Background/Aims: Chicago classification version 4.0 enhances the diagnosis of esophageal motility disorders using position change and provocative tests such as multiple rapid swallows and a rapid drink challenge. This study investigates the diagnostic role of the rapid drink challenge based on Chicago classification 4.0 using a functional luminal imaging probe to estimate the cutoff value. Methods: This study included 570 patients who underwent esophageal manometry with a rapid drink challenge between January 2019 and October 2022. The diagnostic flow was analyzed according to Chicago classification 4.0. Results: Ninety-nine patients (38, achalasia; 11, esophagogastric junction outflow obstruction; 7, ineffective esophageal motility; 1, hypercontractile esophagus; and 42, normal esophageal function) failed the rapid drink challenge. Among the 453 participants, 50and 86 were diagnosed with achalasia and esophagogastric junction outflow obstruction, respectively, using Chicago classification4.0. In 249/453 (55.0%) patients initially diagnosed with esophagogastric junction outflow obstruction using Chicago classification3.0, the diagnosis was changed to achalasia (n = 28), hypercontractile esophagus (n = 7), ineffective esophageal motility (n = 7), or normal esophageal function (n = 121) using Chicago classification 4.0. Rapid drink challenge-integrated relaxation pressure’s diagnostic cutoff value was 19 mmHg. Nine patients had diagnoses changed after the rapid drink challenge, including 3 with panesophageal pressurization. Conclusions Chicago classification 4.0 increased the diagnostic yield of the rapid drink challenge by 2.0% (9/453 patients). However, the rapid drink challenge had a failure rate of 17.9% (99/552 patients). Given the relatively low diagnostic yield and high failure rate of therapid drink challenge, we recommend adopting an individualized approach to manometry.

Background/Aims: Chicago classification version 4.0 enhances the diagnosis of esophageal motility disorders using position change and provocative tests such as multiple rapid swallows and a rapid drink challenge. This study investigates the diagnostic role of the rapid drink challenge based on Chicago classification 4.0 using a functional luminal imaging probe to estimate the cutoff value. Methods: This study included 570 patients who underwent esophageal manometry with a rapid drink challenge between January 2019 and October 2022. The diagnostic flow was analyzed according to Chicago classification 4.0. Results: Ninety-nine patients (38, achalasia; 11, esophagogastric junction outflow obstruction; 7, ineffective esophageal motility; 1, hypercontractile esophagus; and 42, normal esophageal function) failed the rapid drink challenge. Among the 453 participants, 50and 86 were diagnosed with achalasia and esophagogastric junction outflow obstruction, respectively, using Chicago classification4.0. In 249/453 (55.0%) patients initially diagnosed with esophagogastric junction outflow obstruction using Chicago classification3.0, the diagnosis was changed to achalasia (n = 28), hypercontractile esophagus (n = 7), ineffective esophageal motility (n = 7), or normal esophageal function (n = 121) using Chicago classification 4.0. Rapid drink challenge-integrated relaxation pressure’s diagnostic cutoff value was 19 mmHg. Nine patients had diagnoses changed after the rapid drink challenge, including 3 with panesophageal pressurization. Conclusions Chicago classification 4.0 increased the diagnostic yield of the rapid drink challenge by 2.0% (9/453 patients). However, the rapid drink challenge had a failure rate of 17.9% (99/552 patients). Given the relatively low diagnostic yield and high failure rate of therapid drink challenge, we recommend adopting an individualized approach to manometry.

