Automatic identification of areas with low-voltage fragmented electrograms for the detection of the critical isthmus of atypical atrial flutters.

INTRODUCTION: Critical isthmuses of atypical atrial flutters (AAFLs) are usually located at slow conduction areas that exhibit fractionated electrograms. We tested a novel software, intended for integration with a commercially available navigation system, that automatically detects fractionated electrograms, to identify the critical isthmus in patients with AAFL ablation. METHODS AND RESULTS: All available patients were analyzed; 27 patients with 33 AAFLs were included. The PentaRay NAV catheter (Biosense Webster) was used for mapping. The novel software was retrospectively applied; fractionated points with duration ≥80 ms and bipolar voltage between 0.05 and 0.5 mV were highlighted on the surface of maps. In 10 randomly chosen AAFLs, an expert electrophysiologist evaluated the positive predictive value of the algorithm to detect true fractionation: 74.4%. We tested the capacity of the software to identify areas of fractionation (defined as clusters of ≥3 adjacent points with fractionation) at the critical isthmus of the AAFLs (defined using conventional mapping criteria). An area of fractionation was identified at the critical isthmus in 30 cases (91%). Globally, 144 areas of fractionation (median number per AAFL 4 [3-6]) were identified. Duration of the fractionation or the surface of the areas was not different between areas at critical isthmuses and the rest. Setting the fractionation score filter of the software in nine provided best performance. CONCLUSIONS: The novel software detected areas of fractionation at the critical isthmus in most AAFLs, which may help identify the critical isthmus in clinical practice.

Multicenter, randomized, tandem evaluation of EndoRings colonoscopy--results of the CLEVER study.

BACKGROUND AND STUDY AIMS: Adenoma miss rate during colonoscopy has become a widely acknowledged proxy measure for post-colonoscopy colorectal cancer. Among other reasons, this can happen because of inadequate visualization of the proximal aspects of colonic folds and flexures. EndoRings (EndoAid Ltd., Caesarea, Israel) is a silicone-rubber device that is fitted onto the distal end of the colonoscope. Its flexible circular rings engage and mechanically stretch colonic folds during withdrawal. The primary aim of this study was to compare adenoma miss rates between standard colonoscopy and colonoscopy using EndoRings. METHODS: In this multicenter, randomized, tandem colonoscopy study, we performed same-day, back-to-back colonoscopies with EndoRings followed by standard colonoscopy, or vice versa. RESULTS: After exclusion of 10 patients for protocol violations, 116 patients (38.8% female; mean age 58.7) remained for analysis. The adenoma miss rate of EndoRings colonoscopy (7/67; 10.4%) was significantly lower (P<0.001) compared with standard colonoscopy (28/58; 48.3%). Similar results were found for polyp miss rates: EndoRings (9.1%) and standard colonoscopy (52.8%; P<0.001). Mean cecal intubation times (9.3 vs. 8.4 minutes; P=0.142) and withdrawal times (7.4 vs. 7.2 minutes; P=0.286), respectively, were not significantly different between EndoRings and standard colonoscopy. Mean total procedure time was longer with EndoRings than with standard colonoscopy (21.6 vs. 18.5 minutes, P=0.001) as more polyps were removed. CONCLUSIONS: This study demonstrates that colonoscopy with EndoRings has lower adenoma and polyp miss rates than standard colonoscopy, which may improve the efficacy particularly of screening and surveillance colonoscopies. ClinicalTrials.gov NCT01955122.

Comparison of standard forward-viewing mode versus ultrawide-viewing mode of a novel colonoscopy platform: a prospective, multicenter study in the detection of simulated polyps in an in vitro colon model (with video).

BACKGROUND: Although colonoscopy is the criterion standard for detecting colorectal adenomas and cancers, a significant percentage of adenomas are missed. OBJECTIVE: To compare forward-viewing with ultrawide-viewing colonoscopy in the detection of simulated colon polyps in an in vitro colon model. DESIGN: Prospective, multicenter. SETTING: Six endoscopy units (3 in the United States and 3 in Israel). PATIENTS: In vitro colon model with simulated colon polyps (n = 21 metallic beads). INTERVENTIONS: Detection of simulated colon polyps on colonoscope withdrawal. MAIN OUTCOME MEASUREMENTS: Incremental detection of simulated colon polyps and endoscopist evaluation of the usability, visibility, and maneuverability of ultrawide-viewing colonoscopy. RESULTS: On forward-viewing colonoscopy, the number of simulated polyps (mean ± standard deviation) detected per endoscopist was 11.1 ± 2.3 polyps, a 52.9% detection rate. Simulated polyp detection rates per colon segment were 3.0 ± 0.93 (60.0%) right colon, 2.4 ± 0.87 (48.0%) transverse colon, and 5.7 ± 1.5 (51.8%) left colon. On ultrawide-viewing colonoscopy, the simulated polyp detection rate per endoscopist significantly increased to 18.0 ± 1.98 polyps, an overall 85.7% polyp detection rate (P < .001). Simulated polyp detection rates were also significantly higher by using the ultrawide-viewing mode in each colon segment, 4.5 ± 0.65 polyps (90.0%) right colon, 4.0 ± 0.87 (80.0%) polyps transverse colon, and 9.6 ± 1.28 polyps (87.3%) left colon (all comparisons, P < .001). Importantly, the ultrawide-viewing mode detected significantly more "hidden" simulated polyps (81.9% vs 31.9%, P < .0001). LIMITATIONS: Nonrandomized design, use of a colon model, and "simulated" colon polyps. CONCLUSIONS: Ultrawide-view colonoscopy significantly improved simulated polyp detection in a colon model. Clinical studies in human subjects should be pursued to further evaluate this new endoscopic technology.