KCT0004822.

Study name	Infectious surgical site Complications after Oral antibiotic Bowel preparation for minimally‐invasive Rectal cAncer surgery (COBRA) – multicenter prospective randomized controlled trial
Methods	Study type: interventional study Study design Primary purpose: prevention Intervention model: factorial Blinding/masking: open Allocation: RCT
Participants	Condition or disease: neoplasms Inclusion criteria Age 20 ‐ 75 years Pathologically‐confirmed rectal adenocarcinoma of which lower margin is located within 15 cm from anal verge Radiologicall‐ confirmed non‐metastatic rectal cancer (cTanyNantM0) ECOG performance status 0‐2 ASA = 3 A patient who understands this clinical trial and agrees to be enroled Exclusion criteria Anticipated other organ resection Metastatic disease One who have been treated for infections or have taken antibiotics within 2 weeks before surgery Severe major organ dysfunction (heart, lung, liver, kidney) A patient who is taking steroid or immunosuppressants Inflammatory bowel disease A patient who has undergone chemotherapy within 1 month due to malignant disease of other organ Decrease in white blood cell for various reasons Pregnant or lactating women Local resection of rectal cancer Target sample size: 438
Interventions	Treatment arms Experimental group (A): mechanical bowel preparation (PEG) + IV antibiotics Control group (B): mechanical bowel preparation (PEG) + IV antibiotics + oral antibiotics (rifaximin + metronidazole) Mechanical bowel preparation PEG preferred Water only permitted on the day before operation Oral antibiotics 400 mg rifaximin + 500 mg metronidazole 14, 16, 22 hours the day before surgery Perioperative intravenous antibiotic prophylaxis 2nd generation cephalosporin Venous injection within 30 minutes before surgery Additional dose is at the discretion of the operators
Outcomes	Primary outcome Surgical site infection rate during first 30 days Secondary outcomes Adverse event Anastomotic leakage rate C. difficile colitis Incisional SSI Organ/space SSI Overall complication
Starting date	Date of registration: 12.03.2020 Estimated Study Start Date: ‐ Estimated Study Completion Date: ‐ Recruitment status: recruiting
Contact information	Contact person: Ji Woong Bae Affiliation: Korea University Ansan Hospital Country of origin: Korea
Notes	Ethics approval: Approval date: 05/03/2020 Source of funding: Korea University