Hyun JJ, et al. Gut Liver. 2011 Sep;5(3):267-277. http://dx.doi.org/10.5009/gnl.2011.5.3.267

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. 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. 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. 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.

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. 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. 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). 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.

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.