Age and alarm symptoms do not predict endoscopic findings among patients with dyspepsia: a multicentre database study.

INTRODUCTION: Symptoms of dyspepsia are common but most patients do not have major upper gastrointestinal pathology. Endoscopy is recommended for dyspeptic patients over the age of 45, or those with certain "alarm" symptoms. We have evaluated the effectiveness of age and "alarm" symptoms for predicting major endoscopic findings in six practising endoscopy centres. METHODS: Clinical variables of consecutive patients with dyspepsia symptoms undergoing upper endoscopy examinations were recorded using a common endoscopy database. Patients who had no previous upper endoscopy or barium radiography were included. Stepwise multivariate logistic regression was used to identify predictors of endoscopic findings. The accuracy of these for predicting endoscopic findings was evaluated with receiver operating characteristic analysis. The sensitivity and specificity of age thresholds from 30 to 70 years were evaluated. RESULTS: Major pathology (tumour, ulcer, or stricture) was found at endoscopy in 787/3815 (21%) patients with dyspepsia. Age, male sex, bleeding, and anaemia were found to be significant but weak independent predictors of endoscopic findings. A multivariate prediction rule based on these factors had poor predictive accuracy (c statistic=0.62). Using a simplified prediction rule of age > or =45 years or the presence of any "alarm" symptom, sensitivity was 87% and specificity was 26%. Increasing or decreasing the age cut off did not significantly improve the predictive accuracy. CONCLUSIONS: Age and the presence of "alarm" symptoms are not effective predictors of endoscopic findings among patients with dyspepsia. Better clinical prediction strategies are needed to identify patients with significant upper gastrointestinal pathology.

Is prophylactic ciprofloxacin effective in delaying biliary stent blockage?

BACKGROUND: Late stent blockage is a major complication of endoscopic stent insertion for malignant obstructive jaundice. Stents block as a result of bacterial infection and biofilm formation. We report a randomized but unblinded study using an animal model to evaluate the effect of prophylactic ciprofloxacin, which selectively suppresses gram-negative bacteria, in an attempt to prolong stent patency. METHOD: Ten adult cats underwent surgical implantation of 5F polyethylene stents through common bile duct strictures created around the choledochotomy, with the tip of the stent left in the duodenum. Five animals received intravenous ciprofloxacin perioperatively and were then maintained on oral ciprofloxacin 25 mg twice daily. Control cats were not given antibiotics. The animals were sacrificed when signs of biliary obstruction or cholangitis persisted for more than 3 days or at the end of the 16-week study period. Stents were removed and examined for patency. In addition, the stents were cultured to recover the adherent bacteria. RESULTS: All control animals developed stent blockage within 4 weeks. Two ciprofloxacin-treated cats developed stent blockage at 21 and 42 days, respectively, whereas the other 3 cats had patent stents for the entire study period. There was a significant difference between the median stent patency of 112 days for the ciprofloxacin group versus 16 days for the control group (p < 0.02). Bacteriologic cultures showed that the bile and blocked stents from the control group had predominantly gram-negative bacteria, whereas the bile and stents of the ciprofloxacin group had gram-positive and anaerobic bacteria, with an absence of gram-negative bacteria (p < 0.01). CONCLUSION: Ciprofloxacin prophylaxis eliminates gram-negative bacterial infection in bile and minimizes sludge formation and may have a potential benefit in delaying stent blockage.

In vitro evaluation of antibiotic prophylaxis in the prevention of biliary stent blockage.

BACKGROUND: Bacterial adherence and biofilm formation are important factors in the blockage of biliary stents. Clinical studies with oral antibiotic prophylaxis to prevent stent blockage have produced conflicting results. The aim of this study was to evaluate the in vitro effect of single antibiotic (ciprofloxacin, ceftazidime, or ampicillin) treatment on adherence of Escherichia coli and Enterococcus to plastic stents. METHODS: Selected clinical isolates of E coli and Enterococcus were perfused through a modified Robbins device containing segments of polyethylene stents. The stents were removed daily and the number of bacteria attached was measured. The effect of antibiotic treatment on bacterial adherence was tested by the perfusion of individual antibiotics into separate modified Robbins devices using a side-arm adaptor and the results were compared with saline controls. RESULTS: Compared with the saline controls, ciprofloxacin and ceftazidime caused a 10- to 100-fold reduction in the number of E coli attached to the stents, whereas ampicillin had no effect on adherence of E coli. Ampicillin caused a 5- to 10-fold reduction in Enterococcus adherence but there was no change with ceftazidime. Sustained reduction in E coli adherence was observed with prolonged ciprofloxacin perfusion. CONCLUSION: Timely treatment with appropriate antibiotics reduced bacterial adherence in vitro and may be potentially beneficial in the prevention of stent blockage.

