Background and Aims:Preventive temporary stoma has been widely used in surgeries for rectal cancer as a simple and effective method to reduce the severity of postoperative anastomotic leakage.However,some patients with preventive temporary stomas cannot undergo reversal due to various factors,resulting in a permanent stoma.Permanent stomas remain a common adverse outcome in clinical practice,and the reasons behind this are not entirely clear.This study analyzes a continuous surgical sample from a single center to explore the risk factors for forming permanent stoma. Methods:The clinical data of patients who underwent anal-preserving rectal cancer surgery with preventive temporary stoma in Gastrointestinal Cancer Center Ⅲ of Peking University Cancer Hospital from January 2020 to March 2023,with over 12 months of follow-up,were retrospectively collected.The occurrence of permanent stoma was analyzed,and the clinical variables of patients with permanent stoma were compared to those who underwent stoma reversal,along with an analysis of the risk factors for permanent stoma formation.Permanent stoma was defined as ostomy reversal failure for more than 12 months. Results:A total of 299 patients were included,among which 268(89.63％)underwent stoma reversal(stoma closure group),and 31(10.37％)did not(permanent stoma group).Compared to the stoma closure group,the permanent stoma group had a higher incidence of distant organ metastasis at diagnosis(7.5％vs.25.85％,P=0.003)and also had higher proportions of T3 and T4 stages,N2 stage,and clinical stage Ⅳ(all P＜0.05)with an elevated overall postoperative complication rate(19.0％vs.41.9％,P=0.003)as well as a higher rate of severe complications(1.1％vs.9.7％,P=0.016)and an increased incidence of anastomotic leakage(4.9％vs.19.4％,P=0.006).Logistic regression analysis revealed that the presence of distant organ metastasis at diagnosis(OR=5.41,95％CI=1.80-16.27,P=0.003),and occurrence of anastomotic leakage(OR=4.44,95％CI=1.15-17.09,P=0.030)were independent risk factors for the formation of permanent stomas. Conclusion:At present,some patients still cannot undergo reversal of their preventive temporary stoma,resulting in permanent stoma.The formation of permanent stomas is closely related to a low tumor location,distant organ metastasis at diagnosis,and the occurrence of anastomotic leakage.