Sigmoid colon perforation at CT colonography secondary to a possible obstructive mechanism: report of a case

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.

Iatrogenic Colonic Perforation due to Computed Tomographic Colonography

Although the complications of computed tomographic colonography (CTC) are very rare, CTC is associated with potential risk of colonic perforation. In the present report we describe two cases of colonic perforation secondary to CTC. In the first case with ascending colonic carcinoma, insertion of a rigid double-balloon catheter caused direct rectal wall perforation. In the second case with obstructive colonic carcinoma, pneumoperitoneum developed due to automated carbon dioxide insufflation. Both patients were asymptomatic after examination and recovered without any complications. Based on the findings of the current cases, we recommend that a soft-tip catheter be used for CTC, and suggest that colonic perforation can occur even with automatic insufflation, depending on patient characteristics.

Perforation rate in CT colonography: a systematic review of the literature and meta-analysis

PURPOSE

The primary aim was to assess the perforation rate of CTC; the secondary aim was to identify potential clinical/technical predictors of this complication.

METHODS

Methods for analysis were based on PRISMA (preferred reporting items for systematic reviews and meta-analyses). From the selected studies, the rate of CTC perforation and patient/technical characteristics potentially associated with this event were extracted. Forest plots showing individual and pooled estimates of the perforation rate were obtained for all analyses. I(2) was used to evaluate heterogeneity between studies.

RESULTS

Eleven articles out of the 187 initially identified were selected for the analysis (103,399 patients). There were 29,048 (28%) asymptomatic individuals and 30,773 (30%) symptomatic patients; this characteristic was not reported in the remaining subjects (42%). Colon distension was obtained manually in 69,222 (67%) and using an automated carbon dioxide insufflator in 26,479 (26%) patients; in the remaining 7% of patients, this information was missing. Twenty-eight colonic perforations were reported, with the CTC perforation rate estimated to be 0.04% (95% CI. 0.00-0.10), 19-fold higher in symptomatic than in screening subjects (OR: 19.2, CI 3.3-108 and P = 0.001). The surgical rate was 0.008%. No CTC-related deaths were reported.

CONCLUSIONS

The perforation rate in CTC is very low, particularly considering asymptomatic individuals.

KEY POINTS

• This is the first meta-analysis on this topic, based on 100,000 patients. • The CTC-related colorectal perforation rate is 0.04%, 0.02% in asymptomatic subjects. • The CTC-induced surgery rate is 0.008% (1:12,500). • The perforation rate in CTC is low, particularly in average-risk, asymptomatic individuals.

Colorectal cancer screening in an equal access healthcare system

INTRODUCTION

The military health system (MHS) a unique setting to analyze implementation programs as well as outcomes for colorectal cancer (CRC). Here we look at the efficacy of different CRC screening methods, attributes and results within the MHS, and current barriers to increase compliance.

MATERIALS AND METHODS

A literature search was conducted utilizing PubMed and the Cochrane library. Key-word combinations included colorectal cancer screening, racial disparity, risk factors, colorectal cancer, screening modalities, and randomized control trials. Directed searches were also performed of embedded references.

RESULTS

Despite screening guidelines from several national organizations, extensive barriers to widespread screening remain, especially for minority populations. These barriers are diverse, ranging from education and access problems to personal beliefs. Screening rates in MHS have been reported to be generally higher at 71% compared to national averages of 50-65%.

CONCLUSION

CRC screening can be highly effective at improving detection of both pre-malignant and early cancers. Improved patient education and directed efforts are needed to improve CRC screening both nationally and within the MHS.

Novel molecular screening approaches in colorectal cancer

Traditional methods for colorectal cancer (CRC) screening have reduced rates of malignancy and death; however, low compliance and morbidities associated with invasive techniques have encouraged efforts for establishing equally effective, less invasive novel screening approaches. We review the current state of novel screening approaches in CRC to include CT colonography, fecal DNA, DNA methylation, micro-RNA, and protein and molecular markers.

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.

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.

Colonic perforation during screening CT colonography using automated CO2 insufflation in an asymptomatic adult

CT colonography has become a potential alternative technique to optical colonoscopy for the detection of colorectal polyps and cancer. While considered safer than optical colonoscopy, CT colonography is not without risk. We report a case of colonic perforation during CT colonography using automated CO(2) insufflation and present procedural changes to help minimize the adverse effects of perforation when it occurs.