Bhaskar Banerjee

Impact of Obesity on Bowel Preparation for Colonoscopy

BACKGROUND & AIMS An inadequately cleansed colon can lead to missed lesions, repeat procedures, increased cost, and complications from colonoscopy. Because obesity, with its known link to colorectal neoplasia, might be associated with inadequate bowel cleansing, we investigated the impact of increased body mass index (BMI) on quality of bowel preparation at colonoscopy. METHODS All colonoscopy procedures performed at a tertiary referral center during a 4-month period were evaluated. Bowel preparation was assigned a unique composite outcome score that took into account a subjective bowel preparation score, earlier recommendation for follow-up colonoscopy as a result of inadequate bowel preparation, and the endoscopists confidence in adequate evaluation of the colon. Univariate and multivariate logistic regression analyses were performed to identify the role of BMI in predicting an inadequate bowel preparation. RESULTS During the study period, 1588 patients (59.1% female; mean age, 57.4 +/- 0.34 years) fulfilled inclusion criteria. An abnormal BMI (> or =25) was associated with an inadequate composite outcome score (P = .002). In multivariate logistic regression analyses, both BMI > or =25 (P = .04) and > or =30 (P = .006) were retained as independent predictors of inadequate bowel preparation. Each unit increase in BMI increased the likelihood of an inadequate composite outcome score by 2.1%. Additional independent predictors of inadequate preparation exponentially increased the likelihood of an inadequate composite outcome score; 7 additional risk factors identified 97.5% of overweight patients with an inadequate composite outcome score. CONCLUSIONS Obesity is an independent predictor of inadequate bowel preparation at colonoscopy. The presence of additional risk factors further increases the likelihood of a poorly cleansed colon.

Comparison of white light and narrow band high definition images in predicting colon polyp histology, using standard colonoscopes without optical magnification.

BACKGROUND AND STUDY AIMS Narrow band imaging (NBI) with optical magnification is useful in predicting colon polyp histology. As magnifying endoscopes are not routinely available, we investigated the use of NBI and high definition white light imaging in determining polyp histology, using images obtained with colonoscopes without optical magnification. PATIENTS AND METHODS Images (white light and NBI) of colon polyps less than 10 mm in diameter were collected prospectively from patients undergoing screening colonoscopy and digitally stored. Two endoscopists later reviewed all images and predicted polyp histology as neoplastic or non-neoplastic using a modified Kudo classification. Comparison was made with histopathology. RESULTS Separate white light and NBI images of 80 polyps (49 neoplastic, 31 non-neoplastic) from 63 patients were recorded. Mean polyp size was 5.1 +/- 2.1 mm (5.4 +/- 2.2 neoplastic; 4.4 +/- 1.8 non-neoplastic; P = 0.02). In a pooled analysis, NBI correctly predicted neoplastic histology in 93 of 98 images (sensitivity 95 %, positive predictive value [PPV] 94 %) whereas white light did so in 58 of 98 images (sensitivity 59 %, PPV 79 %). NBI correctly predicted non-neoplastic histology in 56 of 62 images (specificity 90 %, negative predictive value [NPV] 92 %) whereas white light did so in 47 of 62 images (specificity 76 %, NPV 54 %). CONCLUSIONS NBI without optical magnification was more accurate in predicting colon polyp histology compared with white light imaging. Image quality and confidence in histology were significantly higher in the NBI group. NBI without optical magnification may be useful in predicting colon polyp histology.

Stenting for malignant colonic obstruction: a comparison of efficacy and complications in colonic versus extracolonic malignancy

BACKGROUND Self-expandable metal stent placement for palliation of malignant colonic obstruction for colorectal cancer (CRC) is safe and efficacious. In contrast, outcomes of stent placement for extracolonic malignancy (ECM) are unclear. OBJECTIVE To compare the success and complication rates of colorectal stenting in patients with CRC versus those with ECM. DESIGN Retrospective chart review. SETTING Tertiary-care academic medical center. PATIENTS AND INTERVENTIONS Between September 2000 and December 2007, all patients with malignant colon obstruction in whom endoscopy was performed with the intention of placing a colonic metal stent. MAIN OUTCOME MEASUREMENTS Technical and clinical success rates, surgical interventions, and procedure-related complications. RESULTS Colonic stenting was performed for CRC in 34 patients and for ECM in 15 patients. Patients with CRC were more likely to have clinical success after all endoscopic therapy (94.1%) than those with ECM (20.0%) (P < .0001). Surgical diversion to relieve persistent obstructive symptoms was required in significantly more patients with ECM. Five patients with ECM (33.3%) had at least one complication, including 2 deaths, compared with 3 patients with CRC (8.8%) (P = .046). Only underlying ECM was predictive of failed colon stent placement by multivariate analysis (hazard ratio 21.0, P = .0013). A history of radiation therapy was the sole predictor of complications (hazard ratio 7.8, P = .048). LIMITATIONS Single institution, retrospective analysis, relatively small sample size. CONCLUSIONS Colon stenting for large-bowel obstruction from ECM is infrequently successful and is associated with a significantly higher risk of complications in comparison with patients with CRC.

