Chih‑Wei Tsenga,b, Felix W. Leungc,d*, Yu‑Hsi Hsieha,b
aDivision of Gastroenterology, Department of Medicine, Dalin Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Chiayi, Taiwan, bSchool of Medicine, Tzu Chi University, Hualien, Taiwan, cDepartment of Medicine, Sepulveda Ambulatory Care Center, Veterans Affairs Greater Los Angeles Healthcare System, North Hill, CA, USA, dDavid Geffen School of Medicine at UCLA, Los Angeles, CA, USA
Open Access funded by Buddhist Compassion Relief Tzu Chi Foundation
Abstract
The high incidence of colorectal cancer and the occurrence of interval cancers after screening colonoscopy support the need to develop methods to increase adenoma detection rate (ADR). This review focuses on the importance of ADR and the impact of new techniques on ADR based on meta‑analysis data. The low‑cost interventions (such as water‑aided colonoscopy, second observation, and dynamic position change) were effective in increasing ADR. So were enhanced imaging techniques and add‑on devices. Increase with higher cost interventions such as newer scopes is uncertain. Water exchange (WE) has the highest ADR compared with water immersion, air insufflation, and carbon dioxide insufflation. Second observation with forward or retroflexed views improved the right colon ADR. Add‑on devices result in only modest improvement in ADR, of particular help in low performing endoscopists. The second‑generation narrow‑band imaging (NBI) provided a two‑fold brighter image than the previous system. The improvement in ADR with NBI required the “best” quality bowel preparation. New endoscopic techniques incur various additional costs, nil for WE, small for tip attachments but large for the newer scopes. In conclusion, one or more of the above methods to improve ADR may be applicable in Taiwan. A comparison of these approaches to determine which is the most cost‑effective is warranted.
Keywords: Adenoma detection rate, Colonoscopy, Meta‑analysis, Water exchange
