Narrow band imaging vs. high definition colonoscopy for detection of colorectal adenomas in patients with positive faecal occult blood test: A randomised trial

BackgroundThe impact of narrow band imaging in improving the adenoma detection rate in a screening scenario is still unclear.AimTo evaluate whether narrow band imaging compared with high definition white light colonoscopy can enhance the adenoma detection rate during screening colonoscopy.MethodsConsecutive patients presenting for screening colonoscopy were included into this study and were randomly assigned to the narrow band imaging group (Group 1) or standard colonoscopy group (Group 2). Primary end point was the adenoma detection rate and secondary aim was the detection rate of advanced adenomas.ResultsOverall, 117 patients were allocated to Group 1 and 120 to Group 2. Both the adenoma detection rate and the detection rate of advanced adenomas were not significantly different between the two groups (respectively, 52.1% vs. 55%, RR = 0.95, 95% CI 0.75–1.20; 32.5% vs. 44.2%, RR = 0.74, 95% CI 0.53–1.02). No significant difference between the proportions of polypoid and flat adenomas was found. Male gender, no prior history of screening, and endoscopist's adenoma detection rate were independent predictive factors of higher advanced adenoma detection rate.ConclusionsIn a screening scenario, narrow band imaging did not improve the adenoma nor advanced adenoma detection rates compared to high definition white light colonoscopy.     

Toward an easier indigocarmine chromoendoscopy

Indigocarmine chromoendoscopy has been proven to improve the detection of colonic lesions during screening colonoscopy, and is associated with increased adenoma detection rates. Furthermore, it is commonly used to help in the delineation and characterization of colorectal neoplasms. However, it usually requires the use of a spraying catheter that decreases the suction capacity of the endoscope, and is time- consuming. Herein, we report on the feasibility of indigo carmine chromoendoscopy during colonoscopy without using a spraying catheter, with the dye being administered through the air/water channel of the endoscope. Since the suction channel remains free, the air can be exsufflated and the staining then applies uniformly onto the colonic walls with the excess indigocarmine dye being immediately eliminated. In our experience with various types of colonoscopes and cap-assisted colonoscopy, this procedure makes indigocarmine chromoendoscopy much easier and quicker to perform, and might save the use of a spray catheter.     

Technological advances for improving adenoma detection rates: The changing face of colonoscopy

Worldwide, colorectal cancer is the third commonest cancer. Over 90% follow an adenoma-to-cancer sequence over many years. Colonoscopy is the gold standard method for cancer screening and early adenoma detection. However, considerable variation exists between endoscopists’ detection rates. This review considers the effects of different endoscopic techniques on adenoma detection. Two areas of technological interest were considered: (1) optical technologies and (2) mechanical technologies. Optical solutions, including FICE, NBI, i-SCAN and high definition colonoscopy showed mixed results. In contrast, mechanical advances, such as cap-assisted colonoscopy, FUSE, EndoCuff and G-EYE™, showed promise, with reported detections rates of up to 69%. However, before definitive recommendations can be made for their incorporation into daily practice, further studies and comparison trials are required.     

When should we perform colonoscopy to increase the adenoma detection rate?

The rate of adenoma detection is the most reliable quality indicator of colonoscopy. Studies have reported that colonoscopy performed in morning has a higher adenoma detection rate (ADR) than that performed in the afternoon. These studies have explained that several physician-related factors such as undergoing an emergency procedure the night before colonoscopy, accumulated workload, and increased fatigue level in the afternoon might have led to such finding. However, several opposing articles have indicated that the time of day and ADR is not quite related. Complex confounding factors can impact study results. Colonoscopy withdrawal time and bowel preparation quality are key factors. However, queue list numbers, participation of academic fellows, nurses' assistance, and the number of colonoscopies allocated per hour are also notable factors. Recently, an attempt has been made to homogenize the ADR in the morning and afternoon through artificial intelligence-assisted colonoscopy. This review article introduces the history of this long-debated topic, discusses points to consider in real-world practice, and suggests new ideas for planning future research. By understanding this issue, the rate of adenoma detection during colonoscopy is expected to be improved further.     

