Mechanical bowel preparation for elective colorectal surgery (Review) Guenaga KKFG, Atallah ÁN, Castro AA, Matos D, Wille-Jørgensen P
This is a reprint of a Cochrane review, prepared and maintained by The Cochrane Collaboration and published in The Cochrane Library 2008, Issue 4 http://www.thecochranelibrary.com
Mechanical bowel preparation for elective colorectal surgery (Review) Copyright © 2008 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.
TABLE OF CONTENTS HEADER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ABSTRACT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . PLAIN LANGUAGE SUMMARY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . BACKGROUND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . OBJECTIVES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . METHODS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . RESULTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . DISCUSSION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . AUTHORS’ CONCLUSIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ACKNOWLEDGEMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . REFERENCES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . CHARACTERISTICS OF STUDIES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . DATA AND ANALYSES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Analysis 1.1. Comparison 1 Mechanical bowel preparation versus no preparation, Outcome 1 Anastomosis leakage stratified for colonic or rectal surgery. . . . . . . . . . . . . . . . . . . . . . . . . . . Analysis 1.2. Comparison 1 Mechanical bowel preparation versus no preparation, Outcome 2 Overall anastomotic leakage for colorectal surgery. . . . . . . . . . . . . . . . . . . . . . . . . . . . . Analysis 1.3. Comparison 1 Mechanical bowel preparation versus no preparation, Outcome 3 Mortality. . . . . Analysis 1.4. Comparison 1 Mechanical bowel preparation versus no preparation, Outcome 4 Peritonitis. . . . . Analysis 1.5. Comparison 1 Mechanical bowel preparation versus no preparation, Outcome 5 Reoperation. . . . Analysis 1.6. Comparison 1 Mechanical bowel preparation versus no preparation, Outcome 6 Wound infection. . Analysis 1.7. Comparison 1 Mechanical bowel preparation versus no preparation, Outcome 7 Infectious extraabdominal complications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Analysis 1.8. Comparison 1 Mechanical bowel preparation versus no preparation, Outcome 8 Non-infectious extraabdominal complications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Analysis 1.9. Comparison 1 Mechanical bowel preparation versus no preparation, Outcome 9 Surgical site infections. Analysis 1.10. Comparison 1 Mechanical bowel preparation versus no preparation, Outcome 10 Sensitivity analysis 1 Studies with dubious randomisation procedure excluded. . . . . . . . . . . . . . . . . . . . Analysis 1.11. Comparison 1 Mechanical bowel preparation versus no preparation, Outcome 11 Sensitivity analysis 2 Studies published as abstract only excluded. . . . . . . . . . . . . . . . . . . . . . . . Analysis 1.12. Comparison 1 Mechanical bowel preparation versus no preparation, Outcome 12 Sensitivity analysis 3 Studies including children excluded. . . . . . . . . . . . . . . . . . . . . . . . . . . Analysis 1.13. Comparison 1 Mechanical bowel preparation versus no preparation, Outcome 13 Sensitivity analysis 4 Studies including patients without anastomosis excluded. . . . . . . . . . . . . . . . . . . . WHAT’S NEW . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . HISTORY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . CONTRIBUTIONS OF AUTHORS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . DECLARATIONS OF INTEREST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . SOURCES OF SUPPORT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . NOTES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . INDEX TERMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Mechanical bowel preparation for elective colorectal surgery (Review) Copyright © 2008 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.
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[Intervention review]
Mechanical bowel preparation for elective colorectal surgery Katia KFG Guenaga1 , Álvaro N Atallah2 , Aldemar A Castro3 , Delcio Matos4 , Peer Wille-Jørgensen5 1 Surgical
Gastroenterology Department, Ferderal University of São Paulo, Guarujá, Brazil. 2 Brazilian Cochrane Centre, Universidade Federal de São Paulo / Escola Paulista de Medicina, São Paulo, Brazil. 3 Department of Public Health, State University of Heath Science, Maceió, Brazil. 4 Brazilian Cochrane Centre, Universidade Federal de São Paulo, São Paulo, Brazil. 5 Department of Surgical Gastroenterology K, Bispebjerg Hospital, Copenhagen NV, Denmark Contact address: Katia KFG Guenaga, Surgical Gastroenterology Department, Ferderal University of São Paulo, Marivaldo Fernandes, 152 apto. 13, Guarujá, São Paulo, 11 440-050, Brazil.
[email protected]. (Editorial group: Cochrane Colorectal Cancer Group.)
Cochrane Database of Systematic Reviews, Issue 4, 2008 (Status in this issue: Edited) Copyright © 2008 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd. DOI: 10.1002/14651858.CD001544.pub2 This version first published online: 24 January 2005 in Issue 1, 2005. Re-published online with edits: 8 October 2008 in Issue 4, 2008. Last assessed as up-to-date: 20 October 2004. (Dates and statuses?) This record should be cited as: Guenaga KKFG, Atallah ÁN, Castro AA, Matos D, Wille-Jørgensen P. Mechanical bowel preparation for elective colorectal surgery. Cochrane Database of Systematic Reviews 2005, Issue 1. Art. No.: CD001544. DOI: 10.1002/14651858.CD001544.pub2.
ABSTRACT Background For over a century the presence of bowel content during surgery has been linked to anastomotic leakage. Mechanical bowel preparation has been considered an efficient agent against leakage and infectous complications. This dogma is not based on solid evidence, but on observational data and expert’s opinions. Objectives To determine the effectiveness and safety of prophylactic mechanical bowel preparation for morbidity and mortality rates in elective colorectal surgery. Search strategy We searched MEDLINE, EMBASE, LILACS, and the Cochrane Central Register of Controlled Trials. We also searched relevant medical journals, and conference proceedings from major gastroenterological congresses and contacted experts in the field. We used the search strategy described by the Colorectal Cancer Review Group, without limitations for date of publication and language. I Selection criteria Randomised, clinical trials that compared any strategy in mechanical bowel preparation with no mechanical bowel preparation. Data collection and analysis Data were independently extracted by the reviewers and cross-checked. The same reviewers assessed the methodological quality of each trial. Details of the randomisation (generation and concealment), blinding, whether an intention-to-treat analysis was done, and the number of patients lost to follow-up was recorded. For analysis the Peto odds ratio (OR) was used as defaults. Main results Mechanical bowel preparation for elective colorectal surgery (Review) Copyright © 2008 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.
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Of the 1592 patients (9 trials), 789 were allocated to mechanical bowel preparation (Group A) and 803 to no preparation (Group B) before elective colorectal surgery. For anastomotic leakage (main outcome) the results were: - Low anterior resection: 9.8% (11 of 112 patients in Group A) compared with 7.5% (9 of 119 patients in Group B); Peto OR 1.45, 95% confidence interval (CI): 0.57 to 3.67 (non-significant); - Colonic surgery: 2.9% (Group A) compared with 1.6% (Group B) ; Peto OR 1.80, 95% CI: 0.68 to 4.75 (non-significant); Overall anastomotic leakage: 6.2% (Group A) compared with 3.2% (Group B); Peto OR 2.03, 95% CI: 1.276 to 3.26 (p=0.003). For the secondary outcome of wound infection the result was: 7.4% (Group A) compared with 5.4% (Group B); Peto OR 1.46, 95% CI: 0.97 - to 2.18 (p=0.07); Sensitivity analyses excluding studies with dubious randomisation, studies published as abstracts only, and studies involving children did not change the overall conclusions Authors’ conclusions There is no convincing evidence that mechanical bowel preparation is associated with reduced rates of anastomotic leakage after elective colorectal surgery. On the contrary, there is evidence that this intervention may be associated with an increased rate of anastomotic leakage and wound complications. It is not possible to be conclusion on the latter issue because of the clinical heterogeneity of trial inclusion criteria, methodological inadequacies in trial (in particular, poor reporting of concealment and allocation), potential performance biases, and failure of intention-to-treat analyses. Nevertheless, the dogma that mechanical bowel preparation is necessary before elective colorectal surgery should be reconsidered.
Mechanical bowel preparation for elective colorectal surgery (Review) Copyright © 2008 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.
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PLAIN LANGUAGE SUMMARY Key findings: Preoperative mechanical bowel preparation before colorectal surgery does not reduce anastomotic leakage. Preoperative mechanical bowel preparation before colorectal surgery is a widely-practised treatment, but its efficacy has never been proven outside observational studies and animal experiments. This systematic review of nine trials (1592 patients) found that there is no convincing evidence that mechanical bowel preparation is associated with reduced rates of anastomotic leakage after elective colorectal surgery, but on the contrary, there is evidence that this intervention may be associated with an increased rate of anastomotic leakage and wound complications. There was no difference in other outcomes, such as mortality, peritonitis, re-operation, infectious extra-abdominal complication, noninfectious extra-abdominal complication, and surgical site infection. Mechanical bowel preparation before colorectal surgery cannot be recommended as routine.
BACKGROUND The importance of efficient mechanical bowel preparation in preventing infectious complications and anastomotic dehiscence after colorectal surgery has been a dogma among surgeons for more than a century (Halsted 1887 ; Thornton 1997 ). Clinical experiences and observational studies have shown that mechanical removal of gross faeces from the colon has been associated with decreased morbidity and mortality in patients undergoing operations of the colon (Nichols 1971). One author (Chung 1979) was categorical: “One of the most important factors within the control of the surgeon, that affect the outcome of a colonic operation, is the degree of emptiness of the bowels”. An early randomised clinical trial questioned this view and concluded that vigorous mechanical bowel preparation is not necessary (Hughes 1972). Omission of enemas and bowel washes from the preoperative procedures will be welcomed by both patients and nursing staff. One trial (Irving 1987) questioned the necessity of preoperative or intra operative mechanical bowel preparation of the colon, before primary anastomosis. The authors argue that preoperative bowel preparation is time-consuming, expensive, and unpleasant for patients - even dangerous on occasion - and completely unnecessary. Traditionally, “bowel preparation” has been used to reduce faecal mass and also bacterial counts. Most surgeons consider mechanical bowel preparation to be essential, and the systematic administration of appropriate antibiotics has been shown effective in reducing infectious complications in numerous randomised trials. Furthermore, mechanical bowel preparation is recommended by many guidelines from surgical associations and scientific societies (ASCGBI 2001; Moore 1999; SIGN 1997). Different methods of mechanical bowel preparation have been tested and approved and the potential danger of having faeces in contact with a newly performed anastomosis when the colon was not prepared has been discussed (Grabham 1995 ; Mealy 1992 ). Both experimental studies (Smith 1983; O’Dwyer 1989;
Schein 1995), and clinical trials in emergency surgery (Baker 1990; Dorudi 1990; Duthie 1990) have been published in order to support this theory. Two randomised trials from Ireland and Brazil concluded that the role of bowel preparation in colorectal surgery requires re-evaluation (Burke 1994; Santos 1994). If bowel preparation is shown to be needless, it could mean a shorter hospital stay for the patient and avoidance of the potential complications associated with the cleansing procedure such as gastric intolerance, low serum potassium level, bowel explosion, mucosal lesions, electrolyte disturbance and fluid overload. Analysed in isolation, the results of published trials have not shown any significant difference in outcomes between patients who underwent mechanical bowel preparation and those who did not, but as the individual studies contain a high risk of a statistical type II error it seemed justified to perform a meta-analysis.
OBJECTIVES To determine the necessity of prophylactic mechanical bowel preparation in patients undergoing elective colorectal surgery. The incidence of anastomotic dehiscence is increasing as more anal the anastomosis is performed (Goligher 1970). Because bowel preparation might have different effect in colon and rectum, we will stratify the analyses for colon and rectum separately whenever possible.
METHODS Criteria for considering studies for this review Types of studies
Mechanical bowel preparation for elective colorectal surgery (Review) Copyright © 2008 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.
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(i) Randomised clinical trials comparing preoperative mechanical bowel preparation versus no preparation (or placebo) in (ii) patients undergoing elective colorectal surgery and in which (iii) the primary outcome (anastomotic leakage) is clearly stated in both treatment arms. To be included in this review, trials had to meet all three criteria. EXCLUSION CRITERIA: Studies evaluating two or more different cleansing methods; studies including patients undergoing emergency surgery. Types of participants Patients undergoing elective colorectal surgery. Types of interventions Any strategy in mechanical bowel preparation for patients undergoing elective colorectal surgery compared to no mechanical bowel preparation. Types of outcome measures PRIMARY OUTCOME MEASURES: 1) Anastomotic leakage, defined as discharge of faeces from the anastomosis site, externalising through the drainage opening or the wound incision; or just the existence of an abscess adjacent to the anastomosis site. The anastomotic leakage was confirmed by either clinical or radiological investigation. The type of surgery and anastomosis site were stratified in: A: Low anterior resection, extra-peritoneal anastomosis (rectum considered extra-peritoneal); B: Colonic surgery, intra-peritoneal anastomosis. 2) Overall anastomotic leakage: total number of anastomotic dehiscence in all of colon and rectum. SECONDARY OUTCOME MEASURES: 3) Mortality: number of postoperative deaths related to the surgery. 4) Peritonitis: presence of postoperative infections at the abdominal cavity, localized (abscess) or not. 5) Re-operation: surgical re-intervention for anastomotic complication. 6) Wound infection: defined as a discharge of pus from the abdominal wound. 7) Infectious extra-abdominal complication: postoperative infectious complication at extra-abdominal site. 8) Non-infectious extra-abdominal complications (e.g. deep venous thrombosis, cardiac complications, wound rupture). 9) Overall infections in surgical sites. SENSITIVITY AND SUBGROUP ANALYSES 10) Anastomotic leakage and wound infection in studies with adequate randomisation. 11) Anastomotic leakage and wound infection in studies published as full articles. 12) Anastomotic leakage and wound infection in studies only dealing with adult patients.
