Clinical Practice Guideline for Percutaneous Endoscopic Gastrostomy / 대한소화기학회지

With an aging population, the number of patients with difficulty in swallowing due to medical conditions is gradually increasing. In such cases, enteral nutrition is administered through a temporary nasogastric tube. However, the long-term use of a nasogastric tube leads to various complications and a decreased quality of life. Percutaneous endoscopic gastrostomy (PEG) is the percutaneous place­ment of a tube into the stomach that is aided endoscopically and may be an alternative to a nasogastric tube when enteral nutritional is required for four weeks or more. This paper is the first Korean clinical guideline for PEG developed jointly by the Korean College of Helicobacter and Upper Gastrointestinal Research and led by the Korean Society of Gastrointestinal Endoscopy. These guidelines aimed to provide physicians, including endoscopists, with the indications, use of prophylactic antibiotics, timing of enteric nutrition, tube placement methods, complications, replacement, and tubes removal for PEG based on the currently available clinical evidence.

Sample Collection Methods in Upper Gastrointestinal Research

In recent years, significant translational research advances have been made in the upper gastrointestinal (GI) research field. Endoscopic evaluation is a reasonable option for acquiring upper GI tissue for research purposes because it has minimal risk and can be applied to unresectable gastric cancer. The optimal number of biopsy samples and sample storage is crucial and might influence results. Furthermore, the methods for sample acquisition can be applied differently according to the research purpose; however, there have been few reports on methods for sample collection from endoscopic biopsies. In this review, we suggested a protocol for collecting study samples for upper GI research, including microbiome, DNA, RNA, protein, single-cell RNA sequencing, and organoid culture, through a comprehensive literature review. For microbiome analysis, one or two pieces of biopsied material obtained using standard endoscopic forceps may be sufficient. Additionally, 5 mL of gastric fluid and 3–4 mL of saliva is recommended for microbiome analyses. At least one gastric biopsy tissue is necessary for most DNA or RNA analyses, while proteomics analysis may require at least 2–3 biopsy tissues. Single cell-RNA sequencing requires at least 3–5 tissues and additional 1–2 tissues, if possible. For successful organoid culture, multiple sampling is necessary to improve the quality of specimens.

Efficacy and Tolerability of 14-Day Tegoprazan- versus Rabeprazole-Based Triple Therapy for Eradication of Helicobacter pylori: A Real-World Evidence Study

Background/Aims@#Tegoprazan, a new, fast, and strong potassium-competitive acid blocker, has been approved for the treatment of gastric acid-related diseases in Korea. However, realworld clinical data regarding this drug are scarce. We aimed to compare the Helicobacter pylori eradication rates of tegoprazan- and rabeprazole-based triple therapy. @*Methods@#We retrospectively reviewed data from patients who received first-line treatment for H. pylori infection using tegoprazan- or rabeprazole-based triple therapy for 2 weeks (50 mg tegoprazan or 20 mg rabeprazole+1,000 mg amoxicillin+500 mg clarithromycin twice daily). The primary endpoint was the eradication rate as determined by intention-to-treat analysis. @*Results@#Of the 677 patients included in our study, 344 and 333 received tegoprazan-based and rabeprazole-based triple therapy, respectively. The eradication rate from intention-to-treat analysis was 76.7% (95% confidence interval [CI], 72.1% to 81.0%) for tegoprazan-based triple therapy and 75.4% (95% CI, 70.5% to 79.8%) for rabeprazole-based triple therapy. There was no significant difference in the eradication rates between the two groups (p>0.999). Per-protocol analysis also revealed no significant difference between the eradication rates of the two groups (tegoprazan 83.4% [95% CI, 79.0% to 87.2%] vs rabeprazole 83.5% [79.0% to 87.4%], p>0.999).Furthermore, there was no significant difference in adverse event rates between the two groups (tegoprazan, 27.6%; rabeprazole, 25.8%; p=0.604). @*Conclusions@#The eradication rate of tegoprazan-based triple therapy was similar to that of rabeprazole-based triple therapy. Further studies on the dose-escalation effect of tegoprazan for H. pylori eradication and the efficacy of tegoprazan in regimens other than conventional triple therapy are needed.

