Bowel Preparation Burden, Rectal Pain and Abdominal Discomfort: Perspective of Participants Undergoing CT Colonography and Colonoscopy

OBJECTIVE

This study aimed to evaluate bowel preparation burden, rectal pain and abdominal discomfort levels and to determine the association between demographic characteristics and those levels among participants undergoing CT colonography and colonoscopy.

METHODS

A cross-sectional survey was conducted in eligible Thai citizens who consented to participate all four visits of a free colorectal cancer screening protocol. Three levels (mild, moderate and severe) of burden, pain and discomfort were used to ask the perspective of participants at the final visit, one week after undergoing those two procedures.

RESULTS

Data from 1,271 participants completed for analyses - females 815 (64.1%), males 456 (35.9%). The majority of participants experienced mild burden, pain and discomfort. Association between characteristic groups and burden levels differed regarding own income, chronic disease and laxative. Between characteristic groups and pain and discomfort levels differed regarding own income and chronic disease. Participants without their own income rated severe burden lower than those who had (p<0.001), but those without chronic disease rated moderate burden lower than who had (p=0.003). Participants prepared bowel with spilt-dose of PEG rated moderate burden higher than those who prepared with NaP (p<0.001). Participants undergoing CT colonography without their own income and presenting no chronic disease faced severe rectal pain lower than those who had (p<0.001 and p=0.04). Participants without their own income rated moderate and severe abdominal discomfort lower than those who had (p<0.01 and p=0.008). Participants undergoing colonoscopy without their own income and no chronic diseases faced severe rectal pain lower than those who had (p<0.001 and p=0.007). Participants without their own income and no chronic disease rated severe abdominal discomfort lower than those who had (p<0.001 and p=0.005).

CONCLUSION

Evaluating the perspectives of customers alongside quality improvement and innovation to reduce unpleasant experiences remains needed in CT colonography and colonoscopy to promote CRC screening.

Pneumoperitoneum after virtual colonoscopy: causes, risk factors, and management

Computed tomographic virtual colonoscopy (CTVC) is a safe and minimally invasive modality when compared with fiberoptic colonoscopy for evaluating the colon and rectum. We have reviewed the risks for colonic perforation by investigating the relevant literature. The objectives of this study were to assess the risk of colonic perforation during CTVC, describe risk factors, evaluate ways to reduce the incidence complications, and to review management and treatment options. A formal search of indexed publications was performed through PubMed. Search queries using keywords "CT colonography," "CT virtual colonoscopy," "virtual colonoscopy," and "perforation" yielded a total of 133 articles. A total of eight case reports and four review articles were selected. Combining case reports and review articles, a total of 25 cases of colonic perforation after CTVC have been reported. Causes include, but are not limited to, diverticular disease, irritable bowel diseases, obstructive processes, malignancies, and iatrogenic injury. Both operative and nonoperative management has been described. Nonoperative management has been proven safe and successful in minimally symptomatic and stable patients. Colonic perforation after CTVC is a rare complication and very few cases have been reported. Several risk factors are recurrent in the literature and must be acknowledged at the time of the study. Management options vary and should be tailored to each individual patient.

[Errors when performing computed tomographic colonography (virtual colonoscopy) and assessing its results]

Computed tomographic colonography (CTC) is a noninvasive diagnostic method for significantly identifying clinically relevant colonic and rectal tumors. Good colonic preparation that includes laxatives or residue-free diet, as well as labelling the intestinal contents is needed to adequately interpret CTC data. However, errors in interpreting the results of CTC can be associated with not only the imperfections of large bowel preparation for examination, but also due to those of the latter and because of the anatomic features of the colon. The paper describes difficulties and the most common errors in CTC, including own experience.

