Gastric conduit ischemia or anastomotic breakdown after esophagectomy with cervical esophagogastrostomy often cause severe complications, such as leakage, necrotic organs, and strictures. Thus, the purpose of this study is the safety and efficacy of endoscopic evaluation about reconstructive organs after esophagectomy. The investigators evaluate endoscopic predictions using classifications in acute phase after esophagogastrostomy.