13) Anastomotic leakage and wound infection in studies in which bowel continuity was restored.
Search methods for identification of studies See: Collaborative Colorectal Cancer Review Group search strategy (Wille-Jørgensen 1999). The studies were identified from the following sources: MEDLINE, EMBASE, CINAHL, LILACS, SCISEARCH, Controlled Clinical Trials Database, Trials Register of the Cochrane Colorectal Cancer Group, and the Cochrane Central Register of Controlled Trials (CENTRAL). Reference lists were checked, handsearching was carried out, and through letters sent to study authors. Conference proceedings from major gastrointestinal conferences (World Congress of Gastroenterology, Annual Meetings of American Sociery of Colon and Rectal Surgery, Annual meetings of Association of Coloproctology of Great Britain and Ireland, Tripartites meetings) were scrutinised back to 1994 (last possible retrieval of abstract-material). There were no limits regarding language, date, or other restrictions in the searches. All searches were performed up to July 2004. Search strategy: #1 Cochrane Collaboration search strategy for randomised controlled trials (Handbook 2004) #2 Tw INTESTIN* or Tw BOWEL #3 Tw LARGE or Tw GROSSO or Tw GRUESO #4 #2 and #3 #5 Tw COLO* or Tw CECO #6 Tw RECT* or Tw RET* #7 #4 or #5 or #6 #8 #3 and #7 #9 Tw PREPARA* #10 Tw SURGERY or SURGICAL #11 #8 and #9 and #10 #12 #1 and #11
Data collection and analysis LOCATING AND SELECTING STUDIES The reviewers (KFG and PWJ) independently selected the trials to be included in this review. Disagreement on selection was solved in a consensus meeting. Only studies designed and stated as randomised controlled trials were considered for inclusion. CRITICAL APPRAISAL OF STUDIES The reviewers assessed the methodological quality of each trial. We recorded details of the randomisation method, blinding, whether an intention-to-treat analysis was done, and the number of patients lost to follow-up to evaluate the risk of bias in the individual studies (Handbook 2004). We assessed the external validity of the studies in an analysis of the characteristics of the participants and the interventions as collected below. COLLECTING DATA
Mechanical bowel preparation for elective colorectal surgery (Review) Copyright © 2008 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.
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We included studies in which allocation concealment was regarded adequate were included. A few studies with unclear allocation concealment were included as well . The reviewers independently extracted and cross-checked the data. The result of each trial was summarised in 2 x 2 tables for each outcome. We evaluated study validity according to participants and interventions: PARTICIPANTS: Category of disease (colorectal cancer, inflammatory disease, megacolon, polyposis, diverticular disease), gender, age, topography, operative procedure, antibiotic therapy, surgeon experience. The calculation of the sample size and the sample representativeness was observed. INTERVENTIONS: Types of mechanical bowel preparation: anterograde (oral) or retrograde (enemas) versus no mechanical bowel preparation. Information data from the studies published more than once, was only included once. Data were entered into Review Manager 4.2 by single data-entry by KFG and controlled by PWJ. ANALYSING AND PRESENTING RESULTS If appropriate we stratified the studies for different meta-analysis (Review Manager 4,2) according to the analysis of the defined outcomes. We used various techniques: in the dichotomous outcome measures, the combined logarithm of the Peto Odds Ratio (fixed effect model) was used as default. We performed a test for statistical heterogeneity in each case. If we detected heterogeneity, results were reported as Odds Ratio using random-effects modelling. For the analysis, we reviewed only patients who underwent elective colorectal surgery; according to type of interventions, type of participants, to assess whether there were important differences between them. All inclusion criteria had to be met. We assessed statistical heterogeneity and potential publication bias in the results of the meta-analysis both by inspection of graphical presentations (“funnel plot”: plotting the study weight or sample size (on the “Y” axis) against the Odds Ratio (on the “x” axis) and by calculating a test of heterogeneity (standard chi-squared test on N degrees of freedom where N equals the number of trials contributing data minus one). The funnel plot is possible for outcomes described in five or more studies. Three possible reasons for heterogeneity were pre-specified: (i) that responses differ according to difference in the quality of the trial; (ii) that response differ according to sample size; (iii) that response differ according to clinical heterogeneity. If we detected heterogeneity, sensitivity analyses were performed in subgroups. SENSITIVITY ANALYSIS. We used a fixed sample model with Peto Odds ratio was used as default. If heterogeneity was apparent, a random effects model was applied. IMPROVING AND UPDATING THIS REVIEW As a minimum, updates will be considered on an biannual basis. This is the first update performed two years after the first appearance in The Cochrane Library. Three additional studies have been
included, and one study previously included as an abstract is now included as a full paper version.
RESULTS Description of studies See: Characteristics of included studies; Characteristics of excluded studies. We identified fourteen studies of which nine were included, and five trials were excluded. The reason for exclusion was absence of a control group (Irving 1987 , Dorudi 1990 , Duthie 1990 ), elemental diet in the control group (Matheson 1978), or lack of description of the primary outcome and insufficient description of the secondary outcomes (Hughes 1972) see “Characteristics of excluded studies”. One of the included studies was published in Portuguese (Fillmann 1995 ), and identified in the Lilacs database. One study was in Spanish (Tabusso 2002 ). The others were published in English language. Three studies were published as abstracts only (Brownson 1992, Bucher 2003 , Fa-Si-Oen 2003 ). Data from the latter study were retrieved from another publication (Slim 2004). Three new studies were identified and included in this update (Bucher 2003 , Tabusso 2002 , Fa-Si-Oen 2003 ). Two were conference proceedings (Bucher 2003, Fa-Si-Oen 2003). TYPES OF PARTICIPANTS The inclusion criteria was the same for all studies: patients admitted for elective colorectal surgery. One trial (Santos 1994) included children. Two studies included patients without anastomosis (Fillmann 1995, Santos 1994); one study (Brownson 1992) excluded these patients in only one of the outcomes: anastomosis leakage; two of them (Burke 1994, Miettinen 2000) excluded patients for whom bowel continuity was not restored. In two of the new trials included in the review (Bucher 2003 , Tabusso 2002) one of the inclusion criteria was patients undergoing elective “left-sided” colorectal surgery. One new trials stated only “elective colorectal surgery” (Fa-Si-Oen 2003). None of the studies reported the use of preoperative adjuvant chemotherapy or radiation. Seven stated use of prophylactic antibiotics, and there was no information on this from two studies (Zmora 2003, Bucher 2003) . Five trials (Burke 1994, Fillmann 1995, Miettinen 2000, Santos 1994, Zmora 2003) described the two allocation groups as being equal according to gender, age, types of operation, and diagnosis. Three of them (Brownson 1992, Bucher 2003, Fa-Si-Oen 2003) did not give details. One (Tabusso 2002 ) described a statistic difference between the two groups regarding age, hemoglobin level and serum albumin. The criteria for exclusion of patients were reported in different ways: A) patients who had been taken antibiotics for at least 15 days before surgery, or if there was evidence of infection, or any associated disease requiring antibiotic therapy, and patients in whom
Mechanical bowel preparation for elective colorectal surgery (Review) Copyright © 2008 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.
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the mechanical bowel preparation was not feasible (Santos 1994); B) any patients who could not tolerate the preparation; C) patients who had bowel preparation for colon one week before surgery, patients who where unable to drink the solution, patients not requiring opening of the bowel, and one patient who refused to be randomised (Miettinen 2000); D: Two trials excluded patients in whom bowel continuity was not restored (Burke 1994, Miettinen 2000). One trial (Brownson 1992) excluded the patients in whom bowel continuity was not restored in the analysis of the primary outcome: anastomotic leakage. E: One of the trials (Zmora 2003) included only patients with primary anastomosis. F) no patients were excluded, (Fillmann 1995 ) ; G) did not give details on exclusion (Brownson 1992, Bucher 2003, Tabusso 2002, Fa-Si-Oen 2003 ). Two studies, (Fillmann 1995 , Santos 1994 ), included patients undergoing any of the following surgical procedures: abdominal excision of the rectum, Hartman’s procedure, defunctioning colostomy, colonic anastomosis with colostomy; some of the patients without anastomosis. One of the trials (Tabusso 2002) included patients without anastomosis. TYPES OF INTERVENTIONS All of the included studies compared mechanical bowel preparation with no preparation of the bowel prior to colorectal surgery : Preparation of the bowel was either polyethylene glycol electrolyte solution; laxatives (mineral oil, agar and phenolphthalein); mannitol; enemas (water, 900 ml; glycerin, 100 ml); sodium picosulphate 10 mg; Bisacodyl (10 mg)+enemas; and diets, low and nonresidue. Only two studies mentioned the experience of the surgeon. wo of them (Burke 1994, Miettinen 2000) described the operations performed by or under the supervision of a consultant surgeon; one (Santos 1994), described the operations performed by senior residents. The duration of follow-up was described as follows: A) 30 days or until hospital discharge (Santos 1994 ); B) 30 days after surgery (Fillmann 1995 , Zmora 2003 ) ; C) 1-2 months after surgery (Miettinen 2000 ); D) less clearly (Burke 1994 , Tabusso 2002 ): 7 days after surgery ; E) not described (Brownson 1992, Bucher 2003, Fa-Si-Oen 2003). TYPES OF OUTCOMES MEASUREMENTS PRIMARY OUTCOMES 1) Anastomotic leakage: two of the studies (Burke 1994; Miettinen 2000) stratified the anastomosis between rectal and colonic. Data on stratification were obtained by personal contact with two authors (Zmora 2003, Santos 1994). The others (Brownson 1992, Fillmann 1995, Tabusso 2002, Fa-Si-Oen 2003) did not refer to the site of the anastomosis. Two studies described all anastomosis to be left-sided (Bucher 2003, Zmora 2003). 2) Overall anastomotic leakage: All the included studies described this outcome. SECONDARY OUTCOMES 3) Mortality: five of the studies described this outcome (Burke
1994, Fillmann 1995, Miettinen 2000, Santos 1994, Zmora 2003). 4) Peritonitis: four of the studies (Brownson 1992, Fillmann 1995, Miettinen 2000,Tabusso 2002) included this. 5) Re operation: four trials described this outcome (Burke 1994, Fillmann 1995, Miettinen 2000, Santos 1994). 6) Wound infection: all of the included studies described it (Brownson 1992, Bucher 2003 , Burke 1994 , Fa-Si-Oen 2003 , Fillmann 1995 , Miettinen 2000 , Santos 1994 , Tabusso 2002 , Zmora 2003). 7) Infectious extra-abdominal complication: two studies (Fillmann 1995; Miettinen 2000) described this outcome. 8) Non-infectious extra-abdominal complication: four studies (Burke 1994; Fillmann 1995; Miettinen 2000, Zmora 2003) described this. 9) Surgical site infection: two studies (Miettinen 2000 , Zmora 2003). OTHER CHARACTERISTICS None of the studies contained an indication of how the sample size was calculated. One author (Fillmann 1995 ) replied to our enquiry that the sample size was calculated, but didn’t give more details. Two of the studies(Burke 1994, Miettinen 2000) described the sampling as consecutive. SENSITIVITY ANALYSIS AND SUBGROUP ANALYSES ON ANASTOMOTIC LEAKAGE AND WOUND INFECTION In five of the studies (Brownson 1992, Bucher 2003, Burke 1994, Tabusso 2002 , Fa-Si-Oen 2003 ) the allocation method was not well-described . A sensitivity analysis was performed leaving out these studies (outcome 10). As three of the studies (Brownson 1992, Bucher 2003; Fa-Si-Oen 2003) were published as abstracts, an analysis was performed, leaving out these studies (outcome 11). In one study (Santos 1994) children were included. This study was excluded in the third sensitivity analysis (outcome 12). In three of the trials (Fillmann 1995 , Santos 1994, Tabusso 2002 ) patients without anastomosis were included and an analysis was carried out without these studies(outcome 13).
Risk of bias in included studies None of the studies used an intention to treat analysis. SELECTION BIAS (Systematic differences in comparison groups) In two trials (Santos 1994, Miettinen 2000), the allocation process was described as randomised cards. One author (Fillmann 1995) replied to our enquiries and described the process using a random number table. In one study a computer generated list was used (Zmora 2003 ). In these studies the allocation process was considered sufficient. In the others (Brownson 1992, Bucher 2003 , Burke 1994, Tabusso 2002, Fa-Si-Oen 2003), the allocation process was not clearly specified and thus considered unclear, leading to a sensitivity analysis. In general, the allocation concealment in all studies was not described. This is known to create biases (Juni 2002).
