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Biomedical subjects

William Dickey

Publications and source records attributed to William Dickey.

12 recordsLinked to original sources

Parallel cannulation technique at ERCP rendezvous.

BACKGROUND: Biliary access at ERCP rendezvous is usually achieved by withdrawing a wire passed antegrade via the accessory channel of the duodenoscope, which is then used for over-the-wire cannulation. The wire is time consuming to maneuver and may be damaged during withdrawal. OBJECTIVE: Description of a simple technique for cannulation at rendezvous that overcomes these problems. DESIGN: Observational study. SETTING: Gastroenterology department of a teaching district general hospital. PATIENTS: Fourteen consecutive patients undergoing rendezvous after percutaneous transhepatic cholangiography (PTC). INTERVENTION: A transpapillary drain was placed at PTC in 13 patients. At rendezvous, cannulation alongside the drain was attempted with a sphincterotome cannula. After successful cannulation, the drain was progressively withdrawn, allowing retrograde therapeutic intervention. RESULTS: In all 13 patients, parallel cannulation was successful, allowing stone removal or biliary stent placement, with cannulation alongside a guidewire in the fourteenth patient. There were no complications except right hypochondrial pain after drain removal. CONCLUSIONS: Parallel cannulation is straightforward and effective, avoiding the need for guidewire manipulation.

Adult↗

Endoscopic markers for celiac disease.

Celiac disease is common and can present with nonspecific upper gastrointestinal symptoms. Patients may therefore undergo esophagogastroduodenoscopy as their initial investigation. Markers of villous atrophy, which can be seen in the duodenum during endoscopy, are well described. They have limited sensitivity for patients with mild enteropathy and duodenal biopsies should be performed if there is strong suspicion of celiac disease irrespective of endoscopic appearance. Endoscopic markers do, however, allow the selection of patients with nonspecific symptoms for duodenal biopsy, and these markers should, therefore, be looked for routinely during esophagogastroduodenoscopy.

Atrophy↗

Overweight in celiac disease: prevalence, clinical characteristics, and effect of a gluten-free diet.

BACKGROUND: It is well established that a minority of celiac patients present with "classic" symptoms due to malabsorption. However, few studies have focussed on the distribution of body mass index (BMI) in celiac populations and its relationship to clinical characteristics, or on its response to treatment. METHODS: We reviewed BMI measurements and other clinical and pathological characteristics from a database of 371 celiac patients diagnosed over a 10-yr period and seen by a single gastroenterologist. To assess response to gluten exclusion, we compared BMI at diagnosis and after 2 yr treatment in patients with serological support for dietary compliance. RESULTS: Mean BMI was 24.6 kg/m2 (range 16.3-43.5). Seventeen patients (5%) were underweight (BMI < 18.5), 211 (57%) were normal, and 143 (39%) were overweight (BMI > or = 25), including 48 (13% of all patients) in the obese range (BMI > or = 30.0). There was a significant association between low BMI and female gender, history of diarrhea, reduced hemoglobin concentration, reduced bone mineral density (BMD), osteoporosis, and higher grades (subtotal/total) of villous atrophy. Of patients compliant with a gluten-free diet, 81% had gained weight after 2 yr, including 82% of initially overweight patients. CONCLUSIONS: Few celiac patients are underweight at diagnosis and a large minority is overweight; these are less likely to present with classical features of diarrhea and reduced hemoglobin. Failed or delayed diagnosis of celiac disease may reflect lack of awareness of this large subgroup. The increase in weight of already overweight patients after dietary gluten exclusion is a potential cause of morbidity, and the gluten-free diet as conventionally prescribed needs to be modified accordingly.

Adult↗

Coeliac disease: is it time for mass screening?

Screening studies indicate a prevalence of coeliac disease (CD) of up to 1% in populations of European ancestry, yet the majority of cases remain undiagnosed. Serological markers for CD now available have high sensitivity and specificity, offering the option of mass population screening. The principles of disease screening as set out by Wilson and Jugner can be applied to CD to predict whether this is appropriate. CD is an important health problem for the individual and the community because of high prevalence, associated specific and non-specific morbidity, and long-term complications of which the most important are gut malignancy and osteoporosis. However, recent studies indicate that the prevalence of malignancy and the health impact of osteoporosis are much less than previously supposed, so the prophylactic benefits of early diagnosis through screening may be low. While CD has an accepted and effective treatment, dietary gluten exclusion, this is difficult for the individual and asymptomatic cases may be poorly motivated to comply. Diagnosis of CD is by histological confirmation on duodenal biopsy. We now recognise milder degrees of gluten sensitive enteropathy without villous atrophy (Marsh I, II lesions) and the benefits to the individual by identifying these early lesions through screening is unknown: whether to treat such individuals needs to be agreed before programmes commence. Screening with serum antibodies is relatively non-invasive but may have to be repeated during each individual's lifetime. HLA typing beforehand to identify the 30% of the population with DQ2 or DQ8, who are at potential risk of CD, will allow one-off exclusion of a large percentage of the population but like all genetic testing has ethical implications. The economic costs of screening and treatment versus morbidity prevented have not been calculated.

