[A prospective, randomised, controlled study on the need to mechanically prepare the colon in scheduled colorectal surgery]

Has network meta-analysis resolved the controversies related to bowel preparation in elective colorectal surgery?

AIM

There are discrepancies in the guidelines on preparation for colorectal surgery. While intravenous antibiotics (IV) are usually administered, the use of mechanical bowel preparation (MBP) and/or oral antibiotics (OA) is controversial. A recent network meta-analysis (NMA) demonstrated that the addition of OA reduced incisional surgical site infections (iSSIs) by more than 50%. We aimed to perform a NMA including only the highest quality randomized clinical trials (RCTs) in order to determine the ranking of different treatment strategies and assess these RCTs for methodological problems that may affect the conclusions of the NMAs.

METHOD

A NMA was performed according to PRISMA guidelines. RCTs of adult patients undergoing elective colorectal surgery with appropriate antibiotic cover and with at least 250 participants recruited, clear definition of endpoints and duration of follow-up extending beyond discharge from hospital were included. The search included Medline, Embase, Cochrane and SCOPUS databases. Primary outcomes were iSSI and anastomotic leak (AL). Statistical analysis was performed in Stata v.15.1 using frequentist routines.

RESULTS

Ten RCTs including 5107 patients were identified. Treatments compared IV (2218 patients), IV + OA (460 patients), MBP + IV (1405 patients), MBP + IV + OA (538 patients) and OA (486 patients). The likelihood of iSSI was significantly lower for IV + OA (rank 1) and MBP + IVA + OA (rank 2), reducing iSSIs by more than 50%. There were no differences between treatments for AL. Methodological issues included differences in definition, assessment and frequency of primary endpoint infections and the limited number of participants included in some treatment options.

CONCLUSION

While this NMA supports the addition of OA to IV to reduce iSSI it also highlights unanswered questions and the need for well-designed pragmatic RCTs.

The Effect of Mechanical Bowel Preparation on the Surgical Field in Laparoscopic Gynecologic Surgeries: A Prospective Randomized Controlled Trial

PURPOSE

To evaluate the effects of mechanical bowel preparation (MBP) on the intraoperative visualization of the surgical field, bowel handling, intestinal load, and overall ease of surgery in patients undergoing elective laparoscopic gynecological surgeries.

METHODS

The patients randomized to a MBP group and a no preparation (NMBP) group. The senior surgeon remained blinded to the bowel regimen used by the patient. Intraoperative visualization of the surgical field, bowel handling, intestinal load, and overall ease of surgery were evaluated using a numeric rating scale (NRS).

RESULTS

We enrolled 120 patients, of whom 109 completed the study, with 51 and 58 patients in the MBP and NMBP groups, respectively. The intraoperative visualization of the surgical field, intestinal load, and NRS scores for overall ease of surgery were better in the NMBP group (p = .03, p = .048, and p = .022, respectively). The results of the assessments also revealed no significant differences in surgical field visualization, ease of bowel handling, overall ease of surgery, or the time that patients experienced passage of flatus between obese (BMI > 30 kg/m²) and non-obese (BMI ≤ 30 kg/m²) patients in the two groups.

CONCLUSIONS

The current study revealed that MBP did not improve the intraoperative visualization of the surgical field or the overall ease of surgery. Moreover, MBP had no benefit when operating on patients who had a high BMI. Therefore, we do not recommend routine MBP before laparoscopic gynecological surgeries.

Strategies for Antibiotic Administration for Bowel Preparation Among Patients Undergoing Elective Colorectal Surgery: A Network Meta-analysis

Importance

There are discrepancies in guidelines on preparation for colorectal surgery. While intravenous (IV) antibiotics are usually administered, the use of mechanical bowel preparation (MBP), enemas, and/or oral antibiotics (OA) is controversial.

Objective

To summarize all data from randomized clinical trials (RCTs) that met selection criteria using network meta-analysis (NMA) to determine the ranking of different bowel preparation treatment strategies for their associations with postoperative outcomes.

Data Sources

Data sources included MEDLINE, Embase, Cochrane, and Scopus databases with no language constraints, including abstracts and articles published prior to 2021.

