Adenoma and polyp detection rates during insertion versus withdrawal phase of colonoscopy: a systematic review and meta-analysis of randomized controlled trials.

BACKGROUND AND AIMS: Colonoscopy is the preferred modality for colorectal cancer screening because it has both diagnostic and therapeutic capabilities. Current consensus states that colonoscopy should be performed with initial rapid passage of the instrument to the cecum, followed by thorough evaluation for and removal of all polyps during a deliberate slow withdrawal. Reports have suggested that polyps that are seen but not removed during insertion are sometimes quite difficult to find during withdrawal. METHODS: We performed a comprehensive literature search of several major databases (from inception to March 2020) to identify randomized controlled trials comparing inspection and polypectomy during the insertion phase as opposed to the traditional practice of inspection and polypectomy performed entirely during the withdrawal phase. We examined differences in terms of adenoma detection rate (ADR), polyps detected per patient (PDPP), cecal intubation time (CIT), withdrawal time, and total procedure time. RESULTS: Seven randomized controlled trials, including 3834 patients, were included in our final analysis. The insertion/withdrawal cohort had 1951 patients and the withdrawal-only cohort 1883 patients. Pooled odds of adenoma detection in the insertion/withdrawal cohort was .99 (P = .8). ADR was 47.2% in the insertion/withdrawal cohort and 48.6% in the withdrawal-only cohort. Although total procedure and withdrawal times were shorter in the insertion/withdrawal cohort, PDPP in both cohorts were not statistically significant (1.4 vs 1.5, P = .7). CONCLUSIONS: Additional inspection and polypectomy during the insertion and withdrawal phases of colonoscopy offer no additional benefit in terms of ADR or PDPP.

Comparison of EUS-guided conventional smear and liquid-based cytology in pancreatic lesions: A systematic review and meta-analysis.

Background and study aims Endoscopic ultrasound (EUS)-guided fine-needle aspiration (EUS-FNA) has limitations of inadequate sampling and false-negative results for malignancy. It has been performed using conventional smear (CS) cytology with rapid on-site evaluation (ROSE) with reasonable diagnostic accuracy. An alternative to ROSE is liquid-based cytology (LBC). Commonly used LBC techniques include precipitation-based (SurePath™) and filtration-based (ThinPrep ® , CellPrep ® ). Data regarding the diagnostic efficacy of LBC compared with CS are limited. Methods Multiple databases were searched through March 2020 to identify studies reporting diagnostic yield of EUS-guided CS and LBC in pancreatic lesions. Pooled diagnostic odds and rates of performance for the cytologic diagnoses of benign, suspicious, and malignant lesions were calculated. Diagnostic efficacy was evaluated by pooled rates of accuracy, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV). Results Nine studies with a total of 1308 patients were included in our final analysis. Pooled diagnostic odds of CS cytology were 1.69 (CI 1.02-2.79) and 0.39 (CI 0.19-0.8) for malignant lesions when compared to filtration-based and precipitation-based LBC techniques, respectively. For CS, precipitation-based and filtration-based LBC, pooled diagnostic accuracy was 79.7 %, 85.2 %, 77.3 %, sensitivity was 79.2 %, 83.6 %, 68.3 %, and specificity was 99.4 %, 99.5 %, 99.5 %, respectively. Conclusions The precipitation-based LBC technique (SurePath™) had superior diagnostic odds for malignant pancreatic lesions compared with CS cytology in the absence of ROSE. It showed superior accuracy and sensitivity, but comparable specificity and PPV. Diagnostic odds of CS cytology in the absence of ROSE were superior to the filtration-based LBC technique (ThinPrep ® , Cellprep ® ) for diagnosing malignant pancreatic lesions.