Mechanical Bowel Preparation In Colorectal Surgery Research Articles

Oral antibiotics and mechanical bowel preparation for colorectal surgery: A prospective observational study of surgical site infection and microbial analysis

PurposeSurgical site infections (SSIs) are common in colorectal surgery. Mechanical bowel preparation (MBP) in conjunction with oral antibiotics (OABs) have been shown to reduce SSI rates. It however is still unclear which OABs to use, and how this can be implemented in practice.MethodsThis is a prospective observational study carried out in Swansea Bay University Health Board during 2019–2021, evaluating the introduction of OABs in a stepwise manner on the incidence of SSI in major colorectal surgery. A control group having MBP only was compared to two OAB groups: one group had MBP plus metronidazole only and the second MBP plus metronidazole and neomycin. A 30-day follow-up after surgery was ascertained via chart review and telephone contact. Logistic regression was performed to estimate the relation between OAB use and SSI, with adjustment for confounding. In a subset of patients, faecal samples were analysed through 16S rRNA amplicon sequencing before and after OAB treatment, depicting the impact of the gut microbiome.ResultsIn total 160 patients were analysed: 46 patients had MBP only, whilst 76 patients had MBP plus metronidazole only and 38 patients had MBP with metronidazole/neomycin. The SSI rate in the entire cohort was 33.8%, whilst the adjusted ORs for the single- and dual-OAB groups were 0.76 (95% CI: 0.17–1.81) and 0.50 (95% CI: 0.17–1.52). The microbial analysis demonstrated that the relative abundance for many bacterial genera was changed before and after OAB treatment, but no link with SSI development could be shown.ConclusionsIntroduction of OABs in conjunction with MBP in colorectal surgery is feasible, and may potentially lead to lower rates of SSI, as well as altering the community structure of the faecal microbiome. More research is needed, especially considering different OABs and mechanistic studies of the gut microbiome in the context of colorectal surgery.

Effectiveness of mechanical bowel preparation versus no preparation on anastomotic leakage in colorectal surgery: a systematic review and meta-analysis.

It has been a standard practice to perform mechanical bowel preparation (MBP) prior to colorectal surgery to reduce the risk of colorectal anastomotic leakages (CAL). The latest Cochrane systematic review suggests there is no benefit for MBP in terms of decreasing CAL, but new studies have been published. The aim of this systematic review and meta-analysis is to update current evidence for the effectiveness of preoperative MBP on CAL in patients undergoing colorectal surgery. Consequently, PubMed, MEDLINE, Embase, CENTRAL and CINAHL were searched from 2010 to March 2017 for randomised controlled trials (RCT) that compared the effects of MBP in colorectal surgery on anastomotic leakages. The outcome CAL was expressed in odds ratios and analysed with a fixed-effects analysis in a meta-analysis. Quality assessment was performed by the cochrane risk of bias tool and grades of recommendation, assessment, development and evaluation (GRADE) methodology. Eight studies (1065 patients) were included. The pooled odds ratio showed no significant difference of MBP in colorectal surgery on CAL (odds ratio (OR) = 1.15, 95% CI = 0.68-1.94). According to GRADE methodology, the quality of the evidence was low. To conclude, MBP for colorectal surgery does not lower the risk of CAL. These results should, however, be interpreted with caution due to the small sample sizes and poor quality. Moreover, the usefulness of MBP in rectal surgery is not clear due to the lack of stratification in many studies. Future research should focus on high-quality, adequately powered RCTs in elective rectal surgery to determine the possible effects of MBP.

Mechanical bowel preparation for elective colorectal surgery: updated systematic review and meta-analysis

Mechanical bowel preparation (MBP) for elective colorectal surgery has been practiced as a clinical routine for many decades. However, earlier randomized clinical trials (RCTs) and meta-analyses suggest that MBP should be abandoned before colorectal surgery because of the futility in reducing postoperative complications and motility. The new published results from three RCTs comparing MBP with no MBP in colorectal surgery in 2010 make the updating of systemic review and meta-analysis necessary. The aim of this study was to estimate efficacy of MBP in prevention of postoperative complications for elective colorectal surgery. A literature search was performed mainly in electronic database including Cochrane Library, EMBASE, and MEDLINE. The inclusion criteria were randomized clinical trials comparing MBP with no MBP before colorectal surgery. Septic complications, reoperation, and death were recorded as primary and secondary outcomes. The meta-analysis was conducted according to the QUOROM statement. Fourteen RCTs were included in our analysis with a total number of 5,373 patients: 2,682 with MBP and 2,691 without. Comparing with no MBP for elective colorectal surgery, our study showed that MBP had not reduce any postoperative complications when concerning anastomotic leak [odds ratio (OR) 95% confidence interval (CI), 1.08 (0.82-1.43); P = 0.56]; overall SSI [OR 95% CI, 1.26 (0.94-1.68); P = 0.12]; extra-abdominal septic complications [OR 95% CI, 0.98 (0.81-1.18); P = 0.81]; wound infections [OR 95% CI, 1.21 (1.00-1.46); P = 0.05]; reoperation or second intervention rate [OR 95% CI, 1.11 (0.86-1.45); P = 0.42]; and death [OR 95% CI, 0.97(0.63-1.48); P = 0.88]. No evidence was noted supporting the use of MBP in patients undergoing elective colorectal surgery. MBP should be omitted in routine clinical practice.

Updated Systematic Review and Meta-Analysis of Randomized Clinical Trials on the Role of Mechanical Bowel Preparation Before Colorectal Surgery

Earlier meta-analyses of small randomized trials suggested that mechanical bowel preparation (MBP) should be omitted before colorectal surgery because it does not affect complication rates 0 mortality and may be even harmful; however, more recent large randomized trials suggested an increased occurrence of pelvic abscesses in the absence of MBP. Therefore, an updated large meta-analysis was conducted to re-evaluate the role of MBP in colorectal surgery. Furthermore, the influence of different kind of MBP regimes on infectious outcomes was examined. The meta-analysis was conducted according to the QUOROM statement; the inclusion criteria were randomized clinical trials comparing MBP with no MBP before colorectal surgery. The primary outcome was anastomotic leakage; secondary outcomes were other septic complications. Fourteen trials were included with a total number of 4859 patients: 2452 in the MBP group and 2407 in the no MBP group. We found no statistical difference between the groups for anastomotic leakage [OR = 1.12 (0.82-1.53), P = 0.46], pelvic or abdominal abscess (P = 0.75), and wound sepsis (P = 0.11). When all surgical site infections were considered, the meta-analysis favored no MBP [OR = 1.40 (1.05-1.87), P = 0.02].Sensitivity analyses showed similar results for all subgroups but when poor or small trials were excluded, there was a slightly higher risk of deep abdominal abscesses with no MBP, however, the number needed to harm was as high as 333 patients, suggesting this difference to be not clinically relevant. The use of different MBP regimes did not influence primary and secondary outcomes. The main limitation concerned rectal surgery for which the limited data preclude any interpretation. Although it did not confirm the harmful effect of mechanical bowel preparation (suggested by previous meta-analyses), this meta-analysis including almost 5000 patients, demonstrates with a high level of evidence that any kind of mechanical bowel preparation should be omitted before colonic surgery.