Does mechanical bowel preparation have a role in preventing postoperative complications in elective colorectal surgery?

B Mermillod,C Soravia

doi:10.4414/smw.2004.10452

Abstract

mechanical bowel preparation (MBP) consists of orthograde fluid preparation to clean the bowel. MBP is considered to prevent postoperative complications. meta-analysis of prospective randomised clinical trials (RCT) evaluating MBP versus no MBP. following a medline search we retrieved 15 prospective trials of which only 5 where RCT comparing MBP versus no MBP in elective colorectal surgery. For the randomised studies, there were respectively 186, 179, 149, 267 and 380 patients, including all type of resections. The total number of patients in these 5 studies was 1144 (565 with MBP and 579 with no preparation). All patients received perioperative antibiotic prophylaxis. Only one of these RCT show a significant decrease in anastomotic leak (AL), but among all the patients enrolled, AL is significantly more frequent in the group with MBP (Odds Ratio 1.8). Wound infection, re-operation and intra-abdominal abscess rates were more frequent in the MBP group but the difference did not reach statistical significance and the odds ratios for a 95% confidence interval were extremely large. there is limited evidence in the literature to support the use of MBP in patient undergoing elective colorectal surgery. Available data tend to suggest that MBP could be harmful with respect to the incidence of anastomotic leak. Moreover, MBP does not reduce the incidence of other infectious complications. Further RCTs are needed to establish an evidence-based rationale for the use of MBP in elective colorectal surgery.

Highlights

Mechanical bowel preparation, either by orthograde fluid ingestion or enema, is commonly used to prepare patients before colorectal surgery [1,2,3]
Among 15 prospective trials published in the world literature, only 5 were randomised trials evaluating mechanical bowel preparation (MBP) versus no MBP in patients undergoing elective colorectal surgery with only these being eligible for this meta-analysis [16, 23,24,25,26]
None of these five trials favour the use of MBP for elective colorectal surgery in patient receiving an antibiotic prophylaxis, and some suggest that MBP could be deleterious in terms of postoperative complication rates

Summary

Introduction

Mechanical bowel preparation, either by orthograde fluid ingestion or enema, is commonly used to prepare patients before colorectal surgery [1,2,3]. In a survey among colorectal surgeons, in 1997, Nichols [4] showed that 100% of responders used MBP in their patients and 87% used antibiotic prophylaxis. MBP is used because it is considered to decrease the rate of postoperative infectious complications and enable the surgeon to work with a clean bowel. In 1966, Plumley [5] developed a new regimen for bowel preparation and claimed that MBP should be performed in patients undergoing colorectal surgery arguing that the “usefulness of bowel cleaning has been recognised by world war surgeons”. In 1971, Goligher [6], in accordance with Everett [7], claimed that MBP should be performed in patients with inflammatory bowel disease before surgery, because gross faecal loading of the bowel was associated with an increase in wound infection incidence, but no increase in anastomotic leak rate. MBP was nearly uniformly accepted as a “dogma” in the seventies [10]

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