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PERFORMANCE BIAS (Systematic differences in care provided apart from the intervention being evaluated) None of the studies reported the use of preoperative adjuvant chemotherapy or radiation. They all used prophylactic antibiotics, and all but two (Brownson 1992, Bucher 2003 ) described the two allocation groups as being equal according to gender, age, types of operation, and diagnosis. Another one (Tabusso 2002 ) indicated a difference between the allocation groups with the age, haemoglobin level and serum albumin. No relevant performance bias was thus detected BLINDING One trial (Fillmann 1995) described as a double-blind, in which orange juice was used as placebo, must be considered only to the surgeon due to the differences in taste for the patient between the intervention and the control. One study (Burke 1994 ) was described as a single-blind study, as the surgeons were aware of allocation of patients to bowel preparation. The rest of the studies contained no mention of blinding methods. ATTRITION BIAS (Systematic differences in withdrawals from the trial) Brownson 1992, Bucher 2003, Tabusso 2002, Fa-Si-Oen 2003 did not describe withdrawals or dropouts. Burke 1994 had 9.1% (17/ 186 patients) withdrawal, and no dropout; Santos 1994 , with 5% (8/157 patients) withdrawal, and no dropout, and Zmora 2003 8.6% (35/415). Two trials (Fillmann 1995, Miettinen 2000) described that all patients completed the study. The author of Fillmann 1995 supplied this information on written request. DETECTION BIAS (Systematic differences in outcomes assessment) No studies described any kind of concealment of assessment was described, except for the blinding procedure in the Fillmann-study (Fillmann 1995). (Burke 1994 ) measured the incidence of anastomotic leakage in the first half of the study by performing water soluble contrast enemas in all patients. In the second half of the study, enema was used on clinical suspicion of leakage due to the experience that two of the six leaks on day 7 after surgery occurred immediately after administration of the routine water-soluble contrast enema. The contrast enema was used on clinical suspicion in four trials (Burke 1994; Miettinen 2000; Santos 1994; Fillmann 1995). For the diagnostics of the various outcomes, the trials: a) did not describe the methodology (Brownson 1992, Bucher 2003, Tabusso 2002, Fa-Si-Oen 2003); b) used clinical symptoms and laboratory results (Burke 1994 , Santos 1994); c) used laboratory results in patients in whom the clinical diagnosis was unclear (Fillmann 1995); d) described all of the methods used for diagnosing the complications (Miettinen 2000, Zmora 2003). As stated in the beginning of this section, none of the studies used an intention to treat analysis. Eight patients were excluded after randomisation from one study (Santos 1994 ), 17 from another
(Burke 1994), and 35 from a third (Zmora 2003). In two studies no patients were excluded (Fillmann 1995, Miettinen 2000). The others, gave no information on exclusion (Brownson 1992, Bucher 2003, Tabusso 2002, Fa-Si-Oen 2003).
Effects of interventions Nine randomised controlled trials including a total of 1592 patients, of whom 789 were allocated for mechanical bowel preparation (Group A), and 803 for no bowel preparation (Group B) prior to elective colorectal surgery were included. The results of each outcome were: PRIMARY OUTCOMES: 1) Anastomotic leakage - stratified: A) Low anterior resection: 9.8% (11 of 112 patients in Group A) compared to 7.5% (9 of 119 patients in Group B); Peto OR 1.45, 95% CI: 0.57 to 3.67 (non-significant) - no statistical heterogeneity (Burke 1994, Miettinen 2000, Santos 1994, Zmora 2003); B) Colonic surgery: 2.9% (11 of 367 patients in Group A) compared to 1.6% (6 of 367 patients in Group B) ; Peto OR 1.80, 95% CI: 0.68 to 4.75 (non-significant) - no statistical heterogeneity (Burke 1994, Miettinen 2000, Santos 1994, Zmora 2003); 2) Overall anastomotic leakage: Overall anastomotic leakage: 6.2% (48 of 772 patients in Group A) compared to 3.2% (25 of 777 patients in Group B); Peto OR 2.03, 95% CI: 1.276 to 3.26 (p=0.003) - no statistical heterogeneity. (Brownson 1992, Bucher 2003 , Burke 1994 , Fillmann 1995 , Santos 1994 , Miettinen 2000 , Tabusso 2002 , Zmora 2003,Fa-Si-Oen 2003); SECONDARY OUTCOMES: 3) Mortality: 1% (5 of 509 patients in Group A) compared to 0.6% (3 of 516 patients in Group B); Peto OR 1.72, 95% CI: 0.43 to 6.95 (non-significant) - no statistical heterogeneity (Burke 1994, Fillmann 1995, Miettinen 2000, Santos 1994, Zmora 2003); 4) Peritonitis: 5.7% ( 16 of 278 patients in Group A) compared to 2.5% (7 of 275 patients in Group B); Peto OR 2.28, 95% CI: 0.99 to 5.25) (p=0.05) - no statistical heterogeneity (Brownson 1992, Fillmann 1995, Miettinen 2000, Tabusso 2002); 5) Reoperation: 4.0% ( 16 of 393 patients in Group A) compared to 2.2% (9 of 392 patients in Group B); Peto OR 1.80, 95% CI: 0.81 to 3.98) (non-significant) - no statistical heterogeneity (Bucher 2003 , Burke 1994 , Fillmann 1995 , Miettinen 2000 , Santos 1994,Tabusso 2002); 6) Wound infection: 7.4% (59 of 789 patients in Group A) compared to 5.4% (43 of 803 patients in Group B); Peto OR 1.46, 95% CI: 0.97 to 2.18 (p=0.07) - no statistical heterogeneity (Brownson 1992, Bucher 2003, Burke 1994, Fillmann 1995, Miettinen 2000, Santos 1994, Tabusso 2002, Zmora 2003); 7) Infectious extra-abdominal complication: 8.3% ( 14 of 168 patients in Group A) compared to 9.4% (15 of 159 patients in Group B); Peto OR, 95%: 0.87 (0.41 to 1.87) (non-significant) no statistical heterogeneity (Fillmann 1995, Miettinen 2000);
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8) Non-infectious extra-abdominal complication: 16.8% ( 73 of 433 patients in Group A) compared to 16.1% (71 of 439 patients in Group B); Peto OR 1.19, 95% CI: 0.61 to 2.32 (non-significant) - no statistical heterogeneity (Burke 1994, Fillmann 1995, Miettinen 2000); 9) Surgical site infection: 9.8% (31 of 325 patients in Group A) compared to 8.3% (27 of 322 patients in Group B); Peto OR 1.20, 95% CI: 0.70 to 2.05 (non-significant) - no statistical heterogeneity (Miettinen 2000, Zmora 2003); SENSITIVITY ANALYSES: Applying the random effects model in the only statistical significant outcome still shows significant difference in favour of avoiding cleansing. OR 2.09, CI: 1.16 to3.78, p =0.01. 10) Excluding the four studies where the allocation procedure was considered unclear did not change the Peto OR substantially for the two clinical most important outcomes (anastomosis leakage and wound infection), although the significance disappeared due to the smaller total the sample size (p = 0.1 and 0.14 respectively). 11) Excluding the two studies only presented as abstracts substantially changed neither the Peto OR nor the level of significance for the two analysed outcomes. 12) Excluding the study which included children did not change the significant higher incidence of anastomotic leakage in the mechanical bowel preparation group, but the potential negative effect of cleansning on wound infection became smaller. 13) Excluding the studies that included patients without anastomosis for the outcome anastomosis leakage, the Peto OR was 2.14 (p = 0.03) compared with the Peto OR of 2.29 (p = 0.002) before these studies were excluded. There was no substantially difference for the wound infection outcome.
DISCUSSION In 1987 Irving (Irving 1987) questioned the efficacy of mechanical bowel cleansing. The study was criticised by the editor (Johnston 1987): “the paper which challenges accepted surgical practice, is a veritable little bomb of a paper, brief, iconoclastic, and disrespectful of hallowed tradition in colorectal surgery”. At that time, the mechanical bowel preparation was an incontestable routine - and still is according to guidelines from some surgical associations and scientific societies (ASCGBI 2001 ; Moore 1999 ; SIGN 1997 ), while other guidelines are now more up to date (Kronborg 2002). The nine included trials were all prospective and randomised. Typically for studies of surgical practice, the allocation procedure was not very well described, but was considered adequate in half of the studies. Most of the studies were performed before the importance of allocation concealment (Schulz 1996) became general knowledge. Only one of the studies tried to include some kind of blinding (Fillmann 1995) - an almost impossible task in trials of this kind. Despite these methodological flaws, the included studies must be considered of such a scientific value that their conclu-
sions should be taken into consideration, when trying to answer the question stated under ’objectives’. We found no convincing evidence that mechanical bowel preparation before elective colorectal surgery reduces the incidence of postoperative complications. When looking at the primary outcome - anastomosis leakage - mechanical bowel preparation was dangerous when looking at colorectal surgery as a whole (statistically significant result). The subgroup analyses did not alter the direction of association, although the statistical significance disappeared. The outcome anastomosis leakage was split into leakage after low anterior resection and leakage after colonic surgery. It was only possible to obtain results from four authors (Burke 1994, Santos 1994 , Miettinen 2000 , Zmora 2003 ). After this stratification, the results tended to favour the group without mechanical bowel preparation. Some of the studies included patients in whom bowel continuity was not restored when analysing the outcome anastomosis leakage (Tabusso 2002; Fillmann 1995; Santos 1994). Because the number of non-anastomotic patients were equally distributed between the groups so we do not feel this potential bias to be of significance. None of the studies included an intention to treat-analysis nor had any of the authors calculated the sample size before the study. Seven of the studies must be considered underpowered from the beginning - only the Peruvian study (Tabusso 2002 ) showed its own significance in favour of no cleansing. In this respect, the metaanalysis is a good tool, and when there is no heterogeneity among the studies the overall result can be accepted as valid. Allthough no statistical heterogeneity was found between the outcomes of the individual studies, some methodological and clinical heterogeneity exists. Whether or not this should modify the conclusions is debatable. We have tried with sensitivity-analysis to elucidate the consequences of the heterogeneity, and none of the analysis led to the conclusion that preparation would be of benefit for the patient. The significance for the primary outcome although disappers in some of the analyses, but the tendency is still strong, and always in the same direction - preparation might lead to more anastomotic leakage. When performing the sensitivity-and subgroup-analyses the reduced volume of material makes the analyses statistically underpowered. This increases the risk of a type II error when evaluating the primary outcome. The Peto Odds Ratio remains almost unchanged during the sensitivity-analyses although the significance disappears. This strongly supports the conclusion: Mechanical bowel cleansing leads to more anastomotic dehiscence in colorectal surgery. A stratified analysis between colonic and rectal surgery was only feasible for four studies, and the results were inconclusive, although the tendency goes in the same direction as the overall results bowel preparation cannot be recommended in patients undergoing elective colorectal surgery.
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Only one of the included trials evaluated the length of hospital stay (Tabusso 2002 ), and found that the group of patients that underwent mechanical bowel preparation had a longer hospital stay than the other group of patients (statistically significant). It would be interesting to know how much time is needed to stay at the hospital before the surgery, just for the bowel to be cleaned. Analysing the types of interventions, from the table of included studies, could provide some indication: A) patients were prepared one day before surgery (Group A); the patients of Group B have to be at the hospital in a few hours before surgery (Brownson 1992, Burke 1994, Miettinen 2000); B) No difference due to the “doublle-blind” design, (Fillmann 1995); C) needed 5 days for Group A; and 1 day, for Group B (Santos 1994); D) patients were admitted to the hospital 48 hours before the surgery (Tabusso 2002). See “Characteristics of included studies”. In the protocol of the review, we discussed “length of hospital stay” as an outcome, but the trials did not describe this point clearly, and thus this outcome was excluded from the comparisons. All included studies and almost all of the excluded studies used prophylactic antibiotics in each group. This has raised the question of whether the antibiotic use could explain why no effect of the mechanical bowel preparation was found. This review cannot give any substantial information on this matter. The results of this review do not show any benefit of performing mechanical bowel preparations. A “semi prepared” colon is usually full of liquid faeces that can be difficult to control, resulting in spillage into the peritoneal cavity which can cause significant contamination. By omitting mechanical preparation one overcomes the problems of the poorly prepared bowel. The content of the bowel (bulky stools) can be manipulated into the bowel segment to be resected , enough to make the site of the anastomosis clear.
AUTHORS’ CONCLUSIONS Implications for practice Prophylactic mechanical bowel preparation before colorectal surgery has not been proven valuable for patients. Controversially it seems that the preparation might lead to more anastomotic leakage and thus the procedure should be omitted.
Implications for research The results of this systematic review show the necessity of completing more trials addressing the safety and the clinical effectiveness of mechanical bowel preparation compared with no preparation before elective colorectal surgery. Concealment of allocation is imperative, especially as such a trial would probably require a multicentre design. Stratification between colonic and rectal surgery is important. The use of pre-operative radiotherapy needs to be registered. Collaborative (properly designed) randomised controlled trials that involve a large, representative number of individuals, with explicit clinical inclusion and exclusion criteria, well defined hospital discharge criteria, sufficient duration of follow-up, description of dropouts and withdrawals, and uniform diagnosis of all relevant outcome measures should be planned.