Efficacy and safety of intragastric balloon for obesity in Korea

Background/Aims@#Intragastric balloon (IGB) is the only available endoscopic bariatric and metabolic therapy in Korea. End-ball (Endalis) has the longest history of clinical use among the IGBs available in Korea. However, little clinical data on this system have been reported. In this study, we aimed to evaluate the efficacy and safety of End-ball in Korea. @*Methods@#We performed a retrospective cohort study of patients who underwent IGB insertion (End-ball) from 2013 to 2019. Demographic and anthropometric data were collected. The efficacy and safety of IGB treatment were analyzed. @*Results@#In total, 80 patients were included. Mean age was 33.7 years and 83.8% were female. Initial body mass index was 34.48±4.69 kg/m2. Body mass index reduction was 3.72±2.63 kg/m2 at the time of IGB removal. Percent of total body weight loss (%TBWL) was 10.76%±6.76%. Percentage excess body weight loss was 43.67%±27.59%. Most adverse events were minor, and 71.4% of participants showed nausea, vomiting, or abdominal pain. @*Conclusions@#IGB treatment showed good efficacy and safety profile in Korean patients with obesity. In terms of %TBWL and percentage excess body weight loss, the efficacy was similar to that in the Western population.

Clinical practice guidelines for percutaneous endoscopic gastrostomy

With an aging population, the number of patients with difficulty in swallowing due to medical conditions is gradually increasing. In such cases, enteral nutrition is administered through a temporary nasogastric tube. However, the long-term use of a nasogastric tube leads to various complications and a decreased quality of life. Percutaneous endoscopic gastrostomy (PEG) is the percutaneous placement of a tube into the stomach that is aided endoscopically and may be an alternative to a nasogastric tube when enteral nutritional is required for four weeks or more. This paper is the first Korean clinical guideline for PEG developed jointly by the Korean College of Helicobacter and Upper Gastrointestinal Research and led by the Korean Society of Gastrointestinal Endoscopy. These guidelines aimed to provide physicians, including endoscopists, with the indications, use of prophylactic antibiotics, timing of enteric nutrition, tube placement methods, complications, replacement, and tube removal for PEG based on the currently available clinical evidence.

Minimal and Maximal Extent of Band Ligation for Acute Variceal Bleeding during the First Endoscopic Session

Background/aims@#The appropriate number of band ligations during the first endoscopic session for acute variceal bleeding is debatable. We aimed to compare the technical aspects of endoscopic variceal ligation (EVL) in patients with variceal bleeding according to the number of bands placed per session. @*Methods@#We retrospectively reviewed multicenter data from patients who underwent EVL for acute variceal bleeding. Patients were classified into minimal EVL (targeting only the foci with active bleeding or stigmata of recent bleeding) and maximal EVL (targeting potential bleeding sources in addition to the aforementioned targets) groups. The primary endpoint was 5-day treatment failure. The secondary endpoints were 30-day rebleeding, 30-day mortality, and intraprocedural adverse events. @*Results@#Minimal EVL was associated with lower rates of hypoxia and shock during EVL than maximal EVL (hypoxia, 0.9% vs 2.9%; shock, 1.3% vs 3.4%). However, treatment failure was higher in the minimal EVL group than in the maximal EVL group (odds ratio, 1.60; 95% confidence interval, 1.06 to 2.41). Age ≥60 years, Model for End-Stage Liver Disease score ≥15, Child-Turcotte-Pugh classification C, presence of hepatocellular carcinoma, and systolic blood pressure <90 mm Hg at initial presentation were also associated with treatment failure. In contrast, 30-day rebleeding and 30-day mortality did not differ between the minimal and maximal EVL groups. @*Conclusions@#Given that minimal EVL was associated with a high risk of treatment failure, maximal EVL may be a better option for variceal bleeding. However, the minimal EVL strategy should be considered in select patients because it does not affect 30-day rebleeding and mortality.

