Although intracorporeal anastomosis (IA) for colon cancer requires longer operative time than extracorporeal anastomosis (EA), its short-term postoperative results, such as early recovery of bowel movement, have been reported to be equal or better. As IA requires opening the intestinal tract in the abdominal cavity under pneumoperitoneum, there are concerns about intraperitoneal bacterial infection and recurrence of peritoneal dissemination due to the spread of bacteria and tumor cells. However, intraperitoneal bacterial contamination and medium-term oncological outcomes have not been clarified.

To clarify the effects of bacterial and tumor cell contamination of the intra-abdominal cavity in IA.

Of 127 patients who underwent laparoscopic colon resection for colon cancer from April 2015 to December 2020, 75 underwent EA (EA group), and 52 underwent IA (IA group). After propensity score matching, the primary endpoint was 3-year disease-free survival rates, and secondary endpoints were 3-year overall survival rates, type of recurrence, surgical site infection (SSI) incidence, number of days on antibiotics, and postoperative biological responses.

Three-year disease-free survival rates did not significantly differ between the IA and EA groups (87.2% and 82.7%, respectively, P = 0.4473). The 3-year overall survival rates also did not significantly differ between the IA and EA groups (94.7% and 94.7%, respectively; P = 0.9891). There was no difference in the type of recurrence between the two groups. In addition, there were no significant differences in SSI incidence or the number of days on antibiotics; however, postoperative biological responses, such as the white blood cell count (10200 vs 8650/mm3, P = 0.0068), C-reactive protein (6.8 vs 4.5 mg/dL, P = 0.0011), and body temperature (37.7 vs 37.5 °C, P = 0.0079), were significantly higher in the IA group.

IA is an anastomotic technique that should be widely performed because its risk of intraperitoneal bacterial contamination and medium-term oncological outcomes are comparable to those of EA.

There is still insufficient discussion of the mid- to long-term safety of the intracorporeal anastomosis (IA) method of reconstruction after laparoscopic colectomy (LAC) for colon cancer. The present study clarified the postoperative mid-term results of IA based on recurrence and the incidence of incision hernia.

This single-institution observational retrospective study included 268 patients with colon cancer who underwent IA or extracorporeal anastomosis (EA) after LAC at our institution between 2018 and 2021. The mid-term results of the IA group were compared with those of the EA group using a propensity score matching method.

The median follow-up periods were 36 and 25 months in the EA and IA groups, respectively (p < 0.0001). In this matched cohort study, the recurrence-free survival (RFS) rates were comparable between the IA and EA groups (each group, n = 72; 3-year RFS: IA, 92.1%; EA, 88.2%; hazard ratio, 0.78; 95% confidence interval, 0.25-2.40; p = 0.66). The cumulative incisional hernia rates were 9.8% and 9.9% (p = 0.99) for the IA and EA groups, respectively.

The safety of IA after LAC was demonstrated in this study, as IA after LAC showed good mid-term results, including with regard to the rates of recurrence and incisional hernia.

A 68-year-old woman was transferred to the emergency room of Okayama City Hospital because of worsening epigastric pain. After the examination, she was diagnosed with descending colon cancer, and laparoscopic colectomy was planned. However, exteriorization of the bowels to produce anastomosis was difficult because the rich adipose tissue of the mesocolon hardly stretched, and the abdominal wall was thick as the patient was obese. Therefore, an intracorporeal triangulating end-to-end anastomosis was performed. The colon was divided at 10 cm either side from the tumor using an endoscopic linear stapler. After the resection of the stumps with staples, the posterior walls were tied with stay sutures and then stapled with an endoscopic linear stapler. The anterior wall was stapled twice in the same manner, and the intracorporeal anastomosis was completed. The patient's postoperative course was uneventful. This technique provided an alternative intracorporeal anastomotic technique as troubleshooting in laparoscopic colectomy.