The risk factors affecting the learning curve for laparoscopic low anterior resection were T stage and male sex. In laparoscopic low anterior resection, rectal transection in particular can be technically difficult, and standardization for accurate performance of the same technique for expanded indications is very important.

L-JIP and L-DT are procedures that maintain gradual intestinal absorption and help improve the quality of life. Intestinal absorption and hormonal secretion were relatively unaffected by the posture of the meal intake after L-DT, so L-DT might be the procedure providing the most stable results.

In CRCLM, we believe that nonanatomic hepatectomy with narrow margin is indicated, and optimal treatment would include functional preservation of as much of the remnant liver as possible.

We herein report a case of an internal hernia projecting through a mesenteric defect following laparoscopic-assisted colectomy to the lesser omental cleft in a 61-year-old female. We performed laparoscopic-assisted partial resection of the transverse colon to treat transverse colon cancer. Three years and 6 months after the operation, the patient developed a bowel obstruction requiring surgical intervention. When we observed the intraperitoneal space under laparoscopy, we determined that the small intestine had passed into the bursa omentalis through the mesenteric defect. Additionally, an abnormal opening of the lesser omentum was present with a portion of the small intestine escaping into the space inferior to the liver. We performed reintegration of the escaped bowel and closed the mesenteric defect laparoscopically. This is the first case of an internal hernia projecting through a mesenteric defect following laparoscopic-assisted colectomy that we have experienced out of more than 2400 cases. Further research is needed to identify the patients who would benefit from the closure of mesenteric defects during laparoscopic-assisted colectomy.

The incidence of successfully completed laparoscopic colectomy after previous abdominal surgery remains high, and the short-term outcomes are acceptable.