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D K Rex

Publications and source records attributed to D K Rex.

At least 55 records · Page 3Linked to original sources
PubMed1997

Relative sensitivity of colonoscopy and barium enema for detection of colorectal cancer in clinical practice.

BACKGROUND & AIMS: The relative sensitivities of barium enema and colonoscopy for colorectal cancer are still debated. The aim of this study was to determine the relative sensitivity of barium enema and colonoscopy in general clinical practice. METHODS: Medical records of 2193 consecutive colorectal cancer cases identified in 20 central Indiana hospitals were reviewed. All procedures performed within 3 years of the diagnosis were identified. RESULTS: The sensitivity of colonoscopy for colorectal cancer (95%) was greater than that for barium enema (82.9%), with an odds ratio of 3.93 for a missed cancer by barium enema compared with colonoscopy. The sensitivity of double-contrast barium enema (85.2%) was not different from that of single-contrast (81.8%). Barium enema performed no better in the right than the left colon. Cancers detected by colonoscopy were more likely to be Dukes' class A (24.9%) than cancers detected by barium enema (9.8%). Colonoscopy performed by gastroenterologists was more sensitive (97.3%) for cancer than colonoscopy by nongastroenterologists (87%), with an odds ratio of 5.36 for a missed cancer by a nongastroenterologist compared with a gastroenterologist. CONCLUSIONS: Hospital quality assurance committees and/or third-party payors should review the sensitivity of barium enema and colonoscopy by practitioners in their institutions. Corrective measures are recommended when sensitivity deviates significantly below the standard set by gastroenterologists performing colonoscopy in this study.

Barium Sulfate↗
PubMed1997

Colonoscopic miss rates of adenomas determined by back-to-back colonoscopies.

BACKGROUND & AIMS: The miss rate of colonoscopy for neoplasms is poorly understood. The aim of this study was to determine the miss rate of colonoscopy by same day back-to-back colonoscopy. METHODS: Two consecutive same day colonoscopies were performed in 183 patients. The patients were randomized to undergo the second colonoscopy by the same or a different endoscopist and in the same or different position. RESULTS: The overall miss rate for adenomas was 24%, 27% for adenomas < or = 5 mm, 13% for adenomas 6-9 mm, and 6% for adenomas > or = 1 cm. Patients with two or more adenomas at the first examination were more likely than patients with no or one adenoma detected at the first examination to have one or more adenomas at the second examination (odds ratio, 3.3; 95% confidence interval, 1.69-6.46). Right colon adenomas were missed more often (27%) than left colon adenomas (21%), but the difference was not significant. There was evidence of variation in sensitivity between endoscopists, but significant miss rates for small adenomas were found among essentially all endoscopists. CONCLUSIONS: Using current colonoscopic technology, there are significant miss rates for adenomas < 1 cm even with meticulous colonoscopy. Miss rates are low for adenomas > or = 1 cm. The results suggest the need for improvements in colonoscopic technology.

Adenoma↗
PubMed1997

Failure of colonoscopy to detect colorectal cancer: evaluation of 47 cases in 20 hospitals.

BACKGROUND: Colonoscopy is the gold standard for the detection of colon polyps and cancers, but failed detections can occur and the reasons are incompletely understood. METHODS: During a retrospective evaluation of the sensitivity of barium enema and colonoscopy in 20 Indiana Hospitals, we encountered 47 cases of colorectal cancer in which a colonoscopy performed within 3 years of the diagnosis had not detected the cancer. Cases were reviewed for location of tumor, extenuating factors, pathologic features, delay in diagnosis from failed detection, and who performed the examination. RESULTS: Failed detection was more likely when colonoscopy was performed by a nongastroenterologist than a gastroenterologist (odds ratio 5:36, 95% CI [2.94,9.77]). Twenty-seven cancers were "missed," and 20 were estimated to be not reached. However, the location of missed tumors and a general absence of adequate documentation of cecal intubation suggested that some cecal and ascending colon cancers recorded as missed may actually have been not reached. Variation in sensitivity among gastroenterologists suggested that meticulous examination is also important in maximizing sensitivity. CONCLUSIONS: These cases suggest several factors that might improve the quality and sensitivity of colonoscopy: (1) examiners should receive adequate training, (2) cecal intubation rates should be high, (3) cecal intubation should be verified by specific landmarks in all cases, (4) failure to reach the cecum should be followed by prompt barium enema, and (5) meticulous examination would appear to improve sensitivity for cancer detection.