2020 Seoul Consensus on the Diagnosis and Management of Gastroesophageal Reflux Disease / 대한내과학회지

Gastroesophageal reflux disease (GERD) is a condition in which gastric contents regurgitate into the esophagus or beyond, resulting in either troublesome symptoms or complications. GERD is heterogeneous in terms of varied manifestations, test findings, and treatment responsiveness. GERD diagnosis can be established with symptomatology, pathology, or physiology. Recently the Lyon consensus defined the “proven GERD” with concrete evidence for reflux, including advanced grade erosive esophagitis (Los Angeles classification grades C and or D esophagitis), long-segment Barrett’s mucosa or peptic strictures on endoscopy or distal esophageal acid exposure time > 6% on 24-hour ambulatory pH-impedance monitoring. However, some Asian researchers have different opinions on whether the same standards should be applied to the Asian population. The prevalence of GERD is increasing in Asia. The present evidence-based guidelines were developed using a systematic review and meta-analysis approach. In GERD with typical symptoms, a proton pump inhibitor test can be recommended as a sensitive, cost-effective, and practical test for GERD diagnosis. Based on a meta-analysis of 19 estimated acid-exposure time values in Asians, the reference range upper limit for esophageal acid exposure time was 3.2% (95% confidence interval 2.7-3.9%) in the Asian countries. Esophageal manometry and novel impedance measurements, including mucosal impedance and a post-reflux swallow-induced peristaltic wave, are promising in discrimination of GERD among different reflux phenotypes, thus increasing its diagnostic yield. We also propose a long-term strategy of evidence-based GERD treatment with proton pump inhibitors and other drugs.

Obesity and the risk of primary liver cancer: A systematic review and meta-analysis

Background/Aims@#In this systematic review and meta-analysis, we aimed to clarify the effect of obesity on the occurrence of and mortality from primary liver cancer. @*Methods@#This study was conducted using a systematic literature search of MEDLINE, EMBASE, and the Cochrane Library until November 2018 using the primary keywords “obesity,” “overweight,” “body mass index (BMI),” “body weight,” “liver,” “cancer,” “hepatocellular carcinoma,” “liver cancer,” “risk,” and “mortality.” Studies assessing the relationship between BMI and occurrence of or mortality from primary liver cancer in prospective cohorts and those reporting hazard ratios (HRs) or data that allow HR estimation were included. @*Results@#A total of 28 prospective cohort studies with 8,135,906 subjects were included in the final analysis. These included 22 studies with 6,059,561 subjects for cancer occurrence and seven studies with 2,077,425 subjects for cancerrelated mortality. In the meta-analysis, an increase in BMI was associated with the occurrence of primary liver cancer (HR, 1.69; 95% confidence interval, 1.50–1.90, I2=56%). A BMI-dependent increase in the risk of occurrence of primary liver cancer was reported. HRs were 1.36 (95% CI, 1.02–1.81), 1.77 (95% CI, 1.56–2.01), and 3.08 (95% CI, 1.21–7.86) for BMI >25 kg/m2, >30 kg/m2, and >35 kg/m2, respectively. Furthermore, increased BMI resulted in enhanced liver cancer-related mortality (HR, 1.61; 95% CI, 1.14–2.27, I2=80%). @*Conclusions@#High BMI increases liver cancer mortality and occurrence of primary liver cancer. Obesity is an independent risk factor for the occurrence of and mortality from primary liver cancer.

