Intestinal malrotation in adults: prevalence and findings based on CT colonography

OBJECTIVES

Intestinal malrotation is largely a pediatric diagnosis, but initial detection can be made in adulthood. CT colonography (CTC) provides an ideal means for estimating prevalence. Our purpose was to evaluate the prevalence and imaging findings of intestinal malrotation in asymptomatic adults at CTC screening, as well as incomplete optical colonoscopy (OC) referral.

METHODS

The CTC database of a single academic institution was searched for cases of intestinal malrotation (developmental nonrotation). Prevalence was estimated from 11,176 adults undergoing CTC. Demographic, clinical, imaging (CTC and other abdominal exams), and surgical data were reviewed.

RESULTS

27 cases of malrotation were confirmed (mean age 62 ± 9 years; 15 M/12F), including 17 from the CTC screening cohort (0.17% prevalence) and 10 from incomplete OC (0.75% prevalence; p < 0.001). Most cases (59%; 16/27) were initially diagnosed at CTC. In 67% (12/18); the presence of malrotation was missed on at least one relevant abdominal imaging examination. At least 22% (6/27) had a history of unexplained, chronic intermittent abdominal pain. At CTC, the SMA-SMV relationship was normal in only 11% (3/27). The ileocecal valve was located in the RLQ in only 22% (6/27). Two patients (7%) had associated findings of heterotaxy (polysplenia).

CONCLUSIONS

The prevalence of intestinal malrotation was four times greater for patients referred from incomplete OC compared with primary screening CTC, likely related to anatomic challenges at endoscopy. Malrotation was frequently missed at other abdominal imaging examinations. CTC can uncover unexpected cases of malrotation in adults, which may be relevant in terms of potential for future complications.

Symptoms and diagnostic criteria of acquired Megacolon - a systematic literature review

BACKGROUND

Acquired Megacolon (AMC) is a condition involving persistent dilatation and lengthening of the colon in the absence of organic disease. Diagnosis depends on subjective radiological, endoscopic or surgical findings in the context of a suggestive clinical presentation. This review sets out to investigate diagnostic criteria of AMC.

METHODS

The literature was searched using the databases - PubMed, Medline via OvidSP, ClinicalKey, Informit and the Cochrane Library. Primary studies, published in English, with more than three patients were critically appraised based on study design, methodology and sample size. Exclusion criteria were studies with the following features: post-operative; megarectum-predominant; paediatric; organic megacolon; non-human; and failure to exclude organic causes.

RESULTS

A review of 23 articles found constipation, abdominal pain, distension and gas distress were predominant symptoms. All ages and both sexes were affected, however, symptoms varied with age. Changes in anorectal manometry, histology and colonic transit are consistently reported. Studies involved varying patient numbers, demographics and data acquisition methods.

CONCLUSIONS

Outcome data investigating the diagnosis of AMC must be interpreted in light of the limitations of the low-level evidence studies published to date. Proposed diagnostic criteria include: (1) the exclusion of organic disease; (2) a radiological sigmoid diameter of ~ 10 cm; (3) and constipation, distension, abdominal pain and/or gas distress. A proportion of patients with AMC may be currently misdiagnosed as having functional gastrointestinal disorders. Our conclusions are inevitably tentative, but will hopefully stimulate further research on this enigmatic condition.

CT colonography: role in FOBT-based screening programs for colorectal cancer

Computed tomographic colonography (CTC) is a minimally invasive imaging examination for the colon, and is safe, well tolerated and accurate for the detection of colorectal cancer (CRC) and advanced adenoma. While the role of CTC as a primary test for population screening of CRC is under investigation, the fecal occult blood test (FOBT) has been recommended for population screening of CRC in Europe. Subjects with positive FOBT are invited to undergo total colonoscopy, which has some critical issues, such as suboptimal compliance, contraindications and the possibility of an incomplete exploration of the colon. Based on available data, the integration of CTC in FOBT-based population screening programs for CRC may fall into three scenarios. First, CTC is recommended in FOBT-positive subjects when colonoscopy is refused, incomplete or contraindicated. For these indications CTC should replace double-contrast barium enema. Second, conversely, CTC is not currently recommended as a second-level examination prior to colonoscopy in all FOBT-positive subjects, as this strategy is most probably not cost-effective. Finally, CTC may be considered instead of colonoscopy for surveillance after adenoma removal, but specific studies are needed.

The correlation between diverticulosis and redundant colon

BACKGROUND

Diverticulosis and redundant colon are colonic conditions for which underlying pathophysiology, management and prevention are poorly understood. Historical papers suggest an inverse relationship between these two conditions. However, no further attempt has been made to validate this relationship. This study set out to assess the correlation between diverticulosis and colonic redundancy.

