Ulcer and gastritis

How to predict the outcome of endoscopic mechanical lithotripsy in patients with difficult bile duct stones?

OBJECTIVE

Endoscopic mechanical lithotripsy is frequently used to overcome the difficulties of removing large bile duct stones endoscopically. The aim of this study was to identify predictors of endoscopic mechanical lithotripsy failure.

MATERIAL AND METHODS

One hundred and thirty-four patients who underwent mechanical lithotripsy for difficult choledocholithiasis were evaluated retrospectively. Predictive factors of outcome and procedure-related complications were analyzed. The clinical outcomes of subsequent management were also evaluated in cases of unsuccessful endoscopic mechanical lithotripsy.

RESULTS

Endoscopic mechanical lithotripsy was successful in 102 patients (76.1%). Stone impaction, size (>or=30 mm), and the stone size to bile duct diameter ratio (>1.0) were significant predictors of endoscopic mechanical lithotripsy failure, with estimated odds ratios of 17.83, 4.32 and 5.47, respectively. There was no difference in complication rates between the successful and failed mechanical lithotripsy groups. When mechanical lithotripsy failed, all patients were successfully treated using various modalities, including surgery, without mortality.

CONCLUSIONS

An impacted stone, stone size (>or=30 mm) and stone size to bile duct diameter ratio (>1.0) were predictors of failure of endoscopic mechanical lithotripsy for a difficult bile duct stone. Alternative approaches should be considered in patients with predictors of unsuccessful endoscopic mechanical lithotripsy in order to avoid wasting time and resources.

Clearance of irretrievable bile duct and pancreatic duct stones by extracorporeal shockwave lithotripsy, using a transportable device: effectiveness and medium-term results

BACKGROUND AND GOALS

Extracorporeal shockwave lithotripsy (ESWL) is an established treatment of irretrievable biliary and pancreatic stones, but the cost of the shockwave generators limits its widespread use. We revised data about the effectiveness of our treatment for refractory stones using a transportable shockwave generator.

STUDY

We retrospectively evaluated the short and medium-term outcomes of patients who underwent ESWL using a transportable electromagnetic shockwave generator between 1998 and 2003 at our unit, for the treatment of irretrievable bile duct or pancreatic duct stones. All patients received intravenous conscious sedation and antibiotic prophylaxis.

RESULTS

Complete stone clearance was achieved in 70/82 patients (85.4%), in 66 of the patients (94.2%) with 1 session of ESWL. Despite the insertion of a stent in the bile duct, 2 patients had moderate cholangitis, while they waited for the next ESWL session. We did not record any moderate-severe complication of ESWL, but 2 patients underwent surgery owing to perforation/bleeding during endoscopic removal of residual fragments. A symptomatic recurrence of stones was recorded in 10/69 (14.5%) patients, who had been previously cleared and whose follow-up data (median follow-up 29 mo; range 7 to 66) were available.

CONCLUSIONS

We obtained satisfactory stone clearance by using a transportable shockwave generator. Most patients required 1 session. Our experience confirmed the safety of the treatment, even though patients may experience cholangitis while awaiting definitive treatment. The use of a transportable ESWL generator may be a valuable option in centers, while ensuring a sufficient proficiency in biliary endoscopy.

Establishment of mouse models with long-term infection of H. pylori

AIM: To develop a mouse model with long-term infection of H. pylori.

METHODS: Each mouse was inoculated with H. pylori Sydney strain 1 (SS1). Noninfected control mice and infected mice were killed at 4, 12 and 24 wk after H. pylori infection. A piece of gastric mucosa obtained from the posterior wall of the antrum of each mouse was used for culture of H. pylori, rapid urease testing and histopathological detection. Serum was obtained to measure the IgG antibody level to H. pylori.

RESULTS: After 4 wk of infection, the H. pylori was cultured from 6 of 7 infected Babl/c mice and 5 of 7 the H. pylori-infected C57BL/6 mice. After 12 and 24 wk of infection, all of 7 infected Babl/c and 6 of 7 the H. pylori-infected C57BL/6 mice showed the positive results. At the different wk, the rapid urease test results were consistent with the H. pylori culture test. At 12 wk after inoculation, chronic inflammation was observed in the pyloric mucosa by histopathological examination. At 24 wk after inoculation, lymphoid follicles were especially conspicuous in the submucosa, and they were also found in the deep portion of the mucosa.

CONCLUSION: H. pylori SS1 can colonize easily in the glandular stomach mucosa of mouse, and the histopathological changes are similar to those of humans with H. pylori infection.

Multilaboratory comparison of proficiencies in susceptibility testing of Helicobacter pylori and correlation between agar dilution and E test methods

Susceptibility testing was performed at seven Canadian microbiology laboratories and the Helicobacter Reference Laboratory, Halifax, Nova Scotia, Canada, to assess susceptibility testing proficiency and the reproducibility of the results for clarithromycin and metronidazole and to compare the Epsilometer test (E test) method to the agar dilution reference method. Control strain Helicobacter pylori ATCC 43504 (American Type Culture Collection) and 13 clinical isolates (plus duplicates of four of these strains including ATCC 43504) were tested blindly. The National Committee for Clinical Laboratory Standards (NCCLS) guidelines for agar dilution testing were followed, and the same suspension of organisms was used for agar dilution and E test. Antimicrobials and E test strips were provided to the investigators. Methods were provided on a website (www.Helicobactercanada.org). Each center reported MICs within the stated range for strain ATCC 43504. Compared to the average MICs, interlaboratory agreements within 2 log(2) dilutions were 90% (range, 69 to 100%) for clarithromycin by agar dilution, with seven very major errors [VMEs], and 85% (range, 65 to 100%) by E test, with three VMEs. Interlaboratory agreements within 2 log(2) dilutions were 83% (range, 50 to 100%) for metronidazole by agar dilution, with six VMEs and eight major errors (MEs), and 75% (range, 50 to 94%) by E test, with four VMEs and four MEs. At lower and higher concentrations of antibiotic, E test MICs were slightly different from agar dilution MICs, but these differences did not result in errors. When a standardized protocol based on NCCLS guidelines was used, most participants in this study correctly identified clarithromycin- and metronidazole-susceptible and -resistant strains of H. pylori 93% of the time by either the agar dilution or E test method, and the numbers of errors were relatively equivalent by both methods.