Endoscopy Nurse Participation May Increase the Polyp Detection Rate by Second-Year Fellows during Screening Colonoscopies

Background/Aims

The aim of this study was to assess the effects of endoscopy nurse participation on polyp detection rate (PDR) and adenoma detection rate (ADR) of second-year fellows during screening colonoscopies.

Methods

This was a single-center, prospective, randomized study comparing a fellow alone and a fellow plus an endoscopy nurse as an additional observer during afternoon outpatient screening colonoscopies. The primary end points were PDR and ADR.

Results

One hundred ninety-one colonoscopies performed by a fellow alone and 192 colonoscopies performed by a fellow plus an endoscopy nurse were analyzed. The PDR was significantly higher when the nurse was involved (53.1% vs. 41.3%, p<0.05); however, there was no significant difference in the ADR between the two groups (38.5% vs. 29.8%, p=0.073). There was no difference in the percentage of patients with ≥2 polyps, advanced adenomas, polyp size, polyp location, and polyp shapes between the two groups. There was no difference in the PDR according to the level of experience of the endoscopy nurse.

Conclusions

Endoscopy nurse participation as an additional observer during screening colonoscopy performed by second-year fellow increases the PDR; however, the level of experience of the nurse was not an important factor.     

Técnicas colonoscópicas para la detección de pólipos: un estudio egipcio

Introduction and aimsThe polyp detection rate (PDR) is defined as the percentage of colonoscopies in which one or more polyps are detected, and has been shown to be highly correlated with the adenoma detection rate. The aim of the present study was to evaluate the PDR at the Endoscopy Unit of the Kasr Al-Ainy Hospital, Cairo University, Egypt, through the i-SCAN, Endocuff, and underwater colonoscopy techniques.Materials and methodsThe study was conducted on 100 Egyptian subjects over 50 years of age. Their polyp detection rate was measured through 4 different colonoscopic techniques. An equal number of patients were divided into 4 groups: i-SCAN, Endocuff, underwater colonoscopy, and controls. The control group was examined using standard white light colonoscopy. The colonoscopy evaluation included the type of agent utilized for bowel preparation, preparation grade, and colonoscopy withdrawal time.ResultsThe general PDR was 48%. The i-SCAN technique had the highest rate (56%), followed by the underwater (52%) and the Endocuff (48%) techniques.ConclusionThe i-SCAN and underwater colonoscopy techniques produced higher PDR than the Endocuff-assisted and standard techniques, but with no statistical significance.     

Inter-centre variability of the adenoma detection rate: A prospective,multicentre study

Background

Suboptimal colonoscopy quality is related to a higher risk of interval cancer. Aim of our study was to explore the variability in detection rate of neoplasia among different endoscopic centres in an unselected population.

Methods

Consecutive patients referred for colonoscopy in 28 Italian centres were included. Detection rate for polyp, neoplasia and advanced neoplasia was assessed at both the individual and centre level. Inter-centre variability in detection rate of colorectal lesions was explored after adjusting for patient-related factors at multivariate analysis.

Results

3150 patients were included. Median detection rates for polyp, neoplasia and advanced neoplasia were 35%, 26% and 13%. At multivariate analysis, patient-related factors associated with neoplasia detection were age, sex, alcohol and smoking history. After adjusting for these variables, a statistically significant difference in the observed/expected ratio among different centres was observed (Chi-squared test: p < 0.01). Among non-patient-related factors, documentation of withdrawal time was associated with neoplasia detection. However, a statistically significant inter-centre variability also remained after adjusting for this variable.

Conclusions

A wide variability was present in the detection rate of neoplasia and advanced neoplasia at the level of endoscopic centres in an unselected population. The adoption of a centre-related neoplasia detection rate could be suggested as a performance indicator.     

