The development and improvement of thoracoscopic esophagectomy (TE) reduced the severe pulmonary complication after esophagectomy. However, the postoperative complications relative to gastric conduit reconstruction are still common issues after esophagectomy. The ischemia of the proximal portion of the graft predisposes these patients to a high incidence of anastomotic complications after esophagectomy. Less commonly, severe graft ischemia can lead to transmural necrosis. Thus, early diagnosis of ischemic reaction may provide the suitable postoperative management and therapeutic intervention to prevent leakage, strictures and necrosis. 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.