ACKNOWLEDGEMENTS We want to thank the Cochrane Colorectal Cancer Group for hosting one of the reviewers (KFG) for three weeks (November, 1999), to finish the review. We also want to thank Dr. Zmora, Dr. Santos and Dr. Fillmann for supplying us with supplementary data. Thanks to Mr. Henning K. Andersen and Mrs. Ina Fjeldmark for assisting with the review, and their special attention, when KFG was in Copenhagen. The Valerie Jefferson Fund kindly supported this review financially
REFERENCES
References to studies included in this review Brownson 1992 {published data only} ∗ Brownson P, Jenkins AS, Nott D, et al.Mechanical bowel preparation before colorectal surgery: results of a prospective randomized trial. Br J Surg. 1992; Vol. 79:461–462. Bucher 2003 {published data only} ∗ Bucher P, Gervaz P, Erné M, Schmid JF, Chautems R, Huber O, et al.[Mechanical bowel preparation vs. no preparation in patients undergoing elective left-sided colorectal surgery: a prospective, randomized trial.]. 2003.
Burke 1994 {published data only} Burke P, Mealy K, Gillen P, Joyce W, Traynor O, Hyland J. Requirement for bowel preparation in colorectal surgery. British Journal of Surgery 1994;81(6):907–910. [MEDLINE: 8044619]
Fa-Si-Oen 2003 {unpublished data only} Fa-Si-Oen PR, Buitenweg JA, van Geldere D, deWaard JW, Swank X, Putter H, et al.The effect of preoperative bowel preparatyion with polyethylene glycol on surgical outcome in elective open colorectal surgery - a randomised multicentre trial.. Fourth Belgian Surgical Week, Ostende 2003; Vol. –:–.
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Fillmann 1995 {published data only} ∗ Fillmann EEP, Fillmann HS, Fillmann LS. Elective colorectal surgery without prepare [Cirurgia colorretal eletiva sem preparo]. Revista Brasileira de Coloproctologia 1995;15(2):70–71. Fillmann HS, Fillmann LS. Elective colorectal surgery without prepare [Cirurgia coloretal eletiva sem preparo.]. São Paulo, 1995. Miettinen 2000 {published data only} Miettinen P, Laitinen S, Makela J, Paakkonen M. Bowel preparation is unnecessary in elective open colorectal surgery. A prospective, randomized study.. Digestion. Vienna, 1998; Vol. supplement 3. [: GaPP0165]
Memon 1997 {published data only} Memon MA, Devine J, Freeney J, From SG. [Is mechanical bowel preparation really necessary for elective left sided colon and rectal surgery?]. International Journal of Colorectal Disease 1997;12:298– 302.
Additional references ASCGBI 2001 The Association of Coloproctology of Great Britain and Ireland. Guidelines for the management of colorectal cancer (2001). Guidelines for the management of colorectal cancer. London: The Association of Coloproctology of Great Britain and Ireland, 2001.
Miettinen RPJ, Laitinen ST, Makela JT, Paakkonen ME. Bowel preparation with oral polyethylene glycol electrolyte solution vs. no preparation in elective open colorectal surgery. Diseases of Colon and Rectum 2000;43(5):669–677.
Chung 1979 Chung RS, Gurll NJ, Berglund EM. A controlled trial of whole gut lavage as a method of bowel preparation for colonic operations. Am J Surg 1979;137:75–81.
Santos 1994 {published data only} Santos JC Jr, Batista J, Sirimarco MT, Guimarães AS, Levy CE. Prospective randomized trial of mechanical bowel preparation in patients undergoing elective colorectal surgery. British Journal of Surgery 1994;81(11):1673–1676. [MEDLINE: 7827905]
Goligher 1970 Goligher JC, Graham NG, De Dombal FT. Anastomotic dehiscence after anterior resection of rectum and sigmoid. Br J Surg 1970;57(2): 109–118.
∗
Tabusso 2002 {published data only} ∗ Tabusso FY, Zapata JC, Espinoza FB, Meza EP, Figueroa ER. Mechanical preparation in elective colorectal surgery, a useful practice or need? [Preparación mécanica et cirgía electiva colo–rectal, costumbre o necesidad]. Rev Gastreoentero Peru 2002;22(2):152–158. Zmora 2003 {published and unpublished data} ∗ Zmora O, Mahajna A, Bar-Zakai B, Rosin D, Hershko D, Shabtai M, Krausz MM, Ayalon A. Colon and rectal surgery wothout mechanical bowel preparation. A randomized prospective trial. Ann Surg 2003;237(3):363–367. [MEDLINE: 12616120]
Grabham 1995 Grabham JA, Moran BJ, Lane RHS. Defunctiong colostomy for low anterior resection: a seletive approach. Br J Surg 1995;82:1331–1332. Halsted 1887 Halstedt WS. Circular suture of the intestine: an experimental study.. Am J Med Sci 1887;94:436–61. Handbook 2004 Alderson P, Green S, Higgins JPT, editors. Cochrane Reviewers Handbook 4.2.2 [updated March 2004]. Cochrane Database of Systematic Reviews 2004, Issue Issue 1.
References to studies excluded from this review
Johnston 1987 Johnston D. Bowel preparation for colorectal surgery [editorial]. Br J Surg 1987;74:553–554.
Dorudi 1990 {published data only} Dorudi S, Wilson NM, Heddle RM. [Primary restorative colectomy in malignant left-sided large bowel obstruction]. Annals of the Royal College of Surgeons of England 1990;72:393–395.
Juni 2002 Juni P, Egger M. Allocation concealment in clinical trials. JAMA 2002;288(19):2407–9. [: PMID: 12435252]
Duthie 1990 {published data only} Duthie GS, Foster ME, Price-Thomas JM, Leaper DJ. [Bowel preparation or not for elective colorectal surgery]. Journal of the Royal College of Surgeons of Edinburg 1990;35:169–171. Hughes 1972 {published data only} Hughes ESR. [Asepsis in large-bowel surgery]. Annals of the Royal College of Surgeons of England 1972;51:347–356. Irving 1987 {published data only} Irving AD, Scrimgeour D. [Mechanical bowel preparation for colonic resection and anastomosis]. British Journal of Surgery 1987;74:580– 581. Matheson 1978 {published data only} Matheson DM, Arabi Y, Baxter-Smith D, Alexander-Williams J, Keighley MRB. [Randomized multicentre trial of oral bowel preparation and microbials for elective colorectal operations]. British Journal of Surgery 1978;65(9):597–600.
Kronborg 2002 Kronborg O, Burchardt F, Bülow S, Christiansen J, Gandrup P, Harling H, Jakobsen A, Nejer J, FengerC. Guidelines for diagnosis and treatment of colorektal cancer, 2 (In Danish). http://www.kirurgisk-selskab.dk/retningslinier/dccg/Bog%20%20Retningslinier%202002.pdf 2002. Mealy 1992 Mealy K, Burke P, Hyland J. Anterior resection without a defunctiong colostomy: questions of safety. Br J Surg 1992;79:305–307. Moore 1999 Moore J, Hewet P, Penfold JC. Practice parameters for the management of colonic cancer I: surgical issues. Recommendations of the colorectal surgical society of Australia. Aust N Z J Surg 1999;69:415– 421. Nichols 1971 Nichols RL, Condon RE. Preoperative preparation of the colon. Surg Gynecol Obstet 1971;2:323–337.
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O’Dwyer 1989 O’Dwyer PJ, Conway W, McDermott EWM, O’Higgins NJ. Effect of mechanical bowel preparation on anastomotic integrity following low anterior resection in dogs. Br J Surg 1989;76:756–8. Schein 1995 Schein M, Assalia A, Eldar S, Wittmann DH. Is mechanical bowel preparation necessary before primary colonic anastomosis?. Dis Colon and Rectum 1995;38:749–754. Schulz 1996 Schulz KF, Grimes DA, Altman DG, Hayes RJ. Blinding and exclusions after allocation in randomised controlled trials: survery of published parallel group trials in obstetrics and gynaecology. BMJ 1996; 312:742–744. SIGN 1997 Scottish Intercollegiate Guidelines Network, Scottish Cancer Therapy Network. Colorectal Cancer, A national clinical guideline recommended for use in Scotland. National clinical guideline recommended for use in Scotland. Edinburgh: SIGN, 1997. Slim 2004 Slim K, Vicaut E, Panis Y, Chipponi J. Meta-analysis of randomized clinical trials of colorectal surgery with or without mechanical bowel preparation. Br J Surg 2004;91:1125–1130.
Smith 1983 Smith SRG, Connolly JC, Gilmore OJA. The effect of faecal loading on colonic anastomotic healing. Br J Surg 1983;70:49–50. Thornton 1997 Thornton FJ, Barbul A. Anastomtic healing in gastrointestinal surgery. Surg Clin of North Am 1997;3:549–573. Wille-Jørgensen 1999 Wille-Jørgensen P, Kronborg O, Simon N, Munro A, McLeod R, Nelson R, editors. Colorectal Cancer Group’s Module of the Cochrane Database of Systematic Reviews. Cochrane Database of Systematic Reviews 1999, Issue Issue 4.
References to other published versions of this review Guenaga 2002 Guenaga, KF. Preoperative bowel cleansing. Seminars in Colon & Rectal Surgery 2002;13:53–61. Wille-Jorgensen 2003 Wille-Jorgensen P, Guenaga KF, Castro AA, Matos D. Clinical value of preoperative mechanical bowel cleasing in elective colorectal surgery: a systematic review.. Disease of Colon and Rectum 2003;46: 1013–1020. ∗
Indicates the major publication for the study
CHARACTERISTICS OF STUDIES Characteristics of included studies [ordered by study ID]
Brownson 1992 Methods
Randomisation, blinding, follow-up, withdrawal and dropout: no details.
Participants
Inclusion criteria: patients undergoing elective colorectal surgery. Exclusion criteria: no details. Diseases: colorectal cancer: 164/179; other: 14/179. Number of participants: 179. Age: no details. Location of study: Liverpool, UK. Antibiotcs: perioperative intravenous (no more details).
Interventions
A: Mechanical bowel preparation (n=86) B: No preparation (n=93)
Outcomes
Wound infection: A=5/86, B=7/93 Intra-abdominal sepsis: A=8/86, B=2/93 Anastomic leakage: A:8/67*, B:1/67* *Patients whom bowel continuity was restored.
Notes
Only conference procreeding - never published as article, results obtained from abstract.
Risk of bias
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Brownson 1992 (Continued ) Item
Authors’ judgement
Description
Allocation concealment?
Unclear
B - Unclear
Bucher 2003 Methods
Randomisation and blinding: no details
Participants
Elective left-sided colorectal surgery
Interventions
A: Mechanical Bowel Preparation, 3 litres Polyethylene glycol (N=47) B: No preparation, (N = 46)
Outcomes
Anastomotic leakage and wound infection
Notes
Conference proceeding.
Risk of bias Item
Authors’ judgement
Description
Allocation concealment?
Unclear
B - Unclear
Burke 1994 Methods
Randomisation: no details. Blinding: single-blind: surgeons was aware of the patient’s bowel preparation. c) Withdrawal/dropout: 31% (17/186 cases) was withdrawed / no dropout. d) Follow-up: 07 days after surgery (unclear).
Participants
Inclusion criteria: patients admitted for elective colorectal surgery with primary anastomosis. Exclusion criteria: any patients who could not tolerate the preparation; patients who had had the bowel ’prepared’ for another procedure within previous week. Diagnoses: 72% colorectal cancer (133/186 cases); 3% inflammatory bowel disease (6/186 cases); 14% diverticular disease (26/186 cases); 2% other (4/186 cases). Number: 186 (95 male; 74 female; 17 undetermined). Age: mean 64 years. Location of study: Dublin, Ireland. Time: October, 1988 - September, 1992. Antibiotics: Ceftriaxone 1 gr and metronidazole 500 mg intravenously starting at induction of anaesthesia. Metronidazole 500 mg: 8 and 16 h, after initial dosis.
Interventions
a) Mechanical bowel preparation group (n = 82): sodium picosulphate 10 mg, the day before surgery (dose at morning and afternoon). b) Group B (n= 87): a normal diet and no other bowel preparation.
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Burke 1994 (Continued ) Outcomes
a) Death: A=2; B=0. b) Cardiorespiratory: A=8; B=9. c) Wound infection: A=4; B=3. d) Anastomotic dehiscence: A=3; B=4. e) Reoperation: A=2; B=4.
Notes
Representative sample: consecutive patients. Surgeries procedures that were excluded: patients submitted a Hartman’s resection (5:5); de functioning colostomy (0:2); abdominal excision of the rectum (1:2); coloanal anastomosis with colostomy (0:1); colotomy for rectal polyp (1:0). All surgery was performed by one of two consultant surgeons or a senior registrar. Excluded patients without anastomosis. Reccurrence because the leakage. Left colectomy: A=26; B=28. Anterior resection: A=56; B=59. Anastomotic leakage/low anterior resection: A=3/39; B=4/36.
Risk of bias Item
Authors’ judgement
Description
Allocation concealment?
Unclear
B - Unclear
Fa-Si-Oen 2003 Methods
Unknown
Participants
Colorectal Surgery
Interventions
A) Mechanical Bowel Preparation - Polyethylene glycol B: No cleansing
Outcomes
Anastomotic leakage, Wound Infection
Notes
Secondary data from another metaanalysis
Risk of bias Item
Authors’ judgement
Description
Allocation concealment?
