Biodegradable stents in gastrointestinal endoscopy

Biodegradable stents(BDSs)are an attractive option to avoid ongoing dilation or surgery in patients with benign stenoses of the small and large intestines.The experience with the currently the only BDS for endoscopic placement,made of Poly-dioxanone,have shown promising results.However some aspects should be improved as are the fact that BDSs lose their radial force over time due to the degradable material,and that can cause stent-induced mucosal or parenchymal injury.This complication rate and modest clinical efficacy has to be carefully considered in individual patients prior to placement of BDSs.Otherwise,the price of these stents therefore it is nowadays an important limitation.

Radiation dose to patients during endoscopic retrograde cholangiopancreatography

Endoscopic retrograde cholangiopancreatography (ERCP) is an important tool for the diagnosis and treatment of the hepatobiliary system. The use of fluoroscopy to aid ERCP places both the patient and the endoscopy staff at risk of radiation-induced injury. Radiation dose to patients during ERCP depends on many factors, and the endoscopist cannot control some variables, such as patient size, procedure type, or fluoroscopic equipment used. Previous reports have demonstrated a linear relationship between radiation dose and fluoroscopy duration. When fluoroscopy is used to assist ERCP, the shortest fluoroscopy time possible is recommended. Pulsed fluoroscopy and monitoring the length of fluoroscopy have been suggested for an overall reduction in both radiation exposure and fluoroscopy times. Fluoroscopy time is shorter when ERCP is performed by an endoscopist who has many years experience of performing ERCP and carried out a large number of ERCPs in the preceding year. In general, radiation exposure is greater during therapeutic ERCP than during diagnostic ERCP. Factors associated with prolonged fluoroscopy have been delineated recently, but these have not been validated.

Submucosal injection of platelet-rich plasma in endoscopic resection of large sessile lesions

AIM To prospectively evaluate the efficacy of submucosal injection of platelet-rich plasma(PRP) on endoscopic resection of large sessile lesions.METHODS Eleven patients were submitted to endoscopic mucosal resection(EMR) with prior injection of PRP, obtained at the time of endoscopy. Patients were followed during 1 mo. The incidence of adverse events(delayed bleeding or perforation) and the percentage of mucosal healing(MHR) after 4 wk were registered. RESULTS EMR was performed in 11 lesions(46.4 mm ± 4 mm, range 40-70 mm). Delayed bleeding or perforation was not observed in any patient. Mean ulcerated area atbaseline was 22.7 cm^2 ± 11.7 cm^2 whereas at week 4 were 2.9 cm^2 ± 1.5 cm^2. Patients treated with PRP showed a very high MHR after 4 wk(87.5%). CONCLUSION PRP is an easy-to-obtain solution with proven and favourable biological activities that could be used in advanced endoscopic resection.

Colonoscopy in rats:An endoscopic,histological and tomographic study

AIM:To describe colon anatomy with colonoscopy and computed tomography(CT) to develop a rat model for future studies of therapeutic colonoscopy.METHODS:Eighteen male Sprague-Dawley rats,on average 400-420 g,underwent total colonoscopy,CT and histological examination.Colonoscopy was performed after bowel preparation with a baby upper gastrointestinal endoscopy with an outer diameter of 6.7 mm.CT obtained a 3D image of total colon after a rectal enema with radiological contrast.Macroscopic and microscopic examinations were examined with a conventional technique(hematoxylin and eosin).Colonic wall thickness,length and diameter measurements were taken from the anus,3,7,14 and 20 cm from the anal margin.RESULTS:The median colonoscope depth was 24 cm(range 20-28 cm).Endoscopic and tomographic study of colon morphology showed an easy access with tubular morphology in the entire left colon(proximal left colon and rectum).Transverse colon was unapparent on colonoscopy.Right colon,proximal to the splenic flexure,was the largest part of the colon and assumed saccular morphology with tangential trabecula.Radiological measurements of the colonic length and diameter substantiate a subdivision of the right colon into two parts,the cecum and distal right colon.In addition,histological measurement of the colonic wall thickness confirmed a progressive decrease from rectum to cecum.The muscular layer was thinner in the proximal left colon.CONCLUSION:The combination of colonoscopy,tomography and histology leads to a better characterization of the entire colon.These data are important for deciding when to perform endoscopic resections or when to induce perforations to apply endoscopic treatments.