Prevalence of Proximal Neoplasms Among Asymptomatic Patients According to Distal Colorectal Findings

Colorectal cancer has been described in association with hyperplastic polyposis. Only half of proximal colon cancers are associated with distal adenomas. To compare the prevalence of proximal and advanced neoplasia between patients with distal hyperplastic polyps only; with distal adenomas with or without hyperplastic polyps; and with no distal polyps, we retrospectively analyzed data of 1,064 adults who underwent colonoscopy. Of these patients, 3% had neoplasia. Proximal neoplasia occurred in 0.8% of 945 patients with no distal polyps, compared to none of 19 with distal hyperplastic polyps (P > 0.05) and 6% with distal adenomas (P > 0.05). Proximal advanced neoplasia occurred in 0.6% patients with no distal polyps, compared with none with distal hyperplastic polyps (P > 0.05) and 6% with distal adenomas (P > 0.05). In conclusion, patients with distal hyperplastic polyps, unlike those with distal adenomas, do not exhibit an increased risk for proximal neoplasia or proximal advanced neoplasia compared to those with no distal polyps.     

Surveillance of colonic polyps: Are we getting it right?

Colorectal cancer(CRC) is the third most commonly diagnosed cancer worldwide. The identification of colonic polyps can reduce CRC mortality through earlier diagnosis of cancers and the removal of polyps: the precursor lesion of CRC. Following the finding and removal of colonic polyps at an initial colonoscopy, some patients are at an increased risk of developing CRC in the future. This is the rationale for postpolypectomy surveillance colonoscopy. However, not all individuals found to have colonic adenomas have a risk of CRC higher than that of the general population. This review examines the literature on post-polypectomy surveillance including current international clinical guidelines. The potential benefits of surveillance procedures must be weighed against the burden of colonoscopy: resource use, the potential for patient discomfort, and the risk of complications. Therefore surveillance colonoscopy is best utilised in a selected group of individuals at a high risk of developing cancer. Further study is needed into the specific factors conferring higher risk as well as the efficacy of surveillance in mitigating this risk. Such evidence will better inform clinicians and patients of the relative benefits of colonoscopic surveillance for the individual. In addition, the decision to continue with surveillance must be informed by the changing profile of risks and benefits of further procedures with the patient’s advancing age.     

Impacto del proceso de enseñanza endoscópica en la detección de adenomas colónicos

BackgroundThere has been little reported experience in the Latin American hospital setting in relation to the impact of the endoscopic training process on colonoscopy quality.AimsTo determine the effect that training in the technique of colonoscopy has on adenoma detection in an Argentinian teaching hospital.Material and methodWithin the time frame of July 2012 and July 2013, 3 physicians received training in colonoscopy from 4 experienced endoscopists. The colonoscopies performed by the supervised trainees were compared with those carried out by the experienced endoscopists.ResultsA total of 318 colonoscopies performed by any one of the 3 supervised trainees and 367 carried out by any one of the experienced endoscopists were included. The univariate analysis showed a non-significant difference in the detection rate of adenomas (30.4 vs. 24.7%, P = .09). In the multivariate analysis, the detection rate of adenomas was significantly higher in the colonoscopies performed by one of the 3 trainees (odds ratio = 1.72 [1.19-2.48]).ConclusionsThe supervised involvement of endoscopic trainees has a positive effect on adenoma detection.     

Colorectal cancer screening: Results of a 5-year program in asymptomatic subjects at increased risk

