Performance characteristics of optical coherence tomography in assessment of Barrett's esophagus and esophageal cancer: systematic review.

Optical coherence tomography (OCT) can generate high-resolution images of the esophagus that allows cross-sectional visualization of esophageal wall layers. We conducted a systematic review to assess the utility of OCT for diagnosing of esophageal intestinal metaplasia (IM; Barrett's esophagus BE)), dysplasia, cancer and staging of early esophageal cancer. English language human observational studies and clinical trials published in PubMed and Embase were included if they assessed any of the following: (i) in-vivo features and accuracy of OCT at diagnosing esophageal IM, sub-squamous intestinal metaplasia (SSIM), dysplasia, or cancer, and (ii) accuracy of OCT in staging esophageal cancer. Twenty-one of the 2,068 retrieved citations met inclusion criteria. In the two prospective studies that assessed accuracy of OCT at identifying IM, sensitivity was 81%-97%, and specificity was 57%-92%. In the two prospective studies that assessed accuracy of OCT at identifying dysplasia and early cancer, sensitivity was 68%-83%, and specificity was 75%-82%. Observational studies described significant variability in the ability of OCT to accurately identify SSIM. Two prospective studies that compared the accuracy of OCT at staging early squamous cell carcinoma to histologic resection specimens reported accuracy of >90%. Risk of bias and applicability concerns was rated as low among the prospective studies using the QUADAS-2 questionnaire. OCT may identify intestinal metaplasia and dysplasia, but its accuracy may not meet recommended thresholds to replace 4-quadrant biopsies in clinical practice. OCT may be more accurate than EUS at staging early esophageal cancer, but randomized trials and cost-effective analyses are lacking.

Safety and efficacy of endoscopic spray cryotherapy for esophageal cancer.

Although surgery is traditionally the standard of care for esophageal cancer, esophagectomy carries significant morbidity. Alternative endoscopic therapies are needed for patients who are not candidates for conventional treatment. The objective of this study is to assess the safety, efficacy, and tolerability of spray cryotherapy of esophageal adenocarcinoma. This study includes patients with esophageal adenocarcinoma who had failed or were not candidates for conventional therapy enrolled retrospectively and prospectively in an open-label registry and patients in a retrospective cohort from 11 academic and community practices. Endoscopic spray cryotherapy was performed until biopsy proven local tumor eradication or until treatment was halted due to progression of disease, patient withdrawal or comorbidities. Eighty-eight patients with esophageal adenocarcinoma (median age 76, 80.7% male, mean length 5.1 cm) underwent 359 treatments (mean 4.4 per patient). Tumor stages included 39 with T1a, 25 with T1b, 9 with unspecified T1, and 15 with T2. Eighty-six patients completed treatment with complete response of intraluminal disease in 55.8%, including complete response in 76.3% for T1a, 45.8% for T1b, 66.2% for all T1, and 6.7% for T2. Mean follow-up was 18.4 months. There were no deaths or perforations related to spray cryotherapy. Strictures developed in 12 of 88 patients (13.6%) but were present before spray cryotherapy in 3 of 12. This study suggests that endoscopic spray cryotherapy is a safe, well-tolerated, and effective treatment option for early esophageal adenocarcinoma.

Endoscopic ultrasound-guided (neurolytic) celiac plexus block.

Celiac plexus neurolysis is an established technique for relieving pain in cancers of the upper abdomen. This article reviews the novel technique of endoscopic ultrasound (EUS)-guided neurolytic celiac plexus block. This recently described procedure is a therapeutic extension of curvilinear array endosonographic fine needle aspiration. The indications, patient preparation, and technical aspects of the procedure are described in detail. The potential complications are mentioned and the results of the published studies are reviewed. We believe that where the expertise is available, this procedure can be integrated into the diagnostic EUS of patients with inoperable upper abdominal malignancy. As such, this would be the safest and most cost-effective approach for celiac plexus neurolysis in these patients. The role of EUS-guided celiac plexus block in patients with chronic pancreatitis may be emerging and needs further study.

