The Role of Behind Folds Visualizing Techniques and Technologies in Improving Adenoma Detection Rate

PURPOSE OF REVIEW

Colorectal cancer is one of the most common malignancies in the Western world and is thought to develop from premalignant polyps. Over the past decade, several behind folds visualizing techniques (BFTs) have become available to improve polyp detection. This systematic review and meta-analysis aims to compare BFTs with conventional colonoscopy (CC).

RECENT FINDINGS

In the past five years, 14 randomized controlled trials (RCTs) including 8384 patients comparing different BFTs with CC were published. The overall relative risks for adenoma detection rate, polyp detection rate, and adenoma miss rate comparing BFTs with CC were 1.04 (95% confidence interval [CI] 0.98-1.10; P = 0.15), 1.03 (95% CI 0.98-1.09; P = 0.28), and 0.70 (95% CI 0.46-1.05; P = 0.08), respectively. Other quality metrics for colonoscopy were not significantly different between BFT-assisted colonoscopy and CC either. This meta-analysis of RCTs published in the past five years does not show a significant benefit of BFTs on any of the important quality metrics of colonoscopy. The lack of additional effect of BFTs might be due to improved awareness of colonoscopy quality metrics and colonoscopy skills among endoscopists combined with improvements of conventional colonoscope technology.

New device to implement the adenoma detection rate

It is well-known that colonoscopy is considered the gold standard for colon cancer prevention. Although performed by experienced endoscopists, the matter remains of polyps missed during this examination. The reasons may include the size, shape and location of the lesions. Many colorectal cancer screening programs have been proposed to increase the adenoma detection rate. The substantial difference between these methods is whether the improvement in vision, particularly the detection of irregularities of the mucosa, is inside the endoscope electronic components (magnification, wide-angle vision, narrow band imaging, flexible spectral imaging colour enhancement, i-Scan) or outside the same, by the use of specific caps (EndoCuff, EndoVision, EndoRings). Endocuff is a plastic device mounted at the end of the scope with a constant vision field of the entire colon. The aim of this study is to explore the potential clinical and technical benefits of Endocuff.

Cap-Assisted Colonoscopy Increases Detection of Advanced Adenomas and Polyps

BACKGROUND

Cap-assisted colonoscopy (CAC) has been reported to increase the adenoma detection rate (ADR) in Asian population. However, CAC trials in non-Asian population have had conflicting results. Studies in North America have shown an improvement in ADRs with the use of CAC, but it mainly included white and African American patients. Given the lack of prospective studies of CAC in Hispanics, we conducted this randomized controlled trial.

MATERIALS AND METHODS

This is a randomized controlled trial comparing CAC with standard colonoscopy (SC) in patients undergoing screening or surveillance colonoscopy. Our primary outcome was the ADR. Secondary outcomes were polyp detection rate, mean polyp and ADR, advanced ADR (AADR) and detection rates based on polyp morphology and location.

RESULTS

A total of 440 patients were included in the study (88.5% Hispanic). Cecal and terminal ileum intubation rates were similar in both groups (CAC: 97% and 86% versus SC: 99% and 81%, respectively). CAC did not improve ADR in comparison with SC (0.65 versus 0.52; P = 0.079); however, CAC had a higher AADR in comparison with SC (9.9% versus 4.6%; P = 0.049). CAC detected significantly more pedunculated polyps as compared with flat and sessile polyps (P = 0.011). Complication rates were similar in the CAC and SC groups (0.9% versus 0%).

CONCLUSIONS

In a predominantly Hispanic population, no difference was seen in the mean ADR with the use of CAC. However, CAC, when compared with SC, resulted in an increased AADR and mean polyp detection rate.

What Influences the Quality of Prevention Colonoscopy?

Background

Colorectal cancer still has a high incidence and mortality. Although colonoscopy is considered as gold standard of colorectal cancer screening, there still exists an unsatisfactory level of adenomas missed in screening and surveillance colonoscopy. Furthermore, patients bear the burden of potentially unpleasant and painful examination and preparation procedures.

Method

A search of the literature using PubMed was carried out, supplemented by a review of the programs of the Digestive Disease Week (DDW) and the United European Gastroenterology Week (UEGW) 2011-2013.

Results

Several new approaches to colonoscopy were described: water, CO₂ and cap colonoscopy, and application of spasmolytics such as hyoscine butylbromide and glucagon. The use of these methods does not necessitate the purchase of new endoscopes. They are feasible and safe, facilitate achieving the aim of more comfort and less pain, and perhaps allow lower doses of sedatives to be used. However, a clear effect on procedure time is lacking. Furthermore, the published data do not consistently answer the question of whether these techniques have a positive impact on the most important goal, the better detection of carcinoma precursors.

Conclusion

More efforts to optimize bowel preparation have to be made to improve visualization of the mucosal surface. The most reliable criteria for the quality of screening and surveillance colonoscopy remain a minimum cecal intubation rate of >90%, a withdrawal time of at least 6 or better 9 min, and an adenoma detection rate of >20%. These results should be achieved with a complication rate lower than 1%, including polypectomy.