Follow up by CT-colonoscopy of patients with colostoma after resection on the occasion of colorectal cancer

The follow up of patients operated for colorectal cancer (CRC) and the early detection of recurrences and metachronous tumors improves significantly the results of treatment and the survival of the patients. Computed Tomography (CT) and fibro-colonoscopy (FCS) are the main applied image diagnostic methods for this aim. Alternative unified method is the CT colonoscopy (CTC -"virtual colonoscopy" ) with i.v. appliance of contrast. A particular group of patients liable to control are those after Miles and Hartmann operation with created colostoma. The performance of CTC and its informativeness in these cases is specific and represents a challenge. For a two-year period were implemented generally 48 "virtual colonoscopies" (CTC) in stoma patients--21 male and 27 female, average age 53.2 ± 9 years. The postoperative interval to the CTC varied 8 to 29 months. The studies were performed on a 32 detector CT - GE: 32 x 0.625mm and rotation time 0.6 sec. with automatic modulation of the dose. The CT images are processed with special software for CTC and analyzed according to standardized system for reporting of findings in CTC - C-RADS. The specific technique for CTC in stoma patients is described. CTC was entirely accomplished in all 48 cases (100%). The duration of the studies varied 10 to 25 min. (average 17 min.). No essential side effects or according to the procedure complications were marked. To one patient a conventional FCS was recommended for accurate assessment of a collapsed bowel segment. Adequate marking of the fecal odds with barium sulfate was marked in all cases. The CTC findings were assessed as normal in 23 cases (48%). In 25 patients (52%) were described pathologic findings of colonic and extra-colonic origin. Conclusions that CTC in patients operated according to the methods of Miles and Hartmann is technically feasible and could be executed for complex assessment of large bowel and extra-colonic abdominal structures. CTC possess the advantage of the possibility for synchronous assessment of the organs and structures in the abdominal cavity, which is economically profitable, saves time and psychical suspense for the patients and avoids the risk of complications and unpleasant experiences of the patient durinf a conventional FCS.

Adverse events of computed tomography colonography: an Italian National Survey

AIM

To retrospectively study the frequency and magnitude of complications associated with computed tomography (CT) colonography in clinical practice.

METHODS

A questionnaire on complications of CT colonography was sent to Italian public radiology departments identified as practicing CT colonography with a reasonable level of training. The frequency of complications and possible risk factors were retrospectively determined. Responses were collated and row frequencies determined. A multivariate analysis of the factors causing adverse events was also performed.

RESULTS

40,121 examinations were performed in13 centers during the study period. No deaths were reported. Bowel perforations occurred in 0.02% (7 exams). All perforations were asymptomatic and occurred in patients undergoing manual insufflation. Five perforations (71%) occurred in procedures performed following a recent colonoscopy. There was no significant difference between perforations associated with rectal balloon (0.017%) and those that were not (0.02%). Complications related to vasovagal reaction (either with or without spasmolytic) occurred in 0.16% (63 exams). All vasovagal reactions resolved in less than 3h, without any sequelae.

CONCLUSIONS

Perforation rate at CT colonography in Italy is comparable with elsewhere in the world, occurring regardless of the experience of radiology centers. Although the risk is very small, it may not be negligible when compared with the risk of diagnostic colonoscopy.

Rescreening of persons with a negative colonoscopy result: results from a microsimulation model

BACKGROUND

Persons with a negative result on screening colonoscopy are recommended to repeat the procedure in 10 years.

OBJECTIVE

To assess the effectiveness and costs of colonoscopy versus other rescreening strategies after an initial negative colonoscopy result.

DESIGN

Microsimulation model.

DATA SOURCES

Literature and data from the Surveillance, Epidemiology, and End Results program.

TARGET POPULATION

Persons aged 50 years who had no adenomas or cancer detected on screening colonoscopy.

TIME HORIZON

Lifetime.

PERSPECTIVE

Societal.

INTERVENTION

No further screening or rescreening starting at age 60 years with colonoscopy every 10 years, annual highly sensitive guaiac fecal occult blood testing (HSFOBT), annual fecal immunochemical testing (FIT), or computed tomographic colonography (CTC) every 5 years.

OUTCOME MEASURES

Lifetime cases of colorectal cancer, life expectancy, and lifetime costs per 1000 persons, assuming either perfect or imperfect adherence.

