Mechanical and oral antibiotic bowel preparation versus no bowel preparation in right and left colectomy: subgroup analysis of MOBILE trial

BACKGROUND: In retrospective series, mechanical and oral antibiotic bowel preparation (MOABP) has been reported to reduce surgical-site infections (SSIs) after colectomy compared with no bowel preparation (NBP). METHOD: This was a subgroup analysis of a multicentre randomized trial that included patients scheduled for elective colectomy. The MOABP group underwent mechanical bowel preparation, and took 2 g neomycin and 2 g metronidazole orally during the day before surgery. The NBP group did not undergo bowel preparation. Patients were categorized according to the side of resection (right versus left colectomy), and these subgroups compared for postoperative outcomes. RESULTS: Among 217 patients undergoing right colectomy (106 in MOABP and 111 in NBP group), SSI was detected in seven (7 per cent) and 10 (9 per cent) patients (odds ratio (OR) 0.71, 95 per cent c.i. 0.26 to 1.95; P = 0.510), anastomotic dehiscence in two (2 per cent) and two (2 per cent) patients (OR 1.05, 0.15 to 7.58; P = 1.000), and the mean(s.d.) Comprehensive Complication Index (CCI) score was 9.4(12.9) and 10.5(18.0) (mean difference -1.09; 95 per cent c.i. -5.29 to 3.11; P = 0.608) in the MOABP and NBP groups respectively. Among 164 patients undergoing left colectomy (84 in MOABP and 80 in NBP group), SSI was detected in five (6 per cent) and eight (10 per cent) patients (OR 0.57, 0.18 to 1.82; P = 0.338), anastomotic dehiscence in four (5 per cent) and five (6 per cent) patients (OR 0.75, 0.19 to 2.90; P = 0.742), and the CCI score was 10.2(13.1) and 6.5(11.0) (mean difference 3.68, -0.06 to 7.42; P = 0.053) in the MOABP and NBP groups respectively. CONCLUSIONS: MOABP did not decrease the rate of SSI or complications in patients undergoing either right or left colectomy compared with NBP.