Serrated polyps <10 mm cannot reliably be characterized by i-Scan without magnification at routine colonoscopy.

BACKGROUND: Colorectal lesions (CRLs) <10 mm found at colonoscopy tend towards "diagnose-and-leave" or "resect-and-discard" strategies based on real-time Kudo glandular pit-pattern's assessment using i-Scan. However, i-Scan has not yet been validated for Kudo's classification. We aimed to assess whether, in routine colonoscopy, i-Scan without magnification and optical enhancement (M-OE) reliably differentiates hyperplastic polyps (HPs) from other serrated lesions (SLs) and conventional adenomas (CAs), and, among SLs, HPs from sessile serrated lesions (SSLs) and traditional or unknown serrated adenomas (TSAs, USAs), in Kudo type II CRLs<10 mm, according to ASGE Preservation and Incorporation of Valuable endoscopic Innovations (PIVI) recommended negative predictive value (NPV) threshold for adenomas. METHODS: Prospectively recorded CRLs over 12 months, classified according to Kudo pit-pattern using i-Scan, were retrospectively compared with histology. RESULTS: Overall, 898 ≤5-mm and 704 6- to 9-mm CRLs were included. Type II pit-pattern was found in 76.6% and 38.7% of HPs and SSLs-TSAs/CAs (P<0.000001), and in 84.1% and 26.6% of SLs and CAs (P<0.000001). Among SLs, it was found in 81.9% and 86.6% of HPs and SSLs-TSAs. In CRLs≤5 mm, HPs were prevalent over other SLs (P=0.00001); in CRLs 6-9 mm, CAs were prevalent (P<0.000001). About 77% of SLs in right colon were SSLs-TSAs; 82% in left colon were HPs. PIVI ≥90% NPV threshold for adenomas was reached for CRLs 6-9mm (92.1%), nearly achieved for CRLs≤5 mm (88.2%), and not reached for SLs independently on the size. CONCLUSIONS: A strategy of "diagnose-and-leave" or "resect-and-discard" cannot be recommended for SLs<10 mm with Kudo type II pit-pattern using i-Scan, especially in right colon, if M-OE unavailable.

Sedation and analgesia in gastrointestinal endoscopy: what's new?

Various types of sedation and analgesia technique have been used during gastrointestinal endoscopy procedures. The best methods for analgesia and sedation during gastrointestinal endoscopy are still debated. Providing an adequate regimen of sedation/analgesia might be considered an art, influencing several aspects of endoscopic procedures: the quality of the examination, the patient's cooperation and the patient's and physician's satisfaction with the sedation. The properties of a model sedative agent for endoscopy would include rapid onset and offset of action, analgesic and anxiolytic effects, ease of titration to desired level of sedation, rapid recovery and an excellent safety profile. Therefore there is an impulse for development of new approaches to endoscopic sedation. This article provides an update on the methods of sedation today available and future directions in endoscopic sedation.

Optical coherence tomography in detection of dysplasia and cancer of the gastrointestinal tract and bilio-pancreatic ductal system.

Optical coherence tomography (OCT) is an optical imaging modality that performs high-resolution, cross-sectional, subsurface tomographic imaging of the microstructure of tissues. The physical principle of OCT is similar to that of B-mode ultrasound imaging, except that it uses infrared light waves rather than acoustic waves. The in vivo resolution is 10-25 times better (about 10 microns) than with high-frequency ultrasound imaging, but the depth of penetration is limited to 1-3 mm, depending upon tissue structure, depth of focus of the probe used, and pressure applied to the tissue surface. In the last decade, OCT technology has evolved from an experimental laboratory tool to a new diagnostic imaging modality with a wide spectrum of clinical applications in medical practice, including the gastrointestinal (GI) tract and pancreatic-biliary ductal system. OCT imaging from the GI tract can be done in humans by using narrow-diameter, catheter-based probes that can be inserted through the accessory channel of either a conventional front-view endoscope, for investigating the epithelial structure of the GI tract, or a side-view endoscope, inside a standard transparent ERCP catheter, for investigating the pancreatico-biliary ductal system. Esophagus and the esophago-gastric junction has been the most widely investigated organ so far; more recently, also duodenum, colon and pancreatico-biliary ductal system have been extensively investigated. OCT imaging of the gastro-intestinal wall structure is characterized by a multiple-layer architecture that permits an accurate evaluation of the mucosa, lamina propria, muscularis mucosae, and part of the submucosa. The technique may be, therefore, used to identify pre-neoplastic conditions of the GI tract, such as Barrett's epithelium and dysplasia, and evaluate the depth of penetration of early-stage neoplastic lesions. OCT imaging of the pancreatic and biliary ductal system could improve the diagnostic accuracy for ductal epithelial changes and the differential diagnosis between neoplastic and non-neoplastic lesions.

Endoscopic pancreatic duct stent placement for inflammatory pancreatic diseases.

The role of endoscopic therapy in the management of pancreatic diseases is continuously evolving; at present most pathological conditions of the pancreas are successfully treated by endoscopic retrograde cholangio-pancreatography (ERCP) or endoscopic ultrasound (EUS), or both. Endoscopic placement of stents has played and still plays a major role in the treatment of chronic pancreatitis, pseudocysts, pancreas divisum, main pancreatic duct injuries, pancreatic fistulae, complications of acute pancreatitis, recurrent idiopathic pancreatitis, and in the prevention of post-ERCP pancreatitis. These stents are currently routinely placed to reduce intraductal hypertension, bypass obstructing stones, restore lumen patency in cases with dominant, symptomatic strictures, seal main pancreatic duct disruption, drain pseudocysts or fluid collections, treat symptomatic major or minor papilla sphincter stenosis, and prevent procedure-induced acute pancreatitis. The present review aims at updating and discussing techniques, indications, and results of endoscopic pancreatic duct stent placement in acute and chronic inflammatory diseases of the pancreas.

Effects of gabexate mesilate, a protease inhibitor, on human sphincter of Oddi motility.

Gabexate mesilate is an antiprotease drug, which reduced the severity of pancreatitis and frequency of post-ERCP pancreatitis. In dogs gabexate inhibits sphincter of Oddi motility but no data are available in humans. The aim of this study was to verify by manometry the action of gabexate on human sphincter of Oddi motility. We enrolled 12 patients with idiopathic recurrent pancreatitis (eight males, five females, mean age 46 +/- 8 years). Standard preendoscopic sphincter of Oddi manometry was done in basal conditions and during infusion of gabexate 20 mg/min: basal pressure, amplitude and frequency of phasic contractions, and motility index (amplitude per frequency) were calculated before and after gabexate injection. Statistical analysis was performed by using Wilcoxon rank test for paired data. Six patients had a manometric diagnosis of stenosis (basal pressure greater than 40 mm Hg); six had normal findings. Phasic activity was not evaluable in five patients with stenosis. Basal pressure was unaffected by drug infusion, while gabexate caused a significant reduction of phasic activity, both in terms of frequency (4.5 +/- 1 vs 3.6 +/- 1; P < 0.05) and amplitude (157.4 +/- 44 vs 80.0 +/- 32; P < 0.05) of contractions. Motility index was reduced on average by 49%. In conclusion, this pilot study confirms, in patients with acute recurrent pancreatitis, the inhibitory action of gabexate on sphincter of Oddi motility already described in dogs. This action needs to be revaluated at therapeutic dosages. On the other hand, prophylactic use of the drug should be avoided during sphincter of Oddi manometry, in order to avoid false negative results.