Jong Jin Hyun

Comparison of the characteristics of submucosal injection solutions used in endoscopic mucosal resection

OBJECTIVE Submucosal injection is used to prevent complications, such as perforation, during endoscopic mucosal resection (EMR). Since injection of normal saline produces mucosal elevation of short duration, repeated injection is needed for extensive resection. To overcome this limitation, various submucosal injection solutions have been developed but there are few data comparing their efficacy. This study was therefore conducted to compare the physical and chemical properties and the duration of mucosal elevation of various submucosal injection solutions. MATERIAL AND METHODS A fresh transverse colon specimen acquired from a mongrel was used. Experiments were repeated four times. To compare the efficacy of mucosal elevation, 1 ml of each solution was injected into the submucosa: 0.9% NaCl, 20% mannitol, 0.1% sodium hyaluronate, 0.3% hydroxypropyl methylcellulose (HPMC), and 2% fibrinogen. Physical and chemical properties such as viscosity and osmolarity were compared. RESULTS The heights of initial mucosal elevations were 6.52+/-0.26 mm, 6.87+/-0.05 mm, 6.92+/-0.09 mm, 6.90+/-0.08 mm, and 6.90+/-0.08 mm for normal saline, mannitol, sodium hyaluronate, HPMC, and fibrinogen, respectively. Whereas injection of normal saline took about 20 min and mannitol about 30 min for the initial elevation to be reduced to more than half the initial height, it took more than 60 min for all the other agents. A correlation was found between the duration of mucosal elevation and viscosity but not with osmolarity. CONCLUSIONS The mucosal elevation lasted longer with sodium hyaluronate, HPMC, and fibrinogen than with mannitol or normal saline, and this seems to be due to the viscosity rather than the osmolarity of each solution.Objective. Submucosal injection is used to prevent complications, such as perforation, during endoscopic mucosal resection (EMR). Since injection of normal saline produces mucosal elevation of short duration, repeated injection is needed for extensive resection. To overcome this limitation, various submucosal injection solutions have been developed but there are few data comparing their efficacy. This study was therefore conducted to compare the physical and chemical properties and the duration of mucosal elevation of various submucosal injection solutions. bA fresh transverse colon specimen acquired from a mongrel was used. Experiments were repeated four times. To compare the efficacy of mucosal elevation, 1 ml of each solution was injected into the submucosa: 0.9% NaCl, 20% mannitol, 0.1% sodium hyaluronate, 0.3% hydroxypropyl methylcellulose (HPMC), and 2% fibrinogen. Physical and chemical properties such as viscosity and osmolarity were compared. b The heights of initial mucosal elevations were 6.52±0.26 mm, 6.87±0.05 mm, 6.92±0.09 mm, 6.90±0.08 mm, and 6.90±0.08 mm for normal saline, mannitol, sodium hyaluronate, HPMC, and fibrinogen, respectively. Whereas injection of normal saline took about 20 min and mannitol about 30 min for the initial elevation to be reduced to more than half the initial height, it took more than 60 min for all the other agents. A correlation was found between the duration of mucosal elevation and viscosity but not with osmolarity. Conclusions. The mucosal elevation lasted longer with sodium hyaluronate, HPMC, and fibrinogen than with mannitol or normal saline, and this seems to be due to the viscosity rather than the osmolarity of each solution.

Comparative study of helicobacter pylori eradication rates with 5-day quadruple concomitant therapy and 7-day standard triple therapy

Background: Several studies have shown the superiority of concomitant quadruple therapy containing 3 antibiotics over triple therapy for Helicobacter pylori infection. The aim of this study was to compare concomitant quadruple therapy with standard triple therapy for first-line H. pylori eradication. Methods: A total of 270 patients with proven H. pylori infection were randomly assigned to one of 2 regimens: amoxicillin 1000 mg with clarithromycin 500 mg and lansoprazole 30 mg twice daily for 7 days (triple therapy) or amoxicillin 1000 mg with clarithromycin 500 mg, metronidazole 500 mg, and lansoprazole 30 mg twice daily for 5 days (concomitant therapy). The success of eradication was evaluated 4 to 5 weeks after completion of treatment. Results: Eradication rates were 86.1% in the triple therapy and 91.4% in the concomitant therapy (per protocol), but the difference was not statistically significant. Mild adverse events were more frequently reported in the concomitant-therapy group (35.6%) than in the triple-therapy group (25.2%) (P=0.09). Conclusions: Five-day quadruple concomitant therapy eradicated H. pylori in over 90% of patients. Accordingly, concomitant therapy is thought to be a promising alternative to triple therapy as a first-line treatment regimen for H. pylori eradication.

Gastrointestinal and biliary stents

Advances in stent design have led to a substantial increase in the use of stents for a variety of malignant and benign strictures in the gastrointestinal tract and biliary system. Whereas early stents were mostly composed of plastic, the majority of contemporary stents are self‐expanding metal stents that are composed of either nitinol or stainless steel. These stents are able to exert an adequate expansile force and, at the same time, are highly flexible and biocompatible. Covered stents have been introduced to minimize tumor ingrowth through the metal mesh but are associated with higher rates for spontaneous migration. This has led to the development of covered stents with uncovered ends and stents with both covered and uncovered layers. Drug‐eluting and biodegradable stents are also likely to become available in the near future. Although stents appear to be the preferred form of palliation for some patients with advanced cancer, many patients will benefit from a multidisciplinary approach that usually includes surgeons and oncologists.

