The impact of mechanical bowel preparation in elective colorectal surgery: a propensity score matching analysis

To evaluate the influence of preoperative mechanical bowel preparation (MBP) based on the occurrence of anastomosis leakage, surgical site infection (SSI), and severity of surgical complication when performing elective colorectal surgery. MBP and non-MBP patients were matched using propensity score. The outcomes were evaluated according to tumor location such as right- (n=84) and left-sided colon (n=50) and rectum (n=100). In the non-MBP group, patients with right-sided colon cancer did not receive any preparation, and patients with both left-sided colon and rectal cancers were given one rectal enema before surgery. In the right-sided colon surgery, there was no anastomosis leakage. SSI occurred in 2 (4.8%) and 4 patients (9.5%) in the non-MBP and MBP groups, respectively. In the left-sided colon cancer surgery, there was one anastomosis leakage (4.0%) in each group. SSI occurred in none in the rectal enema group and in 2 patients (8.0%) in the MBP group. In the rectal cancer surgery, there were 5 anastomosis leakages (10.0%) in the rectal enema group and 2 (4.0%) in the MBP group. SSI occurred in 3 patients (6.0%) in each groups. Severe surgical complications (Grade III, IV, or V) based on Dindo-Clavien classification, occurred in 7 patients (14.0%) in the rectal enema group and 1 patient (2.0%) in the MBP group (p=0.03). Right- and left-sided colon cancer surgery can be performed safely without MBP. In rectal cancer surgery, rectal enema only before surgery seems to be dangerous because of the higher rate of severe postoperative complications.