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.

Determination of the ideal preparation for colonoscopy in a rat model.

BACKGROUND: Quality bowel preparation is essential to examine the entire colon adequately. No trials comparing different purgative regimens are available in animal models. The aim was to compare 5 methods for bowel cleansing to develop a rat model to study therapeutic colonoscopy. METHODS: Twenty-five rats were assigned to one of 5 regimens: (1) high-volume polyethylene glycol electrolyte solution (HV-PEG-ES, 40 mL); (2) low-volume PEG-ES (LV-PEG-ES, 20 mL); (3) high-volume PEG-ES+ascorbic acid (HV-PEG-ES+AA, 20 mL); (4) LV-PEG-ES+AA, 10 mL; (5) rectal enema with saline solution (RE-SS). Bowel preparation quality was rated by total colonoscopy. RESULTS: RE-SS is the best regime for left colon cleansing, whereas HV-PEG-ES and HV-PEG-ES+AA solutions resulted in significantly better cleansing in the whole colon. HV-PEG-ES+AA regimen needed less volume, and administration was easier. CONCLUSIONS: A total of 20 mL of PEG-ES+AA before colonoscopy is the best regimen to explore the whole colon, whereas to explore the left colon RE-SS is adequate.

[Preparation for colonoscopy: types of scales and cleaning products]. / Preparación para colonoscopia: tipos de productos y escalas de limpieza.

Adequate bowel preparation is essential before a colonoscopy, allowing us to make a proper examination of the entire mucosa. The ideal method of colon cleansing should be fast, safe, and get a proper cleaning with minimal discomfort for the patient. Today we have a wide variety of colon cleansing products, information sometimes becomes confused. A good colon preparation depends partly on correct choice of the same, but also upon dietary restriction. Knowledge of all these products, with their advantages and limitations, we can make a better selection for each patient, and although the efficacy is comparable, is the experience of the browser, patient preferences, and the degree of compliance with the instructions preparation, which greatly influence the results.

Preparación para colonoscopia: tipos de productos y escalas de limpieza / Preparation for colonoscopy: types of scales and cleaning products

Una adecuada preparación del colon es fundamental antes de realizar una colonoscopia, ya que nos permite realizar una correcta exploración de toda la mucosa. El método ideal de limpieza del colon debe ser rápido, seguro y conseguir una limpieza apropiada con las mínimas molestias para el paciente. En la actualidad disponemos de una amplia variedad de productos de limpieza de colon, información que en ocasiones llega a ser confusa. Una buena preparación del colon depende por una parte de una correcta elección del mismo, pero también de una restricción dietética previa. El conocimiento de todos estos productos, con sus ventajas y limitaciones, nos permite hacer una mejor selección para cada paciente; y aunque la eficacia sea comparable, es la experiencia del explorador, las preferencias del paciente y el grado de cumplimiento de las instrucciones de preparación, las que influyen notablemente en los resultados(AU)

Adequate bowel preparation is essential before a colonoscopy, allowing us to make a proper examination of the entire mucosa. The ideal method of colon cleansing should be fast, safe, and get a proper cleaning with minimal discomfort for the patient. Today we have a wide variety of colon cleansing products, information sometimes becomes confused. A good colon preparation depends partly on correct choice of the same, but also upon dietary restriction. Knowledge of all these products, with their advantages and limitations, we can make a better selection for each patient, and although the efficacy is comparable, is the experience of the browser, patient preferences, and the degree of compliance with the instructions preparation, which greatly influence the results(AU)

Effect of the administration of fermentable and non-fermentable dietary fibre on intestinal bacterial translocation in ascitic cirrhotic rats.

BACKGROUND: Bacterial infections are frequent in cirrhosis. Experimental studies suggest a pathogenic role of intestinal bacterial translocation in them. Both fermentable and non-fermentable fibre avoided intestinal bacterial translocation (IBT) in animal models of gut starvation and critical illness. AIM: To assess the effect of fermentable (pectin) or non-fermentable (lignin) fibre on IBT in ascitic cirrhotic rats. METHODS: Thirty-six rats induced to cirrhosis with oral CCl4 were randomized (6 weeks after the first CCl4 dose) to receive rat chow+5% lignin (LIG, n=13), rat chow+5% pectin (PEC, n=13), or rat chow only (CON, n=10). Once ascites developed, animals were laparotomized and samples of mesenteric lymph nodes (MLN), ascitic fluid, portal and peripheral blood and liver, were obtained for culture. RESULTS: IBT rate was: LIG=5/13, PEC=4/13, CON=5/10 (P=N.S.). The median amount of translocated bacteria in rats with IBT was lower in the PEC group (2 x 10(2) CFU/g MLN), than in LIG (10(5) CFU/g MLN) and CON (10(4) CFU/g MLN) groups (P<0.05). All other samples were sterile except for a portal blood sample (Enterococcus faecalis) of the LIG group. CONCLUSIONS: IBT incidence is not decreased by either pectin or lignin in ascitic cirrhotic rats, but pectin supplementation reduces the amount of translocated bacteria.

Combining steroids with enteral nutrition: a better therapeutic strategy for severe alcoholic hepatitis? Results of a pilot study.

BACKGROUND: Results of a previous randomized controlled trial comparing the outcome of patients with severe alcoholic hepatitis treated with total enteral nutrition (TEN) or corticosteroids suggest that these treatments act through different mechanisms and may be complementary. We report a pilot study of combined treatment with TEN and a shorter course of steroids in patients with severe alcoholic hepatitis. METHODS: Thirteen patients with severe alcoholic hepatitis were treated with systemic steroids and TEN. Steroid therapy started with 40 mg oral prednisolone daily, and was progressively tapered as soon as both serum bilirubin and prothrombin time decreased below 50% of their baseline values. TEN (2000 kcal, or 8374 kJ, daily) was administered throughout the hospital stay. Patients were followed for at least 12 months or until death. RESULTS: Tapering of prednisolone dose could be started after a mean (SD) of 15.4 (3.8) days, whereas TEN was maintained for 22 (3.8) days. TEN was tolerated in 10 of the 13 patients. The major adverse event attributable to therapy was hyperglycemia requiring insulin therapy, which occurred in 12 of 13 patients. Only two patients (15%) died during the treatment period. Another patient died within the first 2 months of follow-up. In no case was the death due to infectious complications, despite two-thirds of patients developing infections during the treatment period. Infections during follow-up occurred only in three patients. CONCLUSION: This pilot study suggests that TEN associated with a short course of steroids could be a good therapeutic strategy for severe alcoholic hepatitis. This possibility deserves investigation in a randomized controlled trial.