Unclear
B - Unclear
Fillmann 1995 Methods
Randomization: no details. Blinding: double-blind (orange juice for the control group; no details on blinding of the surgeons.
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Fillmann 1995 (Continued ) Withdrawal/dropout: no withdrawal and dropout. Follow-up: 30 days after surgery. Participants
Inclusion criteria: patients admitted for elective colorectal surgery with primary anastomosis. Exclusion criteria: no exclusions. Diseases: colorectal cancer (21:22); diverticular disease (05:06); inflammatory bowel disease (02:02); Chron disease (01:00); ischaemic colitis (00:01). Number: 60 (33 male; 27 female). Age: 31-82 years. Location: Porto Alegre, RS - Brazil. Time: 1992-1993.Antibiotics: metronidazole + gentamicin 1 hour before surgery, and during 48 hours.
Interventions
Group A -Mechanical bowel preparation (n= 30): 500 ml manitol 20% + 500 ml orange juice. Group B (n= 30): orange juice.
Outcomes
Wound infection: A=1; B=2. Peritonitis: A=2; B=1. Extra-abdominal complications (non-infections):-Mechanical obstruction: A=0; B=1.-Dehiscence of wall suture: A=0; B=1. -Pulmonary embolism: A=1; B=0.Extra-abdominal complications (infections):Pneumonia: A=1; B=1.- Urinary infection: A=1; B=2.
Notes
The sample size was calculated, but no more details. Included patients without anastomosis. Recurrence was not mentioned. No death reported in this trial.
Risk of bias Item
Authors’ judgement
Description
Allocation concealment?
Yes
A - Adequate
Miettinen 2000 Methods
Randomization: sealed envelopes; consecutive adult patients. Blinding: not described. Withdrawal/dropout: all the patients completed the study. Follow-up: 1-2 months after surgery.
Participants
Inclusion criteria: all consecutive adults admitted for elective colorectal surgery. Exclusion criteria: patients who had had bowel preparation for colonoscopy one week before surgery (n=5); patients who where unable to drink PEG-ELS (n=2); patients not requiring opening of the bowel (n=4); patient who refused to be randomised (n=1). Disease: colorectal cancer (134/267); benign tumours (24/267); inflammatory bowel disease (32/267); diverticular disease (58/267); other (19/267).Number: 267 (130 male; 137 female).Age: 16-97 years.Location: Kuopio + Oulu, Finland.Time: 1994-1996.Antibiotics: ceftriaxone 2 gr + metronidazole 1 gr at the induction of anaesthesia.
Interventions
Group A - Mechanical bowel preparation (n=138): Polyethylene glycol electrolyte solution, and no solid
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Miettinen 2000 (Continued ) food on the preoperative day. Group B (n=129): no preparations and normal diet. Outcomes
Wound infection: A=5; B=3. Anastomotic leakage: A=5; B=3. Abdominal abscess: A=3; B=4. Non-infection postoperative complication: A=11; B=6. Reoperation: A=4; B=2. Extra-abdominal infections: A=4; B=2. Postoperative stay (range/days): A=8; B=8. Operation time (range/min): A=120; B=110.
Notes
Low colonic anastomosis/Leakage: A = 9/3; B = 14/2. Patients with pre-existing disease: A=48; B=61. The differences between the two groups were not significant. All surgery was carried out by a specialist or by a junior surgeon assisted by a specialist. Excluded patients without anastomosis. Abdominal abscess: treated conservatively. Re-operation (total:7/3 ??): - wound rupture: A=2; B=0; - perfuration of the gallbladder: A=1; B=0; - techinical anastomotic failure: A=0; B=1; - small bowel occlusions: A=1; B=2. Reoccurrence was because the leakage. No death in this trial.
Risk of bias Item
Authors’ judgement
Description
Allocation concealment?
Yes
A - Adequate
Santos 1994 Methods
Randomisation: patients were allocated by randomised cards. Blinding: not described. Withdrawal/dropout: 5% (8/157 cases) was withdrawn / no dropout. Follow-up: 30 days or until hospital discharge.
Participants
Inclusion criteria: Patients admitted for elective colorectal surgery. Exclusion criteria: patients that had taken antibiotics for at least 15 days before surgery or if there was evidence of infection or any associated disease requiring antibiotic therapy; and patients that the mechanical bowel preparation was not feasible. Group A: 5 patients were excluded: associated infectious disease (2 patients), and failure to achieve full mechanical bowel preparation (3 patients). Group B: 3 patients excluded: an intra-abdominal foreign body found during the operation (1 patient), and urinary tract infection (2 patients). Diseases: 43% colorectal cancer (68/157); 34% megacolon (53/157); 6% inflammatory bowel disease
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Santos 1994 (Continued ) (9/157); 3% diverticular disease (5/157); 2% familial adenoma polyposis (3/157); 7% other (11/157). Number: 157 (72 male; 77 female; 8 undetermined). Age: 1 - 93 years. Location: Ribeirão Preto, São Paulo - Brazil. Time: October, 1991 - December, 1992. Antibiotics: Cephalothin 2 gr and metronidazole 1 g intravenously at 2 h before induction of anaesthesia. Cephalothin 1 gr was given 6 and 12 h, and metronidazole 500 mg, 8 and 16 h after the initial dose. Interventions
Group A - Mechanical bowel preparation (n= 72): LAXATIVE (mineral oil, agar and phenolphthalein) 15 ml taken by mouth three times a day for 5 days before surgery; mannitol (1 litre as a 10% solution) taken by mouth at the rate of 100 ml per 5 min at 16:00 hours on the day before surgery. ENEMA (water, 900 ml; glycerin, 100 ml) given once a day for 2 days before surgery. children : enema of water and glycerin (9:1) twice a day for 2 days before surgery. Group B (n= 77): a low-reside diet and no other mechanical bowel preparation.
Outcomes
Wound infection: A=17; B=9. Anastomotic dehiscence: A=7; B=4. Hospital stay (preoperative): A=2-34; B=0-90. Reoperation: A=4; B=1. Microbiology (bacteria isolated): -Bowel content: A=211/62; B=261/72. -Peritoneal fluid: A=116/62; B=134/72. -Wounds: A=38/17; B=17/7.
Notes
Not described the representative sample. Patients/Associated medical problems: A=53/75; B=52/78. Associated medical disease: A=17; B=7. Patients with complications: A=21 (7+17=?); B=11 (4+9=?). Most of the patients were operated on by a senior resident (not the consultant). Included patients without anastomosis. Reoccurrence was because the leakage. No death in this trial.
Risk of bias Item
Authors’ judgement
Description
Allocation concealment?
Yes
A - Adequate
Tabusso 2002 Methods
Randomisation, blinding, withdrawal and dropout: no details. Follow-up: until hospital discharged (not described).
Participants
Inclusion criteria: pacients with colorectal cancer, submitted an elective colorectal surgery . Exclusion criteria: no details. Diseases: colorectal cancer. Participantes: 47 (21 male, 26 female). Age: 22 - 87. Location of study: Lima, Peru. Time: october 1999 - january 2001. Antibiotcs: against anaerobic and Gran negative bacteria, intravenous, 30 minutes before surgery.
Interventions
Group A - Mechanical bowel preparation (n=24): mannitol or polyethylene glycol electrolyte solution +
Mechanical bowel preparation for elective colorectal surgery (Review) Copyright © 2008 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.
16
Tabusso 2002 (Continued ) liquid diet 48 hours before surgery. Group B - No mechanical bowel preparation (n=23): liquid diet 48 hours before surgery. Outcomes
Wound infection: A=2; B=0. Anastomotic leakage: A=5; B=0. Peritonitis: A=3; B=0.
Notes
Length of hospital stay: A=17-19 (14); B=6-15 (11). Analysed only the complications related with the surgery. Patients without anastomosis (2 patients in A; 3 patients in B).
Risk of bias Item
Authors’ judgement
Description
Allocation concealment?
Unclear
B - Unclear
Zmora 2003 Methods
Randomisation: Computer generated. Follow-up after 30 days
Participants
Inclusion criteria: Pateints admitted for elective colon and rectal surgery Exclusion criteria: Not described
Interventions
Group A Mechanical bowel preparation (n= 187) with polyethylene glycol Group B No preparation (n= 193)
Outcomes
Overall Infection: A=19; B=17. Wound Infection: A=12; B=11. Anastomotic leak: A=7; B=2 Intraabdominal Abscess: A=2, B=2
Notes
All anastomises were “left-sided” Extra data after stratification has been obtained
Risk of bias Item
Authors’ judgement
Description
Allocation concealment?
Yes
A - Adequate
Mechanical bowel preparation for elective colorectal surgery (Review) Copyright © 2008 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.
17
Characteristics of excluded studies [ordered by study ID]
Study
Reason for exclusion
Dorudi 1990
None
Duthie 1990
The study is a survey. Without control group.
Hughes 1972
First data as a conference proceedings. Most of the data are unclear. The author did not reply to our enquiries, to complete the review.
Irving 1987
Without control group.
Matheson 1978
Testing antimicrobials. The control group receive elemental diet.
Memon 1997
A retropective and non-randomized study.
Mechanical bowel preparation for elective colorectal surgery (Review) Copyright © 2008 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.
18
DATA AND ANALYSES
Comparison 1. Mechanical bowel preparation versus no preparation
Outcome or subgroup title 1 Anastomosis leakage stratified for colonic or rectal surgery 1.1 Leakage after low anterior resection 1.2 Leakage after colonic surgery 2 Overall anastomotic leakage for colorectal surgery 3 Mortality 4 Peritonitis 5 Reoperation 6 Wound infection 7 Infectious extra-abdominal complications 8 Non-infectious extra-abdominal complications 9 Surgical site infections 10 Sensitivity analysis 1 - Studies with dubious randomisation procedure excluded 10.1 Overall anastomotic leakage for colorectal surgery 10.2 Wound infection 11 Sensitivity analysis 2 - Studies published as abstract only excluded 11.1 Anastomotic leakage 11.2 Wound infection 12 Sensitivity analysis 3 - Studies including children excluded 12.1 Anastomotic leakage 12.2 Wound infection 13 Sensitivity analysis 4 - Studies including patients without anastomosis excluded 13.1 Anastomosis leakage 13.2 Wound infection
No. of studies
No. of participants
Statistical method
Effect size
Peto Odds Ratio (Peto, Fixed, 95% CI)
Subtotals only
4
231
Peto Odds Ratio (Peto, Fixed, 95% CI)
1.45 [0.57, 3.67]
4
734
Peto Odds Ratio (Peto, Fixed, 95% CI)
1.80 [0.68, 4.75]
9
1549
Peto Odds Ratio (Peto, Fixed, 95% CI)
2.03 [1.27, 3.26]
5 4 6 9 2
1025 553 785 1594 327
Peto Odds Ratio (Peto, Fixed, 95% CI) Peto Odds Ratio (Peto, Fixed, 95% CI) Peto Odds Ratio (Peto, Fixed, 95% CI) Peto Odds Ratio (Peto, Fixed, 95% CI) Peto Odds Ratio (Peto, Fixed, 95% CI)
1.72 [0.43, 6.95] 2.28 [0.99, 5.25] 1.80 [0.81, 3.98] 1.45 [0.97, 2.18] 0.87 [0.41, 1.87]
4
872
Peto Odds Ratio (Peto, Fixed, 95% CI)
1.09 [0.75, 1.58]
2
647
Peto Odds Ratio (Peto, Fixed, 95% CI) Peto Odds Ratio (Peto, Fixed, 95% CI)
1.20 [0.70, 2.04] Subtotals only
4
856
Peto Odds Ratio (Peto, Fixed, 95% CI)
1.80 [0.90, 3.61]
4
856
Peto Odds Ratio (Peto, Fixed, 95% CI) Peto Odds Ratio (Peto, Fixed, 95% CI)
1.50 [0.88, 2.56] Subtotals only
6 6
1072 1072
Peto Odds Ratio (Peto, Fixed, 95% CI) Peto Odds Ratio (Peto, Fixed, 95% CI) Peto Odds Ratio (Peto, Fixed, 95% CI)
1.86 [1.03, 3.39] 1.57 [0.96, 2.58] Subtotals only
7 7
1150 1195
Peto Odds Ratio (Peto, Fixed, 95% CI) Peto Odds Ratio (Peto, Fixed, 95% CI) Odds Ratio (M-H, Fixed, 95% CI)
2.38 [1.34, 4.25] 1.26 [0.75, 2.12] Subtotals only
5 5
1043 1088
Odds Ratio (M-H, Fixed, 95% CI) Odds Ratio (M-H, Fixed, 95% CI)
2.14 [1.09, 4.19] 1.25 [0.72, 2.15]
Mechanical bowel preparation for elective colorectal surgery (Review) Copyright © 2008 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.
