Reviews in gastroenterological disorders最新文献

This review focuses on the use of endoscopic techniques in the diagnosis and management of pancreatic disorders. Endoscopic retrograde cholangiopancreatography (ERCP) has been used primarily to evaluate and treat disorders of the biliary tree. Recently, endoscopic techniques have been adapted for pancreatic sphincterotomy, stenting, stricture dilation, treatment of duct leaks, drainage of fluid collections, and stone extraction via the major and minor papillae. In patients with acute and recurrent pancreatitis, ERCP carries a higher than average risk of post-ERCP pancreatitis. This risk can be reduced with the placement of a prophylactic pancreatic stent. Magnetic resonance cholangiopancreatography (MRCP) can establish the anatomy of the biliary and pancreatic ducts, identify pancreas divisum or pancreatic ductal strictures, depict bile duct stones, and demonstrate pancreatic or biliary duct dilation. Endoscopic ultrasound (EUS) provides a safer, less invasive, and often more sensitive measure for evaluating the pancreas and biliary tree, and allows some options for therapy. In acute and recurrent pancreatitis, EUS and MRCP can be used to establish a diagnosis; ERCP can be reserved for therapy.

Intravenous (IV) administration of a proton pump inhibitor (PPI) is a faster way to achieve gastric acid suppression than oral administration of the same agent. Peak suppression after IV administration occurs within hours, compared with several days later after oral administration. Thus the IV route of administration offers a faster onset of gastric suppression, achievement of intragastric pH closer to neutrality, and better bioavailability. The PPIs that have IV formulations in the United States (esomeprazole, lansoprazole, and pantoprazole) are approved for different indications; the key differences among them relate to their ability to reach specific gastric pH, time to maintain a specific gastric pH, and ease of use of the IV formulation (eg, reconstitution, requirement of inline filters, infusion times).

The functional gastrointestinal disorders are defined by the Rome criteria as a heterogeneous group of symptom-based conditions that have no structural or biochemical explanation. However, this definition now seems outdated, because structural and molecular abnormalities have begun to be recognized in subsets of patients with the irritable bowel syndrome (IBS), the prototypic functional bowel disease. A complex classification system based arbitrarily on symptom criteria does not fit in with a number of emerging facts. For example, the symptom overlap of IBS with gastroesophageal reflux disease is not due to chance, and the emergence of post-infectious IBS, dyspepsia, or both after Salmonella gastroenteritis fits better with a 1-disease model. A new paradigm seems to be needed. All of these disorders may arise after infection or gut inflammation, but the phenotype depends on localized neuromuscular dysfunction in the predisposed human host (the "irritable gut").

Sulfasalazine, olsalazine, balsalazide, delayed-release mesalamine, controlled-release mesalamine, mesalamine pellets, and Multi-Matrix System mesalamine are effective first-line therapies for the treatment of mildly to moderately active ulcerative colitis and for subsequent maintenance of remission. For induction therapy it is unclear if there is a dose response above 1.5 g, and for maintenance therapy existing data do not support a dose response above 1.5 g. Sulfasalazine has more frequent side effects than olsalazine, balsalazide, and mesalamine formulations. Once-daily dosing with multi-matrix system mesalamine 1.2 g tablets may lead to optimal compliance. Mesalamine >/= 1.2 g and sulfasalazine >/= 2 g reduce the risk of colorectal cancer in patients with ulcerative colitis. Drug formulations, efficacy expectations and dose response, toxicity expectations, compliance considerations, and chemoprevention considerations are reviewed.

American endoscopists have essentially ignored chromoendoscopy (dye spraying) in the colon and overwhelmingly perform white-light colonoscopy only. The published studies suggest that routine use of chromoendoscopy in Western populations will lead to identification of additional flat lesions. However, a number of these studies have design flaws. The authors' interpretation of the existing data is that pancolonic chromoendoscopy to detect flat and depressed lesions is not yet proven as a useful and therefore necessary adjunct to routine colonoscopic examination in non-inflammatory bowel disease patients in the United States. Chromoendoscopy, particularly combined with magnification, is very effective in delineating the pit pattern of polyps and in allowing real-time differentiation of adenomatous from non-adenomatous lesions. There might be a role for chromo endoscopy with high magnification in the delineation of unresected portions of lateral spreading tumors being removed by piecemeal polypectomy and in the evaluation of polypectomy scars during endoscopic follow-up. The authors suggest that US endoscopists begin to familiarize themselves with shape classification, and that they learn a method to determine histology in real time.

Patients with inflammatory bowel disease (IBD) are at increased risk for osteoporotic fracture. Bone density testing and osteoporosis management are recommended for IBD patients at greater risk for fracture (ie, postmenopausal women, men aged . 60 years, and those with low body mass indices, glucocorticoid use, family history of osteoporosis, and malabsorption). Patient management includes modification of osteoporosis risk factors, such as calcium and vitamin D supplementation, hormone deficiency correction, and smoking cessation. When indicated, bisphosphonates, such as risedronate and alendronate, have been shown to increase bone mass and reduce fracture risk in patients with glucocorticoid-induced osteoporosis. Infliximab, an anti-tumor necrosis factor a antibody, increases bone mineral density, but this effect has not as yet translated into reduced fracture risk.

In the 1960s, the revolution in the diagnosis and management of gastrointestinal diseases began with the introduction of the first flexible fiber endoscope. Since then, the technologies have evolved greatly. Particularly in recent years, much emphasis has been placed on developing new gastrointestinal endoscopy technologies or techniques in order to provide a precise and even a "real time" endoscopic diagnosis. Magnification and high-resolution endoscopy, chromoendoscopy, and narrow band imaging stand at the forefront of the novel endoscopic techniques for the diagnosis of conditions such as squamous cell carcinoma, Barrett's esophagus, and gastroesophageal reflux disease. This review summarizes the recent advances in esophageal imaging and its practical applications for clinicians.

Recent studies have indicated that the levels of protection against colorectal cancer provided by colonoscopy and polypectomy may be considerably lower than what was once commonly believed. Improvements in colonoscopic detection of neoplasia could be enormously beneficial in reducing the incidence of colorectal cancer related to missed lesions. Factors that interfere with detection of neoplasia during colonoscopy, as well as technologic advances that can improve both neoplasia detection and real-time determination of polyp histology, are reviewed.