Background/Aims: Chicago classification version 4.0 enhances the diagnosis of esophageal motility disorders using position change and provocative tests such as multiple rapid swallows and a rapid drink challenge. This study investigates the diagnostic role of the rapid drink challenge based on Chicago classification 4.0 using a functional luminal imaging probe to estimate the cutoff value. Methods: This study included 570 patients who underwent esophageal manometry with a rapid drink challenge between January 2019 and October 2022. The diagnostic flow was analyzed according to Chicago classification 4.0. Results: Ninety-nine patients (38, achalasia; 11, esophagogastric junction outflow obstruction; 7, ineffective esophageal motility; 1, hypercontractile esophagus; and 42, normal esophageal function) failed the rapid drink challenge. Among the 453 participants, 50and 86 were diagnosed with achalasia and esophagogastric junction outflow obstruction, respectively, using Chicago classification4.0. In 249/453 (55.0%) patients initially diagnosed with esophagogastric junction outflow obstruction using Chicago classification3.0, the diagnosis was changed to achalasia (n = 28), hypercontractile esophagus (n = 7), ineffective esophageal motility (n = 7), or normal esophageal function (n = 121) using Chicago classification 4.0. Rapid drink challenge-integrated relaxation pressure’s diagnostic cutoff value was 19 mmHg. Nine patients had diagnoses changed after the rapid drink challenge, including 3 with panesophageal pressurization. Conclusions Chicago classification 4.0 increased the diagnostic yield of the rapid drink challenge by 2.0% (9/453 patients). However, the rapid drink challenge had a failure rate of 17.9% (99/552 patients). Given the relatively low diagnostic yield and high failure rate of therapid drink challenge, we recommend adopting an individualized approach to manometry.

Background/Aims: Epstein-Barr virus (EBV) and Helicobacter pylori (HP) coinfection may synergistically induce severe inflammatory responses in the stomach tissue, increasing the risk of developing gastric cancer. We aimed to analyze the effect of EBV and HP coinfection on the clinicopathologic features and prognosis of gastric cancer, as well as to evaluate the role of EBV infection in non-gastric carcinoma with lymphoid stroma (non-GCLS). Methods: Overall, 956 patients who underwent surgery for gastric cancer between September 2014 and August 2015 were eligible and divided into groups, according to GCLS morphology, EBV infection, and HP infection. Clinicopathologic characteristics and oncologic outcomes were analyzed retrospectively. Results: EBV and HP coinfection was significantly associated with male sex, proximal location, GCLS morphology, and equivocal p53 expression (p<0.001). Multivariate analysis revealed that EBV infection alone (hazard ratio [HR], 0.362; 95% CI, 0.131 to 0.996; p=0.049) and lower third location (HR, 0.624; 95% CI, 0.413 to 0.943; p=0.025) were inversely correlated with overall survival. During median follow-up period of 72 months, overall survival rate was not significantly different between the EBV and HP coinfection group and others (97.6% vs 86.8%, log-rank p=0.144). In non-GCLS patients (n=920), overall survival rate was not significantly different between the EBV infection group and others (96.9% vs 86.4%, log-rank p=0.126). Conclusions EBV and HP coinfection is not an independent prognostic factor for gastric cancer. EBV infection status, regardless of HP infection, affects the clinicopathologic features of all types of gastric cancer. However, it does not lead to a significant difference in overall survival of nonGCLS patients.

Objective: In September 2018, the traffic law revision has enforced all passengers in cars to wear seatbelts. Our study aims to investigate the effects of this law revision on fellow passengers involved in car accidents by considering their seatbelt-wearing rate and severity score. Methods: This study is a retrospective observational study. Data were collected from the Emergency Department-based Injury in-depth Surveillance (for the years 2017 and 2019), Korea Disease Control and Prevention Agency. Candidates were patients who visited emergency rooms (ERs) of 23 hospitals from January to December in the years 2017 and 2019. Patients under the age of 15 years or without Excess Mortality Ratio-adjusted Injury Severity Score (EMR-ISS) data or having accidents on highways were excluded. Results: The total number of patients who visited ERs during the study periods was 91,506 and 14,806 in 2017 and 2019, respectively, and were included in our study. There were more fellow female passengers than male passengers during both the study periods: 5,559 in 2017 (67.9%) and 4,341 in 2019 (66.8%). Compared to 52.2% in 2017, the rate of wearing seatbelts increased to 54.5% in 2019. However, after adjusting for age, sex, use of ambulance, injury time, alcohol use, type of road, and counterpart, multivariate logistic regression revealed that compared to the 2017 group, the odds ratio of severe injuries in the 2019 group was 1.10 (95% confidence interval, 0.98-1.24). Conclusion Increased rate of wearing seatbelts after imposing the traffic law revision was not satisfactory. Therefore, it is necessary to tighten regulations on fellow passengers without seat belts and improve awareness through public relations.