METHODS

Redundant colon, diverticulosis and patient demographics were recorded during colonoscopy. Multivariate binary logistic regression was performed with redundant colon as the dependent variable and age, gender and diverticulosis as independent variables. Nagelkerke R ² and a receiver operator curve were calculated to assess goodness of fit and internally validate the multivariate model.

RESULTS

Redundant colon and diverticulosis were diagnosed in 31 and 113 patients, respectively. The probability of redundant colon was increased by female gender odds ratio (OR) 8.4 (95% CI 2.7-26, p = 0.00020) and increasing age OR 1.7 (95% CI 1.1-2.6, p = 0.017). Paradoxically, diverticulosis strongly reduced the probability of redundant colon with OR of 0.12 (95% CI 0.42-0.32, p = 0.000039). The Nagelkerke R ² for the multivariate model was 0.29 and the area under the curve at ROC analysis was 0.81 (95% CI 0.73-0.90 p-value 3.1 × 10^-8).

CONCLUSIONS

This study found an inverse correlation between redundant colon and diverticulosis, supporting the historical suggestion that the two conditions rarely occur concurrently. The underlying principle for this relationship remains to be found. However, it may contribute to the understanding of the aetiology and pathophysiology of these colonic conditions.

Detailed quantitative assessment of colonic morphology at CT colonography using novel software: a feasibility and reproducibility study

The aim of this study was to evaluate feasibility and reproducibility of quantitative assessment of colonic morphology on CT colonography (CTC). CTC datasets from 60 patients with optimal colonic distension were assessed using prototype software. Metrics potentially associated with poor endoscopic performance were calculated for the total colon and each segment including: length, volume, tortuosity (number of high curvature points <90°), and compactness (volume of box containing centerline divided by centerline length). Sigmoid apex height relative to the lumbosacral junction was also measured. Datasets were quantified twice each, and intra-reader reliability was evaluated using concordance correlation coefficient and Bland-Altman plot. Complete quantitative datasets including the five proposed metrics were generated from 58 of 60 (97 %) CTC examinations. The sigmoid and transverse segments were the longest (55.9 and 51.4 cm), had the largest volumes (0.410 and 0.609 L), and were the most tortuous (3.39 and 2.75 high curvature points) and least compact (3347 and 3595 mm²), noting high inter-patient variability for all metrics. Mean height of the sigmoid apex was 6.7 cm, also with high inter-patient variability (SD 6.8 cm). Intra-reader reliability was high for total and segmental lengths and sigmoid apex height (CCC = 0.9991) with excellent repeatability coefficient (CR = 3.0-3.3). There was low percent variance of metrics dependent upon length (median 5 %). Detailed automated quantitative assessment of colonic morphology on routine CTC datasets is feasible and reproducible, requiring minimal reader interaction.

Diagnostic value of computed tomography colonography (CTC) after incomplete optical colonoscopy

INTRODUCTION

This study evaluated the role of computed tomography colonography (CTC) in patients who previously underwent incomplete optical colonoscopy (OC). We analyzed the impact of colonic lesions in intestinal segments not studied by OC and extracolonic findings in these patients.

METHODS

Between January 2014 and May 2015, 61 patients with a history of abdominal pain and incomplete OC examination were studied by CTC. CTCs were performed by 320-row CT scan in both the supine and the prone position, without intravenous administration of contrast medium. In all patients both colonic findings and extracolonic findings were evaluated.

RESULTS

Among the study group, 24 CTC examinations were negative for both colonic and extracolonic findings while 6 examinations revealed the presence of both colonic and extracolonic findings. In 24 patients CTC depicted colonic anomalies without extracolonic ones, while in 7 patients it showed extracolonic findings without colonic ones.

DISCUSSION

CTC is a noninvasive imaging technique with the advantages of high diagnostic performance, rapid data acquisition, minimal patient discomfort, lack of need for sedation, and virtually no recovery time. CTC accurately allows the evaluation of the nonvisualized part of the colon after incomplete OC and has the distinct advantage to detect clinically important extracolonic findings in patients with incomplete OC potentially explaining the patient's symptoms and conditioning their therapeutic management.

CONCLUSION

CTC accurately allows the assessment of both colonic and extracolonic pathologies representing a useful diagnostic tool in patients for whom complete OC is not achievable.

Fecal tag CT colonography with a limited 2-day bowel preparation following incomplete colonoscopy

PURPOSE

This study aimed to assess the feasibility and patient tolerance of a 2-day limited fecal tag bowel preparation in computed tomographic colonography (CTC) performed for incomplete conventional colonoscopy (CC) patients.

