Routine colorectal surgery is performed first, followed by liver surgery. The LHS cohort first performed the laparoscopic exploration of the entire abdominal-pelvic cavity to determine the resectability of the primary and metastatic lesions. After the blood vessel detachment and bowel detachment, the distal bowel of the tumor was severed and the pneumoperitoneum was closed. The liver metastases were then removed in both cohorts by open resection through the right subcostal incision.

Routine colorectal surgery is performed first, followed by liver surgery. The blood vessel detachment, bowel detachment, the distal bowel of the tumor in the TOS cohort were accomplished by open surgery through the mid-abdominal incision approach. The liver metastases were then removed in both cohorts by open resection through the right subcostal incision.

First performed the laparoscopic exploration of the entire abdominal-pelvic cavity to determine the resectability of the primary and metastatic lesions. After the blood vessel detachment and bowel detachment, the distal bowel of the tumor was severed and the pneumoperitoneum was closed. The liver metastases were then removed in both cohorts by open resection through the right subcostal incision.

Time taken for surgery

Patient haemorrhage during surgery

Time for patients to eat fluids for the first time after surgery

Length of stay of patients after surgery

Complications that occur in patients after surgery

the time after surgical treatment until death for any reason

the time after surgical treatment until the first observation of tumor recurrence or death for any reason