Current concerns on journal article with preprint: Korean Journal of Internal Medicine perspectives

Preprints are preliminary research reports that have not yet been peer-reviewed. They have been widely adopted to promote the timely dissemination of research across many scientific fields. In August 1991, Paul Ginsparg launched an electronic bulletin board intended to serve a few hundred colleagues working in a subfield of theoretical high-energy physics, thus launching arXiv, the first and largest preprint platform. Additional preprint servers have since been implemented in different academic fields, such as BioRxiv (2013, Biology; www.biorxiv.org) and medRxiv (2019, Health Science; www.medrxiv.org). While preprint availability has made valuable research resources accessible to the general public, thus bridging the gap between academic and non-academic audiences, it has also facilitated the spread of unsupported conclusions through various media channels. Issues surrounding the preprint policies of a journal must be addressed, ultimately, by editors and include the acceptance of preprint manuscripts, allowing the citation of preprints, maintaining a double-blind peer review process, changes to the preprint’s content and authors’ list, scoop priorities, commenting on preprints, and preventing the influence of social media. Editors must be able to deal with these issues adequately, to maintain the scientific integrity of their journal. In this review, the history, current status, and strengths and weaknesses of preprints as well as ongoing concerns regarding journal articles with preprints are discussed. An optimal approach to preprints is suggested for editorial board members, authors, and researchers.

Current concerns on journal article with preprint: Anesthesia and Pain Medicine perspectives

Preprints are preliminary research reports that have not yet been peer-reviewed. They have been widely adopted to promote the timely dissemination of research across many scientific fields. In August 1991, Paul Ginsparg launched an electronic bulletin board intended to serve a few hundred colleagues working in a subfield of theoretical high-energy physics, thus launching arXiv, the first and largest preprint platform. Additional preprint servers have since been implemented in different academic fields, such as BioRxiv (2013, Biology; www.biorxiv.org) and medRxiv (2019, Health Science; www.medrxiv.org). While preprint availability has made valuable research resources accessible to the general public, thus bridging the gap between academic and non-academic audiences, it has also facilitated the spread of unsupported conclusions through various media channels. Issues surrounding the preprint policies of a journal must be addressed, ultimately, by editors and include the acceptance of preprint manuscripts, allowing the citation of preprints, maintaining a double-blind peer review process, changes to the preprint’s content and authors’ list, scoop priorities, commenting on preprints, and preventing the influence of social media. Editors must be able to deal with these issues adequately, to maintain the scientific integrity of their journal. In this review, the history, current status, and strengths and weaknesses of preprints as well as ongoing concerns regarding journal articles with preprints are discussed. An optimal approach to preprints is suggested for editorial board members, authors, and researchers.

Rapidly Growing Acinar Cell Carcinoma of the Pancreatic Head: A Case Report and Literature Review / 대한췌담도학회지

Pancreatic acinar cell carcinoma (ACC) is a rare neoplasm accounting less than 1% of malignant pancreatic tumors. A 47-year-old male patient visited the emergency room with epigastric pain. Computed tomography or magnetic resonance imaging revealed a 4.7-cm heterogeneously enhanced solid and cystic mass with internal necrosis located in the head of the pancreas. Radiological diagnosis was borderline malignancy such as neuroendocrine tumor or solid pseudopapillary neoplasm. Two months later, the necrotic mass in the pancreas head had grown up to 11 cm, compressing the duodenum, superior mesenteric vein, and proximal transverse colon. Pylorus preserving pancreatoduodenectomy with segmental resection of transverse colon was performed. Histopathological examination revealed that the tumor was pancreatic ACC. The patient recovered without any complication and was doing well without recurrence for 12 months after surgery.