19
Analysis 1.1. Comparison 1 Mechanical bowel preparation versus no preparation, Outcome 1 Anastomosis leakage stratified for colonic or rectal surgery. Review:
Mechanical bowel preparation for elective colorectal surgery
Comparison: 1 Mechanical bowel preparation versus no preparation Outcome: 1 Anastomosis leakage stratified for colonic or rectal surgery Study or subgroup
Preparation n/N
No preparation
Peto Odds Ratio
n/N
Weight
Peto,Fixed,95% CI
Peto Odds Ratio Peto,Fixed,95% CI
1 Leakage after low anterior resection Burke 1994
3/39
4/36
36.0 %
0.67 [ 0.14, 3.15 ]
3/9
2/14
21.9 %
2.92 [ 0.40, 21.25 ]
Santos 1994
2/21
2/29
20.5 %
1.42 [ 0.18, 11.01 ]
Zmora 2003
3/43
1/40
21.6 %
2.62 [ 0.36, 19.34 ]
112
119
100.0 %
1.45 [ 0.57, 3.67 ]
0/43
0/51
0.0 %
Not estimable
2/129
1/115
18.1 %
1.75 [ 0.18, 17.02 ]
Santos 1994
5/51
2/48
40.1 %
2.34 [ 0.51, 10.80 ]
Zmora 2003
4/144
3/153
41.8 %
1.42 [ 0.32, 6.37 ]
367
367
100.0 %
1.80 [ 0.68, 4.75 ]
Miettinen 2000
Subtotal (95% CI)
Total events: 11 (Preparation), 9 (No preparation) Heterogeneity: Chi2 = 1.77, df = 3 (P = 0.62); I2 =0.0% Test for overall effect: Z = 0.78 (P = 0.43) 2 Leakage after colonic surgery Burke 1994 Miettinen 2000
Subtotal (95% CI)
Total events: 11 (Preparation), 6 (No preparation) Heterogeneity: Chi2 = 0.21, df = 2 (P = 0.90); I2 =0.0% Test for overall effect: Z = 1.19 (P = 0.23) Test for subgroup differences: Chi2 = 0.10, df = 1 (P = 0.75), I2 =0.0%
0.01
0.1
Favors preparation
1
10 100 Favors control
Mechanical bowel preparation for elective colorectal surgery (Review) Copyright © 2008 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.
20
Review:
Mechanical bowel preparation for elective colorectal surgery
Comparison: 1 Mechanical bowel preparation versus no preparation Outcome: 1 Anastomosis leakage stratified for colonic or rectal surgery Study or subgroup
Preparation
No preparation
n/N
Peto Odds Ratio
n/N
Peto,Fixed,95% CI
Peto Odds Ratio Peto,Fixed,95% CI
1 Leakage after low anterior resection Burke 1994
3/39
4/36
0.67 [ 0.14, 3.15 ]
3/9
2/14
2.92 [ 0.40, 21.25 ]
Santos 1994
2/21
2/29
1.42 [ 0.18, 11.01 ]
Zmora 2003
3/43
1/40
2.62 [ 0.36, 19.34 ]
112
119
1.45 [ 0.57, 3.67 ]
Miettinen 2000
Subtotal (95% CI)
Total events: 11 (Preparation), 9 (No preparation) Heterogeneity: Chi2 = 1.77, df = 3 (P = 0.62); I2 =0.0% Test for overall effect: Z = 0.78 (P = 0.43)
0.01
0.1
1
Favors preparation
Review:
10 100 Favors control
Mechanical bowel preparation for elective colorectal surgery
Comparison: 1 Mechanical bowel preparation versus no preparation Outcome: 1 Anastomosis leakage stratified for colonic or rectal surgery Study or subgroup
Preparation n/N
No preparation
Peto Odds Ratio
n/N
Peto,Fixed,95% CI
Peto Odds Ratio Peto,Fixed,95% CI
2 Leakage after colonic surgery Burke 1994
0/43
0/51
Not estimable
2/129
1/115
1.75 [ 0.18, 17.02 ]
Santos 1994
5/51
2/48
2.34 [ 0.51, 10.80 ]
Zmora 2003
4/144
3/153
1.42 [ 0.32, 6.37 ]
367
367
1.80 [ 0.68, 4.75 ]
Miettinen 2000
Subtotal (95% CI)
Total events: 11 (Preparation), 6 (No preparation) Heterogeneity: Chi2 = 0.21, df = 2 (P = 0.90); I2 =0.0% Test for overall effect: Z = 1.19 (P = 0.23)
0.01
0.1
Favors preparation
Mechanical bowel preparation for elective colorectal surgery (Review) Copyright © 2008 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.
1
10 100 Favors control
21
Analysis 1.2. Comparison 1 Mechanical bowel preparation versus no preparation, Outcome 2 Overall anastomotic leakage for colorectal surgery. Review:
Mechanical bowel preparation for elective colorectal surgery
Comparison: 1 Mechanical bowel preparation versus no preparation Outcome: 2 Overall anastomotic leakage for colorectal surgery Study or subgroup
Preparation
No preparation
n/N
Peto Odds Ratio
n/N
Weight
Peto,Fixed,95% CI
Peto Odds Ratio Peto,Fixed,95% CI
Brownson 1992
8/67
1/67
12.3 %
5.23 [ 1.36, 20.14 ]
Bucher 2003
4/47
1/46
7.0 %
3.43 [ 0.57, 20.59 ]
Burke 1994
3/82
4/87
9.8 %
0.79 [ 0.17, 3.58 ]
7/125
6/125
18.0 %
1.18 [ 0.39, 3.58 ]
Fillmann 1995
2/30
1/30
4.2 %
1.99 [ 0.20, 19.94 ]
Miettinen 2000
5/138
3/129
11.3 %
1.56 [ 0.38, 6.36 ]
Santos 1994
7/72
4/77
14.9 %
1.93 [ 0.57, 6.57 ]
Tabusso 2002
5/24
0/23
6.7 %
8.54 [ 1.36, 53.51 ]
Zmora 2003
7/187
4/193
15.6 %
1.81 [ 0.55, 5.99 ]
Total (95% CI)
772
777
100.0 %
2.03 [ 1.27, 3.26 ]
Fa-Si-Oen 2003
Total events: 48 (Preparation), 24 (No preparation) Heterogeneity: Chi2 = 7.18, df = 8 (P = 0.52); I2 =0.0% Test for overall effect: Z = 2.94 (P = 0.0033)
0.01
0.1
Favors preparation
1
10 100 Favors control
Mechanical bowel preparation for elective colorectal surgery (Review) Copyright © 2008 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.
22
Analysis 1.3. Comparison 1 Mechanical bowel preparation versus no preparation, Outcome 3 Mortality. Review:
Mechanical bowel preparation for elective colorectal surgery
Comparison: 1 Mechanical bowel preparation versus no preparation Outcome: 3 Mortality Study or subgroup
Preparation
No preparation
n/N
Peto Odds Ratio
n/N
Weight
Peto,Fixed,95% CI
Peto Odds Ratio Peto,Fixed,95% CI
Burke 1994
2/82
0/87
25.1 %
7.95 [ 0.49, 128.33 ]
Fillmann 1995
0/30
0/30
0.0 %
Not estimable
Miettinen 2000
0/138
0/129
0.0 %
Not estimable
Santos 1994
0/72
0/77
0.0 %
Not estimable
Zmora 2003
3/187
3/193
74.9 %
1.03 [ 0.21, 5.17 ]
Total (95% CI)
509
516
100.0 %
1.72 [ 0.43, 6.95 ]
Total events: 5 (Preparation), 3 (No preparation) Heterogeneity: Chi2 = 1.55, df = 1 (P = 0.21); I2 =35% Test for overall effect: Z = 0.77 (P = 0.44)
0.01
0.1
1
Favours preparation
10 100 Favours control
Analysis 1.4. Comparison 1 Mechanical bowel preparation versus no preparation, Outcome 4 Peritonitis. Review:
Mechanical bowel preparation for elective colorectal surgery
Comparison: 1 Mechanical bowel preparation versus no preparation Outcome: 4 Peritonitis Study or subgroup
Preparation
No preparation
n/N
Peto Odds Ratio
n/N
Weight
Peto,Fixed,95% CI
Peto Odds Ratio Peto,Fixed,95% CI
Brownson 1992
8/86
2/93
42.9 %
3.85 [ 1.08, 13.76 ]
Fillmann 1995
2/30
1/30
13.1 %
1.99 [ 0.20, 19.94 ]
Miettinen 2000
3/138
4/129
31.0 %
0.70 [ 0.16, 3.12 ]
Tabusso 2002
3/24
0/23
13.0 %
7.75 [ 0.77, 78.41 ]
Total (95% CI)
278
275
100.0 %
2.28 [ 0.99, 5.25 ]
Total events: 16 (Preparation), 7 (No preparation) Heterogeneity: Chi2 = 4.14, df = 3 (P = 0.25); I2 =28% Test for overall effect: Z = 1.93 (P = 0.053)
0.01
0.1
Favors preparation
1
10 100 Favors control
Mechanical bowel preparation for elective colorectal surgery (Review) Copyright © 2008 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.
23
Analysis 1.5. Comparison 1 Mechanical bowel preparation versus no preparation, Outcome 5 Reoperation. Review:
Mechanical bowel preparation for elective colorectal surgery
Comparison: 1 Mechanical bowel preparation versus no preparation Outcome: 5 Reoperation Study or subgroup
Preparation
No preparation
n/N
Peto Odds Ratio
n/N
Weight
Peto,Fixed,95% CI
Peto Odds Ratio Peto,Fixed,95% CI
Bucher 2003
5/47
1/46
23.4 %
4.00 [ 0.77, 20.76 ]
Burke 1994
2/82
4/87
24.0 %
0.53 [ 0.11, 2.71 ]
Fillmann 1995
1/30
1/30
8.1 %
1.00 [ 0.06, 16.37 ]
Miettinen 2000
4/138
2/129
24.3 %
1.84 [ 0.37, 9.28 ]
Santos 1994
4/72
1/77
20.1 %
3.68 [ 0.62, 21.80 ]
Tabusso 2002
0/24
0/23
0.0 %
Not estimable
Total (95% CI)
393
392
100.0 %
1.80 [ 0.81, 3.98 ]
Total events: 16 (Preparation), 9 (No preparation) Heterogeneity: Chi2 = 3.84, df = 4 (P = 0.43); I2 =0.0% Test for overall effect: Z = 1.44 (P = 0.15)
0.01
0.1
1
Favours preparation
10 100 Favours control
Analysis 1.6. Comparison 1 Mechanical bowel preparation versus no preparation, Outcome 6 Wound infection. Review:
Mechanical bowel preparation for elective colorectal surgery
Comparison: 1 Mechanical bowel preparation versus no preparation Outcome: 6 Wound infection Study or subgroup
Preparation n/N
No preparation
Peto Odds Ratio
n/N
Weight
Peto,Fixed,95% CI
Peto Odds Ratio Peto,Fixed,95% CI
Brownson 1992
5/86
7/93
12.0 %
0.76 [ 0.24, 2.45 ]
Bucher 2003
4/47
1/46
5.1 %
3.43 [ 0.57, 20.59 ]
Burke 1994
4/82
3/87
7.2 %
1.43 [ 0.32, 6.47 ]
9/125
7/125
16.1 %
1.30 [ 0.47, 3.59 ]
Fillmann 1995
1/30
2/30
3.1 %
0.50 [ 0.05, 5.02 ]
Miettinen 2000
5/138
3/129
8.3 %
1.56 [ 0.38, 6.36 ]
Santos 1994
17/72
9/77
23.0 %
2.28 [ 0.98, 5.29 ]
Tabusso 2002
2/24
0/23
2.1 %
7.40 [ 0.45, 122.11 ]
Fa-Si-Oen 2003
0.01
0.1
Favors preparation
1
10 100 Favors control
Mechanical bowel preparation for elective colorectal surgery (Review) Copyright © 2008 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.
(Continued . . . )
24
(. . . Study or subgroup
Preparation
No preparation
n/N Zmora 2003
Total (95% CI)
Peto Odds Ratio
n/N
Weight
Peto,Fixed,95% CI
Continued)
Peto Odds Ratio Peto,Fixed,95% CI
12/187
11/193
23.1 %
1.13 [ 0.49, 2.63 ]
791
803
100.0 %
1.45 [ 0.97, 2.18 ]
Total events: 59 (Preparation), 43 (No preparation) Heterogeneity: Chi2 = 5.64, df = 8 (P = 0.69); I2 =0.0% Test for overall effect: Z = 1.81 (P = 0.070)
0.01
0.1
1
Favors preparation
10 100 Favors control
Analysis 1.7. Comparison 1 Mechanical bowel preparation versus no preparation, Outcome 7 Infectious extra-abdominal complications. Review:
Mechanical bowel preparation for elective colorectal surgery
Comparison: 1 Mechanical bowel preparation versus no preparation Outcome: 7 Infectious extra-abdominal complications Study or subgroup
Preparation
No preparation
n/N Fillmann 1995 Miettinen 2000
Total (95% CI)
Peto Odds Ratio
n/N
Weight
Peto,Fixed,95% CI
Peto Odds Ratio Peto,Fixed,95% CI
2/30
3/30
17.5 %
0.65 [ 0.11, 4.00 ]
12/138
12/129
82.5 %
0.93 [ 0.40, 2.15 ]
168
159
100.0 %
0.87 [ 0.41, 1.87 ]
Total events: 14 (Preparation), 15 (No preparation) Heterogeneity: Chi2 = 0.12, df = 1 (P = 0.73); I2 =0.0% Test for overall effect: Z = 0.35 (P = 0.73)
0.01
0.1
Favours preparation
1
10 100 Favours control
Mechanical bowel preparation for elective colorectal surgery (Review) Copyright © 2008 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.