Recurrent acute pancreatitis caused by a gastric duplication communicating with an aberrant pancreas.

A 24-year-old female patient who had suffered from recurrent bouts of acute pancreatitis for over 3 years was found on endoscopic retrograde cholangiopancreatography to have an aberrant pancreatic duct that terminated in a cyst. An aberrant lobe of pancreas had been discovered at exploratory laparotomy 3 years previously and was left untreated. Excision of the aberrant lobe of pancreas and accompanying gastric duplication cyst was curative. This case illustrates the importance of obtaining endoscopic retrograde cholangiopancreatography in all young individuals with recurrent pancreatitis to detect this rare, but curable, cause of pancreatitis.

Volunteers as adjunct researchers in a cancer prevention trial: the American Cancer Society Colon Polyp Prevention Study.

BACKGROUND: In April 1991, the Virginia Division of the American Cancer Society (ACS) initiated the feasibility phase of the Colon Polyp Prevention Study (CPPS) to determine whether a high fiber supplement would decrease new adenomatous colorectal polyp occurrence. The feasibility phase had two specific objectives: 1) to evaluate accrual and compliance to the designed protocol and 2) to evaluate and demonstrate the effectiveness of volunteers as research assistants. The CPPS is an innovative project in which trained volunteers play a significant role in the research process. METHODS: In the CPPS, volunteer adjunct researchers (VARs) were trained to perform individual dietary data collection and intervention and other general study monitoring functions. VARs were trained, certified, and monitored in the performance of their assigned tasks by ACS staff and expert consultants. RESULTS: A total of 119 volunteers were trained as VARs, 74 of whom were certified and matched to a study participant. Between 1991-1995, only six VARs left the study. After active accrual of participants to the study ceased in 1995, 38 VARs (50% of the certified VARs) continued to monitor the active study participants. All VARs were consistently able to conduct the functions for which they were trained. CONCLUSIONS: In spite of expected volunteer attrition rates, a core of 38 dedicated VARs were matched to 72 participants and demonstrated the ability to perform selected data collecting activities on a consistent and efficient basis. The use of trained volunteers has allowed the CPPS to function in its feasibility phase at personnel cost considerably less than that of other similar cancer prevention trials.

Half-Fourier RARE MR cholangiopancreatography: experience in 300 subjects.

PURPOSE: To determine prospectively the clinical applications and diagnostic accuracy of half-Fourier rapid acquisition with relaxation enhancement (RARE) magnetic resonance (MR) cholangiopancreatography (MRCP) in a large patient population. MATERIALS AND METHODS: Breath-hold, heavily T2-weighted half-Fourier RARE MRCP was performed in 265 patients with suspected pancreaticobiliary disease and in 35 control patients without symptoms or signs referrable to the biliary tract or pancreatic duct. MRCP findings were correlated with those at direct cholangiography, pathologic examination, cross-sectional imaging, and clinical follow-up. RESULTS: Diagnostic MRCP examinations were obtained in 299 (99.7%) subjects. MRCP yielded an accuracy of 100% in determining the presence of pancreaticobiliary disease, the presence and level of biliary obstruction, and obstruction due to bile duct calculi. The accuracy of MRCP and MR imaging in determining the presence and level of malignant obstruction was 98.2%. MRCP obviated endoscopic retrograde cholangiopancreatography (ERCP) by excluding choledocholithiasis in patients with acute pancreatitis (n = 13) and nonspecific abdominal pain (n = 82). In patients with sclerosing cholangitis and acquired immunodeficiency syndrome cholangiopathy, MRCP depicted the biliary tract as clearly as did ERCP (n = 9). After failed ERCP, MRCP delineated the pancreaticobiliary tract and helped determine therapeutic options (n = 27). CONCLUSION: Half-Fourier RARE MRCP enables accurate evaluation of pancreaticobiliary disease and obviates ERCP in some patients.

