Demonstrating that colonoscopy is high quality

Demonstrating that colonoscopy is high quality

Colonoscopy is the gold standard investigation for examining the lower GI tract [1]. It plays a fundamental role in investigation of symptomatic individuals and in screening for colorectal cancer (CRC) [2] [3]. Colonoscopy must be high quality in order to maximize its benefit [4]. Poor-quality colonoscopy is associated with increased interval cancer rates [4]. High-quality colonoscopy involves a complete procedure that provides comprehensive inspection of colonic mucosa [5].

There are a number of markers of colonoscopy quality, [2] [6] [7] with cecal intubation rate (CIR) historically being the most widely reported [8]. Cecal intubation was previously confirmed by written documentation of the cecal landmarks; however, photo-documentation of the cecum is now the accepted method of confirming colonoscopy completion. The European Society of Gastrointestinal Endoscopy (ESGE) guidelines recommend that such photo-documentation includes images of both the ileocecal valve and the cecum with views of the appendiceal orifice [9]. CIR is variable and many measures have been used to improve it [10] [11] [12]. The United Kingdom has engaged in a comprehensive quality improvement program with significant improvements [10] [13]. Other countries have demonstrated similar results [14].

Although CIR is an important marker of completion of a procedure, other markers of quality include adenoma detection rate (ADR), bowel preparation, rectal examination and rectal retroflexion, colonoscopy withdrawal time (CWT), polyp retrieval, and complication rates [15] [16] [17] [18] [19] [20] [21]. Furthermore, comfort scores, tattooing of suspected malignant lesions in the colon, and taking diagnostic biopsies for unexplained diarrhea are seen as quality markers in addition to the rate of post-colonoscopy colorectal cancer [22] [23] [24] [25]. Clinician performance in each of these areas is variable, but those who perform well tend to do so across all measures [22]. Among all measures, the most important marker of colonoscopy quality is adenoma detection rate [15] [16] [17]. ADR has clearly been shown to correlate with interval cancers [4]. Patients scoped by colonoscopists with high ADRs have lower interval cancer rates [4]. Furthermore, patients scoped by colonoscopists with higher ADRs have lower CRC mortality rates [16]. Polyp detection rate (PDR) can be used as a surrogate marker of ADR [26].

The paper, “Meticulous cecal image documentation at colonoscopy is associated with improved polyp detection,” published in this edition of Endoscopy International Open, explores the link between polyp detection rates and the quality of cecal photo-documentation. The paper reports a correlation between good-quality cecal photo-documentation and higher PDRs, including right-sided polyp detection (although some of these were hyperplastic polyps). Right-sided lesions are of particular interest and it may be that failure to detect them is one reason that screening programs are not adequately preventing right-sided colorectal cancer [27] [28].

The reason for the correlation between PDR and image quality may be that colonoscopists who take time to capture convincing cecal images are generally more careful in their withdrawal examination. Another explanation may be that these “meticulous” colonoscopists have better control over the endoscope, which leads to better mucosal visualization. Longer mean CWTs are associated with increased adenoma detection, and are more relevant than total procedure times, as the majority of mucosal visualisation occurs on withdrawal of the colonoscope [19] [29]. Although there was no statistically significant difference in procedure duration between “meticulous” and “non-meticulous” endoscopists in this study, the relationship between CWT, PDR, and image quality may be important.

This study highlights the importance of high-quality, complete colonoscopy and of demonstrating completion of the procedure. Clear images with or without labelling by the endoscopist were surrogate markers of meticulous practice in this study, but further detail on what constituted a clear image, how well the cecum was seen or who scored the images was not available. Good cecal photo-documentation requires identification of at least the ileo-cecal valve, appendiceal orifice and tri-radiate fold in addition to image clarity as per ESGE guidance [9]. The ileo-cecal valve is best documented when the valve opening is seen. The appendiceal orifice should be imaged with other landmarks because it can be mistaken for a diverticulum when photographed in isolation. Although not a mandatory part of colonoscopy, terminal ileal (TI) photo-documentation is an alternative means of demonstrating complete colonoscopy when classical cecal landmarks are not clearly seen. An observational study found that TI photographs are significantly more convincing than cecal photographs in documenting colonoscopy completeness [30]. Instilling water into TI may make the villi more prominent and thus the images more convincing; however, TI intubation can at times be technically challenging and add significant time to the procedure. TI biopsy is an unnecessary means of confirming completion and carries a small degree of risk. A further alternative to the above is video-documentation of the cecal landmarks, which may be helpful in cases where only one landmark is captured on each image, or where anatomy is distorted.

Colonoscopists should strive for high-quality procedures. They should be meticulous in their visualisation of colonic mucosa and produce clear images to document complete procedures.

