The Necessity And Safety Of Additional Laporascopic-assisted Surgery After T1 Colorectal Cancer Treated With Endoscopic Submucosal Dissection

Objective:To investigate the necessity and safety of additional laporascopic-assisted surgery after T1 colorectal carcinoma treated with endoscopic submucosal dissection.Methods:A total 266 patients with additional laporascopic-assisted surgery after endoscopic submucosal dissection(addtional surgery group)or laporascopic-assisted surgery alone(surgery alone group)from January 2015 to May 2019 were reviewed.Propensity score matching was applied at a ratio of 1:1 comparing the addtional surgery group(n=101)and surgery alone group(n=101).The clinical indexes between the two groups were compared.Results:There were no significant differences between the additional laparoscopic-assisted surgery and laparoscopic-assisted surgery alone groups in lymph node metastasis(p=0.297),operative time(p=0.205),first flatus time(p=0.282),first stool time(p=0.293),time to intake(p=0.079),blood loss(p=0.603),harvest lymph nodes(p=0.438),postoperative surgical complications(p=0.733),and postoperative length of hospital stay(p=0.401).In subgroup analysis,residual cancer or LNM was detected in 12 patients(19.35%).Clinicopathological comparison of patients with the presence or absence of residual cancer and LNM demonstrated that piecemeal resection(P<0.001),submucosal invasion greater than 2000μm(P=0.026),lymphovascular infiltration(P=0.033),and perineuronal invasion(P=0.004)were more frequent in residual cancer and LNM cases.Multivariate analysis identified lymphovascular infiltration(P=0.031)as the only significantly independent risk factor associated with residual cancer and LNM.Conclusion:Piecemeal resection,submucosal invasion greater than 2000 μm,lymphovascular infiltration and perineuronal invasion were risk factors associated with residual cancer and LNM.Among these,lymphovascular infiltration was the only significantly independent risk factor.Meanwhile,additional laparoscopic-assisted surgery has comparable short-term outcomes to laparoscopic-assisted surgery alone group.It is necessary and safe to proceed additional laporascopic-assisted surgery for early colorectal cancer especially T1 colorectal cancer,when patients meet one or more above high-risk factors of LNM or residual tumor.