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Biomedical subjects

Todd H Baron

Publications and source records attributed to Todd H Baron.

At least 91 records · Page 5Linked to original sources

Palliation of patients with malignant gastric outlet obstruction with the enteral Wallstent: outcomes from a multicenter study.

BACKGROUND: Endoscopic placement of self-expandable metallic stents for palliation of patients with malignant gastric outlet obstruction is safe and feasible. METHODS: Patients with malignant gastric outlet obstruction undergoing enteral stent insertion were identified from endoscopy databases. Duration of oral intake after stent insertion was calculated by using the log-rank test. Factors associated with duration of oral intake were assessed by using Cox multivariable regression analysis. RESULTS: A total of 176 patients (mean age 65 [14] years) treated at 4 centers from 1996 to 2003 were identified. Obstruction was caused by cancer of the pancreas in 84, the stomach in 20, the bile duct in 15, the major duodenal papilla in 8, another primary site in 16, and metastases in 33. The site of obstruction was the duodenum in 125, the distal stomach in 17, the stomach and the duodenum in 18, and surgical anastomosis in 16 patients. Stent deployment was technically successful in 173. Complications occurred in 14 patients. Seventeen patients were lost to follow-up. Of the remaining 159 patients, 133 resumed oral intake for a median time of 146 days: 95% CI [65, 202]. On regression analysis, chemotherapy after stent placement was associated with prolonged duration of oral intake (hazard ratio 0.41: 95% CI [0.23, 0.72]). CONCLUSIONS: After enteral stent insertion for malignant gastric outlet obstruction, 84% of patients resumed oral intake for a median time of 146 days. Chemotherapy after enteral stent insertion was independently associated with prolongation of oral intake.

Aged↗

Endoscopic stenting of colonic tumours.

Self-expandable metal stents (SEMS) are useful for the non-surgical relief of malignant colonic obstruction. They may be used both as a palliative measure and as a pre-operative bridge to facilitate a one-stage surgical resection of primary colonic tumours. SEMS may be placed endoscopically or by interventional radiologists without the use of endoscopy. In experienced centres SEMS can be successfully placed in approximately 90% of cases. Although it is known that the placement of these devices is feasible, there are no prospective trials comparing stent placement for colonic obstruction to routine surgical care. Additionally, there are no studies comparing the outcome of the method of placement (endoscopic versus radiological). This chapter reviews the types of expandable metal stent used for treatment of colonic obstruction, the indications for their insertion, their methods of insertion, and outcomes following insertion. Future research directions using expandable stents for colonic tumours are also addressed.

Adenocarcinoma↗

Strategies to address increased demand for colonoscopy: Guidelines in an open endoscopy practice.

BACKGROUND AND AIMS: Since Medicare approval for reimbursement of screening colonoscopies, the number of colonoscopy requests has increased. Physician resources have often been inadequate to meet the demand. We sought to reduce the demand for colonoscopy in an open endoscopy system by using a guideline-based triage system to eliminate inappropriate procedures and to align the timing of surveillance colonoscopies with recommendations made by national organizations. METHODS: This was a cohort study with primary care outpatients. From October 2002 to February 2003, 498 consecutive patients on a waiting list of 2400 awaiting colonoscopy for all indications were triaged and are the focus of the study. Selection of patients for appropriate colonoscopy was based on consensus guidelines developed for institutional use by using established published guidelines for appropriate colonoscopy indications. RESULTS: Of the 498 consecutive patients triaged, 139 (28%) were deemed inappropriate. The most common reason was inappropriate referral for surveillance of colorectal polyps. The percentage of inappropriate referrals by the 3 largest referring specialties (internal medicine, family medicine, and gastroenterology) combined was also 28% with no statistically significant differences between specialties. CONCLUSIONS: Most referrals for colonoscopy in an open-access endoscopy system were appropriate, although about 1 in 4 were not. Use of triage and further education of physicians regarding colonoscopy may optimize colonoscopy utilization.

Cohort Studies↗

A prospective comparison of digital image analysis and routine cytology for the identification of malignancy in biliary tract strictures.

