Systemic versus Oral and Systemic Antibiotic Prophylaxis (SOAP) study in colorectal surgery

There is no consensus regarding the role of mechanical bowel preparation (MBP) and oral antibiotic prophylaxis (OABP) in reducing postoperative complications in colorectal surgery. The aim of this study was to examine the effect of OABP given in addition to MBP in the setting of a prospective randomized trial.Patients awaiting elective colorectal surgery in four Hungarian colorectal centres were included in this multicentre, prospective, randomized, assessor-blinded study. Patients were randomized to receive MBP with or without OABP (OABP+ and OABP- groups respectively). The primary endpoints were surgical-site infection (SSI) and postoperative ileus. Secondary endpoints were anastomotic leak, mortality, and hospital readmission within 30 days.Of 839 patients assessed for eligibility between November 2016 and June 2018, 600 were randomized and 529 were analysed. Trial participation was discontinued owing to adverse events in seven patients in the OABP+ group (2.3 per cent). SSI occurred in eight patients (3.2 per cent) in the OABP+ and 27 (9.8 per cent) in the OABP- group (P = 0.001). The incidence of postoperative ileus did not differ between groups. Anastomotic leakage occurred in four patients (1.6 per cent) in the OABP+ and 13 (4.7 per cent) in the OABP- (P = 0.02) group. There were no differences in hospital readmission (12 (4.7 per cent) versus 10 (3.6 per cent); P = 0.25) or mortality (3 (1.2 per cent) versus 4 (1.4 per cent); P = 0.39).OABP given with MBP reduced the rate of SSI and AL after colorectal surgery with anastomosis, therefore routine use of OABP is recommended