[Feasibility of colorectal surgery without colonic preparation. A prospective study]

Impact of mechanical bowel preparation in elective colorectal surgery: A meta-analysis

AIM

To analyse the effect of mechanical bowel preparation vs no mechanical bowel preparation on outcome in patients undergoing elective colorectal surgery.

METHODS

Meta-analysis of randomised controlled trials and observational studies comparing adult patients receiving mechanical bowel preparation with those receiving no mechanical bowel preparation, subdivided into those receiving a single rectal enema and those who received no preparation at all prior to elective colorectal surgery.

RESULTS

A total of 36 studies (23 randomised controlled trials and 13 observational studies) including 21568 patients undergoing elective colorectal surgery were included. When all studies were considered, mechanical bowel preparation was not associated with any significant difference in anastomotic leak rates (OR = 0.90, 95%CI: 0.74 to 1.10, P = 0.32), surgical site infection (OR = 0.99, 95%CI: 0.80 to 1.24, P = 0.96), intra-abdominal collection (OR = 0.86, 95%CI: 0.63 to 1.17, P = 0.34), mortality (OR = 0.85, 95%CI: 0.57 to 1.27, P = 0.43), reoperation (OR = 0.91, 95%CI: 0.75 to 1.12, P = 0.38) or hospital length of stay (overall mean difference 0.11 d, 95%CI: -0.51 to 0.73, P = 0.72), when compared with no mechanical bowel preparation, nor when evidence from just randomized controlled trials was analysed. A sub-analysis of mechanical bowel preparation vs absolutely no preparation or a single rectal enema similarly revealed no differences in clinical outcome measures.

CONCLUSION

In the most comprehensive meta-analysis of mechanical bowel preparation in elective colorectal surgery to date, this study has suggested that the use of mechanical bowel preparation does not affect the incidence of postoperative complications when compared with no preparation. Hence, mechanical bowel preparation should not be administered routinely prior to elective colorectal surgery.

Laparoscopic colon resection: To prep or not to prep? Analysis of 1535 patients

BACKGROUND

Mechanical bowel preparation (MBP) before elective open colon resection does not reduce the rate of postoperative anastomotic leakage. However, MBP is still routinely used in many countries, and there are very limited data regarding the utility of preoperative MBP in patients undergoing laparoscopic colon resection (LCR). The aim of this study was to challenge the use of MBP before elective LCR.

METHODS

It is a retrospective analysis of a prospectively collected database. All patients undergoing elective LCR with primary anastomosis and no stoma were included. Preoperative MBP with polyethylene glycol solution was used routinely between April 1992 and December 2004, and then it was abandoned. The early postoperative outcomes in patients who had preoperative MBP (MBP group) and in patients who underwent LCR without preoperative MBP (No-MBP group) were compared.

RESULTS

From April 1992 to December 2014, 1535 patients underwent LCR: 706 MBP patients and 829 No-MBP patients. There were no differences in demographic data, indication for surgery and type of procedure performed between MBP and No-MBP group patients. The incidence of anastomotic leakage was similar between the two groups (3.4 vs. 3.6 %, p = 0.925). No differences were observed in intra-abdominal abscesses (0.6 vs. 0.8 %, p = 0.734), wound infections (0.6 vs. 1.4 %, p = 0.149), infectious extra-abdominal complications (1.8 vs. 3 %, p = 0.190), and non-infectious complications (6.1 vs. 6.8 %, p = 0.672). The overall reoperation rate was 4.6 % for MBP patients and 5 % for No-MBP patients (p = 0.813).

CONCLUSION

The use of preoperative MBP does not seem to be associated with lower incidence of intra-abdominal septic complications after LCR.

Comparison of oral polyethylene glycol plus a large volume glycerine enema with a large volume glycerine enema alone in patients undergoing colorectal surgery for malignancy: a randomized clinical trial

AIM

Recent meta-analyses and randomized clinical trials have concluded that mechanical bowel preparation (MBP) before elective colorectal surgery is not associated with a reduction of surgical site infection (SSI). The aim of this randomized clinical trial was to evaluate the impact of preoperative MBP for colon and rectal cancer surgery in comparison with a single glycerine enema.

METHOD

Patients scheduled for radical colorectal resection for malignancy with primary anastomosis were randomized to preoperative MBP (4 l of polyethylene glycol) (group 1, 114 patients) plus a glycerine 5% enema (2 l) or a single glycerine 5% enema (2 l) (group 2, 115 patients). The postoperative incidence of SSI was recorded prospectively. Patients undergoing minimally invasive surgery (laparoscopy or robotic) accounted for 55 and 51 in groups 1 and 2 respectively.

RESULTS

In all, 229 patients were included in the study, 114 in group 1 and 115 in group 2. At least one SSI was reported in 16 (14.0%) group 1 and in 20 (17.8%) group 2 patients (P=0.475). Perioperative mortality was nil. The incidence of SSI was comparable also in the 73 patients who had a low anterior resection (seven of 33 vs eight of 40, P=1.000), and for the 106 patients who underwent a minimally invasive procedure (nine of 55 vs four of 51, P=0.241).

CONCLUSION

A single large-volume glycerine enema is effective bowel preparation before colorectal resection whether performed by an open or minimally invasive technique.

Updated systematic review and meta-analysis of randomized clinical trials on the role of mechanical bowel preparation before colorectal surgery

BACKGROUND

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.

METHODS

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.

RESULTS

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.

CONCLUSION

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.