RESULTS OF BASE-CASE ANALYSIS

Rescreening with any method substantially reduced the risk for colorectal cancer compared with no further screening (range, 7.7 to 12.6 lifetime cases per 1000 persons [perfect adherence] and 17.7 to 20.9 lifetime cases per 1000 persons [imperfect adherence] vs. 31.3 lifetime cases per 1000 persons with no further screening). In both adherence scenarios, the differences in life-years across rescreening strategies were small (range, 30 893 to 30 902 life-years per 1000 persons [perfect adherence] vs. 30 865 to 30 869 life-years per 1000 persons [imperfect adherence]). Rescreening with HSFOBT, FIT, or CTC had fewer complications and was less costly than continuing colonoscopy.

RESULTS OF SENSITIVITY ANALYSIS

Results were sensitive to test-specific adherence rates.

LIMITATION

Data on adherence to rescreening were limited.

CONCLUSION

Compared with the currently recommended strategy of continuing colonoscopy every 10 years after an initial negative examination, rescreening at age 60 years with annual HSFOBT, annual FIT, or CTC every 5 years provides approximately the same benefit in life-years with fewer complications at a lower cost. Therefore, it is reasonable to use other methods to rescreen persons with negative colonoscopy results.

PRIMARY FUNDING SOURCE

National Cancer Institute.

Colonic perforation caused by direct trauma during computed tomographic colonography performed via end colostomy

We report the case of a woman with a history of abdominoperineal resection for cancer, who had an inadvertent perforation during screening computed tomographic colonography performed via end colostomy. Revision of the stoma was promptly performed, which prevented a full laparotomy. We reviewed the literature on the subject and found that such perforations may be more common than previously thought. With appropriate precautions, such occurrences can be minimised in the future.

A randomized double-blind placebo-controlled trial to evaluate the value of a single bolus intravenous alfentanil in CT colonography

BACKGROUND

Although CT colonography is a less invasive alternative for colonoscopy for the detection of colorectal polyps and cancer, procedural pain is common. In several studies, CT colonography pain and burden is higher than in colonoscopy. Apart from discomfort, anxiety and its related stress-induced peri- procedural side effects, this may influence the adherence for CT colonography as a possible screening tool for colorectal cancer. We hypothesize that a single bolus intravenous alfentanil will give a clinically relevant reduction in maximum pain defined as at least 1.3 point reduction on an 11-point numeric rating scale (NRS).

METHODS/DESIGN

A randomized double-blind placebo-controlled trial in which patients scheduled for elective CT colonography in a single tertiary centre are eligible for inclusion. The first 90 consenting patient will be block-randomized to either the alfentanil group or the placebo group. Before bowel insufflation, the alfentanil group receives a single bolus intravenous alfentanil 7.5 μg/kg dissolved in 0.9% NaCl, while the placebo group receives an intravenous bolus injection of pure 0.9% NaCl. For both groups an equal amount of fluid per kilogram (75 μL/kg) is injected. The primary outcome is the difference in maximum pain on an 11-point NRS. Secondary outcomes include: pain and burden of different CT colonography aspects, side effects, procedural time and recovery time. For the primary outcome an independent samples t-test is performed and a P value<0.05 is considered statistically significant.

DISCUSSION

This study will provide evidence whether a single bolus intravenous alfentanil gives a clinically relevant reduction in maximum pain during CT colonography.

TRIAL REGISTRATION

Netherlands Trial Register (NTR): NTR2902. This trial will be conducted in accordance with the protocol and in compliance with the moral, ethical, and scientific principles governing clinical research as set out in the Declaration of Helsinki (1989) and Good Clinical Practice (GCP). The department of radiology of the Academic Medical Center of Amsterdam is responsible for the design and conduct of the trial.

Radiation-related cancer risks from CT colonography screening: a risk-benefit analysis

OBJECTIVE

The purpose of this study was to estimate the ratio of cancers prevented to induced (benefit-risk ratio) for CT colonography (CTC) screening every 5 years from the age of 50 to 80 years.

