Blue-light imaging or narrow-band imaging for proximal colonic lesions: a prospective randomized tandem colonoscopy study

The Effect of the Second Forward View on the Detection Rate of Sessile Serrated Lesions in the Proximal Colon: A Single-Center Prospective Randomized Controlled Study

INTRODUCTION

The detection rate of proximal sessile serrated lesion (PSSLDR) is linked to the incidence and mortality of colorectal cancer. However, research on second forward view (SFV) examinations for PSSLDR remains limited. This first randomized controlled trial assessed the impact of the proximal SFV on the PSSLDR.

METHODS

Patients were randomized into 2 groups during proximal colonoscopy: standard colonoscopy (SC) and SFV. The SC group underwent a standard examination, whereas the SFV group underwent a second examination of the proximal colon (cecum to splenic flexure). The primary outcome was PSSLDR, with secondary outcomes, including the proximal polyp detection rate (PPDR), proximal adenoma detection rate (PADR), and lesion miss rate, compared between the 2 groups.

RESULTS

Among 246 patients (SC = 124; SFV = 122), SFV significantly improved the PSSLDR by 7.4% compared with SC (9.8% vs 2.4%, P = 0.017). SFV increased the PPDR by 20.2% (55.7% vs 35.5%, P = 0.002) and PADR by 12.7% (37.7% vs 25%, P = 0.039). Multivariate analysis revealed that sessile serrated lesions (odds ratio [OR] = 7.70, 95% confidence interval [CI] [1.58, 37.59]), inflammatory polyps (OR = 4.24, 95% CI [1.73, 10.39]), and lesion size (OR = 0.76, 95% CI [0.60, 0.96]) were associated with proximal missed lesions. The overall polyp miss rate was 52.9%, with miss rates of 61.0% for polyps <5 mm, 80% for sessile serrated lesions, and 42.2% for adenomas. Furthermore, 12.3% of patients experienced changes in surveillance intervals from SFV examination.

DISCUSSION

SFV examination of the proximal colon significantly improved the PSSLDR by 7.4%, PPDR by 20.2%, and PADR by 12.7%, while shortening the detection interval by 12.3%, making it a valuable and cost-effective addition to routine colonoscopy.

Diagnostic Accuracy of Referral Biopsy Compared to Optical Biopsy in Large Non-pedunculated Colorectal Polyps

BACKGROUND

Endoscopic mucosal resection (EMR) of large non-pedunculated colorectal polyps (LNPCPs) offers excellent efficacy and safety. Referral biopsies are commonly obtained prior to EMR despite their potential adverse effects. We aimed to assess the diagnostic accuracy of referral biopsy as compared with optical evaluations and the polyp's final pathology.

METHODS

We analyzed a cohort from two centers that included adult patients referred for EMR of LNPCPs between 2017 and 2022. The NICE classification system was used for optical classification. We compared procedural outcomes of lesions with or without a referral biopsy and diagnostic accuracy of referral biopsy and optical evaluation to the final histopathology of the resected polyp.

RESULTS

Of 605 EMR procedures, 398 (65.8%) had referral biopsies. Polyp size was larger in the biopsy group. No significant differences were observed in en-bloc resection rate, adequate lifting, procedural bleeding, or surveillance recurrence rates. Optical biopsies had higher diagnostic concordance with final histology (Cohen's Kappa 0.62 vs. 0.55) and enhanced sensitivity for sessile serrated polyps/hyperplastic polyps (SSP/HP) and cancer as compared to referral biopsies (0.75 vs. 0.72, p < 0.01, and 0.19 vs. 0.0, p < 0.01, respectively). Optical evaluation was more accurate in non-biopsied lesions.

CONCLUSION

Referral biopsies do not offer additional diagnostic accuracy and may reduce the accuracy of optical evaluation for LNPCPs.