Left colectomy may be performed as a standalone procedure or as part of a more extended colectomy. The extent of dissection and resection is dependent on the specific etiology. Although benign diseases may dictate a more conservative resection, most left colectomies are performed for malignancies. Oncologic resection of malignant tumors of the left colon dictates complete mesocolic resection, where the entire nodal basin of the tumor is dissected and removed. Thus, tumor location dictates the anatomic margins of the resection. The blood supply to the left colon arises mainly from the inferior mesenteric artery (IMA) and from the arcades originating from the middle colic pedicle through the marginal artery of Drummond. In recent years, the minimally invasive approach for colon resection has been proved to be an adequate and safe alternative to the open approach both for benign and malignant etiologies. In our department, the percentage of laparoscopic colectomies performed either for malignant disease or benign etiologies has dramatically risen during the past few years. However, open left colectomy is still indicated for complex cases such as locally advanced colon cancer.

The approach for left colectomy is usually performed using the lateral-to-medial approach, in which the colon is first mobilized and then devascularization and resection are performed. However, medial-to-lateral dissection is sometimes indicated when mobilization of the colon from the lateral attachments could be difficult, for instance, when the abdominal wall is involved by the colonic pathology, due to malignant invasion or inflammatory response. This approach allows early control of the vascular pedicle and early identification and preservation of vital structures that might be damaged if the lateral-to-medial approach is chosen. In those cases where lateral mobilization of the colon might be difficult, access to the lateral vital structures (iliac vessels, ureter, renal pelvis, inferior mesenteric vein (IMV), ligament of Treitz, and splenic pedicle) through the mesenteric window may allow early identification and preservation.

The medial-to-lateral approach has primarily been described as a part of the “no-touch isolation technique” developed by Barnes and Turnbull in the 1950s. Their rationale was based on the work by Tyzzer in 1913 and Cole in 1954, who suggested that colon mobilization and tumor manipulation may seed cancerous cells into the venous drainage and worsen prognosis. Using the medial-to-lateral approach, the tumor is left in situ, whereas the vascular pedicle is ligated, thus preventing vascular tumor cell seeding. Turnbull operated on 460 patients with carcinoma of the colon using the “no-touch technique,” achieving an outstanding result of doubling the 5-year survival rate in those patients. Contraindications to the medial-to-lateral approach may include massive lymphadenopathy along the vascular pedicle, or significant fibrosis, thickening, or inflammatory conditions involving the mesenteric bed. In such cases, addressing the vascular pedicle first might be very complicated and potentially dangerous.