Rectal NSAIDs-based combination modalities are superior to single modalities for prevention of post-endoscopic retrograde cholangiopancreatography pancreatitis: a network meta-analysis

Background/Aims@#Different modalities have been employed to reduce the risk and severity of post-endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis (PEP). However, there has been a paucity of studies comparing the efficacy of various prophylactic modalities for preventing PEP. This network meta-analysis (NMA) aimed to determine the relative efficacy of pancreatic duct stents and pharmacological modalities for preventing PEP. @*Methods@#We performed a systematic and comprehensive search to identify and analyze all randomized controlled studies published until June 2020 that examined the effectiveness of pancreatic duct stents, rectal non-steroidal anti-inflammatory drugs (NSAIDs) based regimens, hydration, and their combinations for the prevention of PEP. The primary outcome was the frequency of PEP. An NMA was performed to combine direct and indirect comparisons of different prophylactic modalities. @*Results@#The NMA included 46 studies evaluating 18 regimens in 16,241 patients. Based on integral analysis of predictive interval plots, and expected mean ranking and surface under the cumulative ranking curve values, combination prophylaxis with indomethacin + lactated Ringer’s solution (LR), followed by diclofenac + nitrate and indomethacin + normal saline, was found to be the most efficacious modality for the overall prevention of PEP. Indomethacin + LR, followed by diclofenac and pancreatic duct stents, was the most efficacious modality for high-risk groups. @*Conclusions@#Rectal NSAIDs-based combination regimens with aggressive hydration or nitrate are superior to single modalities for the prevention of PEP.

Effect of calcineurin inhibitor on post-endoscopic retrograde cholangiopancreatography pancreatitis in patients with liver transplantation: a propensity-matched cohort study

Background/Aims@#A calcineurin inhibitor may alter pancreatic function and inflammatory reaction. This study aimed to determine the possible pharmacologic effect of the calcineurin inhibitor, tacrolimus, on pancreatic function, and to determine its preventive effect on post-endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis in liver transplantation (LT) patients. @*Methods@#The serum amylase and lipase values before and after LT were compared. The frequency of post-ERCP pancreatitis was compared between non-LT and LT patients, using propensity score matching method. @*Results@#Median serum amylase values (normal range, 19 to 86 U/L) were 49.0 U/L (38.0 to 68.0) before LT and 27.0 U/L (19.3 to 36.8) after LT, and median serum lipase values (normal range, 7 to 59 U/L) were 40.0 U/L (26.5 to 54.0) before LT and 10.5 U/L (6.0 to 21.0) after LT. Both serum amylase and lipase values significantly decreased after LT (p < 0.001), and to a level comparable to chronic pancreatitis. There was a marginal significant difference between the non-LT and LT groups before the propensity score matching with respect to frequency of post-ERCP pancreatitis (16 [3.2%] in non-LT group vs. 2 [0.9%] in LT group, p = 0.069). After propensity score matching, a marginal significant difference still existed with respect to frequency of post-ERCP pancreatitis (7 [4.8%] in non-LT group vs. 1 [0.7%] in LT group, p = 0.067). @*Conclusions@#The immunosuppression with calcineurin inhibitor may reduce not only the pancreatic enzyme dynamics but also inciting inflammatory event including post-ERCP pancreatitis.

Prevention of post-endoscopic retrograde cholangiopancreatography pancreatitis with rectal non-steroidal anti-inflammatory drugs

Acute pancreatitis is the most common and feared adverse event associated with performance of endoscopic retrograde cholangiopancreatography (ERCP). Unremitting effort has been made for over 40 years to minimize the frequency and severity of this complication. Recently, the use of rectal non-steroidal anti-inflammatory drugs (NSAIDs) have opened a new era for its prevention. This review focuses on the role of NSAIDs in pancreatitis, the pharmacokinetics of these agents, and summarizes the results of clinical trials with rectal NSAIDs alone and combination regimens in the prevention of post-ERCP pancreatitis.