BACKGROUND & AIMS: Digital image analysis (DIA) allows quantification of nuclear DNA content and may help distinguish benign and malignant strictures of the biliary tract. METHODS: One hundred ten consecutive patients undergoing endoscopic retrograde cholangiography for suspicious biliary tract strictures were enrolled in a prospective study comparing the accuracy of DIA and routine cytology (RC). Standard brush cytology sampling was performed twice by using 2 cytology brushes per patient. Both brushes were fixed in a single-specimen vial. Each specimen was formed into 1 pellet, and the sample was equally divided for evaluation by DIA and RC. DNA histograms were generated for ploidy analysis. The DIA criterion for malignancy was demonstration of aneuploidy. RESULTS: Two patients had inadequate samples obtained for DIA analysis, 7 benign patients were excluded because of inadequate follow-up of less than 75 days, and 1 patient was lost to follow-up to clarify malignant versus benign disease. Of the remaining 100 patients, 56 strictures were malignant and 44 were benign. The sensitivities of DIA and RC were 39.3% and 17.9%, respectively (P = 0.014). The specificities of DIA and RC were 77.3% and 97.7%, respectively (P = 0.003). The accuracy of DIA (56.0%) was equivalent to RC (53.0%). CONCLUSIONS: DIA is a valuable adjunct to RC for detecting malignant strictures of the biliary tract.

Adult↗

Endoscopic management of cholangiocarcinoma.

Cholangiocarcinoma (CCA) is an uncommon malignant tumor arising from the biliary epithelium. The incidence increases with age and usually affects individuals in their 6th or 7th decade of life. Those patients with underlying risk factors such as primary sclerosing cholangitis (PSC) and choledochal cysts generally present 2 decades earlier. Most patients clinically present with painless jaundice; however, other common symptoms include pruritus, weight loss, and abdominal pain. Although surgical resection offers the only hope for cure, most patients are found to have unresectable disease on initial presentation and have an extremely grim prognosis. This has led to an emphasis on the role of palliative care, with relief of biliary obstruction, in the management of these patients. Surgical bypass was once the primary means of palliation of jaundice in patients with unresectable cholangiocarcinoma but in the last 2 decades has been superseded by less invasive and less morbid nonsurgical procedures such as endoscopic and percutaneous biliary stent placement. Newer modalities of palliation such as endoscopic delivery of photodynamic therapy and high-intensity ultrasound therapy are emerging nonsurgical modalities that may result in improved survival and may play a future role as an adjunctive therapy to surgical resection.

Bile Duct Neoplasms↗

Assessment of patients' perceptions of bowel preparation quality at colonoscopy.

AIMS: There is little published literature evaluating the accuracy of patients' perceptions of the quality of their own bowel preparation for colonoscopy. The aim of this article was to compare patients' perceptions of the adequacy of their bowel preparation with the endoscopists' rating at colonoscopy. METHODS: Outpatients undergoing elective colonoscopy completed surveys assessing bowel preparation. Patient responses regarding quality of bowel preparation were compared with endoscopists' assessment of colonic preparation. A residual stool score was also calculated for each subject based on the amount of stool, consistency of residual stool, and percentage of bowel visualized. RESULTS: A total of 474 patients were enrolled. Patients' perceptions of the quality of their bowel preparation were inaccurate when compared to the endoscopists' rating (sensitivity, 75%; specificity, 34%; accuracy, 50%). Overall correlation with endoscopists' rating was low, r = 0.08. Young patient age (<61 yr) was an independent predictor of both adequate bowel preparation ( p= 0.009) and agreement of patient/endoscopist ratings ( p= 0.003). CONCLUSIONS: Patients are unreliable judges of the quality of their own bowel preparation, tending to overestimate the cleanliness of their colon. Conversely, a patient's fear that their preparation is suboptimal is also inaccurate. A colonoscopy should not be canceled on the basis of a patient's perception that the quality of their preparation is poor.