MATERIALS AND METHODS

Radiation-related cancer risk was estimated using risk projection models based on the National Research Council's Biological Effects of Ionizing Radiation (BEIR) VII Committee's report and screening protocols from the American College of Radiology Imaging Network's National CT Colonography Trial. Uncertainty intervals were estimated using Monte Carlo simulation methods. Comparative modeling with three colorectal cancer microsimulation models was used to estimate the potential reduction in colorectal cancer cases and deaths.

RESULTS

The estimated mean effective dose per CTC screening study was 8 mSv for women and 7 mSv for men. The estimated number of radiation-related cancers resulting from CTC screening every 5 years from the age of 50 to 80 years was 150 cases/100,000 individuals screened (95% uncertainty interval, 80-280) for men and women. The estimated number of colorectal cancers prevented by CTC every 5 years from age 50 to 80 ranged across the three microsimulation models from 3580 to 5190 cases/100,000 individuals screened, yielding a benefit-risk ratio that varied from 24:1 (95% uncertainty interval, 13:1-45:1) to 35:1 (19:1-65:1). The benefit-risk ratio for cancer deaths was even higher than the ratio for cancer cases. Inclusion of radiation-related cancer risks from CT examinations performed to follow up extracolonic findings did not materially alter the results.

CONCLUSION

Concerns have been raised about recommending CTC as a routine screening tool because of potential harms including the radiation risks. Based on these models, the benefits from CTC screening every 5 years from the age of 50 to 80 years clearly outweigh the radiation risks.

CT colonography: perforation rates and potential radiation risks

Computed tomographic colonography (CTC) has emerged as an alternative screening tool for colorectal cancer due to the potential to provide good efficacy combined with greater acceptability than optical colonoscopy or fecal occult blood testing. However, some organizations have raised concerns about the potential harms, including perforation rates and radiation-related cancer risks, and have not recommended that it currently be used as a screening tool in the general population in the US. In this article the authors review the current evidence for these potential harms from CTC and compare them to the potential harms from the alternatives including colonoscopy and double-contrast barium enema.

CT colonography: Results and limitations

Meta-analysis of data from studies of CT colonography suggests that it has excellent per-patient average sensitivity and average specificity for detection of adenomatous polyps and cancer. However, while its potential as a screening test is undoubted, there are several current limitations that will need to be overcome before it can be considered seriously by health policy makers. These revolve around issues of generalisability, which is inhibited most by a lack of trained observers and access to CT scanners, and a paucity of data relating to cost-effectiveness. Whether offering CT colonography as an alternative to competing strategies will genuinely enhance compliance also needs further and more detailed attention.

Virtual colonoscopy-induced perforation in a patient with Crohn's disease

We report a case of sigmoid colon perforation in a patient with Crohn's disease undergoing computed-tomographic (CT) colonography. A 70-year-old patient with Crohn's disease with terminal ileitis and sigmoid stricture underwent CT colonography after incomplete conventional colonoscopy. During the procedure, the colon was inflated by air insufflation and the patient developed abdominal pain with radiological evidence of retroperitoneal and intraperitoneal free gas. Hartmann's operation was performed. This case highlights that CT colonography is not risk-free. The risk of perforation may be higher in patients with inflammatory bowel disease.

Virtual colonoscopy-induced perforation in a patient with Crohn’s disease

We report a case of sigmoid colon perforation in a patient with Crohn’s disease undergoing computed-tomographic (CT) colonography. A 70-year-old patient with Crohn’s disease with terminal ileitis and sigmoid stricture underwent CT colonography after incomplete conventional colonoscopy. During the procedure, the colon was inflated by air insufflation and the patient developed abdominal pain with radiological evidence of retroperitoneal and intraperitoneal free gas. Hartmann’s operation was performed. This case highlights that CT colonography is not risk-free. The risk of perforation may be higher in patients with inflammatory bowel disease.

