Fernando Castro

Hepatic MRI for fat quantitation: Its relationship to fat morphology, diagnosis, and ultrasound

Purpose: The value of MRI and ultrasound in quantifying hepatic steatosis is assessed and the results compared with those obtained by liver biopsies. Methods: A total of 38 patients undergoing hepatic biopsy for a variety of liver diseases were recruited for this study. Hepatic fat morphology and severity were assessed visually in each biopsy specimen. Steatosis pattern included macrovesicular, microvesicular, or mixed. The severity of hepatic steatosis was assessed by MRI through chemical shift imaging (n = 38) and by ultrasound through echogenicity (n = 31). Results: MRI had a better correlation than ultrasound for microscopic fat content (r = 0.77, P < 0.001 vs. r = 0.41, P < 0.05). In macrovesicular steatosis, MRI and ultrasound both correlated well with microscopic fat content (r = 0.92, P < 0.001 vs. r = 0.90, P < 0.001). In nonalcoholic fatty liver disease, ultrasound revealed severe steatosis in all instances, but MRI fat content ranged greatly (19%-40%). In diagnoses excluding nonalcoholic fatty liver disease, increasing ultrasound severity did not correspond to advanced MRI fat content. Conclusion: Hepatic MRI and ultrasound are both useful in identifying heavy fat accumulation associated with nonalcoholic fatty liver disease. MRI is superior to ultrasound in detecting and quantifying minor degrees of fatty metamorphosis in the liver.

Body mass index and colon cancer screening: The road ahead

Screening for colorectal cancer (CRC) has been associated with a decreased incidence and mortality from CRC. However, patient adherence to screening is less than desirable and resources are limited even in developed countries. Better identification of individuals at a higher risk could result in improved screening efforts. Over the past few years, formulas have been developed to predict the likelihood of developing advanced colonic neoplasia in susceptible individuals but have yet to be utilized in mass screening practices. These models use a number of clinical factors that have been associated with colonic neoplasia including the body mass index (BMI). Advances in our understanding of the mechanisms by which obesity contributes to colonic neoplasia as well as clinical studies on this subject have proven the association between BMI and colonic neoplasia. However, there are still controversies on this subject as some studies have arrived at different conclusions on the influence of BMI by gender. Future studies should aim at resolving these discrepancies in order to improve the efficiency of screening strategies.

Can adjusting BMI for age and sex provide for a better predictor of colonic neoplasia

Objective The aim of this study was to evaluate the influence of BMI on colonic neoplasia in average-risk patients aged between 40 and 59 years, analyzed by sex. Methods A total of 4443 patients aged between 40 and 59 years undergoing a first-time screening or average-risk colonoscopy were included in this study. Data on demographics, smoking, and BMI were collected and correlated to the presence of adenomas and advanced adenomas. Results We evaluated 1197 colonoscopies in patients aged between 40 and 49 years, and 3246 in those aged between 50 and 59 years. Among men between 40 and 49 years, increasing BMI [odds ratio (OR)=1.05, 95% confidence interval (CI): 1.00–1.09] and BMI of at least 27 (OR=1.95, 95% CI: 1.15–3.29) were predictors of adenomas. Younger men with a BMI of at least 27 were more likely to have proximal adenomas (OR=2.23, 95% CI: 1.14–4.37) but not advanced adenomas. There was no relation between BMI and adenomas in younger women. Among women aged between 50 and 59 years, increasing BMI (OR=1.03, 95% CI: 1.01–1.05) and a BMI of at least 24 (OR=1.43, 95% CI: 1.06–2.94) was found to be correlated with adenomas, and increasing BMI was also found to be associated with proximal adenomas (OR=1.67, 95% CI: 1.13–2.45). Among men aged between 50 and 59 years, there was no relation between BMI and adenomas, but there was a positive correlation for advanced adenomas (OR=1.05, 95% CI: 1.002–1.09). Among women aged between 50 and 59 years, BMI was not predictive of advanced adenomas. Conclusion The association between BMI and adenoma differs by age and sex. If BMI is utilized to refine screening practices for colorectal cancer, its influence on sex and age should be taken into account.

A New Scoring System to Predict the Risk for High-risk Adenoma and Comparison of Existing Risk Calculators.