Magnetic resonance cholangiopancreatography: a new technique for evaluating the biliary tract and pancreatic duct.

Magnetic resonance cholangiopancreatography (MRCP) represents a new development in MR technology that provides a noninvasive accurate means of evaluating the biliary tree and pancreatic duct. Recent technical refinements that allow for imaging of the entire biliary tree and pancreatic duct in 18 seconds make this examination easily performed even in critically ill patients. The clinical applications of MRCP are illustrated in a variety of scenarios that include choledocholithiasis, malignant obstruction, incomplete/failed endoscopic retrograde cholangiopancreatographies (ERCPs), postsurgical alterations of the biliary tract and gastrointestinal tract such as biliary-enteric anastomoses, intrahepatic bile duct pathology such as sclerosing cholangitis and AIDS cholangiopathy, chronic pancreatitis, congenital anomalies of the biliary tract and pancreatic duct, and gallbladder pathology.

Endoscopic ultrasound.

Endoscopic ultrasound is currently an accepted part of the clinical practice of gastroenterology. It is used to evaluate submucosal lesions, thickened gastric folds, and depth of gastrointestinal tumor penetration. As the capabilities of the instruments improve, their role in the practice of gastroenterology widens. This review is designed to update the practicing physicians on this rapidly evolving field, pertaining to instrumentation for endosonography, clinical indications for endosonography, and future directions.

Laparoscopic Nissen fundoplication for severe gastroesophageal reflux disease: pros and cons.

The advent of the laparoscopic approach to Nissen fundoplication has led to a resurgence in enthusiasm for the surgical treatment of gastroesophageal reflux disease (GERD). However, controversy exists as to which subgroups of GERD patients are best treated surgically. The relative success of treatment with medical and surgical intervention in terms of both symptom control and objective resolution of esophageal injury must be weighed against the relative costs of each therapeutic strategy in both the short and long term, given that GERD tends to be a lifelong disorder. The following is the transcribed text of a debate held at the Medical College of Virginia as part of a continuing medical education program in which the statement "Laparoscopic antireflux surgery is superior to medical treatment for severe gastroesophageal reflux disease" was contested. Representatives from the departments of surgery and gastroenterology provided arguments supporting their respective sides of this issue. The purpose was not to promote polarization in treatment selection, but to review the available data in a forum that could promote development of a rational algorithm for clinical decision-making in patients with GERD who might benefit from antireflux surgery. Final comments from the authors are provided in an attempt to synthesize the arguments into a reasonable strategy for individual case management.

Small flat adenoma: important in colon carcinogenesis?

The risk for development of colonic carcinoma increases with increasing size of the polyp. Endoscopists have focused attention on large polyps. Small flat adenomas are sessile polyps that measure less than 1 cm; they are nearly flat, and they have a slight depression in the center. They have a high incidence of cancer in situ. Adenomatous polyps follow the adenoma-carcinoma sequence. Small flat adenomas do not appear to follow this sequence, but they may be precursors of so called de novo colonic carcinoma. The genetics of small flat adenomas are not fully elucidated. Small flat adenomas may not be identified during standard colonoscopy due to the small size of the lesion. Chromoendoscopy may increase the rate of detection.

Gallstone pancreatitis: an update.

Gallstone pancreatitis is one of the more prevalent causes of pancreatitis. It accounts for more than two thirds of the cases of acute pancreatitis worldwide and 25 to 45% of the cases in the United States. Furthermore, it is one of the most important treatable causes of pancreatitis. These two important features of the disease make its recognition and proper management critical. Key to recognition and proper management of gallstone pancreatitis is understanding that this disease can exist in three different forms. It can exist as impacted gallstone pancreatitis, as nonimpacted gallstone pancreatitis, or as sludge-related pancreatitis. Each of these forms of the disease will have some unique features relating to their pathogenesis, diagnosis, and treatment. This update focuses on "take-home" features that will allow (1) clinical differentiation between the three forms of the disease and (2) understanding the unique features that relate to their pathogenesis, diagnosis, and management.

