The Role of Oral Antibiotic Preparation in Elective Colorectal Surgery

Abstract

Objectives To compare the impact of the use of oral antibiotics (OAB) with or without mechanical bowel preparation (MBP) on outcome in elective colorectal surgery. Summary Background Data Meta-analyses have demonstrated that MBP does not impact upon postoperative morbidity or mortality, and as such it should not be prescribed routinely. However, recent evidence from large retrospective cohort and database studies has suggested that there may be a role for combined OAB and MBP, or OAB alone in the prevention of surgical site infection (SSI). Methods A meta-analysis of randomized controlled trials and cohort studies including adult patients undergoing elective colorectal surgery, receiving OAB with or without MBP was performed. The outcome measures examined were SSI, anastomotic leak, 30-day mortality, overall morbidity, development of ileus, reoperation and Clostridium difficile infection. Results A total of 40 studies with 69,517 patients (28 randomized controlled trials, n = 6437 and 12 cohort studies, n = 63,080) were included. The combination of MBP+OAB versus MBP alone was associated with a significant reduction in SSI [risk ratio (RR) 0.51, 95% confidence interval (CI) 0.46–0.56, P < 0.00001, I 2 = 13%], anastomotic leak (RR 0.62, 95% CI 0.55–0.70, P < 0.00001, I 2 = 0%), 30-day mortality (RR 0.58, 95% CI 0.44–0.76, P < 0.0001, I 2 = 0%), overall morbidity (RR 0.67, 95% CI 0.63–0.71, P < 0.00001, I 2 = 0%), and development of ileus (RR 0.72, 95% CI 0.52–0.98, P = 0.04, I 2 = 36%), with no difference in Clostridium difficile infection rates. When a combination of MBP+OAB was compared with OAB alone, no significant difference was seen in SSI or anastomotic leak rates, but there was a significant reduction in 30-day mortality, and incidence of postoperative ileus with the combination. There is minimal literature available on the comparison between combined MBP+OAB versus no preparation, OAB alone versus no preparation, and OAB versus MBP. Conclusions Current evidence suggests a potentially significant role for OAB preparation, either in combination with MBP or alone, in the prevention of postoperative complications in elective colorectal surgery. Further high-quality evidence is required to differentiate between the benefits of combined MBP+OAB or OAB alone.

The use of oral antibiotics and mechanical bowel preparation in elective colorectal resection for the reduction of surgical site infection

“…The majority of studies show no differences in CDI rates in patients exposed to OAB. This holds true for retrospective studies [30,31,59-61], RCTs [33][34][35][36][37]45] and in meta-analysis [42]. There is no evidence of harm in terms of increase in CDI rates by using MOAB.…”

“…The need for an RCT to determine this has long been discussed , because data on OAB alone are contradictory. Different reports show that the use of OAB alone is worse than , equivalent to or better than the MOAB combination in reduction of SSI. The problems are a lack of RCTs that focus on OAB alone in the absence of MBP, small numbers in the OAB alone groups and selection bias in the cohort studies.…”

“…Meta-analyses vary in their conclusions regarding the additional benefits of MOAB. No differences in AL rates were seen in a meta-analysis including 16 RCTs published between 1979 and 2007 [38] nor in a recent network meta-analysis including 8458 patients in 38 RCTs, whereas significant multiple additional benefits were reported in two recent large meta-analyses, although these effects were less evident when oral antibiotics (OAB) were considered alone [41,42]. Developing evidence implicating intraluminal bacteria in the pathogenesis of AL and reduction in AL with locally administered antibiotics and selective gut decontamination regimes [46] may go part way to explaining the reduction in AL seen with MOAB.…”

“…The need for an RCT to determine this has long been discussed [17, 84,85], because data on OAB alone are contradictory. Different reports show that the use of OAB alone is worse than [24,25,27,[29][30][31]43,86], equivalent to [22,26,28,42,87] The problems are a lack of RCTs that focus on OAB alone in the absence of MBP, small numbers in the OAB alone groups and selection bias in the cohort studies. In the largest and most recent meta-analysis [42], SSI rates were compared between patients having MOAB and OAB alone.…”

Authors' reply: Meta‐analysis of oral antibiotics, in combination with preoperative intravenous antibiotics and mechanical bowel preparation the day before surgery, compared with intravenous antibiotics and mechanical bowel preparation alone to reduce surgical‐site infections in elective colorectal surgery ( BJS Open 2018; 2: 185–194)

“…The primary reporting of multiple cohort studies from such databases with overlapping time periods leads to great difficulty in determining which are likely to contain duplicate patients and data, and which combination of included studies leads to the least possible bias. This is illustrated by the fact that each of three recent meta‐analyses on the topic, including our own, includes a different combination of cohort studies originating from NSQIP. Furthermore, from certain cohort studies included in all three, each meta‐analysis has utilized different subgroups, dependent on the outcome in question.…”