Volume 62 - 1999 - Fasc.2 - Symposium
Gastric polyps
Endoscopy allows a better diagnosis and treatment of gastric polyps. Current methodology includes a detailed examination of the stomach after good insufflation, necessary to diagnose small fundic polyps, biopsies of the polyp as well as of the surrounding mucosa (antrum and fundus). Endoscopy allows a preliminary diagnosis based on the number, location and size of the polyps. Resection is not performed at initial endoscopy as it is not necessary for all polyps and may be risky if vascular lesions are confused with polyps. Glandulocystic ftmdic polyps are the most frequent (500/0), are always associated with a normal gastric mucosa and sometimes with omeprazole. Resection and follow-up are not indicated. Hyperplastic polyps represent 25% of gastric polyps, are located everywhere, with a mean size of 1 cm, and sometimes erosions or superficial necrosis. Gastritis is present, Helicobacter pytori is frequent and eradication may cause regression or disappearance of polyps. The small risk of cancer and the risk of bleeding increase with size. Polypectomy and follow-up are thus indicated in most cases. Adenomatous polyps, afthougb similar in appearance to hyperplastic polyps concerning macroscopy and gastritis have a higher risk of cancer in the polyp or in the stomach. Polypectomy and follow-up are thus mandatory.
Polypoid and pseudopolypoid lesions of inflammatory bowel disease: diagnosis on double-contrast enema
The radiological and pathological features of ulcerative colitis (UC) and Crohn's disease (CD) are well known for most radiologists and gastroenterologists but on double-contrast enema, polypoid and pseudopolypoid manifestations of inflammatory bowel disease (IBD) often remain a source of major confusion. Inflammatory polyps project above the level of the surrounding mucosa. Pseudopolyposis is seen when extensive ulceration of the mucosa down to the submucosa results in scattered circumscribed islands of relatively normal mucosal remnants. Postinflammatory polyps reflect a nonspecific healing of undermined mucosal and submucosal remnants and ulcers, and are mostly multiple. They have no malignant potential. Patients with long-standing UC and CD are at increased risk for developing colorectal carcinoma. Dysplasia is a precancerous histologic finding and is frequently seen in colitic colons at high risk for carcinoma. Dysplasia may be found in a radiographically normal appearing mucosa or it may be accompanied by a slightly raised mucosal lesion, a so-called dysplasia-associated lesion or mass (DALM lesion) and as a consequence radiographically detectable. Because differentiation of adenocarcinoma and dysplasia from inflammatory or postinflammatory polyps is sometimes difficult or impossible on double-contrast enema, endoscopy and biopsy are necessary for making a final diagnosis.
Evaluation of polyps by endoscopic ultrasonography (EUS): implication for endotherapy
EUS is the single best imaging modality in precise visualization of the five layers structure of G.I. tract wall, space occupying lesion and surrounding structures. In case of "protruding lesioy;' into the G.I. lumen, the site of origin of the tumor can be easily determined by EUS, and then its nature can be presumed (1). However, despite of these tiny details of the G.I. wall obtained by EUS, histology is still mandatoiry,especially when dealing with lesion suspected of malignancy (2). In case of sessile malignant "polypoid" lesion, Endoscopic Mucosal Resection (EMR) guided by EUS, could be considered in specific cases of selected patients. Conventional EUS transducer (7.5 and 12 Mhz) employed for this purpose is not sufficient for differentiating cancers invading the muscularis mucosae from those invading the sub-mucosa. A Miniature Ultrasonic Probe (20 and 30 Mhz) which can be used through the biopsy channel of an endoscope has recently been developed and is accurate in measuring such a superficial infiltration and in assessing regional lymph nodes allowing then an exact pre-treatment staging. In patient not fitted for surgery, with a lesion less than 2 cm and involving less than half circumference of the lumen, EMR could be performed according to the parietal infiltration (T), the nodal involment (N) and the related involved organs (Esophagus, Stomach, Colo-rectum). Conclusions: EUS may be usefull and sometimes is mandatory for assessing the GJ. tract polyps before resection.