Queue Position in the Endoscopic Schedule Impacts Effectiveness of Colonoscopy

OBJECTIVES:Endoscopist fatigue potentially impacts colonoscopy. Fatigue is difficult to quantitate, but polyp detection rates between non-fatigued and fatigued time periods could represent a surrogate marker. We assessed whether timing variables impacted polyp detection rates at a busy tertiary care endoscopy suite.METHODS:Consecutive patients undergoing colonoscopy were retrospectively identified. Indications, clinical demographics, pre-procedural, and procedural variables were extracted from chart review; colonoscopy findings were determined from the procedure reports. Three separate timing variables were assessed as surrogate markers for endoscopist fatigue: morning vs. afternoon procedures, start times throughout the day, and queue position, a unique variable that takes into account the number of procedures performed before the colonoscopy of interest. Univariate and multivariate analyses were performed to determine whether timing variables and other clinical, pre-procedural, and procedural variables predicted polyp detection.RESULTS:During the 4-month study period, 1,083 outpatient colonoscopy procedures (57.5±0.5 years, 59.5% female) were identified, performed by 28 endoscopists (mean 38.7 procedures/endoscopist), with a mean polyp detection rate of 0.851/colonoscopy. At least, one adenoma was detected in 297 procedures (27.4%). A 12.4% reduction in mean detected polyps was detected between morning and afternoon procedures (0.90±0.06 vs. 0.76±0.06, P=0.15). Using start time on a continuous scale, however, each elapsed hour in the day was associated with a 4.6% reduction in polyp detection (P=0.005). When queue position was assessed, a 5.4% reduction in polyp detection was noted with each increase in queue position (P=0.016). These results remained significant when controlled for each individual endoscopist.CONCLUSIONS:Polyp detection rates decline as time passes during an endoscopists schedule, potentially from endoscopist fatigue. Queue position may be a novel surrogate measure for operator fatigue.

Beneficial Effects of a Novel IH636 Grape Seed Proanthocyanidin Extract in the Treatment of Chronic Pancreatitis

Oxygen-derived free radicals mediate tissue damage in acute and chronic pancreatitis. Low levels of natural antioxidants in pancreatitis indicate their increased utilization as scavengers of free radicals. Combination therapy with selenium, β-carotene, methionine, and vitamins C and E are known to improve symptoms of chronic and recurrent pancreatitis. This, however, requires many tablets to be taken daily, which is impractical and may reduce compliance. Three patients with chronic pancreatitis (two with a history of alcohol excess and one idiopathic) are reported. Treatment with narcotic analgesics and pancreatic enzyme supplements had failed to control their symptoms. The addition of a commercially available IH636 grape seed proanthocyanidin extract (commercially known as ActiVin) to their treatment regimen led to a reduction in the frequency and intensity of abdominal pain as well as resolution of vomiting in 1 patient.

Endoscopic band ligation for gastric ulcer bleeding.

Endoscopic band ligation is used commonly to treat variceal bleeding. The use of band ligation has been described in selected cases of nonvariceal bleeding. The successful use of endoscopic band ligation, after the failure of standard techniques, to arrest bleeding in two cases of gastric ulcer hemorrhage is reported. Prospective studies are indicated to further evaluate this technique.

Detection of Murine Intestinal Adenomas Using Targeted Molecular Autofluorescence

There is a significant need for noninvasive methods of evaluating dysplastic and neoplastic lesions in the luminal gastrointestinal tract. We have optimized an approach based on autofluorescence to study dysplastic adenomatous polyps in Apcmin/+ mice. We made recordings from both normal intestinal mucosa and from polyps using a xenon lamp-based fiberoptic device. Seventy-eight polyps in 11 mice revealed an increase in mean autofluorescence intensity ratios of 1.29 ± 0.04 (72 small intestinal polyps; P < 0.0001) and 1.28 ± 0.05 (6 colon polyps; P = 0.0016). Serial measurements of autofluorescence discriminated polyps from normal mucosa with a sensitivity, verified histologically, of 95%. To understand the chemical basis for increased autofluorescence, we examined the tryptophan content of intestinal polyps and the adjacent normal mucosa in a small subset of animals. The findings revealed an increased concentration of tryptophan in polyps (990 ± 240 ng/mg) compared to normal mucosa (720 ± 150 ng/mg; P = 0.03). In conclusion, these findings suggest that autofluorescence intensity increases in the setting of intestinal neoplasia and can be used to detect adenomas in the mouse intestine in real time.

