1035 Meta-Analysis of Mechanical Bowel Preparation for Elective Colon and Rectal Resection

Despite prior publications, including several meta-analyses and randomized controlled trials, mechanical bowel preparation (MBP) remains the standard of practice for patients undergoing elective colorectal surgery.The aim of this paper is to review all the published prospective randomized controlled trials and perform a meta-analysis to evaluate the impact of MBP on anastomotic leak and wound infection rates.Materials and methods: We performed a systematic review of the literature of all trials that prospectively compared MBP with no MBP for patients undergoing elective colorectal surgical resection.We performed a search in MED-LINE, LILACS, and SCISEARCH, followed by a manual search of reference lists for each article found, as well as abstracts of pertinent scientific meetings.Experts in the field were queried as to knowledge of additional reported trials.The outcomes we abstracted were anastomotic leaks and wound infections.Meta-analysis was performed using Peto-Odds ratio.Results: Of 3247 patients (12 trials), 1634 were allocated to MBP (Group 1) and 1613 were allocated to no MBP (Group 2).Anastomotic leaks (Figure 1) occurred in 65(4%) patients in Group 1, and in 44(2.7%)patients in Group 2 (Peto OR=1.488,CI 95%:1.014-2.183,P=0.04).Wound infections occurred in 137(8.4%)patients in Group 1, and in 105(6.5%)patients in Group 2 (Peto OR=1.332,CI 95%:1.024-1.733,P=0.033).Subgroup analysis for low anterior resection favored no preparation.Discussion: This meta-analysis, that includes trials published in 2007, demonstrates that MBP provides no benefit to patients undergoing elective colorectal surgery and in fact, appears to be harmful, because the MBP group experienced higher anastomotic leak rates and wound infection rates.This data supports elimination of routine MBP in elective colorectal surgery and yet the persistence of the practice suggests that a multicenter randomized controlled trial may be necessary to provide sufficient evidence to change clinical practice.In conclusion, mechanical bowel preparation is of no benefit to patients undergoing elective colorectal resection and need not be recommended to meet "standard of care." 1036