The oncologic benefit of high ligation of the inferior mesenteric artery in the surgical treatment of rectal or sigmoid colon cancer

Purpose It remains controversial as to whether high ligation of the inferior mesenteric artery (IMA) should be performed during surgical treatment for sigmoid colon or rectal cancer. The purpose of this study is to attempt to clarify the extent of the oncologic benefit of high ligation of the IMA. Materials and methods From January 1995 to July 2001, a total of 1,389 patients underwent high ligation of the IMA; 387 patients featured non-disseminated sigmoid colon cancer and 1,002 patients had rectal cancer. Pathology of the primary tumors, IMA nodes, and clinical outcome were reviewed. Results Forty-three patients (3.1%) revealed IMA node metastasis. Of these 43 patients, 29 (67.4%) featured tumor recurrences/metastases. After a minimum 5-year follow-up, 11 of these 43 patients (25.6%) were alive and disease free. Of these 43 patients, the 5-year disease-free survival rate for patients featuring sigmoid cancer was 50% and for patients with rectal cancer 13.8%. The beneficial rate of high ligation of the IMA for non-disseminated sigmoid colon cancer and rectal cancer was 0.8%, for non-disseminated sigmoid colon cancer 1.8%, and for non-disseminated rectal cancer, the rate was only 0.4%. The rates of IMA metastasis in patients with T stage tumors were 0% (pT1), 1.0% (pT2), 2.6% (pT3), and 4.3% (pT4). Conclusions Although patients afflicted with IMA node metastasis revealed a rather high incidence of tumor recurrence/metastasis, 25.6% of these patients remained disease free following IMA node dissection after a minimum 5-year follow-up. We consider that IMA node dissection is more beneficial in patients with non-disseminated sigmoid pT4 tumor.