Abstract
Endoscopic diagnosis using acetic acid is classified under the following four methods ; (1) acetic acid enhanced magnifying endoscopy, (2) acetic acid dynamic chemical endoscopy, and (3) acetic acid indigocarmine method, (4) endoscopic observation using NBI after acetic acid spraying. After spraying acetic acid, a white change in the mucosal color and the structure of epithelium can clearly be observed with magnifying endoscopy. This method is named (1) acetic acid enhanced magnifying endoscopy. Several seconds after acetic acid spraying, the white change disappears in cancerous areas, although non-cancerous areas continue to be whitish. A contrast is thus visible between cancerous and non-cancerous areas. That helps endoscopic diagnosis of the extent of the cancer. This diagnostic approach is named (2) acetic acid dynamic chemical endoscopy. When indigocarmine is added after spraying acetic acid, the indigocarmine disappears quickly from cancerous areas, but continues to be visible in the non-cancerous areas. This contrast is good to diagnose the extent of cancerous areas and as known as the (3) acetic acid indigocarmine method. After having been sprayed with acetic acid, cancerous areas appear brownish in color, whereas non-cancerous areas appear green by using NBI. This contrast to diagnose the extent of the cancerous involvement. This method is referred to as (4) endoscopic observation using NBI after acetic acid spraying.