Celiac Disease↗

Surveillance for Barrett's oesophagus: results from a programme in Northern Ireland.

BACKGROUND: The reported incidence of adenocarcinoma in patients with Barrett's oesophagus in surveillance programmes varies widely. Great Britain has one of the highest incidence rates of this cancer in the world, but there are no data from Ireland reporting its incidence in patients with Barrett's oesophagus undergoing surveillance. We carried out a study of all such patients at a large District General Hospital in Northern Ireland. METHODS: A retrospective review of all patients with Barrett's oesophagus from January 1986 to March 2004 at Altnagelvin Area Hospital, Derry, Northern Ireland was performed. Barrett's oesophagus was defined as specialized intestinal metaplasia present in the tubular oesophagus. RESULTS: A total of 277 patients had Barrett's oesophagus. Twenty-one patients had adenocarcinoma and two patients had high-grade dysplasia at initial endoscopy and were excluded. Of the remaining 254 patients, 178 were entered into the surveillance programme (127 men, 51 women). The average follow-up period was 3.4 years, resulting in 613 patient-years of follow-up. Three patients developed adenocarcinoma, an incidence of 1/204 patient-years of follow-up. Two of the three patients had early-stage (T1 or T2) cancers detected and are alive and well. A total of 429 surveillance endoscopies were performed, and a marked year-on-year increase in the workload generated as a result of the surveillance programme was observed. CONCLUSIONS: The incidence of adenocarcinoma in patients in Northern Ireland was similar to the incidence reported by other large institutions. Clinical benefit is suggested but is not certain from these data, because of biases that affect surveillance programmes. Large multicentre studies are required to determine whether surveillance is beneficial.

Adenocarcinoma↗

Erosions in the second part of the duodenum in patients with villous atrophy.

BACKGROUND: There are various, well-documented, duodenal endoscopic markers caused by the villous atrophy of celiac disease. Another abnormality seen in association with villous atrophy, erosions in the second part of the duodenum, is described. To our knowledge, this finding has not been heretofore described in patients with celiac disease. METHODS: Five patients with celiac disease and erosions were encountered over a period of 2 years. OBSERVATIONS: The erosions were multiple, superficial, and present in the second part of the duodenum but not the duodenal bulb. All 5 patients had findings typical of celiac disease (iron deficiency, osteopenia/osteoporosis), and 4 had at least one other endoscopic marker: scalloped duodenal folds (3), fold loss (2), or mosaic pattern mucosa (2). These patients represented 7% of new cases of celiac disease during the same time period. This pattern of erosion was not observed in over 1200 other patients undergoing upper endoscopy during the study period. CONCLUSIONS: In a European population, the finding of erosions confined to the second part of the duodenum is specific for villous atrophy, although sensitivity is low. Erosions in the second part of the duodenum should be added to the list of endoscopic markers of celiac disease.

Adult↗

Does fluoroscopic imaging still have a role in colonoscopy?

GOAL: To assess the use and value of fluoroscopic imaging in difficult colonoscopy. BACKGROUND: Few endoscopy centers have easy access to fluoroscopy to facilitate difficult colonoscopy. Its benefits are therefore unclear. Although interest in colonoscope imaging has recently been stimulated by magnetic imaging techniques, these are expensive and unlikely to be widely available for some time. STUDY: During routine colonoscopy lists, a mobile fluoroscopy unit was used when colonoscopy could not be completed in the absence of stricturing despite changes in patient position and application of external pressure. This retrospective review assesses the percentage of procedures completed with and without fluoroscopy. RESULTS: A series of 1551 procedures in adult patients without colon resection and with satisfactory bowel preparation was analyzed. The cecal intubation rate was 95.1% (1475/1551), rising to 96.5% (1475/1528) when impassable strictures were excluded. Fluoroscopy was used in 61 (4%) of the 1528 procedures without stricture, but allowed completion in only 13% (8/61). In the absence of stricture, fluoroscopy improved completion rate by only 0.5% (from 96.0% to 96.5%). CONCLUSIONS: Fluoroscopy is seldom required and even then contributes little to success. Magnetic imaging, which provides continuous 3-dimensional images, may be more likely to speed and facilitate completion.

Adolescent↗

Endoscopic retrograde cholangiopancreatography is safe and effective in patients 90 years of age and older.