Study Selection

Randomized studies of adults undergoing elective colorectal surgery with appropriate aerobic and anaerobic antibiotic cover that reported on incisional surgical site infection (SSI) or anastomotic leak were selected for inclusion in the analysis. These were selected by multiple reviewers and adjudicated by a separate lead investigator. A total of 167 of 6833 screened studies met initial selection criteria.

Data Extraction and Synthesis

NMA was performed according to Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guidelines. Data were extracted by multiple independent observers and pooled in a random-effects model.

Main Outcomes and Measures

Primary outcomes were incisional SSI and anastomotic leak. Secondary outcomes included other infections, mortality, ileus, and adverse effects of preparation.

Results

A total of 35 RCTs that included 8377 patients were identified. Treatments compared IV antibiotics (2762 patients [33%]), IV antibiotics with enema (222 patients [3%]), IV antibiotics with OA with or without enema (628 patients [7%]), MBP with IV antibiotics (2712 patients [32%]), MBP with IV antibiotics with OA (with good IV antibiotic cover in 925 patients [11%] and with good overall antibiotic cover in 375 patients [4%]), MBP with OA (267 patients [3%]), and OA (486 patients [6%]). The likelihood of incisional SSI was significantly lower for those receiving IV antibiotics with OA with or without enema (rank 1) and MBP with adequate IV antibiotics with OA (rank 2) compared with all other treatment options. The addition of OA to IV antibiotics, both with and without MBP, was associated with a reduction in incisional SSI by greater than 50%. There were minimal differences between treatments in anastomotic leak and in any of the secondary outcomes.

Conclusions and Relevance

This NMA demonstrated that the addition of OA to IV antibiotics were associated with a reduction in incisional SSI by greater than 50%. The results support the addition of OA to IV antibiotics to reduce incisional SSI among patients undergoing elective colorectal surgery.

Mechanical and Oral Antibiotic Bowel Preparation in the Era of Minimally Invasive Surgery and Enhanced Recovery

INTRODUCTION

In the modern era of minimally invasive colorectal surgery and enhanced recovery pathways, the value of preoperative bowel preparation remains debated. In this review, we evaluate evidence regarding the use of mechanical bowel preparation (MBP) and oral antibiotic bowel preparation to make recommendations for their application in contemporary practice.

METHODS

We searched the PubMed database through December 2017 for relevant randomized controlled trials, Cochrane Reviews, American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database studies, and other reviews pertaining to MBP and oral antibiotic bowel preparation in elective colorectal surgery and conducted a narrative review.

RESULTS

The combination of MBP and oral antibiotics reduces the incidence of surgical site infection, anastomotic leak, and postoperative sepsis. MBP improves laparoscopic surgical viewing and facilitates intraoperative manipulation of the bowel in minimally invasive surgery.

CONCLUSION

Based on existing data, we recommend that preoperative care includes MBP and oral antibiotics in elective minimally invasive colorectal surgery.

Prevention of infectious complications after elective colorectal surgery in children: an American Pediatric Surgical Association Outcomes and Clinical Trials Committee comprehensive review

OBJECTIVE

This goal of this review was to examine the clinical evidence in support of commonly utilized measures intended to reduce complications following elective colorectal surgery.

DATA SOURCE

Literature searches were performed to identify relevant studies from Medline, PubMed, and Cochrane databases.

STUDY SELECTION

The American Pediatric Surgery Association Outcomes and Clinical Trials Committee selected eight questions to address this topic systematically in the context of three management areas: 1) appropriate utilization of systemic antibiotics for colorectal procedures, 2) reduction of stool burden through mechanical bowel preparation, and 3) intraluminal gut decontamination through use of enteral nonabsorbable antibiotics. Primary outcomes of interest included the occurrence of infectious and mechanical complications related to stool burden and intraluminal bacterial concentration (incisional surgical site infection, anastomotic leakage, and intraabdominal abscess).

RESULTS

The evidence in support of each management category was systematically reviewed, graded, and summarized in the context of the review's primary outcomes. Practice recommendations were made as deemed appropriate by the committee.

CONCLUSIONS

Clinical evidence in support of interventions to reduce infectious complications following colorectal surgery is derived almost exclusively from the adult literature. High-quality evidence to guide clinical practice in children is sorely needed, as the available data may have only limited relevance to pediatric colorectal diseases.