Healthy range for serum ALT and the clinical significance of "unhealthy" normal ALT levels in the Korean population

Background and Aims:  It remains unclear whether the currently‐used normal range for serum alanine aminotransferase (ALT) levels really reflects a healthy liver. The present study was conducted to evaluate the healthy range of serum ALT in the Korean adult population and to determine the clinical significance of unhealthy levels.

Comparison of the efficacies of lamivudine versus entecavir in patients with hepatitis B virus-related decompensated cirrhosis

Suppression of hepatitis B virus (HBV) DNA is more potent, and occurrence of resistant strain is rare with entecavir than lamivudine, but whether these merits result in a more favourable outcome in HBV‐related decompensated cirrhosis patients is unclear.

Serum aminotransferase levels instead of etiology affects the accuracy of transient elastography in chronic viral hepatitis patients

Background and Aim:  It is still uncertain whether the accuracy of transient elastography (TE) in predicting the fibrosis stage is similar in chronic hepatitis B (CHB) and chronic hepatitis C (CHC). The present study was carried out to evaluate whether the underlying cause of chronic viral hepatitis affects the predictive accuracy of TE.

Incidences of Serious Infections and Tuberculosis among Patients Receiving Anti-Tumor Necrosis Factor-α Therapy

Purpose Anti-tumor necrosis factor-alpha (TNF-α) medications represent a major advancement in the management of chronic inflammatory diseases. However, these agents are associated with increased risks of tuberculosis (TB) and other serious infections. The aim of this study was to evaluate the incidences of such disease among tertiary hospitals in Korea. Materials and Methods We retrospectively studied patients who received anti-TNF-α therapy; we reviewed serious infections including TB that developed within 6 months after initiation of anti-TNF-α therapy. Data concerning patient demographics, types of anti-TNF-α agents, concomitant immunosuppressive drugs use, and infection details were collected. Results A total 175 patients treated with infliximab (n=72) or adalimumab (n=103) with the following conditions were enrolled: Crohns disease, 34 (19.4%); ulcerative colitis, 20 (11.4%); ankylosing spondylitis, 82 (46.9%); and rheumatoid arthritis, 39 (22.2%). There were 18 cases (6.0%) of serious infections. The most common site of serious infection was the intra-abdomen (n=6), followed by TB (n=3), skin and soft tissue (n=3), bone and joints (n=2), ocular neurons (n=2), lower respiratory tract (n=1), and urinary tract (n=1). Of the 175 patients, only 3 cases showed development of TB. Furthermore, of all those who developed TB, none had taken anti-TB chemoprophylaxis prior to treatment with an anti-TNF agent due to negative screening results. Conclusion Serious infections with anti-TNF-α therapy were uncommon among tertiary hospitals in Korea; TB was the second most frequent infection. Nevertheless, there were no TB reactivations after anti-TB chemoprophylaxis. Accordingly, physicians should be aware of TB in subjects undergoing anti-TNF-α therapy, especially in countries with a high prevalence of TB.

Management of Non-Variceal Upper Gastrointestinal Bleeding

Upper gastrointestinal bleeding (UGIB) is a critical condition that demands a quick and effective medical management. Non-variceal UGIB, especially peptic ulcer bleeding is the most significant cause. Appropriate assessment and treatment have a major influence on the prognosis of patients with UGIB. Initial fluids resuscitation and/or transfusion of red blood cells are necessary in patients with clinical evidence of intravascular volume depletion. Endoscopy is essential for diagnosis and treatment of UGIB, and should be provided within 24 hours after presentation of UGIB. Pre-endoscopic use of intravenous proton pump inhibitor (PPI) can downstage endoscopic signs of hemorrhage. Post-endoscopic use of high-dose intravenous PPI can reduce the risk of rebleeding and further interventions such as repeated endoscopy and surgery. Eradication of Helicobacter pylori and withdrawal of non-steroidal anti-inflammatory drugs are recommended to prevent recurrent bleeding.

Helicobacter pylori recurrence after first- and second-line eradication therapy in Korea: the problem of recrudescence or reinfection.

Recurrence of Helicobacter pylori (H. pylori) infection is the result of either recrudescence or reinfection. Annual recurrence rates per patient‐year of follow‐up have been reported to vary across countries. The aim of this study was to analyze recurrence rates of H. pylori after first‐line and second‐line eradication therapies in Korea.

Effectiveness and safety of repeated quadruple therapy in Helicobacter pylori infection after failure of second-line quadruple therapy: repeated quadruple therapy as a third-line therapy.

Backgrounds:  Quadruple therapy using a proton‐pump inhibitor, bismuth, metronidazole, and tetracycline is a standard second‐line therapy for Helicobacter pylori infection, achieving an eradication rate of about 80% in Korea. A standard third‐line therapy is not currently established, although various protocols have been proposed. We performed this study to evaluate the effectiveness of a retrial with quadruple therapy before starting a third‐line treatment with new drugs.