PaO2

This study aims to determine whether postoperative hypoxia (arterial partial pressure of oxygen (PaO₂)\<80 mmHg) is an independent risk factor for anastomotic leakage after esophagectomy. The investigators conducted a retrospective analysis of cases from their center over the past five years, stratifying patients into Low Pa0₂ Group and Normal Pa0₂ Group based on postoperative oxygen levels and comparing the incidence of anastomotic leakage between the groups. The goal is to establish whether hypoxia is a causative risk factor and whether correcting it can reduce the risk of anastomotic leakage.