Bowel Preparation before Elective Surgery

Mechanical bowel preps were initially thought to decrease the bacterial load of the colon and therefore decrease infection. Traditional bowel preps include osmotic, laxative, and combination regimen. Data demonstrate that mechanical bowel preps are generally equivalent; however, the addition of oral antibiotics may further reduce the risk of infection. Recent data suggest that mechanical bowel preparations may not be necessary, and that dietary restrictions before surgery may also be obsolete. In this review, the authors address the types of mechanical bowel preparations (MBPs), differences in outcomes between MBPs, the role of oral antibiosis and enemas, the benefits of no MBP, and dietary preparations for elective colon and rectal surgery.

Mechanical bowel preparation for elective colorectal surgery

BACKGROUND

The presence of bowel contents during colorectal surgery has been related to anastomotic leakage, but the belief that mechanical bowel preparation (MBP) is an efficient agent against leakage and infectious complications is based on observational data and expert opinions only.An enema before the rectal surgery to clean the rectum and facilitate the manipulation for the mechanical anastomosis is used for many surgeons. This is analysed separately

OBJECTIVES

To determine the security and effectiveness of MBP on morbidity and mortality in colorectal surgery.

SEARCH STRATEGY

Publications describing trials of MBP before elective colorectal surgery were sought through searches of MEDLINE, EMBASE, LILACS, IBECS and The Cochrane Library; by handsearching relevant medical journals and conference proceedings, and through personal communication with colleagues.Searches were performed December 1, 2010.

SELECTION CRITERIA

Randomised controlled trials (RCTs) including participants submitted for elective colorectal surgery. Eligible interventions included any type of MBP compared with no MBP. Primary outcomes included anastomosis leakage - both rectal and colonic - and combined figures. Secondary outcomes included mortality, peritonitis, reoperation, wound infection, extra-abdominal complications, and overall surgical site infections.

DATA COLLECTION AND ANALYSIS

Data were independently extracted and checked. The methodological quality of each trial was assessed. Details of randomisation, blinding, type of analysis, and number lost to follow up were recorded. For analysis, the Peto-Odds Ratio (OR) was used as the default (no statistical heterogeneity was observed).

MAIN RESULTS

At this update six trials and a new comparison (Mechanical bowel preparation versus enema) were added. Altogether eighteen trials were analysed, with 5805 participants; 2906 allocated to MBP (Group A), and 2899 to no preparation (Group B), before elective colorectal surgery.For the comparison Mechanical Bowel Preparation Versus No Mechanical Bowel Preparation results were:1. Anastomotic leakage for low anterior resection: 8.8% (38/431) of Group A, compared with 10.3% (43/415) of Group B; Peto OR 0.88 [0.55, 1.40].2. Anastomotic leakage for colonic surgery: 3.0% (47/1559) of Group A, compared with 3.5% (56/1588) of Group B; Peto OR 0.85 [0.58, 1.26].3. Overall anastomotic leakage: 4.4% (101/2275) of Group A, compared with 4.5% (103/2258) of Group B; Peto OR 0.99 [0.74, 1.31].4. Wound infection: 9.6% (223/2305) of Group A, compared with 8.5% (196/2290) of Group B; Peto OR 1.16 [0.95, 1.42].Sensitivity analyses did not produce any differences in overall results.For the comparison Mechanical Bowel Preparation (A) Versus Rectal Enema (B) results were:1. Anastomotic leakage after rectal surgery: 7.4% (8/107) of Group A, compared with 7.9% (7/88) of Group B; Peto OR 0.93 [0.34, 2.52].2. Anastomotic leakage after colonic surgery: 4.0% (11/269) of Group A, compared with 2.0% (6/299) of Group B; Peto OR 2.15 [0.79, 5.84].3. Overall anastomotic leakage: 4.4% (27/601) of Group A, compared with 3.4% (21/609) of Group B; Peto OR 1.32 [0.74, 2.36].4. Wound infection: 9.9% (60/601) of Group A, compared with 8.0% (49/609) of Group B; Peto OR 1.26 [0.85, 1.88].