Comparison of procedural sequence in same-day bidirectional endoscopy: a systematic review and meta-analysis

Background/Aims@#To compare the efficacy and safety of procedural sequence in same-day bidirectional endoscopy. @*Methods@#We searched OVID-MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, and Google Scholar to identify randomized controlled trials that compared the procedural sequences in same-day bidirectional endoscopy, including esophagogastroduodenoscopy (EGD) and colonoscopy. The sedative and analgesic doses required, discomfort and satisfaction scores, procedure time, recovery time, adenoma detection rate, and failed cecal intubation were evaluated. Adverse effects, including respiratory and cardiovascular complications, were also assessed. @*Results@#We included six studies, with 1,848 patients in total. The requirement for sedative treatment was significantly lesser in the EGD-colonoscopy sequence than in the colonoscopy-EGD sequence (standardized mean difference [SMD], –0.39; 95% confidence interval [CI], –0.54 to –0.24; p = 0.12; I2 = 49%). Discomfort, scored by patients during the EGD procedure, was significantly lesser in the EGD-colonoscopy sequence than in the colonoscopy-EGD sequence (SMD, –0.45; 95% CI, –0.80 to –0.09; p = 0.02; I2 = 73%), while it was comparable during colonoscopy between the two sequences. Recovery time was significantly shorter in the EGD-colonoscopy sequence than in the colonoscopy-EGD sequence (SMD, –0.47; 95% CI, –0.65 to –0.30; p = 0.28; I2 = 21%). Total procedure duration, EGD, colonoscopy, cecal intubation time and incidence, incidences of pathologic findings, and adenoma detection were comparable between the two sequences. There was no significant difference in the incidences of desaturation, hypotension, hypertension, bradycardia, and tachycardia between the two sequences. @*Conclusions@#When conducting same-day bidirectional endoscopy, EGD followed by colonoscopy is the most beneficial sequence to be used because patients require lower sedative doses, recover faster, and report lesser discomfort.

Post-ERCP Bleeding in the Era of Multiple Antiplatelet Agents

BACKGROUND/AIMS: This study aimed to determine the risk of post-endoscopic retrograde cholangiopancreatography (post-ERCP) bleeding among patients taking antiplatelet agents (APAs), particularly in the era of multiple APAs. METHODS: The primary outcomes were the frequency, type, and severity of ERCP-related bleeding according to the use of APAs. RESULTS: The frequencies of post-ERCP bleeding among the four different groups were 16 of 2,083 (0.8%) in the no drug group, 12 of 256 (4.7%) in the aspirin group, 3 of 48 (6.3%) in the single APA group, and 4 of 48 (8.3%) in the multiple APA group (p<0.001). In the univariate analysis, post-ERCP bleeding was associated with age, pull-type sphincterotomy, and APA and was inversely associated with balloon dilation of the biliary orifice. In the multivariate analysis, pull-type sphincterotomy (odds ratio [OR], 7.829; 95% confidence interval [CI], 1.411 to 43.453; p=0.019) and country (Korea: OR, 0.124; 95% CI, 0.042 to 0.361; p<0.001) were associated with post-ERCP bleeding. CONCLUSIONS: The frequency of post-ERCP bleeding was statistically higher in patients on any APA within 6 days prior to ERCP. However, in the multivariate analysis, APA use was not associated with post-ERCP bleeding. Until a large, adequately powered study to detect differences is performed, caution is recommended when considering invasive procedures during ERCP in patients on APAs.

Low Serum Pancreatic Amylase and Lipase Values Are Simple and Useful Predictors to Diagnose Chronic Pancreatitis

BACKGROUND/AIMS: This study aimed to evaluate the diagnostic role of low serum amylase and lipase values in the detection of chronic pancreatitis. METHODS: Patients underwent endoscopic retrograde cholangiopancreatography and were diagnosed with non-calcific chronic pancreatitis (NCCP; n=99) and calcific chronic pancreatitis (CCP; n=112). Patient serum amylase and lipase values were compared with those of healthy controls (H; n=170). RESULTS: The median serum amylase (normal range, 19 to 86 U/L) and lipase values (7 to 59 U/L) (P₂₅–P₇₅) were 47.0 (39.8 to 55.3) and 25.0 (18.0 to 35.0) for H, 34.0 (24.5 to 49.0) and 19.0 (9.0 to 30.0) for NCCP, and 30.0 (20.0 to 40.8) and 10.0 (3.0 to 19.0) for CCP, respectively. The cutoff values with the highest diagnostic accuracy for discriminating NCCP from H were 40 U/L for amylase and 20 U/L for lipase, respectively, and for CCP from H were 38 U/L for amylase and 15 U/L for lipase, respectively. For the diagnosis of NCCP with a criterion of serum amylase < 40 and lipase < 20 U/L, the sensitivity, specificity, positive predictive value, and negative predictive values were 37.4%, 88.8%, 66.1%, and 70.9%, respectively. CONCLUSIONS: Serum amylase and/or lipase levels below the normal serum range are highly specific for chronic pancreatitis patients. Clinicians should not ignore low serum pancreatic enzyme values.