Population screening for colorectal cancer: advantages and drawbacks

Screening for colorectal cancer (CRC) has been shown to reduce mortality from the disease as well as incidence. Several methods for screening are available, but none are ideal. The present short review discusses the advantages and drawbacks using fecal occult blood tests (FOBTs), fecal DNA tests, flexible sigmoidoscopy (FS), colonoscopy, double contrast barium enema, and computed tomographic colonoscopy. The use of FOBTs with following colonoscopy in persons with a positive test has been shown to reduce mortality as well as the incidence of CRC in several randomized trials. It is likely that other methods will do the same, but it is not clear how large the benefit will be. Repeated testing is necessary for FOBTs and DNA tests as well as FS, and a high degree of acceptability is crucial for the effectivity of all tests in a national program. National services may be subject to variations in enthusiasm and expertise, resulting in varying acceptability and number of complications. It is recommended to perform pilot studies in limited populations (as in the UK) before embarking on a screening program on a national level.

Resources and costs associated with incidental extracolonic findings from CT colonogaphy: a study in a symptomatic population

CT colonography (CTC) is increasingly used to detect colonic polyps and cancers, but its impact in practice is also influenced by frequent detection of extracolonic lesions. We have previously documented the frequency and nature of such lesions. The current study was performed to assess the clinical resources and costs associated with the investigation and treatment of extracolonic lesions. We reviewed the reports of 225 consecutive CTC examinations carried out on patients with symptoms of bowel cancer. 116 of the 225 were reported to have one or more extracolonic findings. All 116 patients with an abnormality were followed up for 12-24 months. 24 patients underwent further actions (outpatient attendance, investigations, or surgical procedures) as a result of previously undiagnosed lesions unrelated to bowel cancer. The costs of these further actions were derived from the NHS Reference Costs manual 2004. The total cost for further investigations and interventions was 34,329 pounds sterling and the mean cost over the sample of 225 patients was 153 pounds sterling--more than the cost of the CTC itself. The costs were mainly generated by surgical procedures. Resources consumed as a result of extracolonic findings approximately doubled the costs of diagnostic CTC. These costs, along with inconvenience, anxiety, morbidity and occasionally even mortality suffered by patients, must be offset by the good done to some of those with sub-clinical but potentially lethal diseases.

Perforation of the colon and rectum--a newly recognized complication of CT colonography

CT colonography (CTC) and conventional colonoscopy may have similar efficacy for detection of polyps > 6 mm. Perforation of the colon and rectum is a relatively rare, but potentially morbid complication of CTC, especially in symptomatic patients. Older age and underlying concomitant colon pathology increase the risk of perforation. This review describes the incidence, clinical features, and management of colon perforations at CTC, a study that was considered risk-free until recently.

Potentially serious adverse events at CT colonography in symptomatic patients: national survey of the United Kingdom

PURPOSE

To retrospectively determine the incidence of potentially serious adverse events associated with computed tomographic (CT) colonography performed in patients with symptoms of colorectal cancer.

MATERIALS AND METHODS

Ethical approval and informed consent were waived, since the study was deemed a clinical audit and patients would not be approached. With a national survey in the United Kingdom, all departments offering CT colonography in everyday practice were identified. The lead gastrointestinal radiologist from all responding departments was interviewed, and the frequency of potentially serious adverse events associated with CT colonography performed in patients with symptoms of colorectal cancer, the total number of examinations performed, and technical factors possibly related to perforation were determined. Where a potentially serious adverse event was encountered, it was explored in detail. Responses were collated, and raw frequencies were determined. Fisher exact test was used to determine differences in event rates between groups.

RESULTS

At 50 centers, 17 067 CT colonographic examinations (mean number per center, 359; range, 10-3000) were performed. No deaths were reported. Thirteen patients (one [0.08%] of 1313) had had a potentially serious adverse event related to the procedure. There were nine perforations: Four (44%) were asymptomatic and five (56%) were symptomatic, and perforation had an attributable cause, with a symptomatic perforation rate of 0.03% (one in 3413 patients). One patient required laparotomy. An inflated rectal balloon was used to perform 9378 examinations. There was no significant difference between the proportion of perforations associated with rectal balloon inflation (n = 6) and the proportion of those that were not (n = 2) (P = .3).

