The extent of successful colonscopy: its implication for the radiologist

Do indication and demographics for colonoscopy affect completion? A large national database evaluation

BACKGROUND AND AIM

Indication for colonoscopy has not been examined as a predictor of colonoscopy completion. We hypothesized that colonoscopy conducted for colorectal cancer screening might have higher in completion rates than colonoscopy conducted for other indications.

METHODS

The study design was a retrospective cohort. Colonoscopies recorded within the Clinical Outcomes Research Initiative database conducted between 1 January 2002 and 30 June 2003 were analyzed. Indication included: average-risk screening; surveillance; nonspecific abdominal symptoms; bleeding symptoms; or family history of colorectal carcinoma. Demographic factors and indication for colonoscopy were evaluated for the outcome of incomplete colonoscopy using logistic regression analysis.

RESULTS

129 549 Colonoscopy procedures were analyzed. Average risk screening seemed to be protective for completion (relative risk: 0.69; 95% confidence interval: 0.63-0.75). Bleeding and nonspecific symptoms had higher risk of incomplete procedure compared to other indications. Males had higher completion rates compared to females (relative risk: 0.62; 95% confidence interval: 0.58-0.66). Community setting had higher completion rates compared to academic or Veteran's administration sites. Increasing age was associated with higher rate of incomplete colonoscopy.

CONCLUSION

Colonoscopy conducted for screening indication has comparable completion rates when compared with other indications. An overall completion rate of around 95% was noted in this study. This is the largest study to date verifying that completion rates are meeting recommended multisociety guidelines in the USA. Nonspecific abdominal symptoms in Caucasian population, female sex, advanced age, clinical setting, and ethnic groups African-American and Hispanic were found to have increased risk of incomplete procedure.

Use of conscious sedation for lower and upper gastrointestinal endoscopic examinations in children, adolescents, and young adults: a twelve-year review

BACKGROUND

Over the past decade, many pediatric endoscopists have replaced general anesthesia with conscious sedation. Sedation is commonly used to minimize discomfort.

METHODS

To evaluate the safety and efficacy of conscious sedation we reviewed 2711 reports of lower and upper gastrointestinal endoscopic examinations performed in 2026 patients between July 1981 and December 1992.

RESULTS

Intravenous sedation was accomplished using meperidine and diazepam (914 examinations, 35%) or meperidine and midazolam (1427 examinations, 55%). Single agents were used for 83 examinations (3%), and 96 examinations (3.5%) were performed with the patient under general anesthesia. In the lower endoscopy group sedated intravenously (n = 713), the cecum was reached in 82% of examinations. The procedure could not be completed in 17 cases in which patients were uncooperative despite sedation. In the upper endoscopy group sedated intravenously (N = 1653), all but 91 endoscopies were completed to the descending duodenum. Esophagoscopy had been planned in 76% of these procedures. Minor complications occurred in 7 patients (0.3%). This included two episodes of significant oxygen desaturation that responded to oxygen administration and narcotic reversal. A major complication occurred in 1 patient (0.04%) who had a gastric perforation during esophageal dilation over a defective guide wire. There were no deaths, episodes of cardiorespiratory arrest, or pulmonary aspirations in our series. The combined major and minor complication rate was 0.3%.

CONCLUSIONS

Intravenous conscious sedation is safe and effective in children undergoing endoscopic examination of the gastrointestinal tract. Selected patients will require general anesthesia.