MATERIALS AND METHODS

Seventy-five patients who underwent a CTC examination fbecause of incomplete CC were included. A low-residue diet was given for 2 days before CTC. Fecal tagging (FT) was done using a barium sulfate suspension. The quality of the preparation, success of tagging and patient experience with the bowel preparation were investigated.

RESULTS

Four hundred fifty bowel segments were evaluated. The number of solid stool balls of 6-9 mm size was 284; the corresponding figure was 93 for solid stool balls ≥ 10 mm. Residual fluid was present in about one-third of the segments. The fecal tagging efficacy for ≥ 6 mm residual stool balls was 92 %. Overall, 16 (21.3 %) patients presented with colonic lesions at CTC. Three out of four colonic mass lesions had not been diagnosed with CC. Most patients reported mild discomfort.

CONCLUSION

FT-CTC performed after a limited 2-day bowel preparation seems to be a technically feasible, safe and acceptable procedure that allows a complete a colonic study in incomplete CC patients.

Role of CT Colonography in Colonic Lesions and Its Correlation with Conventional Colonoscopic Findings

BACKGROUND

Preoperative evaluation in patients with colorectal carcinoma is essential for a correct therapeutic plan. Conventional colonoscopy has certain limitations including its inability to detect synchronous lesions in case of distal obstructive mass and inaccurate tumour localization. CT colonography combines cross sectional imaging with virtual colonoscopic images and offers a comprehensive preoperative evaluation in patients with colorectal carcinoma including detection of synchronous lesions with accurate segmental localization and loco regional staging.

AIM

The objective was to determine the role of CT colonography in various colonic lesions and to correlate the findings with conventional colonoscopy and histopathological findings.

SETTINGS AND DESIGN

This prospective study included 50 patients with clinical symptoms suspicious of colonic pathology.

MATERIALS AND METHODS

All the patients underwent both CT colonography and conventional colonoscopy on the same day. CT colonography was performed in supine and prone position. Considering histopathological and/or surgical findings as gold standard, sensitivity and specificity of both the modalities were calculated.

RESULTS

Conventional colonoscopy missed two synchronous lesions proximal to occlusive mass and one lesion proximal to the anastomotic site; all were detected with CT colonography. One carpet lesion in rectum and one case of mild ulcerative colitis were missed by CT colonography. Sensitivity and specificity for detection of colorectal cancer were 97.56% and 100%, resp. with PPV and NPV of 100% and 93.75%, for CT colonography and 92.68% and 100%, respectively with PPV and NPV of 100% and 83.3% for conventional colonoscopy. Sensitivity for correct detection of acute and chronic ulcerative colitis of CT colonography was 66.6 % and 100 %, resp.

CONCLUSION

CT colonography has higher sensitivity than conventional colonoscopy for detection of colorectal carcinoma, including its ability to detect abnormalities proximal to obstructing lesion, accurate segmental localization of lesions and staging. However, some limitations of CT colonography were difficulty in detection of flat lesions and lack of information about hyperemia and superficial mucosal erosion, where conventional colonoscopy scored over CT colonography.

Comparison of CT colonography with conventional colonoscopy in patients with ulcerative colitis

RATIONALE AND OBJECTIVE

Patients with ulcerative colitis require recurrent conventional colonoscopy (CC) to define the extent of the disease. Computed tomography (CT) colonography (CTC) can be used as an alternative technique for studying the colon in these patients. The purpose of the study was to compare the findings of CTC to CC in patients with ulcerative colitis.

MATERIALS AND METHODS

Twenty patients proven to have ulcerative colitis on biopsy and in clinical remission state were enrolled in the study. They underwent CTC and CC within 1 week of each test. The investigators performing CTC and CC were blinded to the findings of each other. The chi-square test, kappa test, sensitivity, and specificity were used to compare the findings on CTC and CC. In addition, patient acceptance for both the procedures was compared.

RESULTS

Sensitivity and specificity on CTC for detecting granular appearance were 81.0% and 73.8%, respectively, and for pseudopolyps were 82.1% and 84.5%, respectively. Good correlation was seen between CTC and CC for detection of granular appearance and pseudopolyps. Loss of haustral folds, wall thickening, pericolonic vascularity, and pericolonic lymph nodes seen on CTC were found to correlate with intraluminal findings seen on CC. Patient acceptance for CTC was better than that for CC.

CONCLUSIONS

CTC can be used for evaluating patients with ulcerative colitis who are in remission.