CONCLUSION

Potentially serious adverse events related to CT colonography occurred in 0.08% of symptomatic patients.

Colonic perforation at CT colonography: assessment of risk in a multicenter large cohort

PURPOSE

To assess retrospectively the incidence, clinical features, and treatment of colonic perforation at computed tomographic (CT) colonography in a large multicenter cohort.

MATERIALS AND METHODS

The study was performed in accordance with the institutional ethics committees' requirements of a retrospective review in each of the participating centers, and no informed consent was required. A review of all patients who underwent CT colonography between January 2001 and December 2004 in 11 medical centers representing more than 95% of studies performed in a single country was performed to determine the rate of colorectal perforation. Data about patient demographics and patient- and procedure-related risk were recorded. Information about the location of the perforation, its likely mechanism, and treatment was collected. Analysis included calculation of rates of colonic perforation and surgical treatment and of 95% confidence intervals.

RESULTS

A total of 11 870 CT colonographic studies were performed in 6837 (57.6%) men and 5033 (42.4%) women (mean age, 59.9 years; range, 38-90 years) with seven cases of colorectal perforation, yielding a risk rate of 0.059% (one of 1696 studies; 95% confidence interval: one of 974, 971 of 6537). The mean age of the patients with perforation was 77.8 years. Six (84%) of seven cases of perforation occurred in symptomatic patients at high risk for colorectal neoplasia, and one (16%) occurred in an asymptomatic average-risk patient. All studies were performed after insufflation of room air. Six (84%) cases of perforation occurred in patients in whom a rectal tube was inserted, and in five of them, a balloon was inflated. Five (71%) cases of perforation occurred in the sigmoid colon; and two (29%), in the rectum. Four (57%) patients (one in 2968 patients; 95% confidence interval: 1.5 in 10 000, 14.7 in 10 000) required surgical treatment. Possible factors that contributed to perforation were left inguinal hernia containing colon (n = 4), severe diverticulosis (n = 3), and obstructive carcinoma (n = 1).

CONCLUSION

Perforation of the colon and rectum is a rare complication of CT colonography. Older age and underlying concomitant colonic disease were present in patients with perforation.

Colonic perforation after computed tomographic colonography in a patient with fibrostenosing Crohn's disease

Computed tomographic colonography (CTC) offers great promise in the management of patients with disorders of the colon. Few complications have been reported with its use thus far. We describe herein a case of colonic perforation during CTC in a patient with active stenosing ileocolonic Crohn's disease. To our knowledge, this is the first reported case of CTC-related perforation in the setting of Crohn's disease, and the third reported perforation overall. Perforation likely occurred in this case due to barotrauma in the setting of colonic strictures and an inflamed, weakened colonic wall. Physician awareness of the increased risk of perforation with CTC in the setting of inflammatory and/or obstructive disease of the colon will allow for improved clinical decision-making in the care of these patients.

Colonography by computed tomography

Computed tomographic colonography ('virtual colonoscopy') has shown promising results in the detection of large (> or = 10 mm) polyps in populations with a high prevalence of polyps. Recent studies in low prevalence populations, however, show variable results in sensitivity, ranging from 55% to 94% for the detection of patients with polyps measuring 10 mm or longer. Therefore questions have been raised about computed tomographic colonography as a screening method, probably the most valuable use of this technique. This article describes possible causes of these remarkable differences as well as advances in computed tomographic colonography.

Mass screening with CT colonography: should the radiation exposure be of concern?

BACKGROUND & AIMS

Computed tomography colonography (CTC), particularly using noncathartic techniques, has the clear potential to increase compliance for colorectal cancer screening. Because the geometry for CTC is highly advantageous, it can be performed with lower radiation doses than almost any other CT examination. If CTC were to become a standard screening tool for the population age 50 years and older, the potential market in the United States would soon be over 100 million people. Therefore, it is pertinent to consider the radiation exposure and any potential radiation risk to the population from such a mass CTC screening program.

