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D K Rex

Publications and source records attributed to D K Rex.

At least 37 records · Page 2Linked to original sources
PubMed2000

Colonoscopy.

Colonoscopy and polypectomy are the most effective tools available to prevent colorectal cancer. The technical performance of colonoscopy can be improved by methods that make polyp detection easier and more reliable, facilitate cecal intubation, and reduce recurrence and complication rates after polypectomy. The state-of-the-art and possible future trends in patient preparation, indications, screening and surveillance intervals, sedation issues, and virtual colonoscopy are reviewed in this article.

Cecum↗
PubMed2000

Colonic adenomas: prevalence and incidence rates, growth rates, and miss rates at colonoscopy.

Cost-effective use of colonic imaging studies can be achieved through an understanding of the prevalence, incidence, growth, and miss rates of colon adenomas. High adenoma prevalence rates are associated with increasing age, male gender, and a family history of colorectal cancer or multiple first-degree relatives with colorectal neoplasia or neoplasia diagnosed at a young age. The incidence rate of advanced adenomas is higher in patients with multiple adenomas and is likely also associated with a family history of colorectal cancer, increased age, and large adenoma size at the index examination. Direct observational data on growth rates suggests that adenomas <1 cm in size have a fairly stable size over a 3-year interval. Although colonoscopy is the most sensitive colonic imaging study, substantial miss rates for small adenomas are inherent to the procedure. Advancements in endoscopic technology should lead to reduced miss rates, allowing expansion of intervals between examinations while reducing negative outcomes of fatal interval cancers.

Adenoma↗
PubMed1999

Accuracy of pathologic interpretation of colorectal polyps by general pathologists in community practice.

BACKGROUND: The histologic features of colorectal polyps often guide colonoscopic surveillance and the need for surgical intervention. Our objective was to evaluate the pathologic interpretation of colorectal polyps by general pathologists in community practice. METHODS: Twenty histologic slides of colorectal polyps were reviewed by 20 randomly selected general pathologists in community practice. There were 5 malignant polyps, 9 adenomas, and 6 miscellaneous polyps. RESULTS: Cancer was correctly identified in 91% of readings and adenoma in 94%. The grade of differentiation of cancer was provided in 55% of readings, and comment regarding whether the resection margin was free of cancer was made by 50% of pathologists. Tubular adenoma was called tubulovillous or villous in 35% of readings, but tubulovillous or villous adenoma was seldom (2%) called tubular. High-grade dysplasia was correctly identified in 47% of 60 readings, was called invasive cancer in 22%, and was missed in 31%. Among miscellaneous polyps, hyperplastic polyp was correctly recognized in 75% of cases, and inflammatory polyp and juvenile polyp each were recognized by 16 of 20 pathologists (80%). Peutz-Jeghers hamartoma was identified by 4 of 20 pathologists (20%), and the polypoid phase of solitary rectal ulcer syndrome was recognized by 2 pathologists (10%). CONCLUSION: Areas of strength with regard to interpretation of colon polyps by general pathologists in community practice included identification of cancer, adenoma, and certain non-neoplastic polyps (e.g., inflammatory and juvenile polyps). Areas of weakness included lack of comment on cancer differentiation and proximity to the resection line, erroneous identification of high-grade dysplasia, and identification of rare lesions. The results of this study suggest areas on which to focus continuing education and continuous quality improvement efforts with regard to polyp interpretation.

Adenocarcinoma↗
PubMed1999

Prospective determination of distal colon findings in average-risk patients with proximal colon cancer.

BACKGROUND: Recent guidelines indicate that colonoscopy and sigmoidoscopy are both acceptable options for screening average-risk patients for colorectal cancer. Retrospective studies have found that a majority of patients with cancer proximal to the splenic flexure have a normal screening flexible sigmoidoscopy. METHODS: This was a multicenter, prospective description of colonoscopic findings and family history in consecutive patients with proximal colon cancer. RESULTS: Among 116 prospectively identified average-risk patients with cancer proximal to the splenic flexure, 40 (34.5%) had neoplasia distal to the splenic flexure. The prevalence of patients with adenomas greater than or equal to 1 cm, with only one tubular adenoma less than 1 cm, and with only hyperplastic polyps were 16.4%, 8.6%, and 6.9%, respectively. CONCLUSIONS: Most average-risk patients with cancer proximal to the splenic flexure will have a normal screening flexible sigmoidoscopy. These patients have an unexpectedly high prevalence of large distal adenomas, but the prevalence of both single small tubular adenomas and hyperplastic polyps alone is similar to that expected during screening of the general population. Clinicians and payers should continue to seek methods to improve the cost-effectiveness and availability of screening colonoscopy in average-risk persons.