25
Analysis 1.8. Comparison 1 Mechanical bowel preparation versus no preparation, Outcome 8 Noninfectious extra-abdominal complications. Review:
Mechanical bowel preparation for elective colorectal surgery
Comparison: 1 Mechanical bowel preparation versus no preparation Outcome: 8 Non-infectious extra-abdominal complications Study or subgroup
Preparation
No preparation
n/N
Peto Odds Ratio
n/N
Weight
Peto,Fixed,95% CI
Peto Odds Ratio Peto,Fixed,95% CI
Burke 1994
8/82
9/87
13.9 %
0.94 [ 0.34, 2.55 ]
Fillmann 1995
1/30
2/30
2.6 %
0.50 [ 0.05, 5.02 ]
Miettinen 2000
11/138
6/129
14.4 %
1.74 [ 0.65, 4.65 ]
Zmora 2003
53/183
54/193
69.1 %
1.05 [ 0.67, 1.64 ]
433
439
100.0 %
1.09 [ 0.75, 1.58 ]
Total (95% CI)
Total events: 73 (Preparation), 71 (No preparation) Heterogeneity: Chi2 = 1.43, df = 3 (P = 0.70); I2 =0.0% Test for overall effect: Z = 0.45 (P = 0.65)
0.01
0.1
1
Favours preparation
10 100 Favours control
Analysis 1.9. Comparison 1 Mechanical bowel preparation versus no preparation, Outcome 9 Surgical site infections. Review:
Mechanical bowel preparation for elective colorectal surgery
Comparison: 1 Mechanical bowel preparation versus no preparation Outcome: 9 Surgical site infections Study or subgroup
Preparation
No preparation
n/N
Peto Odds Ratio
n/N
Weight
Peto,Fixed,95% CI
Peto Odds Ratio Peto,Fixed,95% CI
Miettinen 2000
13/138
10/129
39.2 %
1.24 [ 0.53, 2.90 ]
Zmora 2003
19/187
17/193
60.8 %
1.17 [ 0.59, 2.32 ]
325
322
100.0 %
1.20 [ 0.70, 2.04 ]
Total (95% CI)
Total events: 32 (Preparation), 27 (No preparation) Heterogeneity: Chi2 = 0.01, df = 1 (P = 0.92); I2 =0.0% Test for overall effect: Z = 0.65 (P = 0.51)
0.2
0.5
Favours preparation
1
2
5
Favours control
Mechanical bowel preparation for elective colorectal surgery (Review) Copyright © 2008 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.
26
Analysis 1.10. Comparison 1 Mechanical bowel preparation versus no preparation, Outcome 10 Sensitivity analysis 1 - Studies with dubious randomisation procedure excluded. Review:
Mechanical bowel preparation for elective colorectal surgery
Comparison: 1 Mechanical bowel preparation versus no preparation Outcome: 10 Sensitivity analysis 1 - Studies with dubious randomisation procedure excluded Study or subgroup
Preparation n/N
No Preparation
Peto Odds Ratio
n/N
Weight
Peto,Fixed,95% CI
Peto Odds Ratio Peto,Fixed,95% CI
1 Overall anastomotic leakage for colorectal surgery Fillmann 1995
2/30
1/30
9.2 %
1.99 [ 0.20, 19.94 ]
Miettinen 2000
5/138
3/129
24.6 %
1.56 [ 0.38, 6.36 ]
Santos 1994
7/72
4/77
32.4 %
1.93 [ 0.57, 6.57 ]
Zmora 2003
7/187
4/193
33.8 %
1.81 [ 0.55, 5.99 ]
427
429
100.0 %
1.80 [ 0.90, 3.61 ]
Subtotal (95% CI)
Total events: 21 (Preparation), 12 (No Preparation) Heterogeneity: Chi2 = 0.06, df = 3 (P = 1.00); I2 =0.0% Test for overall effect: Z = 1.65 (P = 0.099) 2 Wound infection Fillmann 1995
1/30
2/30
5.4 %
0.50 [ 0.05, 5.02 ]
Miettinen 2000
5/138
3/129
14.4 %
1.56 [ 0.38, 6.36 ]
Santos 1994
17/72
9/77
40.0 %
2.28 [ 0.98, 5.29 ]
Zmora 2003
12/187
11/193
40.2 %
1.13 [ 0.49, 2.63 ]
427
429
100.0 %
1.50 [ 0.88, 2.56 ]
Subtotal (95% CI)
Total events: 35 (Preparation), 25 (No Preparation) Heterogeneity: Chi2 = 2.23, df = 3 (P = 0.53); I2 =0.0% Test for overall effect: Z = 1.49 (P = 0.14) Test for subgroup differences: Chi2 = 0.16, df = 1 (P = 0.69), I2 =0.0%
0.2
0.5
Favours preparation
1
2
5
Favours control
Mechanical bowel preparation for elective colorectal surgery (Review) Copyright © 2008 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.
27
Review:
Mechanical bowel preparation for elective colorectal surgery
Comparison: 1 Mechanical bowel preparation versus no preparation Outcome: 10 Sensitivity analysis 1 - Studies with dubious randomisation procedure excluded Study or subgroup
Preparation
No Preparation
n/N
Peto Odds Ratio
n/N
Peto,Fixed,95% CI
Peto Odds Ratio Peto,Fixed,95% CI
1 Overall anastomotic leakage for colorectal surgery Fillmann 1995
2/30
1/30
1.99 [ 0.20, 19.94 ]
Miettinen 2000
5/138
3/129
1.56 [ 0.38, 6.36 ]
Santos 1994
7/72
4/77
1.93 [ 0.57, 6.57 ]
Zmora 2003
7/187
4/193
1.81 [ 0.55, 5.99 ]
427
429
1.80 [ 0.90, 3.61 ]
Subtotal (95% CI)
Total events: 21 (Preparation), 12 (No Preparation) Heterogeneity: Chi2 = 0.06, df = 3 (P = 1.00); I2 =0.0% Test for overall effect: Z = 1.65 (P = 0.099)
0.2
0.5
1
Favours preparation
Review:
2
5
Favours control
Mechanical bowel preparation for elective colorectal surgery
Comparison: 1 Mechanical bowel preparation versus no preparation Outcome: 10 Sensitivity analysis 1 - Studies with dubious randomisation procedure excluded Study or subgroup
Preparation n/N
No Preparation
Peto Odds Ratio
n/N
Peto,Fixed,95% CI
Peto Odds Ratio Peto,Fixed,95% CI
2 Wound infection Fillmann 1995
1/30
2/30
0.50 [ 0.05, 5.02 ]
Miettinen 2000
5/138
3/129
1.56 [ 0.38, 6.36 ]
Santos 1994
17/72
9/77
2.28 [ 0.98, 5.29 ]
Zmora 2003
12/187
11/193
1.13 [ 0.49, 2.63 ]
427
429
1.50 [ 0.88, 2.56 ]
Subtotal (95% CI)
Total events: 35 (Preparation), 25 (No Preparation) Heterogeneity: Chi2 = 2.23, df = 3 (P = 0.53); I2 =0.0% Test for overall effect: Z = 1.49 (P = 0.14)
0.2
0.5
Favours preparation
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2
5
Favours control
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Analysis 1.11. Comparison 1 Mechanical bowel preparation versus no preparation, Outcome 11 Sensitivity analysis 2 - Studies published as abstract only excluded. Review:
Mechanical bowel preparation for elective colorectal surgery
Comparison: 1 Mechanical bowel preparation versus no preparation Outcome: 11 Sensitivity analysis 2 - Studies published as abstract only excluded Study or subgroup
Preparation n/N
No Preparation
Peto Odds Ratio
n/N
Weight
Peto,Fixed,95% CI
Peto Odds Ratio Peto,Fixed,95% CI
1 Anastomotic leakage Burke 1994
3/82
4/87
15.7 %
0.79 [ 0.17, 3.58 ]
Fillmann 1995
2/30
1/30
6.7 %
1.99 [ 0.20, 19.94 ]
Miettinen 2000
5/138
3/129
18.1 %
1.56 [ 0.38, 6.36 ]
Santos 1994
7/72
4/77
23.9 %
1.93 [ 0.57, 6.57 ]
Tabusso 2002
5/24
0/23
10.6 %
8.54 [ 1.36, 53.51 ]
Zmora 2003
7/187
4/193
24.9 %
1.81 [ 0.55, 5.99 ]
533
539
100.0 %
1.86 [ 1.03, 3.39 ]
Subtotal (95% CI)
Total events: 29 (Preparation), 16 (No Preparation) Heterogeneity: Chi2 = 3.95, df = 5 (P = 0.56); I2 =0.0% Test for overall effect: Z = 2.04 (P = 0.041) 2 Wound infection Burke 1994
4/82
3/87
10.8 %
1.43 [ 0.32, 6.47 ]
Fillmann 1995
1/30
2/30
4.6 %
0.50 [ 0.05, 5.02 ]
Miettinen 2000
5/138
3/129
12.4 %
1.56 [ 0.38, 6.36 ]
Santos 1994
17/72
9/77
34.5 %
2.28 [ 0.98, 5.29 ]
Tabusso 2002
2/24
0/23
3.1 %
7.40 [ 0.45, 122.11 ]
12/187
11/193
34.6 %
1.13 [ 0.49, 2.63 ]
533
539
100.0 %
1.57 [ 0.96, 2.58 ]
Zmora 2003
Subtotal (95% CI)
Total events: 41 (Preparation), 28 (No Preparation) Heterogeneity: Chi2 = 3.45, df = 5 (P = 0.63); I2 =0.0% Test for overall effect: Z = 1.79 (P = 0.074) Test for subgroup differences: Chi2 = 0.19, df = 1 (P = 0.66), I2 =0.0%
0.2
0.5
Favours preparation
1
2
5
Favours control
Mechanical bowel preparation for elective colorectal surgery (Review) Copyright © 2008 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.
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Review:
Mechanical bowel preparation for elective colorectal surgery
Comparison: 1 Mechanical bowel preparation versus no preparation Outcome: 11 Sensitivity analysis 2 - Studies published as abstract only excluded Study or subgroup
Preparation
No Preparation
n/N
Peto Odds Ratio
n/N
Peto,Fixed,95% CI
Peto Odds Ratio Peto,Fixed,95% CI
1 Anastomotic leakage Burke 1994
3/82
4/87
0.79 [ 0.17, 3.58 ]
Fillmann 1995
2/30
1/30
1.99 [ 0.20, 19.94 ]
Miettinen 2000
5/138
3/129
1.56 [ 0.38, 6.36 ]
Santos 1994
7/72
4/77
1.93 [ 0.57, 6.57 ]
Tabusso 2002
5/24
0/23
8.54 [ 1.36, 53.51 ]
Zmora 2003
7/187
4/193
1.81 [ 0.55, 5.99 ]
533
539
1.86 [ 1.03, 3.39 ]
Subtotal (95% CI)
Total events: 29 (Preparation), 16 (No Preparation) Heterogeneity: Chi2 = 3.95, df = 5 (P = 0.56); I2 =0.0% Test for overall effect: Z = 2.04 (P = 0.041)
0.2
0.5
1
Favours preparation
Review:
2
5
Favours control
Mechanical bowel preparation for elective colorectal surgery
Comparison: 1 Mechanical bowel preparation versus no preparation Outcome: 11 Sensitivity analysis 2 - Studies published as abstract only excluded Study or subgroup
Preparation n/N
No Preparation
Peto Odds Ratio
n/N
Peto,Fixed,95% CI
Peto Odds Ratio Peto,Fixed,95% CI
2 Wound infection Burke 1994
4/82
3/87
1.43 [ 0.32, 6.47 ]
Fillmann 1995
1/30
2/30
0.50 [ 0.05, 5.02 ]
Miettinen 2000
5/138
3/129
1.56 [ 0.38, 6.36 ]
Santos 1994
17/72
9/77
2.28 [ 0.98, 5.29 ]
Tabusso 2002
2/24
0/23
7.40 [ 0.45, 122.11 ]
12/187
11/193
1.13 [ 0.49, 2.63 ]
533
539
1.57 [ 0.96, 2.58 ]
Zmora 2003
Subtotal (95% CI)
Total events: 41 (Preparation), 28 (No Preparation) Heterogeneity: Chi2 = 3.45, df = 5 (P = 0.63); I2 =0.0% Test for overall effect: Z = 1.79 (P = 0.074)
0.2
0.5
Favours preparation
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2
5
Favours control
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Analysis 1.12. Comparison 1 Mechanical bowel preparation versus no preparation, Outcome 12 Sensitivity analysis 3 - Studies including children excluded. Review:
Mechanical bowel preparation for elective colorectal surgery
Comparison: 1 Mechanical bowel preparation versus no preparation Outcome: 12 Sensitivity analysis 3 - Studies including children excluded Study or subgroup
Favours preparation n/N
Favours control
Peto Odds Ratio
n/N
Weight
Peto,Fixed,95% CI
Peto Odds Ratio Peto,Fixed,95% CI
1 Anastomotic leakage Brownson 1992
8/67
1/67
18.4 %
5.23 [ 1.36, 20.14 ]
Bucher 2003
4/47
1/46
10.4 %
3.43 [ 0.57, 20.59 ]
Burke 1994
3/82
4/87
14.7 %
0.79 [ 0.17, 3.58 ]
Fillmann 1995
2/30
1/30
6.3 %
1.99 [ 0.20, 19.94 ]
Miettinen 2000
5/138
3/129
16.9 %
1.56 [ 0.38, 6.36 ]
Tabusso 2002
5/24
0/23
9.9 %
8.54 [ 1.36, 53.51 ]
Zmora 2003
7/187
4/193
23.3 %
1.81 [ 0.55, 5.99 ]
575
575
100.0 %
2.38 [ 1.34, 4.25 ]
Subtotal (95% CI)
Total events: 34 (Favours preparation), 14 (Favours control) Heterogeneity: Chi2 = 5.95, df = 6 (P = 0.43); I2 =0.0% Test for overall effect: Z = 2.94 (P = 0.0032) 2 Wound infection Brownson 1992
5/86
7/93
19.7 %
0.76 [ 0.24, 2.45 ]
Bucher 2003
4/47
1/46
8.4 %
3.43 [ 0.57, 20.59 ]
Burke 1994
4/82
3/87
11.8 %
1.43 [ 0.32, 6.47 ]
Fillmann 1995
1/30
2/30
5.1 %
0.50 [ 0.05, 5.02 ]
Miettinen 2000
5/138
3/129
13.6 %
1.56 [ 0.38, 6.36 ]
Tabusso 2002
2/24
0/23
3.4 %
7.40 [ 0.45, 122.11 ]
12/187
11/193
38.0 %
1.13 [ 0.49, 2.63 ]
594
601
100.0 %
1.26 [ 0.75, 2.12 ]
Zmora 2003
Subtotal (95% CI)
Total events: 33 (Favours preparation), 27 (Favours control) Heterogeneity: Chi2 = 4.23, df = 6 (P = 0.65); I2 =0.0% Test for overall effect: Z = 0.88 (P = 0.38) Test for subgroup differences: Chi2 = 2.56, df = 1 (P = 0.11), I2 =61%
0.2
0.5
1
Favours treatment
Mechanical bowel preparation for elective colorectal surgery (Review) Copyright © 2008 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.