Percutaneous Transhepatic Cholangioscopy in Bilioenteric Anastomosis Stricture

Bilioenteric anastomosis strictures are a serious complication of biliary surgery, and often result in recurrent cholangitis, choledocholithiasis, biliary cirrhosis, and hepatic failure. Bilioenteric reconstructive surgery is the standard treatment of choice for such complications. However, percutaneous transhepatic cholangioscopy (PTCS), also known as per-oral endoscopic-guided intervention, is a less invasive procedure that is becoming an increasingly popular alternative. This review describes the PTCS procedure (including the preparation process), as well as the diagnostic and therapeutic role of PTCS in bilioenteric anastomosis strictures.

Prevalence and Risk Factors of Gallbladder Polypoid Lesions in a Healthy Population

PURPOSE: To determine the prevalence of and investigate the risk factors for gallbladder (GB) polypoid lesions in a healthy population. MATERIALS AND METHODS: A total of 23827 subjects who underwent abdominal ultrasonography in conjunction with health screening examinations were retrospectively analyzed. The prevalence of risk factors for GB polypoid lesions were evaluated. In addition, risk factors according to the number of polypoid lesions and the presence of stones with polypoid lesions were investigated. To analyze these risk factors, a control group was established with a 1:2 ratio matched for age and sex. RESULTS: The prevalence of GB polypoid lesions was identified as 9.96%. On multivariate analysis, chronic hepatitis B infection (CHB) and the presence of metabolic syndrome (MS) were risk factors for GB polypoid lesions. CHB and MS were also significant independent risk factors for multiple GB polypoid lesions when compared with solitary GB polypoid lesions. In addition, gastric Helicobacter pylori infection and MS were significant risk factors for GB polypoid lesions with stones when compared with GB polypoid lesions without stones. CONCLUSION: The prevalence of GB polypoid lesions in a healthy Korean population was 9.96%. Patients with CHB and MS need to be carefully examined for such lesions.

Diagnostic accuracy of 22/25-gauge core needle in endoscopic ultrasound-guided sampling: systematic review and meta-analysis

BACKGROUND/AIMS: To compare the diagnostic accuracy of endoscopic ultrasound-guided core needle aspiration with that of standard fine-needle aspiration by systematic review and meta-analysis. METHODS: Studies using 22/25-gauge core needles, irrespective of comparison with standard fine needles, were comprehensively reviewed. Pooled sensitivity, specificity, diagnostic odds ratio (DOR), and summary receiver operating characteristic curves for the diagnosis of malignancy were used to estimate the overall diagnostic efficiency. RESULTS: The pooled sensitivity, specificity, and DOR of the core needle for the diagnosis of malignancy were 0.88 (95% confidence interval [CI], 0.84 to 0.90), 0.99 (95% CI, 0.96 to 1), and 167.37 (95% CI, 65.77 to 425.91), respectively. The pooled sensitivity, specificity, and DOR of the standard needle were 0.84 (95% CI, 0.79 to 0.88), 1 (95% CI, 0.97 to 1), and 130.14 (95% CI, 34.00 to 495.35), respectively. The area under the curve of core and standard needle in the diagnosis of malignancy was 0.974 and 0.955, respectively. The core and standard needle were comparable in terms of pancreatic malignancy diagnosis. There was no significant difference in procurement of optimal histologic cores between core and standard needles (risk ratio [RR], 0.545; 95% CI, 0.187 to 1.589). The number of needle passes for diagnosis was significantly lower with the core needle (standardized mean difference, -0.72; 95% CI, -1.02 to -0.41). There were no significant differences in overall complications (RR, 1.26; 95% CI, 0.34 to 4.62) and technical failure (RR, 5.07; 95% CI, 0.68 to 37.64). CONCLUSIONS: Core and standard needles were comparable in terms of diagnostic accuracy, technical performance, and safety profile.

