The Impact of Mechanical Bowel Preparation and Oral Antibiotics in Colorectal Cancer Surgery (MECCA Study): A Prospective Randomized Clinical Trial

Background: Colorectal cancer surgery has been associated with surgical site infections (SSIs), leading to an increase in postoperative morbidity, length of stay and total cost. The aim of the present randomized study was to investigate the relationship between the preoperative administration of oral antibiotic therapy and SSI rate, as well as other postoperative outcomes in patients undergoing colorectal cancer surgery. Material and Methods: Patients who underwent colorectal cancer surgery in a university surgical department were included in the present study. Patients were randomized into two groups using the "block randomization" method. The intervention group received three doses of 400 mg rifaximin and one dose of 500 mg metronidazole per os, as well as mechanical bowel preparation the day before surgery. The control group underwent only mechanical bowel preparation the day before surgery. The study has been registered in ClinicalTrials.gov (NCT03563586). Results: Two hundred and five patients were finally included in the present study, 97 of whom received preoperative antibiotic therapy per os (intervention group). Patients of this group demonstrated a significantly lower SSI rate compared with patients who did not receive preoperative antibiotic therapy (7% vs. 16%, p = 0.049). However, preoperative antibiotic administration was not correlated with any other postoperative outcome (anastomotic leak, overall complications, readmissions, length of stay). Conclusions: Preoperative antibiotic therapy in combination with mechanical bowel preparation seemed to be correlated with a lower SSI rate after colorectal cancer surgery.