2020 Seoul Consensus on the Diagnosis and Management of Gastroesophageal Reflux Disease

Gastroesophageal reflux disease (GERD) is a condition in which gastric contents regurgitate into the esophagus or beyond, resulting in either troublesome symptoms or complications. GERD is heterogeneous in terms of varied manifestations, test findings, and treatment responsiveness. GERD diagnosis can be established with symptomatology, pathology, or physiology. Recently the Lyon consensus defined the “proven GERD” with concrete evidence for reflux, including advanced grade erosive esophagitis (Los Angeles classification grades C and or D esophagitis), long-segment Barrett’s mucosa or peptic strictures on endoscopy or distal esophageal acid exposure time > 6% on 24-hour ambulatory pH-impedance monitoring. However, some Asian researchers have different opinions on whether the same standards should be applied to the Asian population. The prevalence of GERD is increasing in Asia. The present evidence-based guidelines were developed using a systematic review and meta-analysis approach. In GERD with typical symptoms, a proton pump inhibitor test can be recommended as a sensitive, cost-effective, and practical test for GERD diagnosis.Based on a meta-analysis of 19 estimated acid-exposure time values in Asians, the reference range upper limit for esophageal acid exposure time was 3.2% (95% confidence interval, 2.7-3.9%) in the Asian countries. Esophageal manometry and novel impedance measurements, including mucosal impedance and a post-reflux swallow-induced peristaltic wave, are promising in discrimination of GERD among different reflux phenotypes, thus increasing its diagnostic yield. We also propose a long-term strategy of evidence-based GERD treatment with proton pump inhibitors and other drugs.

Clinical practice guideline for endoscopic resection of early gastrointestinal cancer

Although surgery was the standard treatment for early gastrointestinal cancers, endoscopic resection is now a standard treatment for early gastrointestinal cancers without regional lymph node metastasis. High-definition white light endoscopy, chromoendoscopy, and image-enhanced endoscopy such as narrow band imaging are performed to assess the edge and depth of early gastrointestinal cancers for delineation of resection boundaries and prediction of the possibility of lymph node metastasis before the decision of endoscopic resection. Endoscopic mucosal resection and/or endoscopic submucosal dissection can be performed to remove early gastrointestinal cancers completely by en bloc fashion. Histopathological evaluation should be carefully made to investigate the presence of risk factors for lymph node metastasis such as depth of cancer invasion and lymphovascular invasion. Additional treatment such as radical surgery with regional lymphadenectomy should be considered if the endoscopically resected specimen shows risk factors for lymph node metastasis. This is the first Korean clinical practice guideline for endoscopic resection of early gastrointestinal cancer. This guideline was developed by using mainly de novo methods and encompasses endoscopic management of superficial esophageal squamous cell carcinoma, early gastric cancer, and early colorectal cancer. This guideline will be revised as new data on early gastrointestinal cancer are collected.

Development of a Short Version of ICF Core Set for Stroke Adapted for Rehabilitation in Korea: a Preliminary Study

This study aimed to develop a short version of the International Classification of Functioning, Disability, and Health (ICF) core set and verify functioning levels of patients for stroke rehabilitation in Korea. Using the Delphi technique, a 3-round consensus process was conducted. Thirty multidisciplinary rehabilitation experts from different hospitals completed the consensus study. The questionnaire for this study adopted the comprehensive ICF core set for stroke developed by the Geyh group. A 7-point Likert-type scale was used by participants to weigh the impact of each category on activities of daily living or rehabilitation after a stroke. The consensus of ratings was assessed with Spearman's rho and inter-quartile range indices. A core set to assess functioning levels of patients with stroke was developed from those categories. A short version of ICF core set to assess and verify functioning levels of patients with stroke was developed for 12 categories, including 3 categories (consciousness, muscle power, and attention) from body functions, 1 (structure of brain) from body structures, 5 (eating, walking, moving around, changing basic body position, and carrying out daily routine) from activities and participation, and 3 (individual attitudes of immediate family members, immediate family, and personal care providers/personal assistants) from environmental factors. This preliminary study developed a Delphi consensus process, gathering statistical evidence and expert commands based on the short version of ICF core set for rehabilitation of stroke patients in Korea.