Adenocarcinoma↗
PubMed1999

Patients willing to try colonoscopy without sedation: associated clinical factors and results of a randomized controlled trial.

BACKGROUND: Sedation causes most of the complications of colonoscopy. Sedation is used selectively in some countries but is routine in the United States. METHODS: Cross-sectional survey and randomized controlled trial were used to identify patient factors associated with willingness to try colonoscopy without sedation and to compare pain and satisfaction scores and willingness to return to the same physician in patients randomized to receive routine sedation versus as needed sedation. A single colonoscopist invited 250 consecutive eligible outpatients to be randomized to routine sedation versus as needed sedation. Seventeen who preferred no sedation and 163 who preferred sedation refused. Seventy accepted and were randomized. RESULTS: Male gender (odds ratio 4.33; 95% CI [2.27, 8.26]), increasing age (odds ratio for 10-year increase 1.28; 95% CI [1.01, 1.06]), and absence of abdominal pain (odds ratio 5.13; 95% CI [1.68, 15.63]) were associated with willingness to be randomized. Total colonoscopy was achieved without sedation in 94% of those who received sedation only as needed. Pain scores were higher in the sedation as needed arm. All 35 patients in the routine sedation arm were "very satisfied". In the sedation as needed arm, 31 of the 34 were "very satisfied" and 3 were "somewhat satisfied". All randomized patients said they would return to the same colonoscopist. Patients in the sedation as needed arm had less decline in blood pressure, less hypoxemia, and lower charges than those in the routine sedation arm. CONCLUSIONS: Experienced colonoscopists should consider offering colonoscopy without sedation to selected patients.

Analgesics, Opioid↗
PubMed1999

An initial experience with screening for colon polyps using spiral CT with and without CT colography (virtual colonoscopy)

BACKGROUND: Computed tomographic (CT) colography (virtual colonoscopy) is a new imaging method for detection of colon polyps and cancer. OBJECTIVE: To evaluate the sensitivity of CT colography for polyp detection in a population without symptoms that included persons without colon neoplasia and with radiologists blinded to colonoscopic findings. METHODS: Forty-six persons without symptoms underwent spiral CT followed by same-day colonoscopy with subsequent inspection of two-dimensional axial CT images, interactive multiplanar images, and surfaced and volume-rendered images of the colon (three-dimensional CT colography). RESULTS: Three-dimensional CT colography was superior to two-dimensional axial imaging for detection of colon polyps. Three-dimensional CT colography depicted 1 of 4 (25%) adenomas 2 cm in diameter or larger, 6 of 10 (60%) adenomas 1 to 1.9 cm, 6 of 14 (43%) 6 to 9 mm, and 7 of 65 (11%) 5 mm in diameter or smaller. Three-dimensional CT colography showed a polyp that might have led to colonoscopy in 3 of 4 (75%) patients whose largest adenoma was 2 cm or larger, 5 of 6 (83%) patients with largest adenoma 1 to 1.9 cm, 3 of 7 (43%) patients with largest adenoma 6 to 9 mm, and 4 of 16 patients (25%) with largest adenoma 5 mm or smaller. Large, flat adenomas of the right colon were difficult to identify with three-dimensional CT colography. The specificity of three-dimensional CT colography for patients with adenomas 1 cm in diameter or larger was 89%. Examination of patients with missed adenomas after unblinding indicated that meticulous bowel preparation and adequate distention are critical to accurate interpretation. Perceptual errors were common. CONCLUSIONS: CT colography as performed in this study is not adequate as a colorectal cancer screening test. Several technical factors that appear critical to accurate performance of CT colography are defined.

Adenocarcinoma↗
PubMed1999

Translating clinical research to community-based practice: lessons from colorectal cancer screening and diagnosis.