[Optical colonoscopy and virtual colonoscopy: the current role of each technique]

The importance of optical or conventional colonoscopy in diagnosing colon disease is undisputed. In this context, optical colonoscopy is the gold standard against which other techniques must be validated. Apart from enabling direct inspection of the colonic mucosa, optical colonoscopy enables biopsies and techniques to treat and prevent colorectal cancer. Virtual colonoscopy or CT colonography has been validated in multicenter studies; virtual colonoscopy is as sensitive as optical colonoscopy for the detection of polyps and colon cancer. It is currently the only valid alternative to optical colonoscopy. Its role in patients with medium or high risk of colon cancer is in the process of being defined as multidisciplinary teams gain experience. This article aims to discuss the usefulness of virtual colonoscopy in different clinical situations, emphasizing the situations in which there is enough scientific evidence, and to discuss the controversies surrounding its possible use for population-based screening.

Predictors of CT colonography utilization among asymptomatic medicare beneficiaries

BACKGROUND

Although the Centers for Medicare and Medicaid Services (CMS) denied coverage for screening computed tomography colonography (CTC) in March 2009, little is understood about whether CTC was targeted to the appropriate patient population prior to this decision.

OBJECTIVE

Evaluate patient characteristics and known relative clinical indications for screening CTC among patients who received CTC compared to optical colonoscopy (OC).

DESIGN/PARTICIPANTS

Cross-sectional study of all 10,538 asymptomatic Medicare beneficiaries who underwent CTC between January 2007 and December 2008, compared to a cohort of 160,113 asymptomatic beneficiaries who underwent OC, matched on county of residence and year of examination.

MAIN MEASURES

Patient characteristics and known relative appropriate and inappropriate clinical indications for screening CTC.

KEY RESULTS

CTC utilization was higher among women, patients > 65 years of age, white patients, and those with household income > 75 % (p = 0.001). Patients with relatively appropriate clinical indications for screening CTC were more likely to undergo CTC than OC including presumed incomplete OC (OR 80.7, 95 % CI 76.01-85.63); sedation risk (OR 1.11, 95 % CI 1.05-1.17); and chronic anticoagulation risk (OR 1.46, 95 % CI 1.38-1.54), after adjusting for patient characteristics and known clinical indications. Conversely, patients undergoing high-risk screening, an inappropriate indication, were less likely to receive CTC (OR 0.4, 95 % CI 0.37-0.42). Overall, 83 % of asymptomatic patients referred to CTC had at least one clinical indication relatively appropriate for CTC (8,772/10,538).

CONCLUSION

During the 2 years preceding CMS denial for screening, CTC was targeted to asymptomatic patients with relatively appropriate clinical indications for CTC/not receiving OC. However, CTC utilization was lower among certain demographic groups, including minority patients. These findings raise the possibility that future coverage of screening CTC might exacerbate disparities in colorectal cancer screening while increasing overall screening rates.

Impact of an incomplete colonoscopy referral program on recommendations after incomplete colonoscopy

BACKGROUND

There are limited data on recommendations and adherence to complete colon evaluation (CCE) after incomplete colonoscopy (IC).

AIMS

Our objectives were to (1) identify recommendations and adherence to recommendations after IC, (2) determine the diagnostic yield of CCE after IC, and (3) determine the effect of an IC referral program on recommendations for CCE.

METHODS

We conducted a retrospective review of IC procedures at a teaching hospital over two time periods (January 1 to May 1 2004 and July 1 to November 1 2010). A referral process for repeat colonoscopy after IC was instituted in April 2009. Outcomes included (1) recommendations (2) adherence, and (3) yield of CCE after IC.

RESULTS

A total of 222 patients underwent at least one IC (overall rate of 2.5 %). In 120 patients (54.1 %), CCE was recommended within 1 year; the rate did not change from 2004 to 2010. Patients with IC due to poor preparation were more likely to have specific CCE recommendations (85.5 vs. 72.2 %, P = 0.03) and recommendations of endoscopic follow-up (76.3 vs. 10.4 %, P < 0.0001) than those with IC due to difficult anatomy. When IC was due to difficult colonoscopy, there was increase in endoscopic follow-up recommended (16.3 vs. 2.8 %, P = 0.01) in 2010 compared to 2004. Adherence to recommendations was similar regardless of modality recommended, inpatient/outpatient status, polyps on initial exam, or extent of initial exam. Polyp detection rate was greater utilizing colonoscopy than barium enema (34.3 vs. 3.6 %, P < 0.0001).

CONCLUSIONS

There is a lack of consensus in management strategies for patients after IC. Implementation of a referral program has had minimal impact on provider recommendations.

Suspected extracolonic neoplasms detected on CT colonography: literature review and possible outcomes

RATIONALE AND OBJECTIVES

This study summarizes the literature on the detection of cancer among indeterminate extracolonic findings on computed tomographic (CT) colonography in five targeted organs.

MATERIALS AND METHODS

We searched PubMed for English-language literature published between January 1, 1994, and December 31, 2010. We describe extracolonic findings in the kidney, lung, liver, pancreas, and ovary suspect for malignancy as they are associated with high mortality. For each organ, we calculated the median prevalence, positive predictive value (PPV), and false positive rate of malignancy and a pooled false-positive rate across studies.

