Performance characteristics and optimal cut-off value of triple adenylate nucleotides test versus adenosine triphosphate test as point-of-care testing for predicting inadequacy of duodenoscope reprocessing.

BACKGROUND: Adenosine triphosphate (ATP) test based on one nucleotide has been applied as point-of-care testing (POCT) for bacterial contamination in the medical and food industries. Hypothetically, testing three adenylate nucleotides (A3) may provide better detection of duodenoscope bacterial contamination than ATP test. AIM: To evaluate performance characteristics and optimal cut-off value of A3 and ATP tests in predicting bacterial contamination of duodenoscopes. METHODS: Four hundred duodenoscope samples obtained after 100 endoscopic retrograde cholangiopancreatography procedures were randomized into group A (A3 test) or B (ATP test). Samples were collected from the elevator at the four-step cleaning process of duodenoscope. We defined the new cut-off value of the test for reaching 100% negative predictive value (NPV) from our receiver operating characteristic (ROC). FINDINGS: Using the cultures from the four-step cleaning process as the reference, the areas under ROC (AUROC) were 0.83 and 0.84 for group A (N = 200) and group B (N = 200), respectively. Using the cultures from post-high-level disinfection (HLD) as the reference, the AUROC were 0.35 and 0.74 for group A (N = 50) and group B (N = 50), respectively. We investigated ATP as a POCT after HLD with a new cut-off value of 40 RLU. However, this threshold did not allow detection of low numbers of bacteria. CONCLUSION: A3 and ATP tests provide good performances in predicting bacterial contamination of duodenoscopes for the four-step cleaning process. The ATP <40 RLU is helpful as a POCT after HLD; however, the limitation of this cut-off value is its inability to detect low numbers of bacteria.

Review article: Asia-Pacific consensus recommendations on endoscopic tissue acquisition for biliary strictures.

BACKGROUND: Pre-operative tissue diagnosis for suspected malignant biliary strictures remains challenging. AIM: To develop evidence-based consensus statements on endoscopic tissue acquisition for biliary strictures. METHODS: The initial draft of statements was prepared following a systematic literature review. A committee of 20 experts from Asia-Pacific region then reviewed, discussed, and modified the statements. Two rounds of independent voting were conducted to reach a final version. Consensus was considered to be achieved when 80% or more of voting members voted "agree completely" or "agree with some reservation." RESULTS: Eleven statements achieved consensus. The choice of tissue sampling modalities for biliary strictures depends on the clinical setting, the location of lesion, and availability of expertise. Detailed radiological and endoscopic evaluation is useful to guide the selection of appropriate tissue acquisition technique. Standard intraductal biliary brushing and/or forceps biopsy is the first option when endoscopic biliary drainage is required with an overall (range) sensitivity and specificity of 45% (26%-72%) and 99% (98%-100%), and 48% (15%-100%) and 99% (97%-100%), respectively, in diagnosing malignant biliary strictures. Probe-based confocal laser endomicroscopy and fluorescence in situ hybridisation using 4 fluorescent-labelled probes targeting chromosomes 3, 7, 17 and 9p21 locus may be added to improve the diagnostic yield. Cholangioscopy-guided biopsy and EUS-guided tissue acquisition can be considered after prior negative conventional tissue sampling with an overall (range) sensitivity and specificity of 60% (38%-88%) and 98% (83%-100%), and 80% (46%-100%) and 97% (92%-100%), respectively, in diagnosing malignant biliary strictures. CONCLUSION: These consensus statements provide evidence-based recommendations for endoscopic tissue acquisition of biliary strictures.

The risk of gastric cancer in patients with gastric intestinal metaplasia in 5-year follow-up.

BACKGROUND: Gastric intestinal metaplasia (GIM) is the premalignant stage of gastric cancer; however, consensus on its management has not been established. AIM: To determine the risk factors for gastric cancer in a population of patients with GIM to guide the appropriate clinical recommendations in a low prevalence area for gastric cancer. METHODS: This was a retrospective cohort study. Ninety-one patients with GIM diagnosed between 2004 and 2014 were recruited for surveillance EGD every 6-12 months until a diagnosis of gastric cancer or completion of the planned 5-year follow-up duration. Possible risk factors for gastric cancer were assessed. RESULTS: At initial presentation, 81 of the 91 patients (89%) had complete GIM, whereas the remaining 11% had a study entry diagnosis of incomplete GIM. No cancer developed amongst patients with complete GIM. In contrast, five of the 10 patients exhibiting incomplete GIM (50%) progressed to high-grade dysplasia (n=2) or cancer (n=3). Male gender (P=.027), and incomplete GIM (P=.001) were associated with high-risk histology (dysplasia or cancer) by study end. A trend suggested a possible association with smoking (P=.08). CONCLUSION: Male patients and those with incomplete GIM are at greatest risk of developing dysplasia or early gastric cancer. Further studies in determining optimal surveillance intervals and impact on cancer incidence and mortality are still required.

Asia Pacific consensus recommendations for colorectal cancer screening.

