Endoscopic Removal of Large Sessile Colorectal Adenomas: Is It Safe and Effective?

Large sessile colorectal polyps represent a treatment challenge. Nowadays there are discrepancies regarding how to proceed with them because of morbidity, the possibility of incomplete endoscopic resection, and the high possibility of a coexisting malignancy. This study was performed to determine the safety and effectiveness of endoscopic removal of sessile colorectal adenomas larger than 4 cm. Seventy-four patients with a total of 74 sessile polyps larger than 4 cm in diameter were treated endoscopically. Polyps were removed using argon plasma coagulation (APC) as an adjunct to piecemeal technique. Surgery was recommended in patients with invasive neoplasia. Patients with favorable histology (low-grade dysplasia [LDG] or high-grade dysplasia [HGD]) were followed up with monthly endoscopies untill total ablation of the lesion, and then at 3- to 6-month intervals. LGD was found in 38 patients, HGD in 24, and invasive neoplasia in the remaining 12 patients. A total of 54 patients were followed up for at least 6 months. Recurrence rate of polyps with favorable histology was 9.2% (5/54). Postpolypectomy bleeding was the only complication, observed in 10 patients (13.5%). We conclude that piecemeal polypectomy plus APC without saline injection, performed by an expert endoscopist, is a safe and effective treatment for all LGD or HGD large sessile colorectal polyps.     

Detection and Treatment of Early Flat and Depressed Colorectal Cancer Using High-Magnification Chromoscopic Colonoscopy: A Change in Paradigm for Western Endoscopists?

Japanese researchers reported flat and depressed colorectal lesions in the 1980s. Such lesions were thought irrelevant to Western populations and described as “Phantom” or “Akitas” carcinoma. Many depressed neoplasms arise through the de novo pathogenic sequence and demonstrate early invasive characteristics. All investigators report difficulties in identifying flat and depressed lesions using conventional colonoscopy. Failure to detect and treat such lesions may be responsible for the current shortfalls in secondary colorectal cancer prevention. Given the introduction of colorectal cancer screening programs in the United Kingdom, Europe, and the United States, it is essential to re-evaluate the significance of flat lesions as applicable to Western cohorts and explore the safety and efficacy of new endoscopic technology and interventional therapeutics.     

Help or hindrance? Is current infection control advice applicable in low- and middle-income countries? A review of the literature

BACKGROUND: High-income countries with established infection control programs have demonstrated effective control of infection transmission in health care settings. The guidelines and advice underlying these effective control programs have been produced by high-income countries for their own social, economic, and health environments. These have also been adopted by low- and middle-income (LMI) countries, but these countries appear to have a limited ability to apply these principles using the same methods. METHODS: A systematic search for literature published in English was conducted exploring the relationship between the available infection prevention and control advice and the capacity of LMI countries to apply this guidance in their health care settings. Articles relevant to this exploration were identified and subsequently informed further search terms and identified other significant documents. RESULTS: Infection control guidelines designed for high-income countries are being utilized by LMI countries, with varying degrees of success mainly because of physical, environmental, and socioeconomic factors. There is a lack of published studies exploring the implementation of comprehensive infection control advice and programs, including the minimal advice, which is designed specifically for resource-limited settings. CONCLUSION: What is evident from the literature is that there is a need for the development of infection control and prevention guidelines based on evidence but adapted to the specific needs of health care workers in LMI countries. This must be done in collaboration with those same LMI countries' health care workers. Equally, because of finance and health priorities, health care facilities should choose those interventions most relevant to the needs of their population and workers to prevent infection transmission. Opportunities for further research into application of available infection control advice in LMI countries are identified. Through such research, more appropriate advice may be devised to assist with the development of infection control programs in these settings.     

Does Timing of Dialysis in Patients with ESRD and Acute Myocardial Infarcts Affect Morbidity or Mortality?