RESULTS

Of 91 publications initially identified, 24 were eligible for review. Indeterminate renal masses on CT colonography had 20.5% median PPV and low pooled false positive rate of 1.3% (95% confidence interval 0.6-2.0). In contrast, indeterminate masses of the lung, liver, pancreas, and ovary had low PPV (median values ranged from 0% to 3.8%). Indeterminate masses of the ovary resulted in the highest pooled false-positive rate of 2.2%. Results were similar in studies of both screening and nonscreening populations. We estimated the probability of false positive results through the detection of significant extracolonic findings as 46 per 1000 for men and 68 per 1000 for women.

CONCLUSIONS

Indeterminate renal masses newly detected on CT colonography have an estimated one in five chance of malignancy and therefore warrant further follow-up to provide a definitive diagnosis. Conversely, indeterminate masses of the lung, liver, pancreas, and ovary are associated with high false positive rates and merit more conservative clinical follow-up.

Performing an additional decubitus series at CT colonography

PURPOSE

To determine the rate and associated factors for acquiring a decubitus series at CT colonography (CTC), in addition to the standard supine and prone series.

MATERIALS AND METHODS

CTC examinations read centrally at one institution but performed at three different centers in 6,380 adults were reviewed to determine the frequency of an additional decubitus series. Results were analyzed according to study indication (primary screening vs. diagnostic for incomplete colonoscopy), practice site (academic vs. community), patient age, gender, body mass index (BMI), and temporal variation. At all sites, the CT technologist determined the need for an additional decubitus series, with infrequent radiologist input in select cases.

RESULTS

The frequency for the CT technologist to obtain a decubitus series at screening was 9.7% (578/5,952), compared with 22.9% (98/428) following failed colonoscopy (P < 0.001). The decubitus rate for screening at the academic center (9.4%, 550/5,871) was significantly lower than the community hospitals (34.6% combined, 28/81) (P < 0.001). The rate progressively increased with age, from 5.0% under age 50 to 28.0% over age 80. No significant difference was seen between men and women (10.3 vs. 9.2%), but a strong correlation existed with increased BMI, rising to >25% for BMI over 40. Marked temporal variation existed at the academic center, with quarterly rates ranging from 0 to 17%.

CONCLUSIONS

The frequency for performing a third series at CTC varies considerably according to indication, practice site, patient age, BMI, and time. These results have important implications for clinical practice, including the need for improved training and feedback for CT technologists.

The water method is effective in difficult colonoscopy - it enhances cecal intubation in unsedated patients with a history of abdominal surgery

BACKGROUND: Colonoscopy in unsedated patients in the US is considered to be difficult. Success rate of cecal intubation is limited by discomfort. Colonoscopy in patients with a history of abdominal surgery is also considered to be difficult due to adhesion-related bowel angulations. The water method has been shown to significantly reduce pain during colonoscopy. OBJECTIVE: To test the hypothesis that the water method enhances the completion of colonoscopy in unsedated patients with a history of abdominal surgery. DESIGN: The data bases of two parallel RCT were combined and analyzed. SETTING: Two Veterans Affairs endoscopy units. PATIENT AND METHODS: The water and air methods were compared in these two parallel RCT examining unsedated patients. Those with a history of abdominal surgery were selected for evaluation. MAIN OUTCOME MEASUREMENTS: Completion of unsedated colonoscopy. RESULTS: Among patients with a history of abdominal surgery, the proportion completing unsedated colonoscopy in the water group (19 of 22) was significantly higher than that (11 of 22) in the air group (p=0.0217, Fisher's exact test). LIMITATIONS: Small number of predominantly male veterans, unblinded colonoscopists, not all types of abdominal surgery (e.g. hysterectomy, gastrectomy) predisposing to difficult colonoscopy were represented. CONCLUSION: This proof-of-principle assessment confirms that in patients with a history of abdominal surgery the water method significantly increases the proportion able to complete unsedated colonoscopy. The water method deserves to be evaluated in patients with other factors associated with difficult colonoscopy.

Initial experience with computed tomographic colonography applied for noncolorectal cancerous conditions

PURPOSE

The aim of this study was to asses retrospectively the performance of computed tomography colonography (CTC) for noncolorectal cancerous conditions.

MATERIAL AND METHODS

A total of 44 patients with non-colorectal cancerous conditions underwent CTC. We researched the indications for CTC or present illness and evaluated the CTC imaging findings. We assessed whether diagnosis by CTC reduced conventional colonoscopic examinations.

