pressure in the distal esophagus from -2 mm Hg to 1 mm Hg, corresponding to liquid reflux. Gastroenterology 2006 131, 1725-1733DOI: (10.1053/j.gastro.2006.09.009) Copyright © 2006 AGA Institute Terms and Conditions

Figure 3 Fluoroscopic visualization of endoclip movement (one at the SCJ and one 10 cm proximal to the SCJ) during a tLESR. When the clip data are imported into the isocontour plots (right panel) it is evident that the SCJ clip excursion mirrors movement of the EGJ high-pressure band. Esophageal shortening is most prominent in the distal portion of the 10-cm segment isolated by the endoscopic clips, as seen from the approximately 7-cm movement of the distal SCJ clip concurrent with only minimal movement of the proximal clip. Gastroenterology 2006 131, 1725-1733DOI: (10.1053/j.gastro.2006.09.009) Copyright © 2006 AGA Institute Terms and Conditions

Figure 4 Example of GECC secondary to a strain event shown on an (A) isocontour plot with detailed pressure characterization during the time interval that the common cavity is generated. Relaxation of the EGJ and the onset of tLESR with concurrent movement of the SCJ and esophageal clips (magenta lines). (B) Spatial variation of pressure through the esophagus during a 3-second interval spanning the period of GECC formation. The instant of manometric evidence of EGJ opening (i) and the formation of the GECC (ii) are highlighted in orange. Note that the EGJ opening is evidenced by an increase in distal esophageal pressure from 2 to 3 mm Hg, whereas the first instant of common cavity occurs when the esophageal pressure increases to 7 mm Hg. Note that in both instances, a flow-permissive pressure gradient exists from the stomach into the esophagus. Gastroenterology 2006 131, 1725-1733DOI: (10.1053/j.gastro.2006.09.009) Copyright © 2006 AGA Institute Terms and Conditions

Figure 5 GECC during inspiration with detailed pressure characterization during the time interval that the common cavity is generated. Figure layout is as in Figure 4. Note that the distal esophageal segment shortens from a baseline length of 11.5 to 9.5 cm at the instant of manometric evidence of flow and 9.0 cm at the instant of maximal shortening. The instant of manometric evidence of flow (EGJ opening) and the formation of the GECC are highlighted by the first orange shaded line evidenced by an increase in distal esophageal pressure from -4 to 3 mm Hg. Propagation of the GECC into the proximal esophagus occurs in the second orange shaded line as the pressure in the proximal esophagus increases from -7 to 2 mm Hg. Note that after the EGJ opening, a flow-permissive pressure gradient exists from the stomach into the esophagus. Gastroenterology 2006 131, 1725-1733DOI: (10.1053/j.gastro.2006.09.009) Copyright © 2006 AGA Institute Terms and Conditions

Figure 6 Example of ECC shown on an isocontour plot with detailed pressure characterization during the time interval when the ECC is generated, again using the same layout as Figure 4. Note that the formation of the ECC is shown by an increase in esophageal pressure from subatmospheric to 14 mm Hg and that this is compartmentalized within the esophagus as evident by greater pressures at the UES and EGJ. Gastroenterology 2006 131, 1725-1733DOI: (10.1053/j.gastro.2006.09.009) Copyright © 2006 AGA Institute Terms and Conditions

Figure 7 Pressure gradients across the EGJ during a tLESR associated with (A) manometric evidence of trans-EGJ flow and another (B) without manometric evidence of trans-EGJ flow. The dynamic relationship between intragastric pressure and the residual EGJ pressure band (from 2 cm proximal to the SCJ to 1 cm distal to the SCJ) tracked and measured along the SCJ excursion path is illustrated for each in the lower panels. (A) Note that the GECC on the isocontour plot correlates with the positive gradient shaded in gray in the lower panel. In contrast, there is no GECC in B and the gradient between the intragastric pressure and the residual LES pressure never becomes positive in the lower panel. Black line, maximum EGJ resistance pressure; gray line, gastric pressure. Gastroenterology 2006 131, 1725-1733DOI: (10.1053/j.gastro.2006.09.009) Copyright © 2006 AGA Institute Terms and Conditions

Figure 8 Termination of a tLESR with secondary peristalsis. The peristaltic wavefront traverses the entire esophagus and is associated with esophageal shortening comparable with that occurring during primary peristalsis. Gastroenterology 2006 131, 1725-1733DOI: (10.1053/j.gastro.2006.09.009) Copyright © 2006 AGA Institute Terms and Conditions

Figure 9 Termination of a tLESR with an isolated contractile event limited to the distal esophagus. This focal contraction in the distal esophagus is associated with a greater degree of distal esophageal shortening compared with either primary or secondary peristalsis (Table 2). Gastroenterology 2006 131, 1725-1733DOI: (10.1053/j.gastro.2006.09.009) Copyright © 2006 AGA Institute Terms and Conditions

Figure 10 Termination of a tLESR with primary peristalsis. In this example, the observed magnitude of esophageal shortening is similar to that observed in a normal swallow. Gastroenterology 2006 131, 1725-1733DOI: (10.1053/j.gastro.2006.09.009) Copyright © 2006 AGA Institute Terms and Conditions