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5
Favours control
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Review:
Mechanical bowel preparation for elective colorectal surgery
Comparison: 1 Mechanical bowel preparation versus no preparation Outcome: 12 Sensitivity analysis 3 - Studies including children excluded Study or subgroup
Favours preparation
Favours control
n/N
Peto Odds Ratio
n/N
Peto,Fixed,95% CI
Peto Odds Ratio Peto,Fixed,95% CI
1 Anastomotic leakage Brownson 1992
8/67
1/67
5.23 [ 1.36, 20.14 ]
Bucher 2003
4/47
1/46
3.43 [ 0.57, 20.59 ]
Burke 1994
3/82
4/87
0.79 [ 0.17, 3.58 ]
Fillmann 1995
2/30
1/30
1.99 [ 0.20, 19.94 ]
Miettinen 2000
5/138
3/129
1.56 [ 0.38, 6.36 ]
Tabusso 2002
5/24
0/23
8.54 [ 1.36, 53.51 ]
Zmora 2003
7/187
4/193
1.81 [ 0.55, 5.99 ]
575
575
2.38 [ 1.34, 4.25 ]
Subtotal (95% CI)
Total events: 34 (Favours preparation), 14 (Favours control) Heterogeneity: Chi2 = 5.95, df = 6 (P = 0.43); I2 =0.0% Test for overall effect: Z = 2.94 (P = 0.0032)
0.2
0.5
1
Favours treatment
Review:
2
5
Favours control
Mechanical bowel preparation for elective colorectal surgery
Comparison: 1 Mechanical bowel preparation versus no preparation Outcome: 12 Sensitivity analysis 3 - Studies including children excluded Study or subgroup
Favours preparation n/N
Favours control
Peto Odds Ratio
n/N
Peto,Fixed,95% CI
Peto Odds Ratio Peto,Fixed,95% CI
2 Wound infection Brownson 1992
5/86
7/93
0.76 [ 0.24, 2.45 ]
Bucher 2003
4/47
1/46
3.43 [ 0.57, 20.59 ]
Burke 1994
4/82
3/87
1.43 [ 0.32, 6.47 ]
Fillmann 1995
1/30
2/30
0.50 [ 0.05, 5.02 ]
Miettinen 2000
5/138
3/129
1.56 [ 0.38, 6.36 ]
Tabusso 2002
2/24
0/23
7.40 [ 0.45, 122.11 ]
12/187
11/193
1.13 [ 0.49, 2.63 ]
Zmora 2003
0.2
0.5
Favours treatment
Mechanical bowel preparation for elective colorectal surgery (Review) Copyright © 2008 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.
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2
5
Favours control
(Continued . . . )
32
(. . . Study or subgroup
Favours preparation
Favours control
n/N
Subtotal (95% CI)
Peto Odds Ratio
n/N
594
Peto,Fixed,95% CI
Continued)
Peto Odds Ratio Peto,Fixed,95% CI
601
1.26 [ 0.75, 2.12 ]
Total events: 33 (Favours preparation), 27 (Favours control) Heterogeneity: Chi2 = 4.23, df = 6 (P = 0.65); I2 =0.0% Test for overall effect: Z = 0.88 (P = 0.38)
0.2
0.5
Favours treatment
1
2
5
Favours control
Analysis 1.13. Comparison 1 Mechanical bowel preparation versus no preparation, Outcome 13 Sensitivity analysis 4 - Studies including patients without anastomosis excluded. Review:
Mechanical bowel preparation for elective colorectal surgery
Comparison: 1 Mechanical bowel preparation versus no preparation Outcome: 13 Sensitivity analysis 4 - Studies including patients without anastomosis excluded Study or subgroup
Treatment n/N
Control
Odds Ratio
n/N
Weight
M-H,Fixed,95% CI
Odds Ratio M-H,Fixed,95% CI
1 Anastomosis leakage Brownson 1992
8/67
1/67
7.1 %
8.95 [ 1.09, 73.69 ]
Bucher 2003
4/47
1/46
7.5 %
4.19 [ 0.45, 38.96 ]
Burke 1994
3/82
4/87
30.3 %
0.79 [ 0.17, 3.63 ]
Miettinen 2000
5/138
3/129
24.3 %
1.58 [ 0.37, 6.74 ]
Zmora 2003
7/187
4/193
30.8 %
1.84 [ 0.53, 6.38 ]
521
522
100.0 %
2.14 [ 1.09, 4.19 ]
Subtotal (95% CI)
Total events: 27 (Treatment), 13 (Control) Heterogeneity: Chi2 = 3.98, df = 4 (P = 0.41); I2 =0.0% Test for overall effect: Z = 2.22 (P = 0.026) 2 Wound infection Brownson 1992
5/86
7/93
27.4 %
0.76 [ 0.23, 2.49 ]
Bucher 2003
4/47
1/46
4.0 %
4.19 [ 0.45, 38.96 ]
Burke 1994
4/82
3/87
12.0 %
1.44 [ 0.31, 6.62 ]
5/138
3/129
12.9 %
1.58 [ 0.37, 6.74 ]
12/187
11/193
43.8 %
1.13 [ 0.49, 2.64 ]
540
548
100.0 %
1.25 [ 0.72, 2.15 ]
Miettinen 2000 Zmora 2003
Subtotal (95% CI)
Total events: 30 (Treatment), 25 (Control) Heterogeneity: Chi2 = 1.99, df = 4 (P = 0.74); I2 =0.0% Test for overall effect: Z = 0.79 (P = 0.43)
0.2
0.5
Favours treatment
1
2
5
Favours control
Mechanical bowel preparation for elective colorectal surgery (Review) Copyright © 2008 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.
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Review:
Mechanical bowel preparation for elective colorectal surgery
Comparison: 1 Mechanical bowel preparation versus no preparation Outcome: 13 Sensitivity analysis 4 - Studies including patients without anastomosis excluded Study or subgroup
Treatment n/N
Control
Odds Ratio
n/N
M-H,Fixed,95% CI
Odds Ratio M-H,Fixed,95% CI
1 Anastomosis leakage Brownson 1992
8/67
1/67
8.95 [ 1.09, 73.69 ]
Bucher 2003
4/47
1/46
4.19 [ 0.45, 38.96 ]
Burke 1994
3/82
4/87
0.79 [ 0.17, 3.63 ]
Miettinen 2000
5/138
3/129
1.58 [ 0.37, 6.74 ]
Zmora 2003
7/187
4/193
1.84 [ 0.53, 6.38 ]
521
522
2.14 [ 1.09, 4.19 ]
Subtotal (95% CI) Total events: 27 (Treatment), 13 (Control)
Heterogeneity: Chi2 = 3.98, df = 4 (P = 0.41); I2 =0.0% Test for overall effect: Z = 2.22 (P = 0.026)
0.2
0.5
Favours treatment
Mechanical bowel preparation for elective colorectal surgery (Review) Copyright © 2008 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.
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2
5
Favours control
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Review:
Mechanical bowel preparation for elective colorectal surgery
Comparison: 1 Mechanical bowel preparation versus no preparation Outcome: 13 Sensitivity analysis 4 - Studies including patients without anastomosis excluded Study or subgroup
Treatment
Control
n/N
Odds Ratio
n/N
Odds Ratio
M-H,Fixed,95% CI
M-H,Fixed,95% CI
2 Wound infection Brownson 1992
5/86
7/93
0.76 [ 0.23, 2.49 ]
Bucher 2003
4/47
1/46
4.19 [ 0.45, 38.96 ]
Burke 1994
4/82
3/87
1.44 [ 0.31, 6.62 ]
5/138
3/129
1.58 [ 0.37, 6.74 ]
12/187
11/193
1.13 [ 0.49, 2.64 ]
540
548
1.25 [ 0.72, 2.15 ]
Miettinen 2000 Zmora 2003
Subtotal (95% CI) Total events: 30 (Treatment), 25 (Control)
Heterogeneity: Chi2 = 1.99, df = 4 (P = 0.74); I2 =0.0% Test for overall effect: Z = 0.79 (P = 0.43)
0.2
0.5
Favours treatment
1
2
5
Favours control
WHAT’S NEW Last assessed as up-to-date: 20 October 2004
Date
Event
Description
5 August 2008
Amended
Converted to new review format.
Mechanical bowel preparation for elective colorectal surgery (Review) Copyright © 2008 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.
35
HISTORY Protocol first published: Issue 4, 1999 Review first published: Issue 2, 2003
Date
Event
Description
21 October 2004
New citation required and conclusions have changed
Substantive amendment
CONTRIBUTIONS OF AUTHORS Conceiving the review: DM, ANA. Designing the review: KFG, DM, AAC, ANA. Coordinating the review: KFG. Data collection for the review Developing search strategy: AAC. Undertaking searches: KFG, AAC. Screening search results: KFG, DM, AAC. Organising retrieval of papers: KFG, DM, AAC. Screening retrieved papers against inclusion criteria: KFG, DM, AAC. Appraising quality of papers: KFG, DM, AAC. Abstracting data from papers: KFG, DM, AAC. Writing to authors of papers for additional information: DM, KFG. Providing additional data about papers: DM, KFG. Obtaining and screening data on unpublished studies: Not applicable. Data management for the review: KFG, DM, AAC, PWJ. Entering data into RevMan: KFG, PWJ. Analysis of data: KFG, DM, AAC, PWJ Interpretation of data: KFG, DM, AAC, PWJ. Providing a methodological perspective: KFG, DM, AAC, ANA. Providing a clinical perspective: KFG, DM, AAC, PWJ. Providing a policy perspective: DM. Providing a consumer perspective: none. Writing the review: KFG, DM, AAC, PWJ. Providing general advice on the review: DM , ANA. Securing funding for the review: DM, ANA, PWJ. Performing previous work that was the foundation of current study: Not applicable. Mechanical bowel preparation for elective colorectal surgery (Review) Copyright © 2008 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.
36
DECLARATIONS OF INTEREST None known
SOURCES OF SUPPORT Internal sources • Clinical Trials and Meta-analyses Unit, Federal University of São Paulo, Brazil. • Surgical Gastroenterology Department, Federal University of São Paulo, Brazil. • Cochrane Colorectal Cancer Group, Denmark.
External sources • The Valerie Jefferson Fund, UK. • SanMed - Materiais Médicos Hospitalares Ltda., Brazil.
NOTES This review last updated November 2004
INDEX TERMS Medical Subject Headings (MeSH) Colorectal Surgery; Digestive System Surgical Procedures [∗ adverse effects]; Fecal Incontinence [etiology; prevention & control]; Preoperative Care [∗ methods]; Randomized Controlled Trials as Topic; Surgical Procedures, Elective [∗ adverse effects]; Surgical Wound Dehiscence [prevention & control]; Surgical Wound Infection [prevention & control]
MeSH check words Humans
Mechanical bowel preparation for elective colorectal surgery (Review) Copyright © 2008 The Cochrane Collaboration. Published by John Wiley & Sons, Ltd.
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