Management of occluded biliary Wallstents.

BACKGROUND: Wallstents (Schneider Stent, Inc., USA) used for the palliation of malignant biliary strictures, although associated with prolonged patency, can occlude. There is no consensus regarding the optimal management of Wallstent occlusion. AIMS: To evaluate the efficacy of different endoscopic methods for managing biliary Wallstent occlusion. METHODS: A multicentre retrospective study of patients managed for a biliary Wallstent occlusion. RESULTS: Data were available for 38 patients with 44 Wallstent occlusions, all of which had initial endoscopic management. Twenty four patients had died and 14 were alive after a median follow up of 231 (30-1095) days following Wallstent occlusion. Occlusions were managed by insertion of another Wallstent in 19, insertion of a plastic stent in 20, and mechanical cleaning in five. Endoscopic management was successful in 43 (98%). Following management of the occlusion, bilirubin decreased from 6.0 (0.5-34.3) to 2.1 (0.2-27.7) mg/100 ml (p < 0.05). No complications occurred. The median duration of second stent patency was 75 days (95% confidence interval 43 to 107) after insertion of another Wallstent, 90 days (71 to 109) after insertion of a plastic stent, and 34 days (30 to 38) after mechanical cleaning (NS). The respective median survivals were 70 days (22-118), 98 days (54-142), and 34 days (30-380) (NS). Incremental cost effective analysis showed that plastic stent insertion is the most cost effective option. CONCLUSION: Although all three methods are equally effective in managing an occluded Wallstent, the most cost effective method appears to be plastic stent insertion.

Current induction in a fiberglass guidewire compared to conventional wires during simulated papillotomy.

BACKGROUND: Current induced in a guidewire during papillotomy poses a danger of injury to the bile duct. We measured currents induced in three commercially available guidewires and a prototype fiberglass wire during simulated sphincterotomy under standard and nonstandard conditions. METHODS: Blended current at 55 W was applied to a double-lumen papillotome grounded through a 1000 omega resistor. For extreme conditions, power was increased to 70 W using a single-lumen papillotome. Fault conditions were created with a break in the insulation at the distal end of each wire. Guidewire-induced current was measured, and safety calculations performed for adherence to accepted standards for electrosurgical devices. RESULTS: Induced current was within safety limits for all wires tested under standard conditions. With insulation faults, one of the commercially available wires was unsafe. Under extreme conditions, with or without faults, the three commercial wires produced currents ranging from 9% to 225% above acceptable levels, while only the prototype wire remained safe. CONCLUSIONS: Most guidewires contain metal cores that function as capacitors. Because its core is primarily fiberglass, the prototype wire generates less induced current under nonstandard conditions, thus achieving a greater margin of safety during wire-guided sphincterotomy.

Prevention of biliary stent clogging: a clinical review.

Endoscopic stenting is a well established treatment for obstructive jaundice. The major complication of the technique is late stent blockage, which results from bacterial biofilm and sludge deposition. Numerous approaches to overcoming this problem have been proposed. Large diameter stents can provide longer patency, but they do not prevent blockage indefinitely. Although many plastics have been investigated for resistance to biofilm adherence, there is no convincing evidence that any material prevents clogging in vivo. Changes in stent design and placement techniques to prevent bacterial colonization may provide more lasting effects. Long term antibiotic prophylaxis offers an intriguing possibility for prolonging stent patency. However, its efficacy remains uncertain, and more studies are required to assess timing, dosage, and the optimal spectrum of antibacterial coverage. Metal stent designs now permit delivery of larger diameters; these must be improved to prevent tumor ingrowth and to allow subsequent stent removal. In summary, our understanding of the behavior of bacterial biofilm and its role in stent blockage has improved, but we are still searching for methods to maintain stent function indefinitely.