Serrated Lesion Detection Based Quality Markers in Colonoscopy: Ready for Prime Time?

Background: The adenoma detection rate (ADR) is well established as a quality marker in colonoscopy. Studies have demonstrated the importance of detection of serrated lesions with respect to development of proximal colorectal neoplasia in particular, however quality assurance markers based on serrated lesions are not well defined. Patel VD, Thompson WK et al (2015) suggest novel indicators including the sessile serrated polyp detection rate (SSPDR) defined as any sessile serrated polyp in the colorectum, and the clinically significant serrated polyp detection rate (CSSPDR), defined as all SSP in the colorectum + hyperplastic polyps (HP) proximal to the sigmoid flexure.1 Aims: To examine the rate of serrated lesion detection using the above definitions, as well as ADR in a retrospective cohort of patients at a tertiary referral centre. Methods: A retrospective audit of 842 consecutive colonoscopy procedures performed over a six month period was performed. Patients under 50 y.o. and those with inflammatory bowel disease were excluded, leaving 521 procedures. Results: 139 colonoscopies detected at least one adenoma, giving an ADR of 26.7%. 89 colonoscopies detected at least one adenoma proximal to the splenic flexure, giving a proximal ADR of 17.1%. 83 colonoscopies detected at least one adenoma distal to the splenic flexure, giving an distal ADR of 15.9% 29 colonoscopies detected at least one sessile serrated polyp (SSPDR, 5.6%). 34 colonoscopies detected at least one clinically significant serrated polyp (CSSP), giving a CSSPDR of 6.5%. 16 colonoscopies detected at least one distal CSSP, giving a distal CSSPDR of 3.1%. 20 colonoscopies detected at least one proximal CSSP, giving a proximal CSSPDR of 3.8%. 152 colonoscopies detected at least one adenoma or a CSSP (29.2%). Caecal intubation rate was 90.6%. Quality of bowel preparation was deemed ‘good’ in 285 procedures (54.7%), ‘satisfactory’ in 169 procedures (32.4%), and ‘poor’ in 63 (12.1%). Conclusions: In this study, the ADR was 26.7%, the SSPDR was 5.6% and the CSSPDR was 6.5%. 29.2% of colonoscopies detected either an adenoma or a CSSP; the authors propose a novel quality marker based on this with the acronym ‘PASSCARD’ (clinically significant serrated polyp and adenoma detection rate). The American Society for Gastrointestinal Endoscopy suggests a target ADR > 25% for a mixed male/female population. The authors suggest a target CSSPDR of 5% or a ‘PASSCARD’ of 30% may be alternative or complementary targets in the future, however prospective validation studies are required to further define the role of these serrated lesion based quality markers in terms of reducing interval cancers