Efficacy of cap-assisted colonoscopy according to lesion location and endoscopist training level

AIM: To evaluate the efficacy of cap-assisted colonoscopy (CAC) for detection of colorectal polyps and adenomas according to the lesion location and endoscopist training level.

METHODS: Patients 20 years or older, who underwent their first screening colonoscopy in a single tertiary center from May 2011 to December 2012 were enrolled in this study. All patients underwent either CAC or standard colonoscopy (SC), and all of the procedures were performed by 11 endoscopists (8 trainees and 3 experts). All procedures were performed with high-definition colonoscopes and narrow band imaging. The eight trainees had experiences of performing 150 to 500 colonoscopies, and the three experts had experiences of performing more than 3000 colonoscopies. A 4-mm-long transparent cap was attached to the end of a colonoscope in the CAC group. We retrospectively evaluated the number of polyps and adenomas, polyp detection rate (PDR), and the number of adenomas and adenoma detection rate (ADR) according to the lesion location and endoscopist training level between CAC and SC. We also evaluated the number of polyps and adenomas according to their size between CAC and SC.

RESULTS: Overall, PDR and ADR using CAC were significantly higher than those using SC for both whole colon (48.5% vs 40.7%, P = 0.012; 35.7% vs 28.3%, P = 0.012) and right-side colon (35.3% vs 26.6%, P = 0.002; 27.0% vs 16.9%, P < 0.001). The number of polyps and adenomas per patient using CAC was significantly higher than that using SC for both the whole colon (1.07 ± 1.59 vs 0.82 ± 1.31, P = 0.008; 0.72 ± 1.32 vs 0.50 ± 1.01, P = 0.003) and right-side colon (0.66 ± 1.18 vs 0.41 ± 0.83, P < 0.001; 0.46 ± 0.97 vs 0.25 ± 0.67, P < 0.001). In the trainee group, the PDR and ADR using CAC were significantly higher than those using SC for both the whole colon (46.7% vs 39.7%, P = 0.040; 33.9% vs 26.0%, P =0.012) and right-side colon (34.2% vs 26.5%, P = 0.015; 25.3% vs 15.9%, P = 0.001). In the expert group, the PDR and ADR using CAC were significantly higher than those using SC only for the right-side colon (42.1% vs 27.0%, P =0.035; 36.8% vs 21.0%, P = 0.020).

CONCLUSION: CAC is more effective than SC for detection of colorectal polyps and adenomas, especially when performed by trainees and when the lesions are located in the right-side colon.

Novel use of cap-assisted enteroscopy for detection of colorectal tumor in a patient with incarcerated inguinal hernia

Multiple reports have documented unsuspected inguinal hernias which result in difficulties during the colonoscopic examinations of patients. In most cases, the colonoscopy can be delayed until a surgical consult has further evaluated the inguinal hernia. This case report documents a patient who required a colonoscopy but surgical intervention for the detected inguinal hernia was not appropriate due to his co-morbid medical conditions. With the use of the combination of an enteroscope fitted with a cap and fluoroscopy, the inguinal hernia was able to be negotiated and the diagnosis of a cecal carcinoma was able to be confirmed.

Cap-assisted colonoscopy

Cap-assisted colonoscopy is a simple, practical, and inexpensive technique that serves several useful purposes in enhancing the performance of colonoscopy. It helps improve polyp detection by its ability to visualize otherwise blind mucosal areas on the proximal aspects of folds and flexures, although its effect on adenoma detection is inconsistent. By helping navigate the colon more efficiently, it facilitates intubation of the cecum faster, with lesser patient discomfort. Cap-assisted colonoscopy can be tried as a salvage procedure in cases of failed cecal intubation with regular colonoscopy and can be of assistance during polypectomy, especially for polyps located on the proximal aspects of folds.

Endoscopic treatment of a symptomatic ileal lipoma with recurrent ileocolic intussusceptions by using cap-assisted colonoscopy

A 73-year-old woman presented with intermittent abdominal pain and weight loss of 15 kg for 2 years. Colonoscopy revealed an erythematous polypoid tumor with a long and wide stalk in the cecum, but with air inflation, it abruptly went away through the ileocecal valve (ICV). An abdominal computed tomography showed a well-demarcated pedunculated subepithelial mass of 2.6×2.7 cm size with fat attenuation in the terminal ileum. It was an intussusceptum of the ileal lipoma through the ICV. This ileal lipoma was causing her symptoms because repeated ileocolic intussusceptions resulted in intermittent intestinal obstructions. In order to avoid surgical sequelae of ileal resection, snare polypectomy using cap-assisted colonoscopy technique was performed within the ileum without complications. The histopathology report confirmed it as a subepithelial lipoma. After endoscopic resection of the ileal lipoma, the patient has been free of symptoms and was restored to the original weight.