As we have shown using examples from colorectal cancer screening and diagnosis, translation of published studies into community practice is not a simple task. A literature review may not clearly indicate which strategy is best. Even when one strategy has a definite advantage, there may be variation in its actual clinical performance. Prior to initiating a new strategy or when reconsidering an old one, questions should be asked concerning applicability to the community population, the protocols that will be used, and the training, experience, and skill of the clinicians involved in its use. After a clinical strategy is implemented, ongoing information concerning its clinical performance should be continuously collected so that deficiencies can be identified and corrected. This information may be difficult and costly to obtain, but has enormous relevance for guiding healthcare decisions and improving outcomes.

Colorectal Neoplasms↗
PubMed1999

The small polyp at flexible sigmoidoscopy: an historical perspective on why practices still vary.

Current practices vary regarding the approach to small polyps discovered during screening flexible sigmoidoscopy. The most common practice is to perform colonoscopy whenever any adenoma is detected, a strategy that generally uses biopsy of polyps < or = 5 mm in size. However, data suggest that tubular adenomas < 1 cm in size in the distal colon have less predictive value than other distal adenomas for advanced adenomas in the proximal colon. Thus, some centers reserve colonoscopy for distal adenomas with tubulovillous or villous histology, > 1 cm in size, or with high-grade dysplasia. At the other end of the spectrum, another school of thought advocates screening colonoscopy, recognizing that most patients with advanced proximal adenomas do not have polyps in their distal colon. Advocates of this approach use any excuse to perform colonoscopy, whether it be a positive fecal occult blood test, minor symptoms, or small polyp at flexible sigmoidoscopy, even if hyperplastic. This review describes the history of the controversy regarding management of findings at flexible sigmoidoscopy, the data pertinent to the controversy, and the basis for the three approaches described above, all of which are currently within the standard of medical care.

Colonic Polyps↗
PubMed1999

Colorectal cancer screening: A guide to the guidelines.

The two most recent guidelines for colorectal cancer screening are those of the Agency for Healthcare Policy and Research, and the American Cancer Society. The guidelines are similar in many regards and reflect current literature, consensus opinion and compromise between members of multidisciplinary panels. The emphasis of both guidelines is to increase the options available for colorectal cancer screening. Increasing choice should expand the attractiveness of colorectal cancer screening to more patients and physicians, and the development of guidelines should help compel payers to provide reimbursement for colorectal cancer screening. These guidelines are summarized and evaluated as they pertain to colorectal cancer screening.

Canada↗
PubMed1999

Z-stent for malignant esophageal obstruction.

The Z-stent was one of the first self-expanding metal prostheses used for palliation of malignant esophageal obstruction and respiratory esophageal fistula. Its placement has proved to be effective and relatively safe. This article reviews the evolution of the Z-stent; its multiple designs, placement technique, efficacy, complications, and assets and limitations.

Biocompatible Materials↗
PubMed1999

Disease-specific outcomes assessment for diagnosis of colorectal neoplasia: from clinical trials to community practice.

The value of monitoring the performance of diagnostic testing in clinical practice is emphasized through data showing that experts with apparently equal training have substantially different sensitivity for cancer and polyp detection when performing colonic imaging studies. The authors discuss the effects of variation in study population, testing methodology, and expertise of examiners on the outcomes of diagnostic tests for colorectal cancer.

Colonoscopy↗
PubMed1998

CT and MR colography (virtual colonoscopy): status report.

Computed tomography (CT) and magnetic resonance (MR) colography (virtual colonoscopy) are new techniques being developed for the purpose of imaging colorectal polyps and cancer. Limited data are available regarding the performance characteristics of either technique, particularly MR. Initial reports suggest that the sensitivity of CT and MR colography for patients with adenomas > or = 1 cm ranges from 75-90%, and decreases precipitously for smaller polyps. Very early data suggest that the specificity for patient with large adenomas is around 90%, but for patients with adenomas in the 5-9 mm range has been as low as 65%. This review discusses currently available published and abstracted data on CT and MR colography and discusses the real and potential advantages and disadvantages of CT and MR colography compared to current colonic imaging methods. The review discusses problems that must be overcome in order for CT or MR colography to be demonstrated as practical tests, and suggests guidelines for the performance of clinical trials testing the performance characteristics of these methods.

Adult↗