METHODS

Organ doses from CTC examinations can be estimated with standard techniques. These doses can be applied to organ- and dose-specific radiation cancer risk estimates to estimate the excess cancer risk resulting from the radiation from a paired (supine and prone) CTC examination.

RESULTS

The cancer risks associated with the radiation exposure from CTC are unlikely to be zero, but they are small. A best estimate for the absolute lifetime cancer risk associated with the radiation exposure using typical current scanner techniques is about 0.14% for paired CTC scans for a 50-year-old, and about half that for a 70-year-old. These values probably could be reduced by factors of 5 or 10 with optimized CTC protocols.

CONCLUSIONS

In terms of the radiation exposure, the benefit-risk ratio potentially is large for CTC.

Computed tomographic colonography

Computed tomographic colonography, also called virtual colonoscopy, is an evolving technology under evaluation as a new method of screening for colorectal cancer. However, its performance as a test has varied widely across studies, and the reasons for these discrepancies are poorly defined. We provide an overview of some potential causes and discuss the available, often indirect, evidence. In addition, several other obstacles that may influence implementation are discussed. Future investigations should demonstrate the influence of these potential factors on sensitivity of computed tomographic colonography. Despite a growing body of evidence, it remains uncertain to what extent patient acceptance, radiation issues, flat lesions, and extracolonic findings will be a stumbling block to using computed tomographic colonography for colorectal cancer screening.

CT colonography and colonoscopy: assessment of patient preference in a 5-week follow-up study

PURPOSE

To prospectively evaluate short- and midterm patient preference of computed tomographic (CT) colonography relative to colonoscopy in patients at increased risk for colorectal cancer and to elucidate determinants of preference.

MATERIALS AND METHODS

Consecutive patients at increased risk for colorectal cancer underwent CT colonography prior to scheduled colonoscopy. Patient experience and preference were assessed both directly after the examinations and 5 weeks after the examinations. Differences in pain, embarrassment, discomfort, and preference were assessed with the Wilcoxon signed rank sum test or a binomial test. Potential determinants of preference were investigated with logistic regression analyses.

RESULTS

Data for 249 patients were included. Fewer patients experienced severe or extreme pain during CT colonography (seven [3%] of 245) than during colonoscopy (81 [34%] of 241) (P < .001). Directly after both examinations, 168 (71%) of 236 patients preferred CT colonography; 5 weeks later, 141 (61%) of 233 patients preferred CT colonography (P < .001). Initially, a painful colonoscopy examination (odds ratio, 0.17; 95% confidence interval [CI]: 0.08, 0.38) was a determinant of CT colonography preference. Similarly, a painful (odds ratio, 3.70; 95% CI: 1.54, 8.92) or an embarrassing (odds ratio, 4.46; 95% CI: 1.18, 16.88) CT colonography examination was a determinant of colonoscopy preference. After 5 weeks, the presence of polyps emerged as a determinant of colonoscopy preference (odds ratio, 1.94; 95% CI: 1.02, 3.70), while the role of experiences waned.

CONCLUSION

Patients preferred CT colonography to colonoscopy; however, this preference decreased in time, while outcome considerations gradually replaced temporary experiences of inconvenience.

Actual colonic perforation in virtual colonoscopy: report of a case

Computed tomography colonography, also termed virtual colonoscopy, is a new imaging method to investigate the colon, which may be a potential alternative to the conventional endoscopic colonoscopy in some cases. The high safety profile of this imaging method was considered as an additional advantage of this procedure. A case of colonic perforation in computed tomography colonography is presented, highlighting a potential risk related to this procedure. It is assumed that perforation was the result of overinflation of air into an obstructed colon caused by a lesion at the rectosigmoid junction. Thus, it is suggested that in such cases, air insufflation should be gradual, thereby minimizing the risk of perforation.

Perforated colon secondary to virtual colonoscopy: report of a case

We describe a case of a perforated colon secondary to a virtual colonoscopy in an 81-year-old female with ulcerative colitis. She underwent an emergent right hemicolectomy. The pathologic findings were described as ulcerative colitis with full-thickness perforation. To the best of our knowledge, this is the first complication from a virtual colonoscopy reported in the literature.