• References

• 1 Rex DK, Rahmani EY, Haseman JH et al. Relative sensitivity of colonoscopy and barium enema for detection of colorectal cancer in clinical practice. Gastroenterology 1997; 112: 17-23
• 2 Rees CJ, Rajasekhar PT, Rutter MD et al. Quality in colonoscopy: European perspectives and practice. Expert Rev Gastroenterol Hepatol 2014; 8: 29-47
• 3 Kaminski MF, Hassan C, Bisschops R et al. Advanced imaging for detection and differentiation of colorectal neoplasia: European Society of Gastrointestinal Endoscopy (ESGE) Guideline. Endoscopy 2014; 46: 435-49
• 4 Kaminski MF, Regula J, Kraszewska E et al. Quality indicators for colonoscopy and the risk of interval cancer. N Engl J Med 2010; 362: 1795-1803
• 5 Rembacken B, Hassan C, Riemann JF et al. Quality in screening colonoscopy: position statement of the European Society of Gastrointestinal Endoscopy (ESGE). Endoscopy 2012; 44: 957-968
• 6 Rutter MD, Rees CJ. Quality in gastrointestinal endoscopy. Endoscopy 2014; 46: 526-528
• 7 Lee TJ, Rutter MD, Blanks RG et al. Colonoscopy quality measures: experience from the NHS Bowel Cancer Screening Programme. Gut 2012; 61: 1050-1057
• 8 Rex DK, Schoenfeld PS, Cohen J et al. Quality indicators for colonoscopy. Am J Gastroenterol 2006; 101: 873-885
• 9 Rey JF, Lambert R. ESGE Quality Assurance Committee. ESGE recommendations for quality control in gastrointestinal endoscopy: guidelines for image documentation in upper and lower GI endoscopy. Endoscopy 2001; 33: 901-903
• 10 Gavin D, Valori RM, Anderson JT et al. The National Colonoscopy Audit: a nationwide assessment of the quality and safety of colonoscopy in the UK. Gut 2013; 62: 242-249
• 11 Aslinia F, Uradomo L, Steele A et al. Quality assessment of colonoscopic cecal intubation: an analysis of 6 years of continuous practice at a university hospital. Am J Gastroenterol 2006; 101: 721-731
• 12 Belderbos TD, Grobbee EJ, van Oijen MG et al. Comparison of cecal intubation and adenoma detection between hospitals can provide incentives to improve quality of colonoscopy. Endoscopy 2015; (epub ahead of print, accessed at: https://www.thieme-connect.com/DOI/DOI?10.1055/s-0034-1391968 on 13/07/2015)
• 13 Bowles CJA, Leicester R, Romaya C et al. A prospective study of colonoscopy practice in the UK today: are we adequately prepared for national colorectal cancer screening tomorrow?. Gut 2004; 53: 277-283
• 14 de Jonge V, Sint Nicolaas J, Cahen DL et al. Quality evaluation of colonoscopy reporting and colonoscopy performance in daily clinical practice. Gastrointest Endosc 2012; 75: 98-106
• 15 Millan MS, Gross P, Manilich E et al. Adenoma detection rate: the real indicator of quality in colonoscopy. Diseases of the Colon and Rectum 2008; 51: 1217-1220
• 16 Corley DA, Jensen CD, Marks AR et al. Adenoma detection rate and risk of colorectal cancer and death. N Engl J Med 2014; 370: 1298-1306
• 17 Rex DK. Maximizing detection of adenomas and cancers during colonoscopy. Am J Gastroenterol 2006; 101: 2866-2877
• 18 Grobe JL, Kozarek RA, Sanowski EA. Colonoscopic retroflexion in the evaluation of rectal disease. Am J Gastroenterol 1982; 77: 856-858
• 19 Lee TJ, Blanks RG, Rees CJ et al. Longer mean colonoscopy withdrawal time is associated with increased adenoma detection: evidence from the Bowel Cancer Screening Programme in England. Endoscopy 2013; 45: 20-26
• 20 Valori R, Barton R. BSG Quality and Safety Indicators for Endoscopy. Joint Advisory Group on GI. Endoscopy 2007; (Last accessed online at http://www.thejag.org.uk/downloads%5CUnit%20Resources%5CBSG%20Quality%20and%20Safety%20Indicators.pdf on 13/07/2015)
• 21 Rex DK, Bond JH, Winawer S et al. Quality in the technical performance of colonoscopy and the continuous quality improvement process for colonoscopy: recommendations of the U.S Multi-Society Task Force on Colorectal Cancer. Am J Gastroenterology 2002; 97: 1296-1308
• 22 Ekkelenkamp VE, Dowler K, Valori RM et al. Patient comfort and quality in colonoscopy. World J Gastroenterol 2013; 19: 2355-2361
• 23 Chilton A, Rutter M. BCSP Quality Assurance Endoscopy Group. Quality Assurance Guidelines for Colonoscopy. NHS BCSP Publication. 02/2011 06. Accessed online at http://www.cancerscreening.nhs.uk/bowel/publications/nhsbcsp06.pdf
• 24 Thomas PD, Forbes A, Green J et al. Guidelines for the investigation of chronic diarrhoea, 2nd edition. Gut 2003; 52: v1-v15
• 25 Morris EJA, Rutter MD, Finan PJ et al. Post-colonoscopy colorectal cancer (PCCRC) rates vary considerably depending on the method used to calculate them: a retrospective observational population-based study of PCCRC in the English National Health Service. Gut 2015; 64: 1248-1256
• 26 Francis DL, Rodriguez-Correa DT, Buchner A et al. Application of a conversion factor to estimate the adenoma detection rate from the polyp detection rate. Gastrointest Endosc 2011; 73: 493-497
• 27 Steele RJC, McClements P, Watling C et al. Interval cancers in a FOBT-based colorectal cancer population screening programme: implications for stage, gender and tumour site. Gut 2012; 61: 576-81
• 28 Gill MD, Bramble MG, Rees CJ. Comparison of screen-detected and interval colorectal cancers in the Bowel Cancer Screening Programme. Br J Cancer 107: 417-421
• 29 Butterly L, Robinson CM, Anderson JC et al. Serrated and adenomatous polyp detection increases with longer withdrawal time: results from the New Hampshire Colonoscopy Registry. Am J Gastroenterol 2014; 109: 417-426
• 30 Powell N, Knight H, Dunn J et al. Images of the terminal ileum are more convincing than cecal images for verifying the extent of colonoscopy. Endoscopy 2011; 43: 196-201