BACKGROUND AND AIMS: The province of Ferrara has one of the highest incidences of colorectal cancer (CRC) in Italy. In January 2000, we set up a colonoscopy screening program focussing on first-degree relatives of CRC patients. We now report the results 5 years after the beginning of the project. SCREENEES AND METHODS: In October 1999, we started a campaign stressing the usefulness of colonoscopy for the first-degree relatives of CRC patients. Subjects included in the screening program were aged between 45 and 75 years with at least one first-degree relative affected by CRC. They were invited to an interview where a physician suggested colonoscopy as a screening option. RESULTS: In 5 years, 776 subjects were interviewed and 733 (94.4%) agreed to an endoscopic examination (M/F:375/401; mean age 55 years): 562 colonoscopies were performed. Adenomas and cancers were found in 122 (21.7%) and 12 (2.1%) subjects, respectively. Histological examination in 181 persons with lesions (32.8%) showed (most serious lesion quoted) 47 hyperplastic polyps (26% of all lesions), 2 serrated adenomas (1.1%), 68 tubular adenomas (48%), 24 tubulovillous adenomas (13.3%), 9 adenomas with high grade dysplasia (5%) and 12 adenocarcinomas (6.6%). The majority of the cancers were at an early stage (8 Dukes A and 3 Dukes B). Sedation was used in only 42 colonoscopies (7.5%). CONCLUSIONS: A colonoscopy-based screening in this selected high-risk population is feasible. Even without sedation subjects readily agreed to the endoscopic procedure. We identified a significant number of advanced neoplasms and cancers at an early stage suggesting that this could be a useful tool in early identification of CRC.     

Screening for colorectal cancer: implications for UK and European initiatives

Abstract Colorectal cancer (CRC) is the third most common cancer after lung and prostate cancers, and is the second most common cancer in women in the United Kingdom (UK) after breast cancer. The disease is well suited for prevention with screening programs. CRC is invariably fatal when diagnosed at an advanced stage but curable when diagnosed early, since it passes through a detectable asymptomatic stage. Screening tests with varying degrees of sensitivity and specificity are available. Prior to implementation of a nationwide national programme in the UK, trials are underway to identify the most sensitive and specific screening modality, and to address patient acceptability and resource implications. Screening for CRC using faecal occult blood (FOB) tests may be feasible. There is evidence to show that this modality saves lives at a cost similar to the breast screening programme currently underway in the UK. One-off flexible sigmoidoscopy is an alternative to FOB screening, and pilot data suggest that the technique is logistically feasible in the UK; a multicentre randomised trial is currently underway. Total colonoscopy is the gold standard test, but at present no large randomised controlled trials support this strategy. Colonoscopy is expensive and labour-intensive, and training issues need to be addressed. At the present time, tailored screening (in which intensity is adjusted for individual risk) appears reasonable. FOB and flexible sigmoidoscopy are cost effective but vary in sensitivity and specificity. Public education programmes are essential for any screening strategy to be effective.     

El desafío de cuantificar la calidad de la colonoscopia de tamizaje: el desarrollo y las propiedades psicométricas de la Escala de Calidad en Colonoscopia

Introduction and aimsColonoscopy quality is measured by the degree in which the examination increases the likelihood of obtaining adequate results on health. Our aim was to develop an instrument for evaluating the quality of screening colonoscopies, taking into account the performance of endoscopists and endoscopy units.Materials and methodsMixed methodology was employed. The first stage (qualitative) consisted of a Medline search, from which a group of experts developed the quality score items. The second stage (quantitative) utilized a modified Delphi technique to reach consensus (3 rounds). We evaluated the psychometric properties of the instrument (reliability and construct validity) in elective screening colonoscopies (in patients ≥ 50 years of age), performed within the January-April 2017 time frame.ResultsA final instrument with 8 items was produced: 1) the Boston Bowel Preparation Scale score; 2) cecal intubation rate; 3) colonoscopy withdrawal time; 4) image documentation; 5) adenoma detection rate; 6) endoscopic surveillance planning; 7) perforation rate, and 8) continuous improvement programs. The instrument was evaluated in 323 colonoscopies performed by 31 endoscopists and found to be one-dimensional and reliable (Cronbach's alpha 0.76). Performance was compared between endoscopists (center 1) and an expert endoscopist from another center (center 2): Boston Bowel Preparation Scale score 8.3 vs. 7.36 (P < .001), cecal intubation rate 93.5 vs. 96%, colonoscopy withdrawal time 14.8 vs. 8.4 min (P < .001), and adenoma detection rate 34 vs. 52.2% (P < .001), respectively.ConclusionThe Colonoscopy Quality Score is a reliable and valid instrument for evaluating screening colonoscopy quality. Its results could be adapted to the usual endoscopic report to adjust monitorization frequency post-colonoscopy.     