Aged↗
PubMed1997

Colonoscopy and acute colonic pseudo-obstruction.

There is no well-defined standard of care for the use of colonoscopy in the treatment of acute colonic pseudo-obstruction (ACPO). Colonoscopy can be helpful for ACPO, but it can be accompanied by complications, is not completely effective, and can be followed by recurrence. These possibilities must be weighed against the overall risk of spontaneous perforation, which is low but real. The use of colonoscopy therefore should be selective, and it should be performed by experts and accompanied generally by tube placement.

Acute Disease↗
PubMed1996

Neoplasia distal to the splenic flexure in patients with proximal colon cancer.

BACKGROUND: Current American Cancer Society recommendations are that persons aged 50 years or older undergo screening flexible sigmoidoscopy every 3 to 5 years. In clinical practice, persons with adenomas at sigmoidoscopy are generally referred for full colonoscopy. However, cancers proximal to the splenic flexure may not be accompanied by neoplasia distal to the splenic flexure. METHODS: In order to estimate how often screening flexible sigmoidoscopy would be negative in persons with proximal cancer, we retrospectively reviewed 2053 consecutive colorectal cancer cases diagnosed from 1988 to 1994. Seven hundred ninety-nine (38.9%) had tumors proximal to the splenic flexure. We selected 358 study cases based on full colonoscopy performed and the colonoscopy reports available. RESULTS: Colonoscopy demonstrated distal adenomas in 77 cases (21.5%): 29 (8.1%) had hyperplastic polyps only, 4 (1.1%) had synchronous cancer, and 248 (69.3%) had no distal polyps. In this population, 77.4% of patients with proximal colon cancer had no distal neoplasia. We estimate that 30% of all patients with colorectal cancer would have a negative screening flexible sigmoidoscopy. CONCLUSIONS: Prospective evaluation of colonoscopic findings in persons with proximal cancers is needed. Ongoing evaluation of colonoscopy as a general screening test is appropriate.

Adenocarcinoma↗
PubMed1996

5-year incidence of adenomas after negative colonoscopy in asymptomatic average-risk persons [see comment].

BACKGROUND & AIMS: Cost-effectiveness of colorectal cancer screening will be maximized by selecting the widest screening intervals that effectively prevent cancer mortality. However, data on the incidence of neoplasia in persons with no abnormal findings on initial examination are limited. The aim of this study was to describe the incidence of colonic neoplasia 5 years after negative screening colonoscopy in asymptomatic average-risk persons. METHODS: We previously reported the results of screening colonoscopy in 496 asymptomatic average-risk persons, 368 of whom had no neoplasia identified. Colonoscopy to the cecum was performed in 154 of these persons at a mean of 66 months after the initial negative colonoscopy. RESULTS: Forty-one (27%) had at least one adenoma, but only 1 person had an adenoma > or = 1 cm and none had cancer, severe dysplasia, or villous or tubulovillous histology. Hyperplastic polyps at the initial examination did not predict incident adenomas. Regular nonsteroidal anti-inflammatory drug use was associated with a decreased rate of incident adenomas. CONCLUSIONS: In average-risk persons, the interval between screening examinations can be safely expanded beyond 5 years, provided the initial examination is a carefully performed complete colonoscopy that is negative for colonic adenomas or cancer.

Adenoma↗
PubMed1996

Defecography in healthy subjects: comparison of three contrast media.

