Background: Oral non-absorbable antibiotics work by decreasing intraluminal bacterial content after mechanical bowel preparation. The advantage of adding oral non-absorbable antibiotics to intravenous antibiotics to decrease surgical site infection (SSI) after colorectal surgery is not well known. We conducted a meta-analysis of randomized controlled trials (RCT) comparing the effectiveness of combined oral non-absorbable and intravenous antibiotics versus intravenous antibiotics alone in reducing the incidence of SSI following colorectal surgery.
Method: We included RCT comparing a combination of oral non-absorbable antibiotics and intravenous antibiotics to intravenous antibiotics alone in order to prevent SSI after colorectal surgery. Outcomes assessed included postoperative infectious complications, such as surgical wound infections (SWI) defined as a combination of superficial and deep SSI, organ-space infections and anastomotic dehiscence.
Results: Sixteen RCT published between 1979 and 2007 were included in the meta-analysis. The overall analyses indicated that patients randomly assigned to an oral non-absorbable antibiotic in addition to an intravenous antibiotic had a reduced risk of SWI (RR: 0.57 [95% CI: 0.43-0.76], p = 0.0002) compared with participants receiving only intravenous antibiotics. The use of oral non-absorbable antibiotics in addition to intravenous antibiotics had no significant effect on organ-space infections (RR: 0.71 [95% CI: 0.43-1.16], p = 0.2) or the risk of anastomotic leak (RR: 0.63 [95% CI: 0.28-1.41], p = 0.3).
Conclusion: Our meta-analysis shows that a combination of oral non-absorbable antibiotics and intravenous antibiotics significantly lowers the incidence of SWI compared with intravenous antibiotics alone. In light of our results, the use of oral non-absorbable antibiotics in colorectal surgery should be encouraged.