RESULTS

A total of 47 examinations were performed in 44 patients. The indications for CTC or a present illness were as follows: 15 patients with impossible or incomplete colonoscopy, 7 with diverticular disease, 6 with malignancy (noncolorectal cancer), 6 with Crohn's disease, 4 suspected to have a submucosal tumor on colonoscopy, 2 with ischemic colitis, and 4 with various other diseases. Colonic findings were diagnosed on CTC in 36 examinations, and extracolonic findings were identified in 35 of 44 patients. In all, 17 patients had undergone colonoscopy previously, 9 (52.9%) of whom did not require further colonoscopy by CTC. Five patients underwent colonoscopy after CTC.

CONCLUSION

The indications for CTC were varied for patients with noncolorectal cancerous conditions. CTC examinations could be performed safely. Unlike colonoscopy or CT without preparation, CTC revealed colonic and extracolonic findings and may reduce the indication of colonoscopy in patients with noncolorectal cancerous conditions.

Patient acceptability of CT colonography compared with double contrast barium enema: results from a multicentre randomised controlled trial of symptomatic patients

OBJECTIVES

To determine patient acceptability of barium enema (BE) or CT colonography (CTC).

METHODS

After ethical approval, 921 consenting patients with symptoms suggestive of colorectal cancer who had been randomly assigned and completed either BE (N = 606) or CTC (N = 315) received a questionnaire to assess experience of the clinical episode including bowel preparation, procedure and complications. Satisfaction, worry and physical discomfort were assessed using an adapted version of a validated acceptability scale. Non-parametric methods assessed differences between the randomised tests and the effect of patient characteristics.

RESULTS

Patients undergoing BE were significantly less satisfied (median 61, interquartile range [IQR] 54-67 vs. median 64, IQR 56-69; p = 0.003) and experienced more physical discomfort (median 40, IQR 29-52 vs. median 35.5, IQR 25-47; p < 0.001) than those undergoing CTC. Post-test, BE patients were significantly more likely to experience 'abdominal pain/cramps' (68% vs. 57%; p = 0.007), 'soreness' (57% vs. 37%; p < 0.001), 'nausea/vomiting' (16% vs. 8%; p = 0.009), 'soiling' (31% vs. 23%; p = 0.034) and 'wind' (92% vs. 84%; p = 0.001) and in the case of 'wind' to also rate it as severe (27% vs. 15%; p < 0.001).

CONCLUSION

CTC is associated with significant improvements in patient experience. These data support the case for CTC to replace BE.

Single-balloon colonoscopy versus repeat standard colonoscopy for previous incomplete colonoscopy: a randomized, controlled trial

BACKGROUND

Optical colonoscopy is the only examination allowing complete visualization of the colon with simultaneous polyp removal. In a minority of patients, a complete examination is unsuccessful. It is unknown whether single-balloon, overtube-assisted colonoscopy (SBC) is superior to simply repeating a standard colonoscopy (SC) on an alternate day.

OBJECTIVE

To compare the success rates of SC and SBC in patients with previous incomplete examinations.

DESIGN

Randomized, controlled trial.

SETTING

Tertiary care academic center.

PATIENTS

Thirty subjects with previous incomplete colonoscopy.

INTERVENTIONS

Repeat colonoscopy either by SC or SBC. If cecal intubation was unsuccessful, subjects were crossed over to the alternate group.

RESULTS

Thirty subjects (73.3% female, mean age 59.2 years) with previous incomplete colonoscopy were randomized (SBC, 14 subjects; SC, 16 subjects). Cecal intubation was significantly more successful with SBC (92.9%) than with SC (50%) (P = .016). For all SC failures, cecal intubation was successful after crossover to the SBC group (100%). Cecal intubation time was similar in both groups. Proximal colon adenomas were detected in 38.1% of subjects. There were no procedure-related complications.

LIMITATIONS

Singe endoscopist performing all procedures; inability to ensure all incomplete colonoscopies were included in the study.

CONCLUSIONS

For patients with a previous incomplete colonoscopy, balloon colonoscopy performed by using the single-balloon enteroscope with an overtube was superior to a repeat attempt with a standard colonoscope. For patients with a previous incomplete examination, consideration should be given to a repeat attempt with balloon colonoscopy if available. (

CLINICAL TRIAL REGISTRATION NUMBER

STU00008540.).

Risk factors for colonic perforation after screening computed tomographic colonography: a multicentre analysis and review of the literature

BACKGROUND

Computed tomographic (CT) colonography (or 'virtual' colonoscopy) has become an increasingly popular tool for colorectal cancer screening. Colonic perforation, an uncommon complication, is a risk that has not been widely reported.

METHODS

A systematic review of the literature was undertaken to identify all reported risk factors for colonic perforation following CT colonography. In addition, a retrospective multicentre study was undertaken, evaluating all CT colonographies in 10 major metropolitan tertiary referral centres. All colonic perforations were assessed for risk factors.