Helicobacter pylori Eradication and Gastric Cancer Prevention

Since Warren and Marshall demonstrated Helicobacter pylori (H. pylori) as a cause of gastritis in the early 1980s, H. pylori has been associated with various gastric diseases, including gastric ulcer, gastric mucosa-associated lymphoid tissue (MALT) lymphoma, gastric adenoma, gastric adenocarcinoma, and hyperplastic gastric polyps. H. pylori eradication therapy can treat some associated diseases, including low-grade gastric MALT lymphoma, and significantly reduce the risk of peptic ulcer recurrence or progression of atrophic gastritis and intestinal metaplasia. In East Asia, where H. pylori and gastric cancer are prevalent, several studies have been conducted to prove whether the risk of gastric cancer development is reduced through H. pylori eradication therapy. Early studies failed to show the benefits of H. pylori eradication therapy in gastric cancer prevention. However, recent studies with extended follow-up periods have reported reduced risks of gastric cancer after treatment of H. pylori infection. H. pylori eradication therapy effectively prevents gastric cancer even in patients who were treated for early gastric cancer, and can be used in treating hyperplastic gastric polyps. Herein, we reviewed current evidence supporting the benefits of H. pylori eradication therapy to help clinicians understand its impact on gastric cancer prevention and hyperplastic polyp treatment.

Dietary Intake of Soy Products, Vegetables, and Dairy Products and Gastric Cancer Survival according to Histological Subtype: a Long-term Prospective Cohort Study

Purpose@#Owing to differences in the general characteristics of gastric cancer (GC) according to histological type, the association of GC risk factors, such as diet, may also differ depending on the histological type. We investigated the associations between individual and combined intake of soy products, vegetables, and dairy products and GC mortality by following up cases of death among Korean GC cases and whether these associations differ according to the histological type. @*Materials and Methods@#A total of 508 GC cases were enrolled from two hospitals between 2002 and 2006. Their survival or death was prospectively followed up until December 31, 2016, through a review of medical records and telephonic surveys. Finally, 300 GC cases classified as intestinal- or diffuse-type GC cases were included. The median follow-up period was 7.1 years. @*Results@#In the fully adjusted model, a high intake of soy products (hazard ratio [HR], 0.43; 95% confidence interval [CI], 0.19–0.96) and the combination of soy products and vegetables (HR, 0.34; 95% CI, 0.12–0.96) or soy products and dairy products (HR, 0.37; 95% CI, 0.14–0.98) decreased the mortality from intestinal-type GC. In particular, patients consuming various potentially protective foods (HR, 0.23; 95% CI, 0.06–0.83) showed a highly significant association with a lower mortality from intestinal-type GC. However, no significant association was found with diffuse-type GC. @*Conclusions@#High intake of potentially protective foods, including soy products, vegetables, and dairy products, may help increase survival in intestinal-type GC.

2020 Seoul Consensus on the Diagnosis and Management of Gastroesophageal Reflux Disease

Gastroesophageal reflux disease (GERD) is a condition in which gastric contents regurgitate into the esophagus or beyond, resulting in either troublesome symptoms or complications. GERD is heterogeneous in terms of varied manifestations, test findings, and treatment responsiveness. GERD diagnosis can be established with symptomatology, pathology, or physiology. Recently the Lyon consensus defined the “proven GERD” with concrete evidence for reflux, including advanced grade erosive esophagitis (Los Angeles classification grades C and or D esophagitis), long-segment Barrett’s mucosa or peptic strictures on endoscopy or distal esophageal acid exposure time > 6% on 24-hour ambulatory pH-impedance monitoring. However, some Asian researchers have different opinions on whether the same standards should be applied to the Asian population. The prevalence of GERD is increasing in Asia. The present evidence-based guidelines were developed using a systematic review and meta-analysis approach. In GERD with typical symptoms, a proton pump inhibitor test can be recommended as a sensitive, cost-effective, and practical test for GERD diagnosis.Based on a meta-analysis of 19 estimated acid-exposure time values in Asians, the reference range upper limit for esophageal acid exposure time was 3.2% (95% confidence interval, 2.7-3.9%) in the Asian countries. Esophageal manometry and novel impedance measurements, including mucosal impedance and a post-reflux swallow-induced peristaltic wave, are promising in discrimination of GERD among different reflux phenotypes, thus increasing its diagnostic yield. We also propose a long-term strategy of evidence-based GERD treatment with proton pump inhibitors and other drugs.