Background: Colorectal cancer (CRC) screening guidelines likely over-generalizes CRC risk, 35% of Americans are not up to date with screening, and there is growing incidence of CRC in younger patients. Goals: We developed a practical prediction model for high-risk colon adenomas in an average-risk population, including an expanded definition of high-risk polyps (≥3 nonadvanced adenomas), exposing higher than average-risk patients. We also compared results with previously created calculators. Study: Patients aged 40 to 59 years, undergoing first-time average-risk screening or diagnostic colonoscopies were evaluated. Risk calculators for advanced adenomas and high-risk adenomas were created based on age, body mass index, sex, race, and smoking history. Previously established calculators with similar risk factors were selected for comparison of concordance statistic (c-statistic) and external validation. Results: A total of 5063 patients were included. Advanced adenomas, and high-risk adenomas were seen in 5.7% and 7.4% of the patient population, respectively. The c-statistic for our calculator was 0.639 for the prediction of advanced adenomas, and 0.650 for high-risk adenomas. When applied to our population, all previous models had lower c-statistic results although one performed similarly. Conclusions: Our model compares favorably to previously established prediction models. Age and body mass index were used as continuous variables, likely improving the c-statistic. It also reports absolute predictive probabilities of advanced and high-risk polyps, allowing for more individualized risk assessment of CRC.

Safety of Large-volume, Same-day Oral Bowel Preparations During Deep Sedation: A Prospective Observational Study

BACKGROUND: Colonoscopy quality is directly related to the bowel preparation. It is well established that bowel preparations are improved when at least part of the laxative is ingested on the day of the procedure. However, there is concern that this can result in higher gastric residual volumes (GRV) and increase the risk of pulmonary aspiration. The aim of this study is to evaluate GRV and gastric pH in patients who received day-before bowel preparation versus those ingesting their laxative on the day of colonoscopy under anesthesiologist-directed propofol deep sedation. METHODS: This is a prospective observational study for patients undergoing same-day upper endoscopy and colonoscopy. All included patients had large-volume polyethylene glycol lavage preparation and received propofol sedation. Gastric fluid was collected during the upper endoscopy for volume and pH measurement. RESULTS: The study included 428 patients with 56% receiving same-day laxative preparation and the remainder evening-before preparation. Mean ± SD GRV was 18.1 ± 10.2 mL, 16.3 ± 16.5 mL in each of these preparation groups, respectively (P = .69). GRV ≥ 25 mL or higher than expected GRV adjusted by weight (0.4 mL/kg) were also not different among the study groups (P = .90 and P = .87, respectively). Evaluating GRV based on time since last ingestion of preparation (3–5, 5–7, >7 hours) did not result in any differences (P = .56). Gastric pH was also similar between the bowel preparation groups (P = .23), with mean ± SD of 2.5 ± 1.4 for evening-before and 2.5 ± 1.3 for the same-day preparation. There were more inadequate bowel preparations in day before bowel preparations (P = .001). CONCLUSIONS: A large-volume bowel preparation regimen finished on the day of colonoscopy as close as 3 hours before the procedure results in no increase in GRV or decrease in gastric pH.

Crohn's disease presenting as acute gastrointestinal hemorrhage

Severe gastrointestinal (GI) hemorrhage is a rare complication of Crohns disease (CD). Although several surgical and non-surgical approaches have been described over the last 2 decades this complication still poses significant diagnostic and therapeutic challenges. Given the relative infrequency of severe bleeding in CD, available medical literature on this topic is mostly in the form of retrospective case series and reports. In this article we review the risk factors, diagnostic modalities and treatment options for the management of CD presenting as GI hemorrhage.

Comparison of Adenoma Detection Rates in Afro-Caribbeans and Non-Hispanic Whites Undergoing First Screening Colonoscopy.

Objectives The African American population has a higher prevalence of advanced colon adenomas when compared with non-Hispanic whites and Hispanics, but the risk in other black populations has not been evaluated. Although the Afro-Caribbean population is a significant demographic segment in some regions of the United States, the data are limited on the prevalence of colon adenomas in this group and there is no comparison with a non-Hispanic white population. The objective of our study was to compare the prevalence of adenomas in Afro-Caribbean versus non-Hispanic white populations. Methods A total of 880 Afro-Caribbean patients and 1828 non-Hispanic white patients undergoing their first screening colonoscopy between January 2008 and August 2014 was included in the study. Results A total of 2708 patients met entry criteria for the study. The adenoma detection rate among Afro-Caribbeans was 29% and 31% among non-Hispanic whites. There was no statistically significant difference in the prevalence of adenomas in the two groups (P = 0.28), and the rate of advanced adenomas also was similar in both groups (8.6% in Afro-Caribbeans, 9.2% in non-Hispanic whites; P = 0.60). A multivariate analysis also found no difference in the occurrence of adenomas (P = 0.60) or advanced adenomas (P = 0.99) between Afro-Caribbeans and non-Hispanic whites. Conclusions We found a similar adenoma detection rate and advanced adenoma prevalence among Afro-Caribbeans and non-Hispanic whites undergoing their first screening colonoscopy. As such, the Afro-Caribbean population may not have the same risk of colorectal neoplasia as what has been described for African Americans. Based on these results, it is appropriate to initiate colorectal cancer screening for Afro-Caribbeans at age 50 as recommended for non-Hispanic whites.