Background/Aims: We developed a new endoscopic submucosal dissection (ESD) simulator and evaluated its efficacy and realism for use training endoscopists. Methods: An ESD simulator was constructed using polyvinyl alcohol hydrogel sheets and compared to a previous ESD simulator. Between March 1, 2020, and December 30, 2021, eight expert endoscopists from three different centers analyzed the procedure-related factors of the simulator. Five trainees performed gastric ESD exercises under the guidance of these experts. Results: Although the two ESD simulators provided overall favorable outcomes in terms of ESD-related factors, the new simulator had several benefits, including better marking of the target lesion’s limits (p<0.001) and overall handling (p<0.001). Trainees tested the usefulness of the new ESD simulator. The complete resection rate improved after 3 ESD training sessions (9 procedures), and the perforation rate decreased after 4 sessions (12 procedures). Conclusions We have developed a new ESD simulator that can help beginners achieve a high level of technical experience before performing real-time ESD procedures in patients.

Background/Aims: Real-time polymerase chain reaction (RT-PCR) is a fast and simple method for the simultaneous detection of clarithromycin (CLR) resistance and Helicobacter pylori. We evaluated the effectiveness of RT-PCR compared to that of the rapid urease test (RUT) and assessed its value in verifying CLR resistance. Methods: A total of 70 specimens with confirmed H. pylori infection in culture were enrolled and analyzed in this prospective study. All specimens were subjected to RT-PCR assay using fluorescence melting peak signals to detect H. pylori infection and CLR resistances caused by either A2142G or A2143G mutations in the 23S ribosomal RNA gene (23S rRNA). The results were compared to those of RUT and antimicrobial susceptibility culturing tests to investigate the efficacy of RT-PCR. Results: Among the 70 specimens analyzed, the positivity rate was 97.1% (68/70) with RT-PCR and 82.9% (58/70) with RUT. CLR resistance (minimum inhibitory concentration >1.0 μg/mL) was confirmed in 18.6% (13/70), and fluorescence melting curve analysis showed that 84.6% (11/13) had point mutations in 23S rRNA. Ten specimens had only A2143G mutation, and one specimen contained both A2142G and A2143G mutations. Conclusions RT-PCR assay was found to be more efficient than RUT in detecting H. pylori infection and could effectively verify CLR resistance compared to the antimicrobial susceptibility culturing test. Considering the high sensitivity and accessibility of RT-PCR method, it could be used to easily detect CLR-resistant H. pylori, thus helping clinicians select suitable treatment regimen and improve the eradication rate.

Background/Aims: Although an association between achalasia and esophageal cancer has been reported, whether achalasia confers a substantial increase in mortality is unknown. Moreover, the causes of death related to achalasia have not been investigated. We performed this nationwide, population-based cohort study on achalasia because no such study has been performed since the introduction of high-resolution manometry in 2008. Methods: This study was performed using data extracted from the Korean National Health Insurance Service database, covering a 9-year period from 2009 to 2017. Control participants without a diagnostic code for achalasia were randomly selected and matched by sex and birth year at a case-to-control ratio of 1:4. Data on the cause of death from Statistics Korea were also analyzed. Results: The overall incidence of achalasia was 0.68 per 100,000 person-years, and the prevalence was 6.46 per 100,000 population. Patients with achalasia (n=3,063) had significantly higher adjusted hazard ratio (aHR) for esophageal cancer (aHR, 3.40; 95% confidence interval [CI], 1.25 to 9.22; p=0.017), pneumonia (aHR, 2.30; 95% CI, 1.89 to 2.81; p<0.001), aspiration pneumonia (aHR, 3.92; 95% CI, 2.38 to 6.48; p<0.001), and mortality (aHR, 1.68; 95% CI, 1.44 to 1.94; p<0.001). Esophageal cancer carried the highest mortality risk (aHR, 8.82; 95% CI, 2.35 to 33.16; p=0.001), while pneumonia had the highest non-cancer mortality risk (aHR, 2.28; 95% CI, 1.31 to 3.96; p=0.004). Conclusions In this nationwide study, achalasia was associated with increased risk of mortality.Esophageal cancer and pneumonia were the most common comorbidities and the major causes of death in patients with achalasia.

