Antibiotics, Bowel Prep Reduced Site Infections for Rectal Cancer Surgery

A combination of oral antibiotics and mechanical bowel preparation (MBP) helped to decrease the rate of surgical site infections (SSIs) in patients undergoing left colon and rectal cancer resections, according to the results of a study published in JAMA Surgery.

“SSIs are a common postoperative complication after surgery for colorectal disease and significantly affect patient morbidity and mortality. Given the high rate of SSIs after colorectal surgery as well as the lack of effectiveness of other preventive programs, the use of oral antibiotics and MBP, which was initially evaluated in the 1970s and subsequently fell out of favor, has resurfaced as a potential intervention,” wrote Elaine Vo, MD, of the Michael E. DeBakey Department of Surgery at Baylor College of Medicine in Houston, and colleagues. “Our study demonstrated that use of oral antibiotics and MBP was associated with a decrease in overall rates of SSIs and organ space SSIs for patients undergoing left colon and rectal cancer resections.”

The single-center study was a retrospective review of 89 patients who underwent left colon and rectal cancer resections between October 2013 and December 2016. The primary outcome was SSIs within 30 days of the procedure and time to adjuvant therapy.

Of the 89 patients in the study, 49 had surgery with MBP only and 40 with both MBP and oral antibiotics. Patients who received oral antibiotics and MBP were younger than those who received MBP only, and the median operative time was also longer in the group that received the combination.

However, the overall rate of SSIs was lower in patients who received oral antibiotics and MBP compared with MBP alone (8% vs 27%; P = .03). Patients who received antibiotics had no deep or organ space SSIs or anastomotic leaks compared with nine organ space SSIs (P = .004) and five anastomotic leaks (P = .06) in patients who received MBP only.

There was no difference in the median number of days it took to begin adjuvant therapy between the two groups. Both oral antibiotics and MBP (odds ratio, 0.11; P = .04) and minimally invasive surgery (odds ratio, 0.22; P = .03) were independently associated with a reduced odds of infection.

“Future work is also needed to understand whether the benefits of oral antibiotics and MBP are also present for patients undergoing right colon resections,” the researchers wrote. “Until such data become available, clinicians should consider using oral antibiotics and MBP for all patients undergoing left-sided colorectal cancer resections.”

In an editorial that accompanied the research, Marc D. Basson, MD, PhD, MBA, of the University of North Dakota School of Medicine and Health Sciences in Grand Forks, pointed out that despite the small sample size in the study, significant decreases in superficial and deep infections were seen in patients given oral antibiotics and MBP.

“The study by Vo and colleagues does seem to confirm what we have known since 1973; preoperative oral antibiotics reduce the number of wound infections in elective surgery on the mechanically prepared colon,” Basson wrote. “SSIs produce substantial morbidity among our patients. Given all the efforts that we have made to reduce infection rates by ineffective methods such as mandating compliance with the Surgical Care Improvement Project and experimenting with varieties of decontamination and skin preparation techniques, perhaps it is time to stop studying this issue and simply (re)adopt the practice of oral antibiotic use more universally, at least for elective surgery on the mechanically prepared left colon.”