Nonsteroidal antiinflammatory drug-induced gastroduodenal lesions: prophylaxis and treatment.

Nonsteroidal antiinflammatory drugs (NSAIDs) are one of the most commonly prescribed agents, especially for elderly patients. These drugs frequently produce mucosal petechiae and erosions in the stomach and duodenum, but these conditions are rarely of clinical significance. NSAIDs, however, cause considerable morbidity and mortality due to their ability to cause gastric and duodenal ulcers. NSAID-induced ulcers are most likely to develop in elderly women receiving multiple NSAIDs for prolonged periods. NSAIDs injure gastric and duodenal mucosa by both a topical and a systemic effect. The latter is responsible for the pathogenesis of NSAID-associated ulcers. These ulcers are particularly prone to perforation and hemorrhage. Both complications frequently occur in asymptomatic long-term users of NSAIDs. H2 antagonists prevent NSAID-related duodenal ulcers but are not effective for prevention of gastric ulcers. Misoprostol is the only agent proven to decrease the risk of gastric ulcers in patients receiving NSAIDs. Both H2 antagonists and omeprazole are highly effective for the treatment of established duodenal ulcers in patients receiving NSAIDs. H2 antagonists also heal gastric ulcers in these patients but at slower rates than in patients not receiving NSAIDs. The existing literature is reviewed, and guidelines for prophylaxis against NSAID-induced ulcers and treatment of established ulcers are provided.

Pharmacological control of gastric acid secretion.

Gastric acid produced by the parietal cells has a significant role in a variety of gastrointestinal diseases, such as duodenal ulcer, gastric ulcer, and gastroesophageal reflux disease. We address acid production by the parietal cell and the pharmacological means to control gastric acid secretion. The physiology of parietal cell acid secretion is reviewed. The role of acid-suppressive therapy with histamine H2 antagonists and omeprazole in duodenal ulcer, gastric ulcer, and gastroesophageal reflux disease is discussed. Pharmacology, side-effect profile, and dosage requirements of the histamine H2 antagonists and omeprazole are outlined.

Stapled ileoanal anastomosis for ulcerative colitis and familial polyposis without a temporary diverting ileostomy.

Between March 1989 and August 1990, we performed 21 stapled J pouch ileonal procedures (20 ulcerative colitis [UC], 1 familial polyposis [FP]) without an ileostomy in 19, of whom 13 were taking prednisone and eight underwent semi-emergent surgery for uncontrollable bleeding. During the same time, an additional four patients required a standard ileonal procedure. The results of anal manometry and clinical function were compared to 25 patients who had previously undergone mucosal stripping and a sutured J pouch ileoanal anastomoses with a temporary diverting ileostomy between October 1982 and August 1990. During this same time period, an additional 19 patients underwent an anti-peristaltic reversed J pouch and 18 an S pouch, for a total of 83 ileoanal procedures. The reversed J pouch had a lower stool frequency than a standard J pouch but had an unacceptable incidence of complications and problems with pouch emptying. The S pouch had a stool frequency similar to the standard J pouch but provided greater length in patients with a short mesentery. Stapled J pouch ileoanal patients had a better (p less than 0.02) maximum and sphincter resting pressure (46 +/- 11 versus 34 +/- 12 mmHg), fewer (p less than 0.05) night-time accidents (22% versus 68%), daytime (17% versus 55%) or night-time (28 versus 61%) spotting, or use of a protective pad at night (11% versus 42%) than nonstapled J pouch ileoanal patients. Stool frequency was similar in the two groups. All but one UC patient had residual disease at the anastomosis. Anal mucosa between the dentate line and stapled anastomosis was 1.8 +/- 1.3 cm (range, 0 to 3.5 cm). Complications in the nonstapled J pouch group included 4 pouches excised (2 for complications, 2 for excessive stool frequency), 1 pelvic abscess, 2 stenosis requiring dilation under anesthesia, 1 enterocutaneous fistula after ileostomy closure, 1 ileostomy site hernia, and 2 small bowel obstructions. Of the 65 patients who underwent ileostomy closure in the entire series, 8 (12%) developed a complication requiring surgical intervention. Complications in the stapled group included 1 anastomotic leak, 1 pouch leak, and 1 pelvic abscess. Patients were managed successfully with drainage (all 3) and diverting ileostomy (1). One patient developed stenosis requiring dilation under anesthesia. The stapled J pouch ileoanal anastomosis is a simpler, safer procedure with less tension than a standard handsewn J pouch but leaves a very small cuff of residual disease. It provides significantly better stool control and may obviate the need for an ileostomy with its complications.

