Earlier meta-analyses of small randomized trials suggested that mechanical bowel preparation should be omitted before colorectal surgery.
The earlier reasons were because it does not affect complication rates and may be even harmful.
However, more recent large randomized trials suggested an increased occurrence of pelvic abscesses in the absence of mechanical bowel preparation.
Therefore, an updated large meta-analysis was conducted to re-evaluate the role of mechanical bowel preparation in colorectal surgery.
|Mechanical bowel preparation regimes did not influence primary outcomes|
|Annals of Surgery|
Furthermore, the influence of different kind of mechanical bowel preparation regimes on infectious outcomes was examined.
Dr Karem Slim and colleagues from the Netherlands conducted a meta-analysis according to the QUOROM statement.
The inclusion criteria were randomized clinical trials comparing mechanical bowel preparation with no mechanical bowel preparation before colorectal surgery.
The primary outcome was anastomotic leakage, and secondary outcomes were other septic complications.
The research team included 14 trials with a total number of 4859 patients, with 2452 in the mechanical bowel preparation group, and 2407 in the no mechanical bowel preparation group.
The team found no statistical difference between the groups for anastomotic leakage, pelvic or abdominal abscess, and wound sepsis.
When all surgical site infections were considered, the meta-analysis favored no mechanical bowel preparation.
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 mechanical bowel preparation.
The research team found that the number needed to harm was as high as 333 patients, suggesting this difference to be not clinically relevant.
The use of different mechanical bowel preparation regimes did not influence primary and secondary outcomes.
The main limitation concerned rectal surgery for which the limited data preclude any interpretation.
Dr Slim’s team commented, “This study does not confirm the harmful effect of mechanical bowel preparation.”
“However, 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.”