A bacteriologic and scanning electron microscope study after implantation of foreign bodies in the biliary tract in rats

Comparison of bacterial profile of gallbladder with gallstones from patients undergoing cholecystectomy due to complicated and uncomplicated cholelithiasis: changes in the epidemiological scenario

INTRODUCTION

cholelithiasis is a highly prevalent disease of the digestive system in the world. In Brazil, it is a routine condition, whose studies suggest a prevalence of around 10% of adults. Colonization of bile and gallstone pathogens can occur when there is bacterial stasis and proliferation. This proliferation is facilitated by the adhesion and biofilm formation capacity of some bacteria. There are also lithogenic processes that involve bacterial participation. Studies have shown changes in the microbiota of the gallbladder of patients undergoing cholecystectomy, which may impact empirical treatment with antibiotics.

METHODOLOGY

microbiological analyzes of the sonication fluid of the gallstones and of two samples with bile were performed. Identification and antimicrobial susceptibility testing were performed according to a standard routine.

RESULTS

of the 34 patients, 76.4% were female. The age group was 48 years +/- 16.61. Acute cholecystitis occurred in 50% of cases. Bactobilia was evidenced in 32.1% of the cases. Klebisiella pneumoniae was noted as the most prevalent pathogen in acute cholecystitis; and Enterobacter sp, in cases of uncomplicated cholelithiasis. Greater sensitivity was obtained in the search for microorganisms in the sonication fluid samples of the stones in relation to the bile samples (p=0.0058).

CONCLUSION

there was a higher prevalence of bactobilia in patients with acute cholecystitis compared to those with uncomplicated cholelithiasis. The use of sonication in bacterial investigation proved to be superior to the conventional method and can be considered.

Expanded polytetrafluoroethylene in canine bile duct injury: a critical analysis

PURPOSE: Analyze the morphological and structural outcomes of a patch of expanded polytetrafluoroethylene in the treatment of an iatrogenic injury of the common bile duct. METHODS: In Group 1 (Sham), 7 dogs underwent 3 laparotomies with intervals of 30 days between them. In Group 2, 10 dogs underwent transient common bile duct obstruction. After 30 days, this biliary occlusion was undone and a patch of expanded polytetrafluoroethylene replaced a fragment removed from the duct's wall. Thirty days after this last surgery, cholangiographic assessment of prosthesis patency and macro and microscopic evaluation of the biliary tract were performed. Daily clinical inspection completed the study outcomes. The Wilcoxon non-parametric test was used for statistical analysis. RESULTS: In all dogs enlargement of the biliary tree diameter was observed 30 and 60 days after the first surgical procedure. Partial adhesion of the patch to the common bile duct as a free luminal foreign body was found in 6 dogs. The prosthesis was completely integrated to surrounding tissue in the remaining four. CONCLUSION: Although a feasible option for the treatment of biliary duct iatrogenic lesions, the expanded polytetrafluoroethylene prosthesis must be used with caution considering the potential risks for complications.

A novel antireflux metal stent for the palliation of biliary malignancies: a pilot feasibility study (with video)

BACKGROUND

Antireflux stents that prevent duodenal biliary reflux may improve biliary drainage and prolong stent patency. However, the use of antireflux metal stents (ARMSs) in the human biliary system has not been reported.

OBJECTIVE

To evaluate the safety and efficacy of ARMSs for the palliation of unresectable distal biliary malignancies.

DESIGN AND SETTING

A retrospective case series in a tertiary referral center.

PATIENTS

From August 2007 to April 2009, a total of 23 patients with unresectable nonhilar malignant biliary obstruction.

INTERVENTION

Endoscopic placement of an ARMS.

MAIN OUTCOME MEASUREMENTS

Technical success and early complications with follow-up of stent patency and patient survival.

RESULTS

Placement of an ARMS was successful on the first attempt in all patients. There were no procedure-related complications. Follow-up was obtained in 22 cases. Serum bilirubin level returned to normal within 1 month of stenting in 20 patients. Six stent malfunctions occurred as a result of tumor ingrowth (1 patient), tumor overgrowth (2 patients), and stent migration (3 patients). The remaining patients were free of biliary symptoms until death or final follow-up. The median duration of stent patency of ARMSs was 14 months, with cumulative patency rates at 3, 6, and 12 months of 95%, 74%, and 56%, respectively. The median survival of the patients was 7.9 months (range, 1-14 months).

LIMITATIONS

Small number of patients in single endoscopy center.

CONCLUSIONS

Endoscopic insertion of an ARMS is technically feasible, safe, and effective in patients with distal malignant biliary obstruction. The impact of ARMSs in prolonging stent patency and life expectancy deserves further randomized evaluation.

Impact of reducing duodenobiliary reflux on biliary stent patency: an in vitro evaluation and a prospective randomized clinical trial that used a biliary stent with an antireflux valve

BACKGROUND

The mechanisms leading to occlusion of plastic biliary stents (PBS) are not known.

OBJECTIVE

To evaluate the impact of reducing duodenobiliary reflux on stent patency rate.

