Changes in the esophagogastric junction outflow obstruction manometric feature based on the Chicago Classification updates

BACKGROUND The critical diagnostic criteria for esophagogastric junction outflow obstruction(EGJOO)were published in the latest Chicago Classification version 4.0(CCv4.0).In addition to the previous criterion[elevated integrated relaxation pressure(IRP)in supine position],manometric diagnosis of EGJOO requires meeting the criteria of elevated median-IRP during upright wet swallows and elevated intrabolus pressure.However,with the diagnostic criteria modification,the change in manometric features of EGJOO remained unclear.AIM To evaluate the esophageal motility characteristics of patients with EGJOO and select valuable parameters for confirming the diagnosis of EGJOO.METHODS We performed a retrospective analysis of 370 patients who underwent highresolution manometry with 5 mL water swallows×10 in supine,×5 in upright position and the rapid drink challenge(RDC)with 200 mL water from November 2016 to November 2021 at Peking University First Hospital.Fifty-one patients with elevated integrated supine IRP and evidence of peristalsis were enrolled,with 24 patients meeting the updated manometric EGJOO diagnosis(CCv4.0)as the EGJOO group and 27 patients not meeting the updated EGJOO criteria as the isolated supine IRP elevated group(either normal median IRP in upright position or less than 20%of supine swallows with elevated IBP).Forty-six patients with normal manometric features were collected as the normal high-resolution manometry(HRM)group.Upper esophageal sphincter(UES),esophageal body,and lower esophageal sphincter(LES)parameters were compared between groups.RESULTS Compared with the normal HRM group,patients with EGJOO(CCv4.0)had significantly lower proximal esophageal contractile integral(PECI)and proximal esophageal length(PEL),with elevated IRP on RDC(P<0.05 for each comparison),while isolated supine IRP elevated patients had no such feature.Patients with EGJOO also had more significant abnormalities in the esophagogastric junction than isolated supine IRP elevated patients,including higher LES resting pressure(LESP),intrabolus pressure,median supine IRP,median upright IRP,and IRP on RDC(P<0.05 for each comparison).Patients with dysphagia had significantly lower PECI and PEL than patients without dysphagia among the fifty-one with elevated supine IRP.Further multivariate analysis revealed that PEL,LESP,and IRP on RDC are factors associated with EGJOO.The receiver-operating characteristic analysis showed UES nadir pressure,PEL,PECI,LESP,and IRP on RDC are parameters supportive for confirming the diagnosis of EGJOO.CONCLUSION Based on CCv4.0,patients with EGJOO have more severe esophagogastric junction dysfunction and are implicated in the proximal esophagus.Additionally,several parameters are supportive for confirming the diagnosis of EGJOO.