Oncologic and Anastomotic Safety of Low Ligation of the Inferior Mesenteric Artery With Additional Lymph Node Retrieval: A Case-Control Study

PURPOSE: We assessed the oncologic and anastomotic benefits of low ligation of the inferior mesenteric artery (IMA) with additional lymph node (LN) retrieval. METHODS: We performed a retrospective case-control study between January 2011 and July 2015. All patients underwent curative resection of a primary sigmoid or rectal tumor. We excluded patients with distant metastases at the time of diagnosis. The case group included patients who underwent high ligation of the IMA (high group, HG). The control group included patients who underwent low ligation of the IMA with low group with additional LN retrieval (LGAL). Controls were identified by matching patients based on age (±5 years), sex, tumor location, and final histopathological stage. Finally, each group included 97 patients. RESULTS: Clinical characteristics did not significantly differ between groups. The mean number of additional harvested LN was 2.19 (range, 0–11), and one patient in the LGAL had a metastatic LN among the additional harvested LN. The overall morbidity was 22.7% in the HG and 30% in the LGAL (P = 0.257). Anastomotic leakage occurred in 14 patients (14.4%) in the HG and 5 patients (5.2%) in the LGAL (P = 0.030). The mean disease-free survival time in the HG was longer than that in the LGAL (P = 0.008). The mean overall survival (OS) time was 70.4 ± 1.3 months. The mean OS was 63.7 ± 1.6 months in the HG and 69.1 ± 2.6 months in the LGAL (P = 0.386). CONCLUSION: Low ligation of the IMA with additional LN retrieval is technically safe. However, the oncologic effect was better after high ligation of IMA.