RESULTS

A range of 'patient'-related and 'procedure'-related risk factors were identified in the literature. Among 3458 CT colonographies, there were two cases of colonic perforation contributing to an incidence of perforation of 0.06%. There was no statistical correlation between the incidence of perforation and institutional experience (P = 0.66). Risk factors common to both cases and the literature included age, recent colonoscopy and manual colonic insufflation. Diverticular disease and recent colonic biopsy were also notable factors.

CONCLUSION

There is a small but real risk of perforation following CT colonography. Patient selection and preventative procedural measures may reduce this risk. The importance of the consent process is emphasized.

An overview of the method, application, and various findings of computed tomographic colonography in patients after incomplete colonoscopy

Colon cancer is the third most common malignancy in the USA with 154,000 new cases and 52,000 deaths in 2007. The current screening method is optical colonoscopy; however, the compliance rate of the screening population is very low. Computed tomographic (CT) colonography has been used as an alternative to optical colonoscopy as a screening method. The purpose of this article is to explain how CT colonography has been used as a supplemental screening tool in a subset of patients in whom optical colonoscopy was either incomplete or not possible. We examined a group of 222 patients at our institution in which a complete colonoscopy could not be performed for a variety of reasons. Routine CT colonography imaging of the insufflated colon was performed in both the supine and the prone positions with oral contrast. 3D reconstructed images were then obtained using Viatronix software and were interpreted along with the axial images. Each patient was classified into groups based on the quality/adequacy of the examination, presence, number, and size of polyps. The patients were also evaluated for any diverticula, benign lesions such as lipoma, stricture, or mass. In addition to its use as a primary screening tool, CT colonography can be used as an adjunct to optical colonoscopy as in our institution. A cooperative use of both screening modalities can result in a higher number of completed examinations when combining the results of both tests. On review of our 222 cases, there were 37 patients in whom the CT colonography was deemed incomplete for several reasons, including inadequate insufflation, persistent stricture, or incomplete preparation. Of these cases, when reviewing the previous incomplete colonoscopy report, 18 patients (49%) had a complete screening study when combining the results of both tests. In these cases, areas that could not be evaluated by CT colonography were properly screened with colonoscopy. A large number of patients in our study group were able to receive an essentially complete screening evaluation when both tests were combined. In the case of our study, the combination of both tests brought the rate of complete studies to 91%.

Performance of CT colonography in clinical trials

The amount of data accumulated in trials of CT colonography (CTC) has greatly increased in the past decade. The information from these studies is shaping clinical practice and public health policy regarding screening for colorectal cancer (CRC). This article examines the performance of CTC in clinical trials for individuals at average risk and increased risk for CRC. It also addresses the efficacy of CTC after incomplete colonoscopy, when colon preparations are reduced or eliminated, and in academic versus nonacademic environments. The data suggest that CTC is effective especially for the detection of larger lesions and when more advanced imaging technology is used.

Bowel preparation in CT colonography: electrolyte and renal function disturbances in the frail and elderly patient

PURPOSE

Elderly patients are at increased risk of biochemical disturbances secondary to cathartic medications. This study investigates the renal function, electrolyte and clinical disturbances associated with CT colonography (CTC) with sodium picosulphate-magnesium citrate (SPS-MC) in a subgroup of frail, elderly patients.

METHODS

Patients aged over 70 years considered at risk of complication during SPS-MC administration by a physician specialised in care of the elderly were included in this retrospective study. Biochemical parameters pre- and post-CTC and the presence of co-morbidities were recorded. Imaging findings and quality of bowel preparation at CTC were graded by consensus by two radiologists.

RESULTS

Of the 72 patients 56% had co-morbidities that caution the use of SPS-MC. No significant changes in serum urea, sodium, potassium or estimated glomerular filtration rate (eGFR) occurred post-CTC (p > 0.10). Serum magnesium increased by 0.11 mmol/L in 14 patients (p = 0.03) without clinical sequelae. Good overall preparation was achieved in 88% of patients, allowing confident identification of signs of colonic neoplasia in 20 patients (27%). A mild increase in serum magnesium but no other significant biochemical disturbance was observed.

CONCLUSION

In our group CTC with SPS-MC was safe and effective; however, we advise an alternate preparation be considered in patients with decreased renal function due to decreased magnesium clearance.

Diagnostic accuracy of CT colonography and optical colonoscopy evaluated using surgically resected specimens

OBJECTIVE

The aim of this study was to clarify the diagnostic ability of CT colonography (CTC) using surgically resected specimens to avoid inaccuracy associated with optical colonoscopy (OC).