Aged↗

Endoscopic balloon dilation of the biliary sphincter compared to endoscopic biliary sphincterotomy for removal of common bile duct stones during ERCP: a metaanalysis of randomized, controlled trials.

OBJECTIVES: To compare the effect of endoscopic balloon dilation (EPBD) of the papilla with that of endoscopic biliary sphincterotomy (EST) in the treatment of patients with common bile duct stones. METHODS: Searches of computerized bibliographic and scientific citations, and review of citations in relevant primary articles. Eight fully published prospective, randomized trials in English that compared EPBD with EST for the removal of common bile duct stones were subjected to metaanalysis. RESULTS: EPBD compared with EST resulted in similar outcomes with regards to overall successful stone removal (94.3% vs 96.5%) and overall complications (10.5% vs 10.3%). Bleeding occurred less frequently with EPBD (0% vs 2.0%, p = 0.001). Post-ERCP pancreatitis occurred more commonly in the EPBD group (7.4% vs 4.3%, p = 0.05). No significant differences were seen in the rates of perforation or infection. Patients undergoing EPBD were more likely to require mechanical lithotripsy for stone extraction (20.9% vs 14.8%, p = 0.014). CONCLUSIONS: On the basis of lower rates of bleeding, EPBD should be the preferred strategy over EST for endoscopic removal of common bile duct stones in patients with coagulopathy. Although EPBD is theoretically attractive for use in young patients for biliary sphincter preservation, the rate of pancreatitis is higher with EPBD and cannot be routinely recommended at this time.

Ampulla of Vater↗

A comparison of routine cytology and fluorescence in situ hybridization for the detection of malignant bile duct strictures.

BACKGROUND AND AIM: The aim of this study was to assess the relative sensitivities and specificities of fluorescence in situ hybridization (FISH) and routine cytology for the detection of malignancy in biliary tract strictures. METHODS: Bile duct brushing and aspirate specimens were collected from 131 patients being evaluated for possible malignant bile duct strictures. Both specimen types were assessed by FISH but only brushing specimens were assessed by cytology. The FISH assay used a mixture of fluorescently-labeled probes to the centromeres of chromosomes 3, 7, and 17 and chromosomal band 9p21 (Vysis UroVysion) to identify cells having chromosomal abnormalities. A case was considered positive for malignancy if five or more cells exhibited polysomy. RESULTS: Sixty-six of the 131 patients had surgical pathologic and/or clinical evidence of malignancy. Thirty-nine patients had cholangiocarcinoma, 19 had pancreatic carcinoma, and 8 had other types of malignancy. The sensitivity of cytology and FISH for the detection of malignancy in bile duct brushing specimens in these patients was 15% and 34% (p < 0.01), respectively. The sensitivity of FISH for the bile aspirate specimens was 23%, and the combined sensitivity of FISH for aspirate and brushing specimens was 35%. The specificity of FISH and cytology brushings were 91% and 98% (p= 0.06), respectively. CONCLUSIONS: FISH is significantly more sensitive than and nearly as specific as conventional cytology for the detection of malignant biliary strictures in biliary brushing specimens. FISH may improve the clinical management of patients who are being evaluated for malignancy in bile duct strictures.

Adolescent↗

Postpolypectomy lower gastrointestinal bleeding: potential role of aspirin.

INTRODUCTION: Limited data exist on the role of aspirin in increasing the risk of clinically significant postpolypectomy bleeding (PPB), which is defined as lower gastrointestinal (GI) hemorrhage following colonoscopic polyp removal requiring transfusion, hospitalization, endoscopic intervention, angiography, or surgery. OBJECTIVES: To determine if aspirin use prior to colonoscopy increases the risk of clinically significant PPB. METHODS: A case-control study of patients with clinically significant PPB at Mayo Clinic Scottsdale and Rochester was performed. Information collected included age, gender, recent use of aspirin or NSAIDs (within three days of colonoscopy), polyp characteristics, and polypectomy technique. The control group consisted of patients matched for age (+/-3 yr), gender, and cardiovascular morbidity who had undergone polypectomy without any complications. The populations were compared to determine the odds ratio (OR) of PPB with aspirin use. RESULTS: During the study period, 20,636 patients underwent colonoscopy with polypectomy at the two institutions and 101 patients presented with clinically significant PPB. Twenty patients were excluded from analysis because of prior anticoagulant use. The remaining 81 patients were matched to 81 patients who had undergone colonoscopy without complications. The two groups were comparable in terms of polyp size (97%< or = 10 mm, bleeding group; 95%< or = 10 mm, control group). Aspirin use prior to polypectomy was 40% in the bleeding group and 33% in the control group (OR 1.41; 95% C.I. 0.68 to 3.04). CONCLUSION: Postpolypectomy bleeding is an uncommon but important complication of endoscopic polypectomy. There was no statistically relevant difference in prior aspirin use before polypectomy in the bleeding group and the matched controls.

