Kavel Visrodia

Persistent contamination on colonoscopes and gastroscopes detected by biologic cultures and rapid indicators despite reprocessing performed in accordance with guidelines

BACKGROUND Pathogens have been transmitted via flexible endoscopes that were reportedly reprocessed in accordance with guidelines. METHODS Researchers observed reprocessing activities to ensure guideline compliance in a large gastrointestinal endoscopy unit. Contamination was assessed immediately after bedside cleaning, manual cleaning, high-level disinfection, and overnight storage via visual inspection, aerobic cultures, and tests for adenosine triphosphate (ATP), protein, carbohydrate, and hemoglobin. RESULTS All colonoscopes and gastroscopes were reprocessed in accordance with guidelines during the study. Researchers collected and tested samples during 60 encounters with 15 endoscopes. Viable microbes were recovered from bedside-cleaned (92%), manually cleaned (46%), high-level disinfected (64%), and stored (9%) endoscopes. Rapid indicator tests detected contamination (protein, carbohydrate, hemoglobin, or ATP) above benchmarks on bedside-cleaned (100%), manually cleaned (92%), high-level disinfected (73%), and stored (82%) endoscopes. Visible residue was never observed on endoscopes, but it was often seen on materials used to sample endoscopes. Seven endoscopes underwent additional reprocessing in response to positive rapid indicators. Control endoscope channels were free of biologic residue and viable microbes. CONCLUSION Despite reprocessing in accordance with US guidelines, viable microbes and biologic debris persisted on clinically used gastrointestinal endoscopes, suggesting current reprocessing guidelines are not sufficient to ensure successful decontamination.

Magnitude of Missed Esophageal Adenocarcinoma After Barrett's Esophagus Diagnosis: A Systematic Review and Meta-analysis

BACKGROUND & AIMS A proportion of patients with Barretts esophagus (BE) are diagnosed with esophageal adenocarcinoma (EAC) within 1 year of an endoscopic examination that produced negative findings. These cases of missed cancers have not been well studied, despite current surveillance strategies for BE. We performed a systematic review and meta-analysis to determine the magnitude of missed EAC in cohorts of patients with BE. METHODS We searched MEDLINE, EMBASE, and Web of Science from their inception to May 31, 2015 to identify cohort studies of adults with BE (baseline nondysplastic BE ± BE with low-grade dysplasia) and at least a 3-year follow-up period, providing data on missed and incident EACs (diagnosed within 1 year and diagnosed more than 1 year after the initial endoscopy in which BE was diagnosed, respectively). The main outcome measure was pooled proportion of missed and incident EACs (of all EACs detected after initial endoscopy) among BE cohorts, using a random effects model. RESULTS In a meta-analysis of 24 studies reporting on 820 missed and incident EACs, 25.3% were classified as missed (95% confidence interval: 16.4%-36.8%) and 74.7% as incident EACs (95% CI: 63.2%-83.6%), although there was substantial heterogeneity among studies (I2 = 74%). When the analysis was restricted to nondysplastic BE cohorts (15 studies), 23.9% of EACs were classified as missed (95% confidence interval: 15.3%-35.4%; I2 = 0%). In a meta-analysis of 10 studies with follow-up periods of ≥5 years (a total of 239 EACs), 22.0% were classified as missed (95% confidence interval: 8.7%-45.5%), with substantial heterogeneity (I2 = 68%). CONCLUSIONS Among adults with nondysplastic BE (or BE with low-grade dysplasia) at their index endoscopy and at least a 3-year follow-up period, 25% of EACs are diagnosed within 1 year after the index endoscopy. Additional resources should be allocated to detect missed EAC.