Background and objectives: Patients with ESRD have an increased incidence of coronary events with a relatively higher risk for mortality after acute myocardial infarction (AMI). We evaluated whether it is safer to delay dialysis in AMI or if delay poses separate risks.Design, setting, participants, & measurements: We conducted a retrospective review of 131 long-term hemodialysis patients who had AMI and were admitted between 1997 and 2005 at three New York City municipal hospitals. Patients were separated into three groups on the basis of time between cardiac symptoms and first dialysis (<24 h, 24 to 48 h, and >48 h).Results: A total of 17 (13%) patients died, 10 (59%) of whom had either hypotension or an arrhythmia during their first cardiac care unit dialysis. Although these groups were comparable in acuity and cardiac status, there were no findings of increased morbidity (26, 36, and 20%, respectively) or mortality (11, 18, and 13%, respectively), despite differences in the timing of each group''s dialysis. We found that previous cardiac disease, predialysis K⁺, ΔK⁺ after dialysis, and APACHE scores were significantly higher in patients with peridialysis morbidity.Conclusions: We conclude that there is no increased morbidity with early dialysis in AMI, but rather close attention needs to be paid to the rate of decrease in serum potassium in patients with ESRD and their level of acuity when undergoing dialysis.Patients with ESRD have an increased incidence of coronary events and a relatively higher risk for mortality after acute myocardial infarction (AMI) (1,2). In fact, cardiac disease is the major cause of death in American hemodialysis (HD) patients, accounting for 43% of all-cause mortality between 2001 and 2003 (3). As a result, this population has between a 10- and 20-fold increased incidence of cardiac-related death compared with the general population (4). This includes patients with sudden cardiac death, an event that has been postulated to be due to potassium (K⁺) changes related to the dialysis schedule (5), and remains the most common form of cardiovascular death in patients with ESRD (6,7). These observations illustrate that beyond issues of coronary ischemia, the dialysis patient may also be subjected to electrolyte abnormalities that indirectly add to the risk for cardiac-related death. Considering such risks, cardiologists and nephrologists have been plagued with the question of how safe the dialysis procedure is during an AMI. In the acutely damaged myocardium, electrolyte fluxes such as K⁺, as well as osmolar and volume fluxes, may potentiate arrhythmias and their consequent hemodynamic insults. Arrhythmic mechanisms account for 58 and 64% of the cardiac deaths in peritoneal dialysis and HD, respectively (6).The issue of the optimal timing of HD after an acute cardiac event has still not been clearly answered. The customary practice has been to err on the side of delaying HD. We sought to determine the potential sequelae of early or late dialysis in the setting of an AMI and how this may affect overall morbidity and mortality.     

Does chemoprevention of Barrett's esophagus using acid suppression and/or COX-2 inhibition prevent neoplastic progression?

Barrett's esophagus--intestinal metaplasia within the tubular esophagus - is a premalignant histologic lesion and a marker of cancer risk. Strategies to prevent Barrett's-related esophageal cancer have focused on reversal of Barrett's using pharmacological or surgical antireflux therapies and endoscopically-induced injury. Currently, however, there is little compelling evidence to support the reversal of Barrett's through pharmacological or surgical therapy, and endoscopic reversal of Barrett's has not yet been validated. Chemoprevention using intensive acid suppression and/or inhibition of cyclooxygenase-2 (COX-2) with nonsteroidal anti-inflammatory drugs remains a biologically plausible strategy that is supported by a rapidly growing body of scientific evidence. Data suggest that a combination of acid suppression with COX-2 inhibition might be the most effective chemopreventive strategy. Whether this approach is effective awaits the results of well-designed outcomes studies.     

Does Intracoronary Thrombus Influence the Outcome of High Risk Percutaneous Transluminal Coronary Angioplasty? Clinical and Angiographic Outcomes in a Large Multicenter Trial

Objectives. We sought to evaluate the impact of angiographically visible thrombus on short- and long-term clinical outcomes after percutaneous transluminal coronary angioplasty (PTCA).Background. Intracoronary thrombus is frequently seen on angiography in patients with acute ischemic coronary syndromes or complex lesion morphology, or both, and is often considered to predict a higher rate of complications in patients undergoing PTCA.Methods. Prospectively collected data from 2,099 patients undergoing high risk PTCA in the Evaluation of IIb/IIIa Platelet Receptor Antagonist 7E3 in Preventing Ischemic Complications (EPIC) trial were analyzed. In addition to aspirin and heparin, patients were randomized to receive either abciximab bolus and infusion, abciximab bolus alone or placebo. Based on an angiographic core laboratory interpretation, patients were classified into three groups: thrombus absent, thrombus possible or thrombus present. The primary end point at 30 days was the composite of death, myocardial infarction or urgent revascularization. The 6-month end point was the composite of death, myocardial infarction or any revascularization.Results. Although abrupt closure was most common in patients with thrombus present compared with thrombus absent or possible (13%, 10.0% and 7.4%, respectively), neither the 30-day nor the 6-month clinical end points were different among the three groups (9%, 11% and 11.7%, respectively, and 30%, 34% and 31%, respectively). Most notably, the benefit of treatment with abciximab was present in all three thrombus groups, and the magnitude of benefit was not different among the thrombus groups.Conclusions. In high risk patients undergoing percutaneous coronary revascularization, features of thrombus on the preprocedure angiogram do not indicate an augmented risk of adverse clinical outcomes. Abciximab therapy reduces the rate of adverse outcomes regardless of the presence of thrombus and should therefore not necessarily be reserved for patients whose angiograms have features of intraluminal thrombus.     

