All patients were orally administered with 20,000 U Pronase (Pronase MS; Kaken Pharmaceutical Products Inc., Tokyo, Japan) before the administration of pharyngeal anesthesia to eliminate mucus in the esophagus. All endoscopic inspections were performed under deep sedation through intravenous administration of pethidine hydrochloride (35–70 mg, Opystan; Mitsubishi Tanabe Pharma, Osaka, Japan) and flunitrazepam (0.2–0.8 mg, Rohypnol; Chugai Pharmaceutical, Tokyo, Japan).
NBI-ME and LCE-PS were performed by using a high-definition zoom endoscope (GIF-H260Z; Olympus Co., Tokyo, Japan) and a 19-in high-resolution liquid-crystal monitor (OEV191H; Olympus Co.) that enabled endoscopic observation at a 90-fold maximum magnification. A black rubber attachment (MB-46, Olympus Co.) was mounted on the tip of the zoom endoscope to maintain the focal distance between the tip of the scope and the lesion surface at 2 mm, and it facilitated precise focusing during the magnification observation.
NBI-ME and LCE-PS were performed by using a high-definition zoom endoscope (GIF-H260Z; Olympus Co., Tokyo, Japan) and a 19-in high-resolution liquid-crystal monitor (OEV191H; Olympus Co.) that enabled endoscopic observation at a 90-fold maximum magnification. A black rubber attachment (MB-46, Olympus Co.) was mounted on the tip of the zoom endoscope to maintain the focal distance between the tip of the scope and the lesion surface at 2 mm, and it facilitated precise focusing during the magnification observation.