The Use of Rapid Indicators for the Detection of Organic Residues on Clinically Used Gastrointestinal Endoscopes with and without Visually Apparent Debris

BACKGROUND Outbreaks of multidrug-resistant organisms have been linked to endoscope reprocessing lapses. Meticulous manual cleaning before high-level disinfection (HLD) is essential in reducing residual contamination that can interfere with HLD. Current reprocessing guidelines state that visual inspection is sufficient to confirm adequate cleaning. OBJECTIVE Our aim was to evaluate contamination of clinically used endoscopes, using visual inspection and rapid indicator tests before and after manual cleaning. A second objective was to determine which rapid indicator instruments and methods could be used for quality improvement initiatives in endoscope reprocessing. DESIGN Clinical use study of endoscope reprocessing effectiveness. SETTING Tertiary care teaching hospital with an inpatient endoscopy center. METHODS Researchers sampled endoscopes used for gastrointestinal procedures before and after manual cleaning. The external surfaces and 1 channel of each endoscope were visually inspected and tested with rapid indicators to measure protein, blood, and adenosine triphosphate (ATP) contamination levels. RESULTS Multiple components were sampled during 37 encounters with 12 unique endoscopes. All bedside-cleaned endoscopes had high levels of ATP and detectable blood or protein, whether or not any residue was visible. Although there was no visible residue on any endoscopes after manual cleaning, 82% had at least 1 positive rapid indicator test. CONCLUSIONS Relying solely on visual inspection of endoscopes prior to HLD is insufficient to ensure reprocessing effectiveness. For quality assurance initiatives, tests of different endoscope components using more than 1 indicator may be necessary. Additional research is needed to validate specific monitoring protocols.

Breath Testing for Barrett’s Esophagus Using Exhaled Volatile Organic Compound Profiling With an Electronic Nose Device

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 Jacques Bergman and Patrick Yachimski, Section Editors 61 62 63 64 65 Breath Testing for Barrett’s Esophagus Using Exhaled Volatile Organic Compound Profiling With an Electronic Nose Device 66 67 68 69 70 71 Daniel K. Chan, Liam Zakko, Kavel H. Visrodia, Cadman L. Leggett, Lori S. Lutzke, Magdalen A. Clemens, James D. Allen, Marlys A. Anderson, and Kenneth K. Wang

Endoscopic management of benign biliary strictures.

Endoscopic management of biliary obstruction has evolved tremendously since the introduction of flexible fiberoptic endoscopes over 50 years ago. For the last several decades, endoscopic retrograde cholangiopancreatography (ERCP) has become established as the mainstay for definitively diagnosing and relieving biliary obstruction. In addition, and more recently, endoscopic ultrasonography (EUS) has gained increasing favor as an auxiliary diagnostic and therapeutic modality in facilitating decompression of the biliary tree. Here, we provide a review of the current and continually evolving role of gastrointestinal endoscopy, including both ERCP and EUS, in the management of biliary obstruction with a focus on benign biliary strictures.

Systematic review with meta-analysis: prevalent vs. incident oesophageal adenocarcinoma and high-grade dysplasia in Barrett's oesophagus.

The proportion of oesophageal adenocarcinoma that is detected concurrently with initial Barretts oesophagus diagnosis is not well studied.

Radiofrequency Ablation of Barrett’s Esophagus: Efficacy, Complications, and Durability

In the last decade, radiofrequency ablation in combination with endoscopic mucosal resection has simplified and improved the treatment of Barretts esophagus. These treatments not only reduced the progression of dysplastic Barretts esophagus to esophageal adenocarcinoma but also decreased treatment-related complications. More recent data from larger series with extended follow-up periods are emerging to refine expectations in patients treated with radiofrequency ablation. Although most patients achieve eradication of neoplasia and intestinal metaplasia, in the long-term a substantial portion of patients develop recurrent disease. This article provides an updated review of radiofrequency ablation efficacy, complications, and durability.

Reprocessing of single-use endoscopic variceal band ligation devices: a pilot study