Home parenteral nutrition in adults : the current use of an experienced method
Home parenteral nutrition (HPN) is now commonly used in industrialized countries. In Europe, the mean incidence of newly enrolled cases is about 3 patients per 106 inhabitants, per year. The use of HPN is much larger in North America. Cancer has become the largest single indication of HPN over the world. The complications are either related to the central catheter (sepsis, thrombosis, migration) or metabolic (liver abnormalities, bone disorder, deficiencies). Complications rate may be lowered by an adequate nutritional regimen, a good teaching of the patients and the presence of a nutritional team in specialized centres. The survival probability for patients with benign diseases is about 65% at 5 years. The mortality rate related to HPN itself is less than 10%. For patients with benign diseases, weaning of HPN is observed in 40 to 70% of the cases. Sixty percent of the patients have a very good quality of life. HPN must be used selectively in cancer patients.
Parenteral nutrition in pediatrics Indications and perspectives
Progress in experimental intestinal transplantation in small animal models
The unique immune response after small bowel transplantation (SBT) has been the subject of extensive research using small animal models in rats and mice. These animals are inexpensive, for most societies ethically acceptable and the existence of inbred strains allows for reproducibility and defined immunobiological conditions. The basic immunological reactions, such as giraft-versus-host-reactions (GVHR), host-versus-giraft-reactions (HVGR), a combination of both reactions, chronic rejection and tolerance have been described. Almost all immunosupprmive agents of proven or potential clinical relevance have been tested for their efficacy in small bowel transplantation. All techniques which are applied to intestinal transplantation in humans including multiorgan transplantation, can also be performed in rats. Intestinal transplantation in mice is methodically restricted to heterotopic transplantation. The mouse however, offers several advantages compared to the rat model. A large number of congenic and knockout strains is available as well as many analytical tools. In the future, intriguing new insights into the unique immunological mechanisms of allograft rejection will be discovered using murine models.
Contribution of large animal models to the development of clinical intestinal transplantation
The intestine has long been seen as a "forbiddeif' organ to transplant and even nowadays it remains the most challenging abdominal organ to transplant. Large animal experiments have been pivotal, first in developing reproducible and clinically applicable surgical techniques for transplanting the intestine and second, in revealing the unique physiological, immunological, and microbiological challenge that intestinal transplantation (lTx) represents. More recently, large animal models have been used to test new immunosuppressive drugs (FK 506) that have been then successfully used clinically. lTx is no more an experimental endeavor and survival figures of about 70 % can be reached at one year, justifying routine application of lTx to patients who do not tolerate total parenteral nutrition. However lTx remains in 1999 an "unfinished producf' and further rssearch will need to be done to allow wider application of lTx to patients without total parenteral nutrition (TPN) related complications. Further research will focus on the following aspects : (1) refined understanding of the factors accounting for the high immunoge@city of the intestine; (2) development of immunomodulatory strategies to reduce graft immunogenicity and to induce specific hyporesponsiveness; (3) development of new immtmosuppressants, and their usage in combination, to act more specifically on the immune response, and at the price of less toxicity ; (4) development of surgical alternatives to alleviate the organ shortage : graft size reduction, live related lTx. Importantly these questions will need to be addressed in clinically relevant animal models before they are applied to man.
Kinetics of inflammatory parameters after intestinal ischemia reperfusion injury
Determination of intestinal ?-glutathione S-transferase after ischemia-reperfusion injury
Klinik für Transplantationschurgie 1, Abteilung Histologie 2 and Zentrum Pathologie 3, Georg-August-Universität, Gottingen, Germany.
Intestinal transplantation
Adult small intestinal transplantation in Europe
The results of clinical adult intestinal transplantation in eight European centres between 1988 and 1998 are presented. Data were available on a total of 29 transplants in 28 adult patients. Nine patients received ten isolated small intestinal grafts and a further 2 patients received grafts of small intestine and colon. Seventeen patients received multiviscerat grafts including small bowel. After 1994 all cases have received FK506 as their primary immunosuppressive agent, more recently increasingly often in combination with Mycophenolate. Ten out of twenty patients surviving more than one week after transplantation had no recorded episodes of rejection, five one episode of rejection, three two episodes of rejection and two three or more episodes. Eighteen patients have died, Sepsis being the cause of death in twelve of these cases. Actuarial survival figures for patients/grafts following isolated small intestinal transplantation are 64/53% at one year and 48/36% at three years following transplantation. Patient and graft survival are identical following multivisceral transplantation and are 44% at one year and 30% at three years in the thirteen patients managed under FK506 immunosuppression, none of the four patients transplanted under Cyclosporin therapy having survived beyond three months.
Clinical intestinal transplantation in 1998 : Pittsburgh experience