GOALS: To review our experience of endoscopic retrograde cholangiopancreatography (ERCP) in patients 90 years and older. BACKGROUND: ERCP is effective in the investigation and treatment of biliary disease; however, in the very elderly, a perception of high procedural risk and lack of efficacy may limit its use. STUDY: Retrospective analysis of ERCPs performed on patients 90 years of age and older from one institution. RESULTS: Between 1987-2000, 23 ERCPs were performed on patients 90 years of age and more (16 women; age range, 90-96 years). The primary indications were obstructive jaundice (16 patients), pancreatitis (2), cholangitis (1), unexplained abdominal pain (1), and planned follow-up (3). The main endoscopic findings were common bile duct (CBD) stone (15 patients), pancreatic carcinoma (2), cholangiocarcinoma (2), and dilated duct (only 1). Sixteen sphincterotomies were performed, with successful common duct clearance in 10 patients. Seven biliary stents were inserted for benign disease and three, for malignancy. In two patients, CBD cannulation was unsuccessful. Three minor hemorrhages were controlled endoscopically. Three patients died of nonprocedural causes. CONCLUSIONS: ERCP is safe and effective in the very elderly. The decision to undergo ERCP should be determined by clinical need.

Aged↗

Racial and ethnic composition of volunteer cord blood donors: comparison with volunteer unrelated marrow donors.

BACKGROUND: Umbilical cord blood is an alternative peripheral blood progenitor cell source for patients who need transplantation. A presumed advantage of cord blood is the ability to increase minority recruitment. STUDY DESIGN AND METHODS: The racial composition of five member cord blood banks of the National Marrow Donor Program (NMDP) was compared, representing 9020 cord blood donors with NMDP marrow donors from comparable geographic areas, representing 417,676 donors. Cord blood and marrow donors self-reported racial designations on questionnaires. Donor statistics were compared with baseline racial data of deliveries from participating hospitals for cord blood donors and with geographic census data for marrow donors. RESULTS: The California, Florida, and Massachusetts cord blood banks recruited a lower percentage of minorities than the corresponding marrow donor centers. In New York and Colorado, minority recruitment was equivalent. In California, Florida, Massachusetts, and New York, the cord blood banks recruited a lower percentage of minorities than those delivering at the respective hospitals. The cord blood banks in California, Colorado, Florida, and Massachusetts recruited a lower percentage of minorities compared with delivery data than the corresponding marrow donor centers compared with census population (p < 0.001). In New York, the percentages were similar. CONCLUSION: The problem of insufficient minority recruitment of cord blood has not yet been solved. Better strategies are needed to recruit minority donors.

Adult↗

Low serum vitamin B12 is common in coeliac disease and is not due to autoimmune gastritis.

OBJECTIVE: Although coeliac disease is a disorder of the proximal small bowel, associated vitamin B12 deficiency has been reported. This study aimed to assess the prevalence of B12 deficiency in a large series of coeliac patients, and to exclude the possibility that it is due to associated autoimmune gastritis. DESIGN: Prospective routine measurement of serum B12 in coeliac patients, with investigations for pernicious anaemia/autoimmune gastritis in B12-deficient patients. SETTING: Gastroenterology department of a large district general hospital. INTERVENTIONS: If they were not taking vitamin B12 supplements already, patients had serum B12 measured before starting dietary gluten exclusion. Those with low levels also had gastric biopsies taken and plasma gastrin and serum gastric parietal cell and intrinsic factor antibodies measured. MAIN OUTCOME MEASURES: Prevalence of low serum B12, and presence or absence of indicators of pernicious anaemia/autoimmune gastritis in patients with low serum B12. RESULTS: Of 159 patients, 13 had low serum B12 at diagnosis. A further six had been receiving B12 replacement therapy for 3-37 years before diagnosis, giving an overall prevalence of 12% (19 patients). Only 2/19 patients had gastric corpus atrophy, one with intrinsic factor antibodies and the other with hypergastrinaemia. There was no relationship between low B12 and clinical characteristics. CONCLUSIONS: Low B12 is common in coeliac disease without concurrent pernicious anaemia, and may be a presenting manifestation. B12 status should be known before folic acid replacement is started.

Adult↗

Colonoscope length and procedure efficiency.

OBJECTIVE: We set out to compare the success of colonoscopy using long and intermediate length standard adult instruments. METHODS: An intermediate length (133 cm working length) and long (168 cm) videocolonoscope were used on an alternate patient basis during routine endoscopy lists. Completion rates, times, and the need for external abdominal pressure were documented, as were causes of failed cecal intubation. RESULTS: Among patients with no history of colon resection and with satisfactory bowel preparation, 173 procedures were performed with the intermediate and 167 with the long colonoscope. There was no significant difference in completion rates (96% for both, excluding patients with strictures), completion times (intermediate mean = 7.73 min, long = 8.11 min; p = 0.44), or need for external abdominal pressure. Similarly, no difference was observed for male and female patients analyzed separately. Though there was no significant difference in completion rates for males and females overall (99% vs 95% excluding patients with strictures, p = 0.08), the latter had significantly longer completion times (mean = 8.75 vs 6.76 min, p < 0.001) and were more likely to require external abdominal pressure. Intermediate colonoscope length was responsible for failure to reach the cecum in one patient only (0.6%). CONCLUSIONS: Although the length of the intermediate instrument rarely compromises colonoscopy, it offers no significant advantage over the long scope for routine procedures.

Cecum↗