Su1057 Sex Hormone Binding Globulin (Shbg) and MRI Fat Quantification As Markers for Non-Alcoholic Steatohepatitis (NASH)

A S L D A b st ra ct s between NAFLD and colorectal adenoma in asymptomatic patients, who underwent screening colonoscopy. Methods: Electronic database including Pubmed and Embase were searched for relevant studies that investigate the Association between Nonalcoholic fatty liver disease and colorectal adenoma. Study designs and locations in addition to characteristics of adenoma were added to subgroup analysis. The random-effects model was used to pool the effect size across studies and calculated the pooled odds ratio (OR) with 95% confidence interval (CI) for infectious complications. Results: Overall Four cross-sectional studies and three cohort studies with a total of14, 095 subjects were included in the final meta-analysis. The association between NAFLD and colorectal adenoma was statistically significant [pooled odds ratio (OR) 1.42, 95% confidence interval (CI): 1.271-1.587]. The association was more significant in Asian population five studies compared to European/North American population two studies. Conclusions: According to our results in asymptomatic patients undergoing screening colonoscopy, NAFLD is significantly associated with the presence of colorectal adenoma. Our results suggest that extra carful screening for colorectal cancer in patients with NAFLD. The majority of subjects were from Asian country; Further studies of western population might be needed to confirm our results.

Mo1077 Clinical Efficacy of Same Day CT Colonography Following Incomplete Colonoscopy

Background: Colonoscopy is the preferred screening method for colorectal cancer (CRC) but may be incomplete in 4% to 25% of cases. CT colonography (CTC) is an adjunct to evaluate the colon after an incomplete colonoscopy (IC). No study has focused on same day CTC after an IC. Our primary aim was to determine the yield of same day CTC after IC. Methods: Our institution has the capability to perform same day CTC in patients with an incomplete colonoscopy. This was a retrospective review of all CTC done immediately following IC from January 2008 to December 2012. 198 CTC met inclusion criteria. Descriptive statistics were used. Results: Of 198 patients with IC and CTC 50 patients had 61 intracolonic findings. 23/50 (46%) were screening procedures, 1/50 (2%) high risk screening, 17/50 (34%) had a diagnostic colonoscopy and 9/50 (18%) surveillance colonoscopy. 10/50 patients had 12 findings on CTC on areas that were not reached by incomplete colonoscopy. 6 of these 10 patients had a follow up intervention: 2 had retrograde double balloon enteroscopy and 4 had colonoscopies. 3 findings correlated with CTC (1 ascending colon adenocarcinoma and 2 polyps) and 3 did not ( normal colonoscopy/DBE). 40 patients had 49 colonic findings on CTC on areas reached but not described during IC. 19/49 (39%) findings were not described during the initial colonoscopy. Only 6 of these 40 pts had a repeat colonoscopy. 9 findings did not correlate with subsequent complete colonoscopy. Only 1 CTC finding correlated with repeat colonoscopy. There were 30 colonic findings on CTC in areas that were reached and described during the incomplete colonoscopy. Nineteen were sigmoid diverticular strictures with no additional findings in the rest of the colon, 10 were diverticulosis of the sigmoid and 1 ascending colon adenocarcinoma with no synchronous lesions. Conclusions: Same day CTC can be of added value in patients with incomplete colonoscopy. Potential benefits include no need to repeat bowel cleansing and no extra day lost from work. Our data showed that correlation of findings by CTC in areas not visualized by incomplete colonoscopy was poor as 50% of patients had CTC abnormalities which did not correlate with a repeat colonoscopy. When CTC described an abnormality in an area already reached but not described during IC correlation was also poor as only one patient had correlation between CTC and repeat colonoscopy. When CTC reported the same findings described during IC correlation was 100%. More data on the efficacy and cost-effectiveness of same day CTC compared to repeating a colonoscopy or maybe performing a retrograde overtube assisted enteroscopy is needed to determine which effort is worthwhile.