Neville D. Bamji

Clinical trial: 2-L polyethylene glycol-based lavage solutions for colonoscopy preparation – a randomized, single-blind study of two formulations

Aliment Pharmacol Ther 2010; 32: 637–644

Is gastroduodenal biopsy safe in patients receiving aspirin and clopidogrel?: a prospective, randomized study involving 630 biopsies.

Goals To assess prospectively the bleeding risk attributable to gastroduodenal biopsy in subjects taking antiplatelet medications. Background No prospective data exist regarding the bleeding risk attributable to endoscopic biopsy in patients taking antiplatelet agents. A majority of Western endoscopists withdraw antiplatelet agents before upper endoscopy, despite expert guidelines to the contrary. Study We performed a prospective, single-blind, randomized study in healthy volunteers participating in a larger study regarding the effect of antiplatelet agents on gastroduodenal mucosal healing. Multiple gastroduodenal biopsies were performed during 2 esophagogastroduodenoscopy in subjects dosed with aspirin enteric-coated 81 mg once daily or clopidogrel 75 mg once daily. Data for endoscopic bleeding, clinical bleeding, blood vessel size, and depth of biopsy in histology specimens were collected. Results Four hundred and five antral biopsies and 225 duodenal biopsies were performed during 90 esophagogastroduodenoscopy in 45 subjects receiving aspirin or clopidogrel. Median maximum blood vessel diameter per biopsy was 31.9 &mgr; (range: 9.2 to 133.8). About 50.8% of biopsy specimens breached the muscularis mucosa. In the clopidogrel group, no bleeding events were noted after 350 biopsies [upper confidence limit (UCL) for probability of bleeding=0.0085]. In the aspirin group, there were no clinical events (UCL=0.0106) and one minor endoscopic bleeding event (UCL=0.0169). Conclusions Consistent with expert guidelines, the absolute risk attributable to gastroduodenal biopsy in adults taking antiplatelet agents seems to be low. Half of routine biopsies enter submucosa. The largest blood vessels avulsed during biopsy correspond to midsized and large arterioles and venules.

Endoscopic sedation of patients with chronic liver disease.

Endoscopic procedures are often necessary in patients with chronic liver disease. The preprocedure evaluation of such patients should include an assessment of hepatic synthetic function and identification of neuropsychiatric findings suggestive of hepatic encephalopathy. It may be possible, in some cases, to perform diagnostic esophagogastroduodenoscopy without administration of sedation; this is desirable to eliminate the risks of sedation, especially encephalopathy. Nonetheless, most patients undergoing upper and lower endoscopy require sedation. Currently, the use of propofol is preferred to benzodiazepines and opioids for endoscopic sedation of patients with advanced liver disease due to its short biologic half-life and low risk of provoking hepatic encephalopathy. In appropriately selected patients, gastroenterologist-directed propofol administration seems safe.

Does Better Specimen Orientation and a Simplified Grading System Promote More Reliable Histologic Interpretation of Serrated Colon Polyps in the Community Practice Setting? Results of a Nationwide Study.

Introduction: Colonoscopic surveillance guidelines for serrated polyps (SPs) are predicated upon the histologic characteristics of the index polyp. However, discrimination between SP subtypes [hyperplastic polyps vs. sessile serrated adenoma/polyps (SSA/P)] is often unreliable. Materials and Methods: We studied the impact of (1) a novel tissue orientation method, performed in the endoscopy laboratory, whereby polyps are flattened in a small paper envelope immediately after resection (modified protocol); and (2) 2012 consensus-modified criteria (CM-2012). These interventions were compared with conventional tissue-handling protocol (CP) and traditional 2008 World Health Organization criteria (WHO). Twenty blinded community pathologists from around the United States scored 100, independent, 0.5 to 2.0 cm, proximal colonic SPs randomly selected from a 2-site tissue section archive. We compared interobserver agreement and diagnostic grading. Results: Interobserver agreement was higher using CM-2012 than WHO criteria (absolute agreement: 13% vs. 4%, P<0.01; 75% agreement: 54% vs. 38%, P<0.01). Interobserver agreement was higher with the modified protocol than with CP (WHO absolute agreement: 6% vs. 2%, P>0.05; WHO 75% agreement: 46% vs. 30%, P>0.05, and CM-2012 absolute agreement: 20% vs. 6%, P=0.07; CM-2012 75% agreement: 66% vs. 42%, P=0.03). Compared with WHO, use of CM-2012 criteria resulted in fewer diagnoses of “indeterminate”; more diagnoses of SSA/P (P<0.01); and “upgraded” the diagnosis from hyperplastic polyps to SSA/P in approximately 7% of cases. These observations were independent of polyp size, patient gender, and study site. Conclusions: Simple enhancements to postresection SP handling and diagnostic criteria markedly improve interobserver agreement of SP diagnosis among nongastrointestinal community pathologists. This finding, if confirmed, has important implications for SP colonoscopy surveillance guidelines.

Endoscopic Criteria Used to Distinguish Benign From Malignant Polyps

Endoscopic Criteria Used to Distinguish Benign From Malignant Polyps Neville D. Bamji, Purnima Balachandran, Sudhakar V. Balachandran, Jerome D. Waye Aims: The goal of our study is to determine the visual characteristics used by endoscopists to decide whether a polyp is benign or malignant. Design: A video disc containing 20 cases of 8 benign and 12 malignant polyps was sent to endoscopists of varying experience. The respondent was asked to view the video of each polyp and then fill out a questionnaire which listed various characteristics (size, color, margins, surface irregularity, depression, ulceration, bleeding, waxy, and nodularity) and make a visual estimation as to whether the polyp was benign, malignant or indeterminate. Results: Our sample consisted of responses from 61 physicians (1220 observations). Overall, 68% of the responses were correct, 65% of the benign polyps were identified correctly, as were 70% of the malignant polyps. There were substantial differences in the rate of correct response by question, ranging from 27% to 98%. Gastroenterology fellows answered correctly 67% of the time, whereas, gastroenterology attendings responded correctly 69% of the time (the difference was not statistically significant). The criteria of size, irregularity, margins, and color were used more often when describing a malignant polyp. Lack of nodularity and size were used more often when describing a benign polyp. These differences were statistically significant. Surprisingly, irregularity showed a negative association with correctly identifying the polyp as benign (p-value !0.01). In a logistic regression of the overall data for both benign and malignant polyps, the use of ulceration was most positively associated with the likelihood of a correct answer. Color and margins were also predictive of a correct answer. Although ‘‘waxiness’’ is a term often cited in the literature as a determining visual characteristic, it was rarely used in these responses. Taken together, these results suggest that ulceration in a polyp, combined with an evaluation of its margins and its size increase the likelihood of correctly differentiating between a benign and a malignant polyp. Conclusion: Size, margins, bleeding and ulceration were the visual characteristics most often used by physicians to differentiate benign from malignant polyps. Malignant polyps are most often correctly diagnosed by their larger size, irregular margins, bleeding and surface ulcerations. Conversely, smaller size and lack of irregular margins are often used as determinants of benign polyps. Abstracts