Vo E, et al. - This study was meant to assess the association of the addition of oral antibiotics to mechanical bowel preparation (MBP) with preventing surgical site infections (SSIs) in left colon and rectal cancer resections and its relation to the timely administration of adjuvant therapy. For patients undergoing elective left colon and rectal cancer resections, oral antibiotics plus MBP was recommended as this combined prevention strategy was found to be associated with a significant decrease in the rate of SSIs.

Methods

• Researchers retrospectively reviewed 89 patients who underwent left colon and rectal cancer resections from October 1, 2013, to December 31, 2016, at a single institution.
• A bowel regimen of oral antibiotics and MBP (neomycin sulfate, metronidazole hydrochloride, and magnesium citrate) was implemented August 1, 2015.
• Using univariate analysis, a comparison was performed between patients receiving MBP and oral antibiotics and those undergoing MBP without oral antibiotics.
• For assessing the link between use of oral antibiotics and MBP and the occurrence of SSIs, multivariable logistic regression was used controlling for factors that may affect SSIs.
• Main outcomes and measures included surgical site infections within 30 days of the index procedure and time to adjuvant therapy.

Results

• This study included 89 patients (5 women and 84 men; mean [SD] age, 65.3 [9.2] years), of those, 49 underwent surgery with MBP but without oral antibiotics and 40 underwent surgery with MBP and oral antibiotics.
• Data demonstrated that patients who received oral antibiotics and MBP were younger than those who received only MBP (mean [SD] age, 62.6 [9.1] vs 67.5 [8.8] years; P = .01), however, in terms of baseline demographic, clinical, and cancer characteristics, these 2 cohorts of patients were otherwise similar.
• Researchers found that surgical approach (minimally invasive vs open) and case type were similarly distributed; however, a longer median operative time was reported for patients who received oral antibiotics and MBP than those who received MBP only (391 minutes [interquartile range, 302-550 minutes] vs 348 minutes [interquartile range, 248-425 minutes]; P = .03).
• They also noted that for patients who received oral antibiotics and MBP than those who received MBP only (3 [8%] vs 13 [27%]; P = .03), the overall SSI rate was lower, with no deep or organ space SSIs or anastomotic leaks in patients who received oral antibiotics and MBP compared with 9 organ space SSIs (18%; P = .004) and 5 anastomotic leaks (10%; P = .06) in patients who received MBP only.
• Despite this finding, researchers observed no difference in median days to adjuvant therapy between the 2 cohorts (60 days [interquartile range, 46-73 days] for patients who received MBP only vs 72 days [interquartile range, 59-85 days] for patients who received oral antibiotics and MBP; P = .13).
• In addition, results indicated that oral antibiotics and MBP (odds ratio, 0.11; 95% CI, 0.02-0.86; P = .04) and minimally invasive surgery (odds ratio, 0.22; 95% CI, 0.05-0.89; P = .03) were independently related to reduced odds of SSIs.