Ucr co2regulation unit

Patients underwent colonoscopy with an Elite CF290 endoscopy system (CV-290 and CLV-290, Olympus, Japan) with a 290 series colonoscope (CF-HQ290Z, CF-HQ290, or PCF-H290Z, Olympus, Japan) or a 260 series colonoscope (PCF-PQ260 or CF-H260) and a carbon dioxide (CO
₂) insufflator (UCR CO
₂regulation unit, Olympus, Japan). NBI was available for all the scopes. A flushing pump (OFP-2, Olympus, Japan) was used for the 290 series colonoscope. PCF-H290Z and PCF-PQ260 were used for patients aged 80 years or older, patients aged 70 years or older who had undergone a previous abdominal surgery, and patients likely to experience a difficult insertion due to a colon adhesion found during a previous colonoscopy
9 (link)
. We used an image filing system (T-File System; STS Medic, Japan).

The CF260 group patients underwent colonoscopy using a high-definition endoscopy system with a high-definition colonoscope (CV-260 HiVision and CLV-260 with CF-H260AI, Evis Lucera Spectrum system; Olympus). Elite CF290 group patients underwent colonoscopy using a new-generation endoscopy system with a new-generation colonoscope (CV-290 and CLV-290, with CF-HQ290ZI, CF-HQ290I, or PCF-H290ZI, Evis Lucera Elite system; Olympus), a new-generation flushing pump (OFP-2; Olympus), and a carbon dioxide (CO
₂) insufflator (UCR CO
₂regulation unit; Olympus). PCF-H290ZI was used for patients aged 80 years or older, patients aged 70 years or older and who had undergone a previous abdominal surgery, and patients with difficult insertion due to a colon adhesion found during a previous colonoscopy. Narrow band imaging (NBI) is available for both the 260 series and 290 series.

All the endoscopists who participated in the study were certified by the Japan Gastroenterological Endoscopy Society and had >10 years of experience in endoscopic diagnosis and treatment. All endoscopic procedures were carried out by a therapeutic-type video colonoscope (PCF-Q260AZI or CF-HQ290L/I; Olympus Medical Systems, Tokyo, Japan) with a video endoscopy system (EVIS LUCERA ELITE; Olympus Medical Systems). Video colonoscope insertion and endoscopic resection were carried out with a CO₂ insufflation regulation unit (UCR CO2 Regulation Unit; Olympus Medical Systems) in all patients. All the lesions diagnosed as SSA/P by M-NBI were treated by endoscopic mucosal resection (EMR), polypectomy, cold polypectomy, or underwater EMR. EMR, polypectomy and underwater EMR were performed using a bipolar snare (DRAGONARE™; Xemex, Tokyo, Japan). Cold snare polypectomy was mainly performed with a Profile snare (Boston Scientific, Marlborough, MA, USA). After resection, the specimens were retrieved and one biopsy specimen was removed by the same endoscopist from the center of the resected lesions using biopsy forceps (Radial Jaw4 Standard Capacity; Boston Scientific, Marlborough, MA). The specimens were promptly immersed in 10% formalin and sent to the Department of Pathology.