Differences between sporadic hyperplastic gastric polyps and portal hypertensive gastric polyps: a review.

Portal hypertension (PH) is one of the most severe complications of chronic liver diseases. It is defined as an increase in pressure in the portal venous system which results in a portosystemic gradient >5 mmHg. In the western world, cirrhosis is the most frequent cause of PH, mainly due to nonalcoholic fatty liver disease and alcoholic liver disease. Patients with PH have esophageal varices in 68-73% of cases, portal hypertensive gastropathy in 51-73% and hyperplastic polyps (HPs) in 0.9-2%. Recent studies have shown that HPs found in PH patients are different from classical HPs. They constitute a new entity called portal hypertensive polyps (PHPs). The main difference between sporadic HPs and PHP is the presence of larger and more numerous vascular capillaries in the lamina propria. The clinical course of PHPs is unknown. Their physiopathology seems different from HPs: the increased congestion caused by higher portal pressure in the stomach may induce capillaries proliferation and neoangiogenesis. PHPs may be responsible for symptoms, such as pyloric obstruction, iron deficiency and anemia. Their prevalence in portal hypertensive and cirrhotic patients is from 1% to 8%. PHPs can be single or numerous, in the antrum or the gastric corpus. Their size ranges from 2 to 3 cm. PHPs seem to disappear or shrink with the treatment of PH. They should be resected in case of symptom and if >10 mm, after Helicobacter pylori eradication if present. However, their recurrence is frequent (40-79%), thus surveillance endoscopy is mandatory, at the same time as esophageal varices.

Video clips compared with high-definition still images for characterization of colorectal neoplastic lesions: a randomized comparative prospective study.

Background and study aims Accurate real-time characterization of colorectal neoplastic lesions (CNLs) during colonoscopy is important for deciding appropriate treatment. No studies have evaluated whether still images or video clips are better for characterization. We compared histological predictions and size estimations of CNLs between two groups of gastroenterologists: one viewing still images and the other viewing video clips. Materials and methods Participants were shown 20 CNLs as either 3-5 still images or a video clip. Three endoscopy experts obtained the images using high-definition white light and virtual chromoendoscopy without magnification. Stratified randomization was performed according to experience. For each lesion, participants assessed the size and histological subtype according to the CONECCT classification (hyperplastic polyp [IH], sessile serrated lesion [IS], adenoma [IIA], high-risk adenoma or superficial adenocarcinoma [IIC], or deeply invasive adenocarcinoma [III]). The correct histological status and size were defined by the pathology reports or combined criteria between histology and expert opinion for high-risk adenoma or superficial adenocarcinoma (CONECCT IIC). Results 332 participants were randomized and 233 performed the characterization. Participants comprised 118 residents, 75 gastroenterologists, and 40 endoscopy experts; 47.6 % were shown still images and 52.4 % viewed video clips. There was no statistically significant difference between the two groups in histological prediction, our primary end point. However, the lesion size was better assessed using still images than video clips ( P  = 0.03). Conclusions Video clips did not improve the histological prediction of CNLs compared with still images. Size was better assessed using still images.

Colon phantoms with cancer lesions for endoscopic characterization with optical coherence tomography.

Optical coherence tomography (OCT) is a growing imaging technique for real-time early diagnosis of digestive system diseases. As with other well-established medical imaging modalities, OCT requires validated imaging performance and standardized test methods for performance assessment. A major limitation in the development and testing of new imaging technologies is the lack of models for simultaneous clinical procedure emulation and characterization of healthy and diseased tissues. Currently, the former can be tested in large animal models and the latter can be tested in small animal disease models or excised human biopsy samples. In this study, a 23 cm by 23 cm optical phantom was developed to mimic the thickness and near-infrared optical properties of each anatomical layer of a human colon, as well as the surface topography of colorectal polyps and visual appearance compatible with white light endoscopy.