SUBJECTS AND METHODS

CTC and OC were performed in 152 consecutive patients with colorectal cancer. Forty patients had simultaneous lesions other than the ones for which the surgery was intended, and these lesions were used as the gold standard. In 24 patients without stenosis, the sensitivity and positive predictive values (PPV) of CTC and OC were evaluated. In 16 patients with stenosis, the diagnostic ability of CTC for lesions located proximal to the stenosis was assessed.

RESULTS

Sensitivity of CTC and OC was 81% and 66% (P = 0.16), and PPV was 90% and 100% (P = 0.13), respectively. For 22 lesions larger than 5 mm, the sensitivity of CTC and OCS was 96% and 91% (P > 0.50), and PPV was 100% and 100%, respectively. In patients with stenosis, sensitivity and PPV were 89% and 80%, respectively. These results were not significantly different from those in patients without stenosis.

CONCLUSIONS

CTC is a reliable modality for the diagnosis of colorectal polyps. It is also useful to evaluate the colon proximal to severe stenosis which could not be observed by OC.

The use of carbon dioxide for insufflation during GI endoscopy: a systematic review

BACKGROUND

Insufflation of the lumen is required for visualization during GI endoscopy. Carbon dioxide (CO(2)) has been proposed as an alternative to room air for insufflation.

OBJECTIVES

To assess the safety and efficacy of CO(2) insufflation for endoscopy.

DESIGN

Systematic review that focuses on evidence from randomized controlled trials (RCT).

METHODS

Two investigators independently searched MEDLINE from 1950 to February 13, 2008, to identify all articles that reported the use of CO(2) in a GI endoscopy application. Bibliographies of relevant articles were also hand searched to identify other pertinent reports. Data from RCTs, as well as from nonrandomized studies, were extracted.

RESULTS

Nine RCTs were identified that compared CO(2) and air insufflation for GI endoscopy. Fifteen other nonrandomized studies or reports were also reviewed. In the 8 RCTs in which postprocedural pain was assessed, pain was lower in the CO(2) insufflation group compared with the air group. Two RCTs found decreased flatus in the CO(2) group compared with the air group, and 3 RCTs showed there was decreased bowel distention on abdominal radiography in the CO(2) group compared with the air group. Also, in all 9 RCTs and 6 additional studies in which safety was assessed, there was no CO(2) retention and no adverse pulmonary events related to CO(2) insufflation.

LIMITATIONS

Because of study heterogeneity, meta-analytic techniques could not be used.

CONCLUSIONS

Consistent RCT evidence indicates that CO(2) insufflation is associated with decreased postprocedural pain, flatus, and bowel distention. CO(2) insufflation also appears to be safe in patients without severe underlying pulmonary disease.

Detection of occult colonic perforation before CT colonography after incomplete colonoscopy: perforation rate and use of a low-dose diagnostic scan before CO2 insufflation

OBJECTIVE

The purpose of this study was to obtain a low-dose CT scan before CT colonography to estimate the prevalence of occult colonic perforation among patients referred for same-day or next-day CT colonography after incomplete colonoscopy.

MATERIALS AND METHODS

Two hundred sixty-two patients (74 men, 188 women; mean age, 64 years; range, 21-92 years) consecutively referred for same-day or next-day CT colonography after incomplete colonoscopy underwent low-dose diagnostic CT before rectal tube insertion and CO(2) insufflation.

RESULTS

Perforation was found on the low-dose CT scans of two of the 262 patients (0.8%; 95% CI, 0.1-2.7%). One of these patients had no symptoms; the other had mild abdominal discomfort at the time of CT.

CONCLUSION

The rate of occult colonic perforation after incomplete colonoscopy may be significant. For patients referred for CT colonography after incomplete endoscopy, use of low-dose diagnostic CT before rectal tube insertion and insufflation is indicated.

Future expectations in digestive endoscopy: competition with other novel imaging techniques

Digestive endoscopy has been evolving from primary diagnostic to extensive therapeutic modalities in the management of gastrointestinal diseases. The present endoscopic imaging includes (A) standard endoscopy alone and /or with adjunct technologies such as point enhancement, e.g. confocal endomicroscopy and field enhancement technologies such as chromoendoscopy, NBI and FICE and (B) endoscopic ultrasound. Other novel imaging technologies including virtual colonoscopy or CT/MR colonography, CT or MRI enterography and capsule endoscopy have also been developed. This article reviews the diagnostic and therapeutic role of digestive endoscopy and future directions of digestive endoscopy are discussed. Digestive endoscopy is also compared with emerging novel imaging techniques in gastrointestinal diseases such as capsule endoscopy and CT colonography. The fact that digestive endoscopy has become a multidisciplinary specialty combining advances in all fields (radiology, bioengineering, surgery and gastroenterology) is highlighted.