Fig 1.
(a) On endoscopy, the esophagus looks normal without dilation. However, increased resistance was observed through the esophago-gastric junction in a patient with achalasia. (b) Esophagography showing a bird-beak appearance with remnant barium in a non-dilated esophagus. (c) High-resolution manometry showing pan-esophageal pressurization (type-II achalasia) with elevated integrated relaxation pressure (IRP) (43.3 mmHg; the IRP measurement was taken after deglutitive upper sphincter relaxation, based on the 4-s window in which the e-sleeve value is lowest, noting that the 4 s did not have to be continuous, but could be distributed within a 10 s time window (white closing box).
Fig 2.
(a) Endoscopy showing a mucosal pinstripe pattern with increased resistance through the esophago-gastric junction.[11] (b) On esophagography, bird-beak appearance and remnant barium in a non-dilated esophagus were observed. (c) High-resolution manometry showing 100% failed peristalsis (type-I achalasia) with normal integrated relaxation pressure (22.9 mmHg).
Fig 3.
(a) Endoscopy showing a totally dilated esophagus. (b) Esophagography showing sigmoid-like appearance with retention of contrast medium. (c) High-resolution manometry showing 100% failed peristalsis (type-I achalasia) with normal integrated relaxation pressure (18.5 mmHg).
Fig 4.
Flowchart of patient enrollment.
From 61 cases of peroral endoscopic myotomy, 20 cases were excluded and 41 patients with achalasia were finally enrolled. Thereafter, twenty-seven achalasia patients were categorized into a subgroup with integrated relaxation pressure (IRP) > 26 mmHg (impaired lower esophageal sphincter [LES] relaxation on high-resolution manometry [HRM]), whereas 14 were placed into the IRP ≤ 26 mmHg group (normal LES relaxation on HRM).
Table 1.
Patient characteristics.
Fig 5.
Spearman's correlation coefficient to determine the correlation between integrated relaxation pressure (IRP) and age (Fig 5a) or IRP and symptom duration (Fig 5b), calculated as -0.308 (P = 0.05) and -0.371 (P = 0.02), respectively. The dotted horizontal line means IRP = 26 mmHg, whereas the red solid line shows the linear regression of all measurements of patients in the IRP > 26 mmHg and IRP ≤ 26 mmHg groups. (c) IRP was higher in patients with non-dilated esophagus than in those with dilated esophagus (P < 0.01). Bars indicate median values.
Fig 6.
(a) Changes in the Eckardt score before and after peroral endoscopic myotomy (POEM) in the integrated relaxation pressure (IRP) > 26 mmHg group (pre-op Eckardt score 7 ± 2.1 vs. post-op 1 ± 0.9, P < 0.01) and IRP ≤ 26 mmHg group (pre-op 7 ± 2.6 to 1 ± 0.6, P < 0.01). (b) Changes in IRP (mmHg) before and after POEM in the IRP >26 mmHg subgroup (pre-operative 38.6 ± 13.3 vs. post-operative 8.9 ± 5.3 mmHg, P < 0.01) and IRP ≤ 26 mmHg subgroup (pre-operative 21.5 ± 5.0 vs. post-operative 9.9 ± 4.0 mmHg, P < 0.01).
Fig 7.
(a) Grading of lower esophageal sphincter (LES) fibrosis in the integrated relaxation pressure (IRP) > 26 mmHg subgroup (n = 21) and IRP ≤ 26 mmHg subgroups (n = 11). (b) Cases of severe fibrosis (grade 3) in the LES were only observed in the IRP ≤ 26 mmHg subgroup. Azan-Mallory staining (200×magnification) revealing severe atrophic changes with replacement by fibrosis in the smooth muscle bundles (yellow triangle). Fibrotic tissue extension in the inter-smooth muscle bundles is also seen (red triangle).