Oral udenafil and aceclofenac for the prevention of post-endoscopic retrograde cholangiopancreatography pancreatitis in high-risk patients: a randomized multicenter study

BACKGROUND/AIMS: Acute pancreatitis is a common complication of endoscopic retrograde cholangiopancreatography (ERCP). Combination therapy w ith ora l udenafil and aceclofenac may reduce the occurrence of post-ERCP pancreatitis by targeting different pathophysiological mechanisms. We investigated whether combining udenafil and aceclofenac reduced the rates of post-ERCP pancreatitis. METHODS: A prospective, randomized, double-blind, placebo-controlled, multicenter study was conducted in four academic medical centers. Between January 2012 and June 2013, a total of 216 patients who underwent ERCP were analyzed for the occurrence of post-ERCP pancreatitis. Patients were determined to be at high risk for pancreatitis based on validated patient and procedure-related risk factors. RESULTS: Demographic features, indications for ERCP, and therapeutic procedures were similar in each group. There were no significant differences in the rate (15.8% [17/107] vs. 16.5% [18/109], p = 0.901) and severity of post-ERCP pancreatitis between the udenafil/aceclofenac and placebo groups. One patient in each group developed severe pancreatitis. Multivariate analyses indicated that suspected dysfunction of the sphincter of Oddi and endoscopic papillary balloon dilation without sphincterotomy were associated with post-ERCP pancreatitis. CONCLUSIONS: Combination therapy with udenafil and aceclofenac is not effective for the prevention of post-ERCP pancreatitis.

Bilateral ovarian metastasis from distal common bile duct carcinoma developing after choledochal cyst excision

Ovarian metastases represent about 3-5% of all ovarian malignancies. Most of these tumors originate in the digestive tract and cholangiocarcinoma rarely involves the ovary. A 60-year-old woman was admitted for the investigation of abdominal distension that had lasted 1 week. One and a half years prior, the patient had undergone choledochal cyst excision, Roux-en Y hepaticojejunostomy and cholecystectomy. Computed tomography scans of the abdomen revealed a papillary mass in the remnant distal common bile duct and enlargement of both ovaries with a huge amount of ascites. An explorative laparotomy disclosed no peritoneal seeding with resectable cholangiocarcinoma and bilateral ovarian mass. Pylorus-preserving pancreatoduodenectomy and bilateral salphingo-oophorectomy with hysterectomy were performed. Histologically, it was a well-differentiated adenocarcinoma and all surgical margins were free of tumor. Both ovarian masses were consistent with metastatic adenocarcinoma from the common bile duct. The patient received six cycles of postoperative adjuvant systemic chemotherapy, dying after 10 months due to pulmonary embolism.

Indication and Efficacy of Endoscopic Ultrasonography-Guided Ablation for Pancreatic Cystic Tumors / 대한내과학회지

Pancreatic cystic lesions are being recognized with increasing frequency because of the widespread use of cross-sectional imaging. Although most pancreatic cysts are incidentally detected, pancreatic cysts represent a wide spectrum of histopathology, and neoplastic cysts are more prevalent than previously estimated. Some histologic types have malignant potential. Considering the incidence of perioperative morbidity in patients undergoing surgical resection, deciding whether to operate on or observe an indeterminate pancreatic cyst is challenging. This clinical dilemma has created the need to develop a minimally invasive approach for treating pancreatic cysts. EUS-guided pancreatic cyst ablation has been investigated in several clinical trials and has the potential to become an alternative to surgical resection.

A Second Assisting Endoscope for the Removal of an Accidentally Unreleased Detachable Snare during Colon Polypectomy

No abstract available.