PURPOSE: To determine if differences in the viscosity of defecographic contrast media influence radiographic findings. MATERIALS AND METHODS: Twenty asymptomatic volunteers underwent defecography three times with a different contrast medium used for each examination. The contrast media varied in viscosity from a thin barium liquid to a commercial barium paste formulated for defecography and to an extremely thick, specially prepared barium contrast paste. RESULTS: Significant differences (P < .05) between media were demonstrated for measurements of the anorectal angle and anorectal junction during liquid medium voiding. Differences in pelvic floor descent and evacuation time were not significant (P > .05). Rectoceles occurred in 14 subjects and were demonstrated with all media. Low-grade intussusceptions were more prevalent with the liquid medium, but their occurrence was not statistically significantly more frequent (P > .05). CONCLUSION: Altering the viscosity of the barium contrast medium used for defecography does not substantially affect the subsequent radiographic findings.

Adult↗
PubMed1996

Colonoscopy evaluations: justification by cost?

The type of colonic imaging (radiological vs colonoscopic) for evaluating symptomatic patients without evidence of bleeding in both an efficacious and cost-conserving manner has become a very debated issue. In a randomized, controlled clinical trial, the authors hoped to examine the prevalence of neoplasm and the effectiveness and cost-effectiveness of initial diagnostic strategies of colonoscopy versus flexible sigmoidoscopy and air contrast barium enema in patients without evidence of intestinal bleeding. One hundred forty-nine patients over the age of 40 with symptoms suggestive a colonic disease without evidence of bleeding (no hematechezia, negative test for fecal occult blood, and normal serum hemoglobin) were randomized to undergo either initial colonoscopy or flexible sigmoidoscopy plus barium enema. Patients with incomplete lower GI tests were referred for the corresponding alternative imaging modality. Cost analyses using sensitivity analysis were performed. Baseline information with respect to age, race, sex, inpatient status, reason for referral, mean weight loss, hemoglobin, blood urea nitrogen, and albumin were similar in both groups. Eighteen patients (24%) who initially received air contrast barium enema and flexible sigmoidoscopy then required colonoscopy, whereas only five patients (6%) who initially underwent colonoscopy first required air contrast barium enema plus flexible sigmoidoscopy. The study found that: a) The prevalence of cancer in the study was low (one of 149 patients); b) initial colonoscopy detected more persons with adenomas than that of air contrast barium enema plus flexible sigmoidoscopy (23 of 75 patients vs 13 of 74 patients, odds radio, 2.07, CI,0.90-4.92; this approached significance); and c) air contrast barium enema plus flexible sigmoidoscopy detected more diverticulosis (46 of 74 patients vs 31 of 75 patients, odds ratio, 0.41, 95% CI, 0.21-0.87). The significant conclusions were that patients undergoing flexible sigmoidoscopy plus air contrast barium enema were more likely to undergo alternative procedures and that sensitivity analysis suggested that, for most areas in the United States, initial colonoscopy would be more cost-effective for the outcome of detection of adenomas (1).

Barium Sulfate↗
PubMed1995

Flexible sigmoidoscopy plus air-contrast barium enema versus colonoscopy for evaluation of symptomatic patients without evidence of bleeding.