Primary adrenal insufficiency: a new cause of reversible gastric stasis.

Primary adrenal insufficiency is known to cause a wide spectrum of sometimes severe upper gastrointestinal symptoms; however, it has not previously been shown to be the cause of reversible gastric stasis. We have documented such a case in which the symptoms and physiologic abnormalities associated with gastric stasis were reversed by steroid replacement. A follow-up radionuclide gastric-emptying study after physiologic steroid replacement showed complete normalization of gastric emptying. Although gastric stasis has long been suspected of being present with primary adrenal insufficiency, this represents the first case in which it has been documented, and so should be included in the differential diagnosis of patients presenting with chronic nausea and vomiting.

A prospective assessment of the Garren-Edwards Gastric Bubble and bariatric surgery in the treatment of morbid obesity.

Morbid obesity is a serious medical hazard, and effective alternatives to surgery have been unsuccessful. In 1985, the Garren-Edwards Gastric Bubble (GEGB) was offered as an adjunct to dietary and behavioral therapy for weight loss treatment. The safety and efficacy of the GEGB were compared with bariatric surgery, the current standard for the treatment of morbid obesity. Fifty-seven patients received GEGB and 77 underwent bariatric surgery. GEGB patients were divided into two groups: those who attended group therapy and those who did not. This study showed that bariatric surgery was far more effective in reducing excess body weight during a 12-month period compared with the GEGB plus group therapy and the GEGB alone. The morbidity from bariatric surgery was greater than in the GEGB-treated groups, while the cost for uncomplicated cases for a year's treatment was comparable. It is concluded that the GEGB does not offer an effective alternative to bariatric surgery in the treatment of morbid obesity.

Small intestinal motility: normal and abnormal function.

This review outlines the properties and function of intestinal smooth muscle and the mechanisms that underlie contraction and relaxation. Both tonic and phasic (rhythmic) contraction are mediated by an increase in intracellular calcium. Phasic contraction is paced electrically by rhythmic changes in membrane potential (slow waves) which, upon reaching a threshold, lead to opening of membrane calcium channels and the entry of calcium into muscle cells; this inwardly directed calcium current or spike initiates a cascade of events resulting in contraction. Slow waves and spike potentials and, thus, phasic contraction, are influenced by neurotransmitters, hormones, and drugs. In circular muscle, these agents can also increase calcium by releasing it from intracellular stores, thus inducing tonic contraction. Ingestion of food initiates peristaltic propulsive activity which, in its rhythm, is superimposed on spontaneous phasic activity. The peristaltic reflex consists of two successive phases: relation of circular muscle distal to the distending bolus (descending relaxation) and contraction proximal to the bolus (ascending contraction). In-between meals, a different, slower pattern of muscle activity prevails, known as the migrating motor complex, which helps to maintain the lumen of the intestine free of contents. Improved understanding of normal muscle function is beginning to reflect itself in improved management of patients with motility disorders.