Does osteoprotegerin or receptor activator of nuclear factor-kappaB ligand mediate the association between bone and coronary artery calcification?

CONTEXT: Accumulating evidence indicates that vascular and bone mineralization may be related, although the exact mechanism remains unknown. OBJECTIVE: Our objective was to investigate whether an observed inverse association between bone mineral density (BMD) and coronary artery calcification (CAC) in postmenopausal women currently taking estrogen therapy is mediated by osteoprotegerin (OPG) or receptor activator of nuclear factor-kappaB ligand (RANKL). DESIGN: Participants were 92 postmenopausal women (aged 58-81 yr) taking estrogen therapy who had hip and spine BMD assessed by dual-energy x-ray absorptiometry and CAC measured by electron-beam computed tomography in 1998-2002 and serum RANKL and OPG levels measured in samples collected in 1997-1999. Total CAC score was dichotomized as none/minimal (10). RESULTS: OPG serum levels were higher in women who had some CAC compared with those who had none/minimal (126.8 +/- 1.08 vs. 102.9 +/- 1.07 pg/ml, respectively, P = 0.03); these differences became nonsignificant after adjustment for age and other risk factors (P = 0.51). A 1 sd increase in hip BMD was associated with significantly lower odds of having CAC > 10 (odds ratio = 0.52; 95% confidence interval = 0.29-0.93) independent of age, fat-free mass, high-density lipoprotein cholesterol, current smoking, and use of cholesterol-lowering medications. Other skeletal sites demonstrated a similar pattern. Addition of RANKL and/or OPG to the model had minimal effect on the magnitude or statistical significance of the BMD-CAC association. Additionally, a test of interaction indicated that RANKL and OPG are not significant effect modifiers. CONCLUSIONS: Serum OPG and RANKL do not account for the observed association between bone and coronary artery calcification among postmenopausal women using hormone therapy.     

Does a diet high or low in fat influence the oxidation potential of VLDL,LDL and HDL subfractions?

Background and aimsHigh-fat diets have become increasingly popular for weight-loss, but their effect on the oxidation potential of lipoprotein subfractions has not been studied. Therefore, this study compared the effects of high-fat vs. low-fat weight reduction diets on this parameter.Methods and resultsVery-low, low- and high-density lipoprotein (VLDL, LDL & HDL) subfractions were isolated by rapid ultracentrifugation from 24-overweight/obese subjects randomised to a high- or low-fat diet. The lipoprotein subfractions were assessed for oxidation potential by measuring conjugated diene (CD) production and time at half maximum. We found a significant between-group difference in oxidation potential. Specifically, a high-fat diet led to increased CD production in VLDL_A–D and HDL_2&3, and a prolongation of time at half maximum. Within-group differences found that CDs increased in VLDL_A&D, LDL_I–III and HDL_2&3 in the high-fat group and fell in VLDL_A–C and HDL_2&3 and increased in LDL_I&II, in the low-fat group. Furthermore, following both diets all lipoprotein subfractions, except LDL_II in the low-fat group, were protected against oxidation.ConclusionThese results demonstrate that at first glance, a high-fat diet may be indicative of having heart-protective properties. However, this may be erroneous, as although the time for oxidation to occur was prolonged, once this occurred these lipoproteins had the potential to produce significantly more oxidised substrate. Conversely, a low-fat diet may be considered anti-atherogenic, as these subfractions were protected against oxidation and mainly contained fewer oxidised substrate. Thus, increased fat intake may, by increasing the oxidation product within lipoprotein subfractions, increase cardiovascular disease.