One hundred forty-nine patients aged 40 years or more with symptoms suggestive of colonic disease but without evidence of gastrointestinal bleeding (absence of hematochezia, normal serum levels of hemoglobin, and at least one test negative for fecal occult blood) were randomized to undergo either initial colonoscopy or initial flexible sigmoidoscopy plus air-contrast barium enema. Patients with incomplete initial colonoscopy and certain patients with polyps seen on flexible sigmoidoscopy plus barium enema underwent the alternative procedure (barium enema or colonoscopy). The main results were as follows: First, the overall prevalence of cancer in the study was very low (0.67%). Second, initial flexible sigmoidoscopy plus barium enema detected more patients with diverticulosis than did initial colonoscopy (46% versus 31%; p = .01). Initial colonoscopy detected more persons with adenomas (p = .06) than did initial flexible sigmoidoscopy plus barium enema. Patients undergoing initial flexible sigmoidoscopy plus barium enema require the alternative procedure (24%) than were patients undergoing initial colonoscopy (6%; p = .002). Third, sensitivity analyses suggested that for most areas in the United States, initial colonoscopy would be more cost-effective for the outcomes of detection of adenomas and detection of large adenomas, although very few patients in the study had large adenomas. We conclude that the prevalence of colorectal cancer in persons with colonic symptoms but no evidence of bleeding is low and is comparable with the prevalence in an asymptomatic population. Cost-effective selection of imaging strategies in this population can be based on demographic factors such as age and sex, which are better predictors of the presence of adenomas than are symptoms.

Adenoma↗
PubMed1995

Does routine intravenous glucagon administration facilitate colonoscopy? A randomized trial.

BACKGROUND: Previous studies on the routine use of glucagon in colonoscopy have produced conflicting results. METHODS: Two separate studies were performed. In one study (Study 1), 80 consecutive patients were randomized after cecal intubation to receive 1 mg glucagon (n = 41) or placebo (n = 39), intravenously, in double-blind fashion. In a second study (Study 2) 90 sedated patients undergoing colonoscopy were randomized to receive 1 mg glucagon (n = 46) or placebo (n = 44), intravenously, just before colonoscope insertion. In each study, colonoscope insertion and withdrawal time, therapeutic intervention time, the presence and severity of colonic spasm, colonoscopy yield, and side effects were recorded. RESULTS: Mean withdrawal time in Study 1 was similar in those receiving glucagon (6.85 min) and in those receiving placebo (6.92 min). Mean insertion time in Study 2 (5.07 min) was identical between groups. Spasm scores and colonoscopy yield did not differ between glucagon and placebo in either study. There was a trend toward more side effects (nausea and vomiting) with glucagon in Study 1. Glucagon did not facilitate insertion or withdrawal in the subset of patients with diverticulosis. CONCLUSIONS: Routine use of intravenous glucagon in a dosage of 1 mg does not facilitate colonoscopy by experienced examiners.

Adult↗
PubMed1995

Prevalence and natural history of colonic angiodysplasia among healthy asymptomatic people.

OBJECTIVE: The prevalence of colonic angiodysplasia (AD) among healthy asymptomatic people is unknown, and the natural history of these lesions has not been clearly defined. The purpose of our study was to determine prevalence and to review and assess the natural history of AD. METHODS: Each of the authors had previously published his own prospective study that involved screening colonoscopy for the detection of neoplasia in asymptomatic adult men and women who had never bled. All pathological lesions diagnosed by endoscopy were recorded, but only data pertaining to polyps were published. We pooled and analyzed the endoscopic findings (raw data) from those studies and assessed the natural history of the lesions by reviewing the medical charts of affected subjects to determine whether bleeding had occurred. Nine hundred sixty-four patients were evaluated (mean age, 62 yr). All were > or = 50 yr old (range, 50-79 yr), not anemic, Hemoccult negative, asymptomatic, and had full colonoscopy to the cecum. RESULTS: Eight subjects had AD (prevalence, 0.83%). Lesions in affected individuals were usually small (mean size, 4.0 mm) and most often were located in the right colon (62%). No subject bled, and all maintained a stable hemoglobin (mean, 14.6 g%) with a mean follow-up of 3 yr. CONCLUSIONS: We conclude that 1) colonic AD is uncommon among healthy asymptomatic people (prevalence, 0.83%), 2) lesions are usually small (< 10 mm) and are located proximal to the hepatic flexure, 3) the natural history for AD in these people is benign, and the risk of bleeding over a 3-yr period is low (0% in 3 yr), and 4) because of this low risk, endoscopic treatment for incidental (nonbleeding) AD is unnecessary.

Aged↗