Clinical practice guideline for endoscopic resection of early gastrointestinal cancer

Although surgery was the standard treatment for early gastrointestinal cancers, endoscopic resection is now a standard treatment for early gastrointestinal cancers without regional lymph node metastasis. High-definition white light endoscopy, chromoendoscopy, and image-enhanced endoscopy such as narrow band imaging are performed to assess the edge and depth of early gastrointestinal cancers for delineation of resection boundaries and prediction of the possibility of lymph node metastasis before the decision of endoscopic resection. Endoscopic mucosal resection and/or endoscopic submucosal dissection can be performed to remove early gastrointestinal cancers completely by en bloc fashion. Histopathological evaluation should be carefully made to investigate the presence of risk factors for lymph node metastasis such as depth of cancer invasion and lymphovascular invasion. Additional treatment such as radical surgery with regional lymphadenectomy should be considered if the endoscopically resected specimen shows risk factors for lymph node metastasis. This is the first Korean clinical practice guideline for endoscopic resection of early gastrointestinal cancer. This guideline was developed by using mainly de novo methods and encompasses endoscopic management of superficial esophageal squamous cell carcinoma, early gastric cancer, and early colorectal cancer. This guideline will be revised as new data on early gastrointestinal cancer are collected.

Changes in Gastric Microbial Composition before and after Helicobacter pylori Eradication Therapy

Owing to advancements in next-generation sequencing and non-culture-based microbial research techniques, we have recognized that many bacterial taxa other than Helicobacter pylori (H. pylori) are present in the human stomach. Gastric microbial composition depends on gastric diseases, including gastritis, atrophic gastritis, intestinal metaplasia, and gastric cancer. Although H. pylori is a major factor associated with gastric cancer development, other bacterial taxa may affect gastric carcinogenesis. Because the risk of gastric cancer development can be reduced through H. pylori eradication, many investigators have studied the changes in the microbial composition in the stomach after H. pylori eradication. The gastric microbiome in patients with H. pylori infection typically shows abundance of H. pylori and a low microbial diversity index. If we treat H. pylori-infected patients with antibiotics, microbial diversity increases, and the relative abundance also increases in many bacterial taxa. Several studies suggested that the microbial composition in patients with H. pylori infection could be restored by H. pylori eradication therapy; however, there have been inconsistent findings of the abundant bacterial taxa after H. pylori eradication in patients with atrophic gastritis and intestinal metaplasia. More studies are required to reach a definitive conclusion on restoration of the microbial composition after H. pylori eradication according to the severity of gastric inflammation.

Clinical Practice Guideline for Endoscopic Resection of Early Gastrointestinal Cancer

Although surgery was the standard treatment for early gastrointestinal cancers, endoscopic resection is now a standard treatment for early gastrointestinal cancers without regional lymph node metastasis. High-definition white light endoscopy, chromoendoscopy, and image-enhanced endoscopy such as narrow band imaging are performed to assess the edge and depth of early gastrointestinal cancers for delineation of resection boundaries and prediction of the possibility of lymph node metastasis before the decision of endoscopic resection. Endoscopic mucosal resection and/or endoscopic submucosal dissection can be performed to remove early gastrointestinal cancers completely by en bloc fashion. Histopathological evaluation should be carefully made to investigate the presence of risk factors for lymph node metastasis such as depth of cancer invasion and lymphovascular invasion. Additional treatment such as radical surgery with regional lymphadenectomy should be considered if the endoscopically resected specimen shows risk factors for lymph node metastasis. This is the first Korean clinical practice guideline for endoscopic resection of early gastrointestinal cancer. This guideline was developed by using mainly de novo methods and encompasses endoscopic management of superficial esophageal squamous cell carcinoma, early gastric cancer, and early colorectal cancer. This guideline will be revised as new data on early gastrointestinal cancer are collected.