Background and study aims The preferred management of bleeding esophageal varices includes endoscopic band ligation. Endoscopic ligation devices (ELDs) are expensive and designed for single use, limiting their uptake in developing countries. We aimed to assess the efficacy of reprocessing ELDs using terminal microbial cultures and adenosine triphosphate (ATP) testing. Materials and methods ELDs were recovered after clinical use and their components (cap, handle, and cord) were subjected to reprocessing. This included manual cleaning, automated high-level disinfection (HLD), and drying with forced air. Using sterile technique, ELD components were sampled for ATP at three stages: before manual cleaning, after manual cleaning, and after HLD. Components were sent to an external laboratory for culturing. Cultures were interpreted as positive upon identification of Gram-negative bacilli. Results A total of 14 clinically used ELDs were studied, and 189 ATP tests and 41 cultures were evaluated. Overall, 95 % (39/41) of components and 86 % (12/14) of ELDs were culture-negative or did not yield Gram-negative bacilli. Two components (5 %; one handle and one cord) harbored Gram-negative bacilli in quantities of 1 CFU per component. There was no apparent correlation between ATP at any juncture of reprocessing and terminal cultures. Conclusions Reprocessing of ELDs is effective, resulting in infrequent and minimal microbial contamination. Microbial culturing can be used to ensure adequacy of ELD reprocessing if pursued. Until reusable ELDs are commercially available, continued efforts to better define the adequacy and long-term effects of reprocessing ELDs are needed.

Factors Associated with Progression of Barrett’s Esophagus: A Systematic Review and Meta-analysis

Background & Aims: Endoscopic surveillance of patients with Barretts esophagus (BE) is inefficient. Risk stratification of patients might improve the effectiveness of surveillance. We performed a systematic review and meta‐analysis to identify factors associated with progression of BE without dysplasia or BE with low‐grade dysplasia (LGD) to high‐grade dysplasia or esophageal adenocarcinoma. Methods: We performed a systematic search of databases through May 2016 to identify cohort studies of patients with baseline BE without dysplasia or BE with LGD that reported predictors of progression. Pooled estimates (odds ratios) of associations of age, sex, smoking, alcohol use, obesity, baseline LGD, segment length, and medication use with progression were calculated. Results: We identified 20 studies, reporting 1231 events in 74943 patients. The studies associated BE progression with increasing age (12 studies; odds ratio [OR], 1.03; 95% CI, 1.01–1.05), male sex (11 studies; OR, 2.16; 95% CI, 1.84–2.53), ever smoking (current or past, 8 studies; OR, 1.47; 95% CI, 1.09–1.98), and increasing BE segment length (10 studies; OR, 1.25; 95% CI, 1.16–1.36), with a low degree of heterogeneity. LGD was associated with a 4‐fold increase in risk of BE progression (11 studies; OR, 4.25; 95% CI, 2.58–7.0). Use of proton pump inhibitors (4 studies; OR, 0.55; 95% CI, 0.32–0.96) or statins (3 studies; OR, 0.48; 95% CI, 0.31–0.73) were associated with lower risk of BE progression. Alcohol use and obesity did not associate with risk of progression. Conclusions: In a systematic review and meta‐analysis, we associated older age, male sex, smoking, longer BE segment, and LGD with risk of progression of BE. Individuals with these features should undergo more intensive surveillance or endoscopic therapy. Smoking is a modifiable risk factor for cancer prevention in patients with BE.

Reply to Whiteley et al

triplicate testing. Reliance by Visrodia et al. upon the sample means of groups of singular ATP readings is undermined by the knowledge of variability where the standard deviation can be as high as 40% of the data mean for the individual brand of device used. The authors themselves note the risk of singular testing in the body of the discussion: “to sample more than one... and to use more than 1 rapid indicator,” but we wonder how the statistical assumptions hold valid without multiple (replicate) samples taken for the ATP testing. We also note 2 problems with the scaling of all commercial ATP devices. First, the scale of RLU is completely relative and cannot be used interoperatively between differently branded devices. Second, the variability for each of the brands is so high that without a sampling approach that accounts for multiple samples at any one point, the ability of the scientists involved to meaningfully apply statistical methods renders the article subject to first principle flaws. Reporting the RLU readings on a log scale is not the same as taking multiple samples, identifying the median value, and then log plotting the data. Perhaps this was done, but it remains unclear within the text. We feel obliged to inform those who may be reliant upon the work to take care in not applying the work using one brand of ATP device to another brand of ATP device, as noted in the commentary by Petersen. Likewise, we caution against relying on the statistical positioning in the field use of ATP without an appropriately constructed sampling plan to account for inherent variability. This overlay of concern will continue to apply until all ATP device manufacturers can agree to a commonly applicable scale that minimizes the impact of variability, no matter what the assignation given to the replacement reading scale.