DESIGN

A newly designed antireflux PBS (AR-PBS) was tested in vitro by using ox bile. A prospective randomized trial in human beings was conducted.

SETTING

Tertiary medical center.

PATIENTS

Patients with malignant bile-duct strictures were studied.

INTERVENTIONS

A PBS or an AR-PBS stent was placed by using standard techniques, and the patients were followed at regular intervals. Patients presenting with stent occlusion underwent re-stent placement with either a PBS or a metal stent.

MAIN OUTCOME MEASUREMENTS

In vitro: resistance to retrograde flow and comparison of the basal and peak antegrade flow pressures between the 2 stents. In vivo: stent patency rates, complications, and the efficacy of the stents in improving the liver test.

RESULTS

The AR-PBS stent could withstand a retrograde pressure gradient of >320 mm Hg compared with <1 mm Hg for the PBS. Secondary to the siphon effect of the valve, the antegrade flow resistance offered by the AR-PBS was on the negative side for all flow rates compared with PBS (P < .001). The median patency of the AR-PBS in human studies was 145 days (range, 52-252 days) compared with 101 days (range, 41-210 days) for the PBS (P = .002). Both stents were equally effective in improving the liver test, and complication rates were similar in the 2 groups.

LIMITATIONS

The occluded stents were not examined microscopically.

CONCLUSIONS

The antireflux biliary stent remains patent for a longer time and hence duodenobiliary reflux may be contributing to stent occlusion.

Antireflux biliary stents: are they the solution to stent occlusions?

Endoscopic insertion of plastic or metal stents is a well-established treatment for malignant biliary obstruction. The major limitation of this technique is stent occlusion. Duodenobiliary reflux has been considered a key contributor to stent occlusion. The presence of plant fibers in 35% to 60% of occluded stents on confocal laser microscopy has further confirmed the presence of reflux when the stent is placed across the papilla. Antireflux stents address this problem by allowing normal antegrade flow but preventing reflux. Recent studies comparing these antireflux stents with the standard Tannenbaum stents have shown significantly prolonged patency. Although initial results are encouraging, larger randomized trials are required to establish efficacy.

Malignant biliary obstruction: treatment with ePTFE-FEP- covered endoprostheses initial technical and clinical experiences in a multicenter trial

PURPOSE

To determine and present the initial technical and clinical results of using an expanded polytetrafluoroethylene-fluorinated ethylene propylene (ePTFE-FEP)-covered biliary endoprosthesis to treat malignant biliary obstruction.

MATERIALS AND METHODS

This prospective nonrandomized study included 42 patients with malignant obstruction of the common bile duct, common hepatic duct, and hilar confluence. Unilateral (n = 38) or bilateral (n = 4) bile duct drainage was performed by using fully covered endoprostheses with anchoring fins. To avoid branch duct blockage, endoprostheses with drainage holes at the proximal end were available. Procedure- and device-related complications were recorded. Patient survival and stent patency rates were calculated with Kaplan-Meier survival analysis. Mean follow-up bilirubin and alkaline phosphatase levels were calculated, and differences in means were evaluated with a paired t test.

RESULTS

Successful deployment, correct positioning, and patency of the device were achieved in all patients. Procedure-related complications occurred in two (5%) patients. Thirty-day mortality rate was 20% (eight of 41 patients), and median survival time was 146 days. Laboratory values decreased significantly after the procedure (P <.001). Recurrent obstructive jaundice occurred in six (15%) patients. Primary patency rates at 3, 6, and 12 months were 90%, 76%, and 76%, respectively. Calculation of the composite end point of death or obstruction revealed a median patency duration of 138 days. No endoprosthesis migration was observed. Branch duct obstruction was observed in four (10%) patients. Postmortem examination of one stent revealed a widely patent endoprosthesis with intact covering.

CONCLUSION

Initial results of percutaneous treatment of malignant biliary obstructions with fully covered ePTFE-FEP endoprostheses suggest that they are safe and potentially clinically effective.

Enterococcus faecalis surface proteins determine its adhesion mechanism to bile drain materials

An important step in infections associated with biliary drains is adhesion of micro-organisms to the surface. In this study the role of three surface proteins of Enterococcus faecalis (enterococcal surface protein, aggregation substances 1 and 373) in the adhesion to silicone rubber, fluoro-ethylene-propylene and polyethylene was examined. Four isogenic E. faecalis strains with and without aggregation substances and one strain expressing enterococcal surface protein were used. The kinetics of enterococcal adhesion to the materials was measured in situ in a parallel plate flow chamber. Initial deposition rates were similar for all strains, whereas the presence of surface proteins increased the total number of adhering bacteria. Nearest neighbour analysis demonstrated that enterococci expressing the whole sex-pheromone plasmid encoding aggregation substances 1 or 373 adhered in higher numbers through mechanisms of positive cooperativity, which means that adhesion of bacteria enhances the probability of adhesion of other bacteria near these bacteria. Enterococci with the enterococcal surface protein did not adhere through this mechanism. These findings indicate that the surface proteins of E. faecalis play a key role in the adhesion to bile drains and bile drain associated infections.