Guidelines for Nonvariceal Upper Gastrointestinal Bleeding

Nonvariceal upper gastrointestinal bleeding (NVUGIB) refers to bleeding that develops in the gastrointestinal tract proximal to the ligament of Treitz. NVUGIB requires hospitalization and is associated with significant morbidity and mortality.Although European and Asian-Pacific guidelines have been published, there have been no previous guidelines regarding management of NVUGIB in Korea. Korea has a high prevalence of Helicobacter pylori infections, and patients have easy accessibility to endoscopy. Therefore, we believe that guidelines regarding management of NVUGIB in Korea are essential. The Korean Society of Gastroenterology reviewed the recent evidence and recommends practical management guidelines on NVUGIB in Korea.

Clinical Guidelines for Drug-Related Peptic Ulcer, 2020 Revised Edition

Korean guidelines for nonsteroidal anti-inflammatory drug (NSAID)-induced peptic ulcer were previously developed in 2009 with the collaboration of the Korean College of Helico-bacter and Upper Gastrointestinal Research and Korean So-ciety of Gastroenterology. However, the previous guidelines were based mainly upon a review of the relevant literature and expert opinion. Therefore, the guidelines need to be revised. We organized a guideline Development Commit-tee for drug-related peptic ulcer under the auspices of the Korean College of Helicobacter and Upper Gastrointestinal Research in 2017 and developed nine statements, includ-ing four for NSAIDs, three for aspirin and other antiplatelet agents, and two for anticoagulants through a de novo process founded on evidence-based medicine that included a literature search and a meta-analysis, A consensus was reached through the application of the modified Delphi method. The primary target of these guidelines is adult pa-tients undergoing long-term treatment with NSAIDs, aspirin or other antiplatelet agents and anticoagulants. The revised guidelines reflect the expert consensus and is intended to assist clinicians in the management and prevention of druginduced peptic ulcer and associated conditions.

The Role of Acid Suppressants in the Prevention of Anticoagulant-Related Gastrointestinal Bleeding: A Systematic Review and Meta-Analysis

Background/Aims@#Although acid suppressants are widely used for the prevention or treatment of drug-induced upper gastrointestinal bleeding (GIB), evidence regarding the prevention of anticoagulant-related GIB is scarce. The aim of this study was to evaluate the protective effect of acid suppressants against anticoagulant-related GIB. @*Methods@#A systematic review was conducted of studies that evaluated the protective effect of acid suppressants against anticoagulant-related GIB found in PubMed, the Cochrane library, Embase, and KoreaMed from the date of database inception to April 2018. Random effect model meta-analyses with sensitivity analyses were conducted. The methodological quality of each included publication was evaluated using the Risk of Bias Assessment Tool for Nonrandomized Studies. Publication bias was assessed. @*Results@#In total, six nested case-control or cohort studies were identified and analyzed. Proton-pump inhibitors (PPI) had a protective effect against upper GIB in patients on dicumarinics (risk ratio [RR], 0.56; 95% confidence interval [CI], 0.38 to 0.83; I2, 0%); however, the histamine-2 receptor antagonist did not have the same effect (RR, 0.97; 95% CI, 0.52 to 1.81; I2, 0%). Acid suppressants did not have a protective effect against GIB in patients on dabigatran (hazard ratio, 0.78; 95% CI, 0.44 to 1.37; I2, 81.8%). @*Conclusions@#The protective effect of PPIs against dicumarinics-related upper GIB was clear, while there was no evidence supporting the protective effect of acid suppressants against dabigatran-related GIB. However, in the absence of randomized trials demonstrating a lack of bias, solid conclusions cannot be drawn.