Colorectal cancer (CRC) is rapidly increasing in Asia, but screening guidelines are lacking. Through reviewing the literature and regional data, and using the modified Delphi process, the Asia Pacific Working Group on Colorectal Cancer and international experts launch consensus recommendations aiming to improve the awareness of healthcare providers of the changing epidemiology and screening tests available. The incidence, anatomical distribution and mortality of CRC among Asian populations are not different compared with Western countries. There is a trend of proximal migration of colonic polyps. Flat or depressed lesions are not uncommon. Screening for CRC should be started at the age of 50 years. Male gender, smoking, obesity and family history are risk factors for colorectal neoplasia. Faecal occult blood test (FOBT, guaiac-based and immunochemical tests), flexible sigmoidoscopy and colonoscopy are recommended for CRC screening. Double-contrast barium enema and CT colonography are not preferred. In resource-limited countries, FOBT is the first choice for CRC screening. Polyps 5-9 mm in diameter should be removed endoscopically and, following a negative colonoscopy, a repeat examination should be performed in 10 years. Screening for CRC should be a national health priority in most Asian countries. Studies on barriers to CRC screening, education for the public and engagement of primary care physicians should be undertaken. There is no consensus on whether nurses should be trained to perform endoscopic procedures for screening of colorectal neoplasia.

Risk of bacteremia in bleeding and nonbleeding gastric varices after endoscopic injection of cyanoacrylate.

BACKGROUND AND STUDY AIM: Bacteremia is common in cirrhosis with gastrointestinal bleeding, including variceal bleeding. Elective esophageal sclerotherapy and banding have been reported to cause bacteremia. The risk associated with therapeutic endoscopy in patients with gastric varices has not yet been reported. This study was conducted to compare the risk of bacteremia between patients with active gastric variceal bleeding and those with gastric varices that were not actively bleeding who underwent N-butyl-2-cyanoacrylate injection. PATIENTS AND METHODS: Patients were categorized into three groups: group I, patients with bleeding gastric varices who underwent cyanoacrylate injection for hemostasis (n = 20); group II, patients who underwent elective cyanoacrylate injection for further obliteration of gastric varices (n = 18); and group III, patients with cirrhosis who underwent endoscopic surveillance for varices, and patients with gastric varices who presented for a follow-up endoscopy without a requirement for treatment (n = 17). Blood culture was obtained before and 5 minutes and 3 hours after endoscopy. Needle tips were also sent for culture. RESULTS: Before procedures, blood cultures were positive in 4 patients (20 %) from group I. The number of positive blood cultures in group I at 5 minutes and 3 hours after the procedure were 3 (15 %) and 2 (10 %) respectively. The identified organisms were: Klebsiella pneumoniae (2), Escherichia coli (1), Vibrio cholerae non-O1 (1). No patient from group II had a positive culture at any point of blood drawn. Only one in group III had a positive culture, for Streptococcus mitis at 5 minutes. No clinical evidence of infections occurred in any patient. Needle-tip cultures grew mainly organisms from the oral and gastrointestinal tracts. CONCLUSIONS: Elective cyanoacrylate injection for nonbleeding gastric varices is not associated with significant bacteremia or infection. For this reason, prophylactic antibiotics may not be needed in this patient group. By contrast, prophylactic antibiotics are strongly recommended for patients with bleeding gastric varices undergoing cyanoacrylate injection.

Endoscopy in HIV infected patients.

HIV is a very common infection in Thailand, affecting about one million of the population already, with 99,555 persons with full blown AIDS at the end of 1999. The first case of AIDS was reported in Thailand in 1984. Gastrointestinal involvement is very common, the commonest presentations are diarrhea, esophageal symptoms, hepatobiliary symptoms, and weight loss. When the CD4+ T cell count falls below 200, the body becomes highly susceptible to opportunistic infections and neoplasms. Almost all AIDS patients will have GI symptoms at sometime during the course of their illness. This is because the GI tract contains an abundant quantity of lymphoid tissue and is likely to function as a reservoir of HIV infection. In chronic diarrhea cases, apart from other investigations, small bowel biopsy and aspiration may help to find the cause. If oral candidiasis is present, one should keep HIV in mind and look for oral hairy leucoplakia, dysphagia and odynophagia as one-third of patients with AIDS will develop dysphagia or odynophagia in the course of their disease. Those with esophageal candidiasis will usually have oral candidiasis and odynophagia while 18 per cent of the patients will not have oral thrush. CMV esophagitis and HIV ulcer (or idiopathic oesophageal ulcer) are also common. Upper gastrointestinal endoscopy and biopsy are helpful in finding the exact cause of the oesophageal symptoms. Hepatobiliary manifestations are present with jaundice, hepatomegaly, and pain. ERCP is very helpful in diagnosing and classifying these conditions. Papillary stenosis and dominant biliary stricture can be treated by endoscopy but long term results are still poor due to late manifestation of these conditions.

Endoscopic management of cholangiocarcinoma.

Cholangiocarcinoma constitutes the second most common primary liver cancer after hepatocellular carcinoma. It is particularly prevalent in regions where liver flukes are hyperendemic. Obstructive jaundice is the most common presentation. To evaluate patients suspected for cholangiocarcinoma, endoscopy is becoming more popular. Endoscopy can provide important information especially cholangiogram and tissue diagnosis. Recently, the role of endoscopy has not only been used for diagnosis but also for treatment. In this article, the roles of endoscopy for diagnosis, therapy, and future modality of treatment for cholangiocarcinoma are provided.