G-EYE advanced colonoscopy for improved polyp detection rates – a randomized tandem pilot study with different endoscopists

Abstract

Background and aims The most commonly missed polyps in colonoscopy are those located behind haustral folds. The G-EYE system is a standard colonoscope consisting of re-processable balloon at its distal tip. The G-EYE balloon improves the detection of polyps by straightening the haustral folds. In our back-to-back tandem study, we aimed to determine whether and to what extent the G-EYE system could reduce adenoma miss rates in screening colonoscopy.

Methods Patients referred to colonoscopy were randomized into 2 groups. Group A underwent a standard colonoscopy (SC) followed by balloon colonoscopy (BC), and Group B underwent BC followed by SC. In this randomized tandem study, the investigator’s level of training and the endoscopists themselves were changed after each withdrawal. Each endoscopist was blinded to the results of the first withdrawal.

Results Fifty-eight patients were enrolled and randomized into 2 groups with similar baseline characteristics. Nine patients were excluded from the study. Twenty-five patients underwent SC followed by BC while 24 underwent BC followed by SC. The adenoma miss rate for SC was 41 %, with an additional detection rate of 69 % for BC (ratio 1.69). The overall miss rate for polyps was 60 % for SC, with an additional detection rate of 150 % for BC (ratio 2.5). Experienced investigators who used BC were able to identify an additional 7 polyps while inexperienced investigators.

Conclusions Although our results could not clearly confirm that BC improves adenoma detection, the investigator’s experience appears to be a major determinant of the adenoma detection rate.

Zusammenfassung

Hintergrund und Ziele Die meisten übersehenen Polypen im Darm liegen verborgen hinter Kolonfalten. Das G-EYE Ballonkoloskop ist ein Standardkoloskop an dessen Spitze ein aufblasbarer Ballon angebracht ist, der die Falten des Kolons glättet und somit die Detektion von Polypen im Kolon verbessern kann. In unserer back-to-back Tandemstudie untersuchten wir daher die Wirksamkeit des G-EYE Systems in Hinblick auf eine Verbesserung der Detektionsraten von Polypen und Adenomen während einer diagnostischen Koloskopie mit unterschiedlichen Untersuchern.

Methoden Die Patienten für eine diagnostische Koloskopie wurden in zwei Gruppen randomisiert. In Gruppe A erfolgte eine Standardkoloskopie (SC) gefolgt von einer Ballonkoloskopie (BC) und Gruppe B erhielt der Patient erst die BC mit anschließender SC. In dieser randomisierten Tandemstudie wurden nach jedem Rückzug die Untersucher gewechselt. Zudem hatten die Untersucher unterschiedliche Erfahrungslevel und waren für die Ergebnisse des Voruntersuchers verblindet.

Ergebnisse 58 Patienten wurden in zwei Gruppen randomisiert. Neun Patienten wurden aus der Studie ausgeschlossen. 25 Patienten begannen mit der SC gefolgt von der BC, während 24 in umgekehrter Reihenfolge untersucht wurden. Die Missrate für Adenome für SC betrug 41 %, mit einer zusätzlichen Detektionsrate von 69 % für die BC (ratio 1,69). Die gesamte Missrate für Polypen betrug 60 % mit der SC und einer zusätzlichen Detektionsrate von 150 % für die BC (ratio 2,5). Erfahrenere Untersucher konnten mit dem BC im Mittel 7 Polypen mehr finden als unerfahrene Untersucher.

Schlussfolgerung Auch wenn unsere Ergebnisse nicht eindeutig belegen, dass der Einsatz des BC mehr Adenome findet, so zeigt die Arbeit, dass die Erfahrung des Untersuchers einer der wichtigsten Indikatoren für die Adenomdetektionrate zu sein scheint.

Key words

balloon colonoscopy - polyp detection rate - polyp miss rate - adenoma detection rate - interval colorectal cancer

Schlüsselwörter

Ballonkoloskop - Polypendetektionsrate - Polypenmissrate - Adenomdetektionsrate - Intervallkarzinom

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