Age Distribution↗

Prospective, blinded assessment of factors influencing the accuracy of biliary cytology interpretation.

OBJECTIVES: There is little published data assessing factors that influence the accuracy of biliary cytology. The aim of this study was to (a) prospectively compare interobserver variability among two blinded pathologists interpreting biliary cytology specimens, (b) to describe the predictors of interpathologist agreement, and (c) to characterize the predictors of accurate cytology interpretation. METHODS: In total, 113 consecutive patients undergoing endoscopic retrograde cholangiopancreatography with brushing of suspicious biliary tract strictures were prospectively enrolled to assess routine cytology (RC) accuracy. The initial RC interpretation was performed by the pathologist on duty with the benefit of the patient's clinical information. Subsequent interpretation was performed by two independent pathologists blinded to the patients' clinical details. RESULTS: Of the 113 patients, 67 had malignant strictures and 46 had benign strictures. The sensitivity of RC varied from 9% to 24% (p= 0.02), while the specificity varied from 61% to 100% (p < 0.001). Accuracy varied from 43% to 51% (p= n.s.). The rate of equivocal readings was lowest for the initial interpretation (1.7%), p < 0.0001 versus pathologist 1, p= 0.002 versus pathologist 2. Overall correlation of the blinded pathologists' interpretations was moderate, k= 0.66. Neither cytology accuracy nor interpathologist agreement improved with increasing specimen cellularity. CONCLUSIONS: There is a high rate of interpathologist variation for the biliary cytology interpretation. The knowledge of the patient's clinical information appears to clarify cytology interpretation resulting in fewer equivocal results. We did not detect any reliable predictors of cytology accuracy.

Bile Duct Neoplasms↗

The role of endoscopy in the evaluation and treatment of patients with pancreaticobiliary malignancy.

This is one of a series of statements discussing the utilization of GI endoscopy in common clinical situations. The Standards of Practice Committee of the American Society for Gastrointestinal Endoscopy prepared this text. In preparing this guideline, a MEDLINE literature search was performed, and additional references were obtained from the bibliographies of the identified articles and from recommendations of expert consultants. When little or no data exist from well-designed prospective trials, emphasis is given to results from large series and reports from recognized experts. Guidelines for appropriate utilization of endoscopy are based on a critical review of the available data and expert consensus. Further controlled clinical studies are needed to clarify aspects of this statement, and revision may be necessary as new data appear. Clinical consideration may justify a course of action at variance to these recommendations.

Adenocarcinoma↗

Obscure gastrointestinal bleeding.

This is one of a series of statements discussing the utilization of GI endoscopy in common clinical situations. The Standards of Practice Committee of the American Society for Gastrointestinal Endoscopy prepared this text. In preparing this guideline, a MEDLINE literature search was performed, and additional references were obtained from the bibliographies of the identified articles and from recommendations of expert consultants. When little or no data exist from well-designed prospective trials, emphasis is given to results from large series and reports from recognized experts. Guidelines for appropriate utilization of endoscopy are based on a critical review of the available data and expert consensus. Further controlled clinical studies are needed to clarify aspects of this statement, and revision may be necessary as new data appear. Clinical consideration may justify a course of action at variance to these recommendations.

Endoscopy, Gastrointestinal↗