Background/Aims: Diverticular peroral endoscopic myotomy (D-POEM) is known to be a safe and feasible technique for managing diverticular diseases of the esophagus. In this study, we aim to report our experience with D-POEM and to investigate the usefulness of endoscopic functional luminal imaging probe (EndoFLIP) in determining the need for cardiomyotomy with septotomy for symptomatic epiphrenic diverticulum. Methods: Consecutive patients who underwent D-POEM for symptomatic epiphrenic diverticulum between September 2019 and September 2021 were eligible for this study. EndoFLIP and high-resolution manometry results and endoscopic treatment outcomes were retrospectively investigated. Results: A total of 9 patients with symptomatic epiphrenic diverticulum were included. The median size of the diverticulum and septum was 50 (interquartile range [IQR], 48-80) mm and 20 (IQR, 20-30) mm, respectively. The overall technical success rate was 100%, with a median procedure time of 60 (IQR, 46-100) minutes. The 5 patients (high-resolution manometry results; 3 normal, 1 ineffective esophageal motility, and 1 Jackhammer esophagus) who had decreased esophagogastric junction distensibility index on pre-procedure EndoFLIP underwent cardiomyotomy with septotomy regardless of the presence of esophageal motility disorders, and the distensibility index increased and normalized after procedure. The mean dysphagia score decreased from 2.0 ± 1.0 pre-procedure to 0.4 ± 0.7 during a median follow-up of 11 (IQR, 4-21) months post-procedure. No serious adverse events that required surgical intervention or delayed discharge were noted. Conclusions EndoFLIP may help decide whether to perform combined cardiomyotomy and septotomy for the treatment of an epiphrenic diverticulum. Further large-scale studies are needed to confirm these results.

Background/Aims: We aim to investigate the diagnostic accuracy and differences between Chicago classification version 3.0 (CC v3.0) and 4.0 (CC v4.0). Methods: Patients who underwent high-resolution esophageal manometry (HRM) for suspected esophageal motility disorders were prospectively recruited between May 2020 and February 2021. The protocol of HRM studies included additional positional change and provocative testing designed by CC v4.0. Results: Two hundred forty-four patients were included. The median age was 59 (interquartile range, 45-66) years, and 46.7% were males.Of these, 53.3% (n = 130) and 61.9% (n = 151) were categorized as normalcy by CC v3.0 and CC v4.0, respectively. The 15 patients diagnosed of esophagogastric junction outflow obstruction (EGJOO) by CC v3.0 was changed to normalcy by position (n = 2) and symptom (n = 13) by CC v4.0. In seven patients, the ineffective esophageal motility (IEM) diagnosis by CC v3.0 was changed to normalcy by CC v4.0. The diagnostic rate of achalasia increased from 11.1% (n = 27) to 13.9% (n = 34) by CC v4.0. Of patients diagnosed IEM by CC v3.0, 4 was changed to achalasia based on the functional lumen imaging probe (FLIP) results by CC v4.0. Three patients (2 with absent contractility and 1 with IEM in CC v3.0) were newly diagnosed with achalasia using a provocative test and barium esophagography by CC v4.0. Conclusions CC v4.0 is more rigorous than CC v3.0 for the diagnosis of EGJOO and IEM and diagnoses achalasia more accurately by using provocative tests and FLIP. Further studies on the treatment outcomes following diagnosis with CC v4.0 are needed.