4491 Use of a shorter wavelength autofluorescence band to separate adenomatous from hyperplastic polyps of the colon.

INTRODUCTION: The majority of work on autofluorescence has been at emission wavelengths greater than 450 nm. A short wavelentgh emission band was investigated to see if it could distinguish hyperplastic from adenomatous polyps of the colon. METHODS: Endoscopically obtained tissue samples were snap frozen in liquid Nitrogen and stored at -70 Celcius. For each specimen, a sample of normal colonic mucosa from the same patient served as control. Prior to spectroscopy, all samples were thawed over ice and moistened in PBS at pH of 7.4. A spectrofluorometer with a Xenon lamp and excitation and emission spectrometers (Shimatzu RF- 5301 PC Columbia, MD)was used, with a specially constructed tissue holder placed in its measuring chamber. Tissue samples were excited at wavelengts below 350 nm and the maximum intensity of an emission peak below 450 nm digitally recorded. Intensity in arbitrary units (y- axis) were plotted against wavelength (x- axis). All tissue samples were fixed in Formalin and submitted for histology. The emission intensities of hyperplastic polyps (n= 15) and adenomatous polyps (n= 22) were expressed as a ratio of the corresponding fluorescence intensity of normal colonic mucosa (n= 37) in each patient. RESULTS: The ratios of mean emission intensity ± SE were: 1.35 ± 0.07 (hyperplastic) and 2.22 ± 0.12 (adenomatous). The difference between groups (unpaired t test) was significant (p ≤ 0.0001). CONCLUSIONS: The intensity of this emission band increses with adenomatous change, with significant separation between histologic groups. The use of this autofluorescence band during screening flexible sigmoidoscopy may help to distinguish adenomatous polyps from hyperplastic ones in real time. The need to wait for biopsy results could be avoided. Patients with hyperplastic polyps could be advised not to have a colonoscopy at the end of screening flexible sigmoidoscopy, without the need to wait for biopsy results. Unlike chromoendoscopy, this technique will not require any dye or exogenous chemicals. Further work using a hand held, portable fiberoptic spectrometer is being planned.

3518 USE OF A SHORTER WAVELENGTH AUTOFLUORESCENCE BAND IN BARRETT'S ESOPHAGUS: EFFECT OF DYSPLASIA AND INFLAMMATION.

INTRODUCTION: Most work on autofluorescence spectroscopy has been done at emission wavelengths greater than 450 nm. The use of a shorter wavelength emission band was studied in Barrett’s esophagus to observe the effects of dysplasia and inflammation. METHODS: Endoscopically obtained tissue samples were were snap frozen inliquid Nitrogen and stored at -70 Celcius. Prior to measurements, samples were thawed over ice and moistened over phosphate buffered saline at pH 7.4 (PBS). A spectrometer with a Xenon lamp and excitation and emission spectrometers (Shimatzu RF-5301 PC Columbia,MD) was used, with a specially constructed tissue holder placed in its measuring chamber. Tissue was excited below 350 nm and the maximum intensity of an emission peak below 450 nm was measured. Emission intensity in arbitrary units (y-axis) was plotted against wavelength (x-axis). The intensities of intestinal metaplasia (n= 21 ) low grade dysplasia (n= 12) and esophagitis (n= 10)were expressed as a ratio of the corresponding emission intensity of normal squamous mucosa (n= 43) in each patient. RESULTS:The ratios of mean emission intensity ± SE were: 0.63 ± 0.06 (intestinal metaplasia); 2.07 ± 0.26 (low grade dysplasia); 0.62 ± 0.03 (esophagitis). The differences between groups (by ANOVA) were significant (p ≤ 0.0001). CONCLUSIONS: Changes in the intensity of this emission band can differentiate between low grade dysplasia (increased intensity) and inflammation (decreased intensity) when compared to normal squamous mucosa. This emission band also allows columnar epithelium to be distinguished from squamous epithelium. Further work with a hand held portable fiberoptic spectrometer is planned.

Simultaneous cannulation and needle-knife papillotomy using a large- channel duodenoscope

cant ly prolong procedures. Because of the abili ty of the t rac t ion papil lotome to bow, the re is g rea te r control over the perpendicu la r axis for directed guide wire placement , bu t again, the na tu ra l or ien ta t ion is usually to the right. The use of ro ta t ional torque at the handle , which is t hen t r ansmi t t ed to the distal tip of the papillotome, allows for more complete control of the axis perpendicu la r to the bi l iary tree. There m a y be a potent ia l r isk of t r aumat i c in jury to the bil iary t ree if a t t empts are made to ro ta te the papil lotome in a fully bowed position in a nondi la ted system; therefore, this m a n e u v e r should be avoided. The use of a s t anda rd t rac t ion doublelumen papillotome, available in most bi l iary units, to direct wire access dur ing ERCP should be added to the growing a rmamen ta r ium of techniques available to bi l iary endoscopists.