The frequency of total colonoscopy and terminal ileal intubation in the 1990s

We examined the frequency of total colonoscopy and terminal ileal intubation in a training setting using modern videoendoscopic equipment and techniques with examinations supervised or done by the two authors. The cecum was considered reached if the endoscopic report included a description of the cecal landmarks visualized and if electronic images documenting these landmarks were obtained. One of us also routinely attempted terminal ileal intubation for documentation purposes, allotting a minute or two for the purpose. In cases of chronic diarrhea and possible inflammatory bowel disease, a more prolonged attempt was made to visualize the terminal ileum. Among 418 consecutive colonoscopies, the cecum was reached in 96% of cases. If cases of malignant obstruction were excluded, the success rate improved to 97%. When routinely attempted, the terminal ileum was intubated and inspected in 74% of cases (excluding cases of malignant obstruction). In cases in which terminal ileal intubation and inspection was deemed necessary, the success rate was 91%. We conclude that total colonoscopy can be accomplished in the 1990s in excess of 90% of cases and can be documented by high-quality photographs that can be attached to the procedure report. High rates of successful total colonoscopy should be attainable even in training programs. Routine intubation of the terminal ileum can be performed to provide further objective proof of the extent of colonoscopy and to allow the endoscopist to develop and maintain the skill. A skilled, practiced endoscopist can inspect the terminal ileum in about 90% of cases in which such examination is needed.

The role of the barium enema in the detection of colonic neoplasms

The variability in the published results for colonoscopy and barium enema examinations is confusing. With both, optimum studies depend on meticulous preparation, technical excellence, and operator proficiency. The equivalency of results and the lower cost of the radiologic study indicate that the double-contrast barium enema is the technique of choice for the examination of asymptomatic patients or symptomatic individuals without known antecedent disease. The relatively small difference between the cost of the double-contrast enema examination and sigmoidoscopy ($193 versus $135) suggests that it should replace the latter on the 3-5-year screening schedule because, on average, 50% more of the colon is examined by the barium study. It is a mistake to place colonoscopy and barium enema in competitive positions; the two methods ideally complement one another. The exclusion of significant pathologic findings by the double-contrast enema can be accepted, but the detection of abnormalities should be followed, when necessary, by colonoscopic verification and/or biopsy. The number of times both will be required are few. Radiologically demonstrated colon carcinomas seldom require biopsy verification, and 90% of all polyps are smaller than 5 mm in diameter with a negligible incidence of malignant transformation. When the examinations are used in the proper sequence, they provide a cost-effective approach to the early detection and control of cancer of the large bowel.

Colorectal cancer: the case for barium enema

Both colonoscopy and barium enema are important techniques for examining the colon for polyps and cancer. They are approximately equally sensitive in detecting polypoid lesions of 7 to 10 mm or larger. A major limitation of colonoscopy is that the cecum cannot be visualized in 10 to 36% of cases. The comparable accuracy for detecting significant lesions, greater safety, and greater cost-effectiveness of barium enema favor its use in most patients.

Colonoscopy in ostomy patients. Results at the first postoperative examination

Patients with a personal history of rectal cancer are considered at high risk for metachronous large-bowel primaries. Since a malignant growth was the main reason for performing a colostomy in patients followed at the centers of the authors' association (AISTOM), a correct follow-up approach for these patients is very important. A multicentric clinical trial was thus carried out to evaluate the efficacy of transstomal endoscopic exploration (TEE) of the residual colon, and data collection began on May 31, 1984. Nine hundred fifty-seven patients were submitted to TEE after curative abdominoperineal resection (Miles) for rectal cancer. The male-female ratio was 1.3; 89.6 percent of the patients were over 50 years of age. A family history of large-bowel cancer was present in 18 percent, and in 23 percent of the patients the cancer was associated with synchronous adenomas. Only 31 percent of the patients had colonoscopy or double-contrast barium enema x-ray beyond the neoplastic area before surgery. TEE was done in 96.8 percent of the patients; in 3.3 percent the examination was not possible, mainly for stenosis of the stoma (in 2.3 percent). In 82 percent of the patients a complete large-bowel exploration was possible: a new large, bowel cancer was found in 22 patients (2.2 percent) and an adenoma in 183 patients (19.1 percent). These results show that, because it is safe, practical, and effective, endoscopy plays an important role in the follow-up of ostomates.