Prevalence and Risk Factor of Erosive Esophagitis Observed in Korean National Cancer Screening Program

Prevalence of erosive esophagitis (EE) has been increasing in Korea. The purpose of this study was to estimate prevalence of EE among low socioeconomic population in Korea and to investigate risk factors for EE. We reviewed the medical records of 7,278 subjects who were examined by upper endoscopy in the Korean National Cancer Screening Program at Chung-Ang University Yong-san Hospital from March 2003 to March 2008. The study population included subjects > or = 40 yr of age who were Medicaid recipients and beneficiaries in the National Health Insurance Corporation. Multivariate analysis was used to determine risk factors for EE. Prevalence of EE was 6.7% (486/7,278). According to the LA classification system, LA-A in 344 subjects, LA-B in 135 subjects, and LA-C and D in 7 subjects. In multivariate analysis, age > or = 60 yr, male sex, BMI > or = 25, current smoking, alcohol consumption, fasting glucose level > or = 126 mg/dL, and endoscopic hiatal hernia were significant risk factors for EE. The prevalence of EE in low socioeconomic Korean population is similar to that in personal annual medical check-ups. Risk factors for EE among them include old age, male sex, BMI > or = 25, current smoking, alcohol consumption, fasting glucose level > or = 126 mg/dL, and hiatal hernia.

Duodenal Carcinoid Tumor Treated by Endoscopic Mucosal Resection / 대한소화기내시경학회지

Duodenal carcinoid tumors are rare, and they represent only 2.0~8.9% of all gastrointestinal carcinoid tumors in the western countries. Duodenal carcinoid tumors have previously been treated by surgical resection. The recently recommended treatment for a carcinoid tumor smaller than 1 cm in diameter is endoscopic resection. We experienced a case of a duodenal carcinoid tumor in a 56 year-old man who presented with upper abdominal pain. On the endoscopic examination, a 6 mm sized polypoid lesion with a central depression was noticed on the duodenal bulb. The biopsy confirmed the diagnosis of carcinoid tumor. The endoscopic ultrasound probe showed a hypoechoic tumor that was confined to the submocosal layer. The tumor was completely resected by an endoscopic mucosal resection technique and using a transparent cap.

A Case of Recurrent Pancreatitis Induced by Trimethoprim-Sulfamethoxazole Re-Exposure

A 32-year-old man presented with epigastric pain. He had a previous episode of acute pancreatitis of undetermined cause 2 years earlier. The patient had taken trimethoprim (80 mg) and sulfamethoxazole (400 mg) twice daily because of acute urethritis 3 days prior to admission. No definite cause of acute pancreatitis could be identified on baseline studies. A thorough history-taking revealed that the patient had an episode of acute pancreatitis while taking trimethoprim (80 mg) and sulfamethoxazole (400 mg) twice daily for 2 weeks for prostatitis prior to the previous admission. Therefore, a cause-and-effect relationship between trimethoprim-sulfamethoxazole (TMP-SMX) and repeated episodes of pancreatitis was highly suggested. The patient was presumably diagnosed as TMP-SMX-induced pancreatitis. The final diagnosis was TMP-SMX-induced pancreatitis. Since drugs are rare causes of acute pancreatitis and the diagnosis of drug-induced pancreatitis is difficult to establish, we report this interesting case along with a review of medical literature.

Acute Hyponatremic Encephalopathy after Ingestion of Polyethylene Glycol Solution before Colonoscopy / 대한소화기내시경학회지

Preparation for colonoscopy involves a thorough cleansing of the large bowel. Cleansing is performed using several methods, including ingestion of 4 liters of polyethylene glycol solution. However, these methods can induce hyponatremia by various mechanisms. Severe or rapidly progressing hyponatremia can result in the swelling of the brain, and the symptoms of hyponatremia are mainly neurological. Recently, we encountered a 41-year-old woman who developed acute hyponatremia with encephalopathy after undergoing bowel preparation for colonoscopy. She presented with general weakness, nausea, headache, agitation, delusions, and slurred speech one day after the ingestion of polyethylene glycol solution. Her serum sodium level was very low (110 to 115 mEq/L). Her symptoms pertaining to hyponatremia continued to persist for more than 2 days despite continuous intravenous administration of hypertonic saline for the correction of hyponatremia.