Cardiovascular Effects at Multi–Detector Row CT Colonography Compared with Those at Conventional Endoscopy of the Colon

PURPOSE

To compare the cardiovascular effects of computed tomographic (CT) colonography and conventional endoscopy in a group of patients undergoing both procedures.

MATERIALS AND METHODS

A total of 144 patients underwent CT colonography followed by flexible sigmoidoscopy (40 patients) or colonoscopy (104 patients). Pulse, blood pressure, and oxygen saturation were measured before, during, and after the procedures. Forty patients also underwent continuous Holter electrocardiographic (ECG) monitoring. Periprocedural pain was assessed by using a handheld counting device. Outcome variables were assessed by using a combination of paired t testing and multilevel linear regression.

RESULTS

When a spasmolytic was not used, CT colonography was associated with only a small increase in oxygen saturation (P =.03), while use of a spasmolytic caused an increase in pulse (mean increase, 19.9 beats per minute; P <.001) and diastolic blood pressure (mean increase, 5 mm Hg; P <.001). Compared with that at CT, oxygen saturation decreased significantly during and after colonoscopy and sigmoidoscopy (mean decrease after colonoscopy with sedation, 1.0%; P <.001). Systolic and diastolic blood pressure also decreased during and after colonoscopy (mean systolic decrease after colonoscopy with sedation, 16.6 mm Hg, P <.001; mean diastolic decrease after colonoscopy with sedation, 7.5 mm Hg, P <.001). Patients were 30.3 times more likely to develop bradycardia after endoscopy (95% CI: 2.65, 346; P =.006). Ventricular couplets were significantly higher at endoscopy than at CT in patients with a history of cardiac disease (odds ratio: 72.5 and 95% CI: 4.56, 1,153 at CT vs odds ratio: 14.6 and 95% CI: 0.96, 222 at endoscopy; P =.002). Patients were 1.89 times more likely to register pain during colonoscopy than during CT (95% CI: 1.06, 3.38; P =.03).

CONCLUSION

CT colonography had no significant cardiovascular effect other than spasmolytic-induced tachycardia. Endoscopy-and colonoscopy in particular-causes cardiovascular effects that are largely related to sedation. CT colonography is less painful than colonoscopy and is comparable to flexible sigmoidoscopy.

Virtual colonoscopy. Potential clinical applications of a new technique

The potential role of virtual colonoscopy is not limited to colorectal cancer screening, although that is its greatest potential. Same-day VC should be offered for patients undergoing an incomplete colonoscopy. Conversely, faster, more accurate interpretation by the radiologist on the same day as a VC should lead to the consideration by the gastroenterologist of same-day colonoscopy for patients with a suspicious, significantly sized polyp.

Colorectal polyp detection with virtual colonoscopy (computed tomographic colonography); the reliability of the method

BACKGROUND/AIMS

The aim of this study was to compare the reliability of virtual colonoscopy with conventional colonoscopy in detection of colorectal polyps.

METHODOLOGY

Between November 1997 and February 2000, 23 patients (14 males, 9 females) aged 43-86 years (mean: 63) with colorectal polyps who underwent colonoscopy in our endoscopy unit, were referred for virtual colonoscopy. The colon was distended with an enema tube for rectal insufflation and subsequently was scanned by helical CT (Toshiba X-vision) using the following parameters: KV 120, mAs 200, table feed 5 mm/sec, slice thickness 5 mm and reconstruction intervals 2.5 mm. Using SPARC Station 20, virtual colonoscopy was generated.

RESULTS

A total of 30 polyps (19 with diameter 8-15 mm and 11 larger than 15 mm) were detected with conventional colonoscopy. Virtual colonoscopy visualized 27 polyps (17 with diameter 8-15 mm and 10 with diameter > 15 mm).

CONCLUSIONS

Virtual colonoscopy is a non-invasive, well-tolerated, safe technique and can be useful for detection of colorectal polyps. Weaknesses of the method are the inability to detect small lesions and to perform biopsies.