Adenoma Detection Rate: The Real Indicator of Quality in Colonoscopy

Purpose  Completion rate is the most commonly used index of quality in colonoscopy, and yet a complete examination is not necessarily a good examination. The ability to detect and treat adenomas is an important component of endoscopic skill, because many colonoscopies are performed for this express purpose. Adenoma detection rate is rarely reported, although it seems to depend on the time taken for withdrawal. The literature suggests that adenomas should be detected in approximately 25 percent of men and 15 percent of women older than age 50 years. We have reviewed the adenoma detection rates of six colorectal surgeons to provide insight into the range of adenoma detection rates and the factors that influence them. Methods  A prospective departmental colonoscopy database was queried. Colonoscopy completion rates, adenoma detection rates, and times of insertion and withdrawal were noted and stratified by the six staff colonoscopists. Adenoma detection rates were tabulated for the four common indications for colonoscopy. Results  Each staff endoscopist performed >250 examinations per year and had performed >1,000 total examinations. Although completion rates are fairly uniform (mean, 96.5 (range, 94.8–97.9) percent), there is a wide range of ADR, especially when adenomas are common (polyp or cancer surveillance; range, 14.2–27.4 percent). With the exclusion of one outlier staff, regression of withdrawal time against adenoma detection rate produced an r² of 0.975 (P = 0.0016). Conclusions  Adenoma detection rate is independent of completion rate as a colonoscopy quality indicator. There is a wide range of adenoma detection rates among experienced colorectal surgeons. Colonoscopists need to be aware of their adenoma detection rate. Read at the meeting of The American Society of Colon and Rectal Surgeons, Seattle, Washington, June 3 to 7, 2006. Reprints are not available.     

黑色先端帽联合窄带光成像在结肠镜检查中的作用

目的评估黑色先端帽辅助结肠镜联合窄带光成像（narrow band imaging,NBI）技术对腺瘤/息肉检出效能的影响。方法连续纳入2016年10月—2018年10月行结肠镜检查的患者,采用随机数字表法分为黑色先端帽组和对照组,黑色端帽组采用黑色先端帽辅助结肠镜联合NBI技术,对照组采用标准白光结肠镜,比较两组的息肉检出率、腺瘤检出率等指标,并进行亚组分析。结果共1 000例患者纳入本研究（每组500例）,黑色先端帽组和对照组近端结肠腺瘤检出率分别为24.2%(121/500)和17.2%(86/500),近端结肠息肉检出率分别为28.8%(144/500)和21.4%(107/500),平均腺瘤检出数分别0.41±0.94和0.26±0.68,平均息肉检出数为0.63±1.16和0.40±0.85,差异均有统计学意义（P均<0.05）,但该联合技术对于远端结直肠病变的检出率相较对照组无明显优势。结论黑色先端帽辅助结肠镜联合NBI能显著提高近端结肠腺瘤和息肉等微小病变的检出效能。     

Pólipos serrados del colon y el recto: una revisión concisa

“Serrated polyps” is the term used for epithelial lesions of the colon and rectum that have a “sawtooth” pattern on the polyp's surface and crypt epithelium. The so-called serrated pathway describes the progression of sessile serrated adenomas and traditional serrated adenomas to colorectal cancer. Said pathway is well recognized as an alternative mechanism of carcinogenesis and accounts for 15-30% of the cases of colorectal cancer. It also explains a large number of the cases of interval colorectal cancer. Thus, due to their usually aggressive and uncertain behavior, serrated polyps are of the utmost importance in colorectal cancer screening. Our aim was to review the history, current nomenclature, pathophysiology, morphology, treatment, and surveillance of serrated polyps.