Patients and methods: 459 patients underwent potentially curative surgery with lateral dissection from 2001 to 2016, for rectal cancers located below the peritoneal reflection were reviewed in the present study. Results: T2 tumors: 66 %, T3: 85 %, T4a: 74 % and T4b:92 percent underwent systemic and partial lateral dissection. Lateral nodal involvement (LNI) was observed in 55 patients (12 %). LNI was observed T2 tumor was 7 %, T3: 19 %, T4a: 16% and T4b: 25 %. And Local disease free survival who had LNI was T2: 78 %, T3: 82 % and T4a/T4b 64 %. Patients who had nodal involvement in IMA area and Mesorectal area were observed 23.1%. A significantly increased incidence of positive lateral lymph node was found in patients with the following factors: nodal metastasis, high CEA and venous invasion. Five year overall survival decreased patients with LMI 60.7% against without LMI (87.1%, p<0.001). Efficiency Index (EI) was drawn from metastatic rate and 5 year survival was 7.28 underwent the dissection of LNI. EI of SMA area lymph node dissection was 4.06 and Mesorectal area was 21.0. Middle rectal root node was most efficiency dissection in lateral pelvic lymph node (EI; 6.87). Conclusion: Preoperative risk factors of PNI were CEA and p venous invasion. It was important for advanced lower rectal cancer that underwent lateral pelvic lymph node dissection. |