The extent of successful colonoscopy: a second assessment using modern equipment

Records of 200 consecutive and unselected colonoscopies were reviewed to determine both the success in viewing the entire colon and the average extent of colon visualized, using the most modern equipment. Colonoscopy was completed to the cecum or ileum in 82.5% of studies, and an average of 93.8% of the colon was viewed. These data show considerable improvement compared to those previously reported by us. However, the significant number of incomplete colonoscopies still suggests that colonoscopy and barium enema examination must remain complementary for maximum detection of colonic lesions.

Computed tomographic distinction of submucosal lipoma and adenomatous polyp of the colon

Described here is a patient with 2 large pedunculated colonic tumors detected by barium enema radiography. By computed tomography (CT) 1 was found to be a submucosal lipoma characterized by oval shape, smooth demarcation, and homogeneous density with a CT number of -68 HU, whereas the other was an adenomatous polyp with slightly fuzzy outline and a much higher CT number. This case indicates that CT can be a definitive diagnostic modality for distinguishing between a colonic lipoma and other solid or cystic tumor of the colon.

Diagnosis of carcinoma of the colon by barium enema

Double-contrast barium enemas can detect 96% of colonic carcinomas. This is similar to the detection rate for colonoscopy. Single-contrast enemas compare badly. Small sigmoid tumours are most likely to be missed. Inadequate bowel preparation, single-contrast examinations and observer error account for most barium enema failures.

Importance of total colonoscopy in the diagnosis of colonic disorders

The need for colonoscopic examination of the whole colon was determined by evaluating the accuracy of a barium enema X-ray report with particular reference to the right colon. Long colonoscopies were performed on 108 patients. The reports of the barium enema X-ray examination in these patients were compared with the colonoscopy reports. Over all, the barium enema X-ray report was accurate in 47% of cases. The rate of false negative reports was 10% and that of false positive reports 43%. For lesions of the right colon, the barium enema X-ray report was accurate in only 32% of cases, with 68% false positive and 15% false negative reports. False positive reports of carcinoma or polyps result mainly from imperfect preparation. Of the eight right colonic lesions missed in the barium enema X-ray examination, five were polyps and one was carcinoma. Long colonoscopy, rather than short colonoscopy, or flexible sigmoidoscopy and barium enema X-ray examination, would be accompanied by the greatest diagnostic accuracy. Air-contrast barium enema X-ray examination and long colonoscopy together offer the best methods of diagnosis of occult lesions in the right colon.

Reliability of barium enema in detecting colonic neoplasia

Three hundred and seven unselected patients were examined by double contrast barium enemas. Twenty-four patients (7.8%) had carcinomas; 11 patients (3.6%) had polyps; six patients (2%) had possible polyps, not confirmed by colonoscopy; and in four patients (1.3%) the radiological findings were misleading or wrong. No carcinoma was missed by barium enema X-ray examination, to be diagnosed by other means. Two patients had radiological lesions, not demonstrable endoscopically, but confirmed surgically. Extensive follow-up of 286 patients (93.2%) revealed only one subsequent case of carcinoma. The shortcomings of colonoscopy are briefly discussed. It is recommended that barium enema examination precede colonoscopy in the investigation of suspected large bowel neoplasia, and that both be used alternately to screen high-risk patients.

Causes of error in gastrointestinal radiology. II. Barium enema examination

A study of causes of error on barium enema examinations is reported. There were 144 patients with 189 inflammatory and neoplastic lesions of the large bowel examined endoscopically and with a preceding barium enema. Twelve lesions were not reported radiologically, a false negative error rate of 6.3%. Radiographic errors included 11 polyps and 1 sigmoid carcinoma. Causes for these errors were analyzed and classified into perceptive, technical, or combined categories. Ten lesions were visible in retrospect. Five lesions, clearly visible but not noted, were due to perceptive error. Five other lesions, poorly visible due to faulty studies, represented combined error. Two lesions could not be identified and represented purely technical failure. All unreported lesions were distal to the splenic flexure with the majority located in the sigmoid colon.