AUTHORS' CONCLUSIONS

Despite the inclusion of more studies with a total of 5805 participants, there is no statistically significant evidence that patients benefit from mechanical bowel preparation, nor the use of rectal enemas. In colonic surgery the bowel cleansing can be safely omitted and induces no lower complication rate. The few studies focused in rectal surgery suggested that mechanical bowel preparation could be used selectively, even though no significant effect was found. Further research on patients submitted for elective rectal surgery, below the peritoneal verge, in whom bowel continuity is restored, and studies with patients submitted to laparoscopic surgeries are still warranted.

Mechanical bowel preparation for elective colorectal surgery

BACKGROUND

The presence of bowel contents during colorectal surgery has been related to anastomotic leakage, but the belief that mechanical bowel preparation (MBP) is an efficient agent against leakage and infectious complications is based on observational data and expert opinions only.An enema before the rectal surgery to clean the rectum and facilitate the manipulation for the mechanical anastomosis is used for many surgeons. This is analysed separately

OBJECTIVES

To determine the security and effectiveness of MBP on morbidity and mortality in colorectal surgery.

SEARCH STRATEGY

Publications describing trials of MBP before elective colorectal surgery were sought through searches of MEDLINE, EMBASE, LILACS, IBECS and The Cochrane Library; by handsearching relevant medical journals and conference proceedings, and through personal communication with colleagues.Searches were performed December 1, 2010.

SELECTION CRITERIA

Randomised controlled trials (RCTs) including participants submitted for elective colorectal surgery. Eligible interventions included any type of MBP compared with no MBP. Primary outcomes included anastomosis leakage - both rectal and colonic - and combined figures. Secondary outcomes included mortality, peritonitis, reoperation, wound infection, extra-abdominal complications, and overall surgical site infections.

DATA COLLECTION AND ANALYSIS

Data were independently extracted and checked. The methodological quality of each trial was assessed. Details of randomisation, blinding, type of analysis, and number lost to follow up were recorded. For analysis, the Peto-Odds Ratio (OR) was used as the default (no statistical heterogeneity was observed).

MAIN RESULTS

At this update six trials and a new comparison (Mechanical bowel preparation versus enema) were added. Altogether eighteen trials were analysed, with 5805 participants; 2906 allocated to MBP (Group A), and 2899 to no preparation (Group B), before elective colorectal surgery.For the comparison Mechanical Bowel Preparation Versus No Mechanical Bowel Preparation results were:1. Anastomotic leakage for low anterior resection: 8.8% (38/431) of Group A, compared with 10.3% (43/415) of Group B; Peto OR 0.88 [0.55, 1.40].2. Anastomotic leakage for colonic surgery: 3.0% (47/1559) of Group A, compared with 3.5% (56/1588) of Group B; Peto OR 0.85 [0.58, 1.26].3. Overall anastomotic leakage: 4.4% (101/2275) of Group A, compared with 4.5% (103/2258) of Group B; Peto OR 0.99 [0.74, 1.31].4. Wound infection: 9.6% (223/2305) of Group A, compared with 8.5% (196/2290) of Group B; Peto OR 1.16 [0.95, 1.42].Sensitivity analyses did not produce any differences in overall results.For the comparison Mechanical Bowel Preparation (A) Versus Rectal Enema (B) results were:1. Anastomotic leakage after rectal surgery: 7.4% (8/107) of Group A, compared with 7.9% (7/88) of Group B; Peto OR 0.93 [0.34, 2.52].2. Anastomotic leakage after colonic surgery: 4.0% (11/269) of Group A, compared with 2.0% (6/299) of Group B; Peto OR 2.15 [0.79, 5.84].3. Overall anastomotic leakage: 4.4% (27/601) of Group A, compared with 3.4% (21/609) of Group B; Peto OR 1.32 [0.74, 2.36].4. Wound infection: 9.9% (60/601) of Group A, compared with 8.0% (49/609) of Group B; Peto OR 1.26 [0.85, 1.88].

AUTHORS' CONCLUSIONS

Despite the inclusion of more studies with a total of 5805 participants, there is no statistically significant evidence that patients benefit from mechanical bowel preparation, nor the use of rectal enemas. In colonic surgery the bowel cleansing can be safely omitted and induces no lower complication rate. The few studies focused in rectal surgery suggested that mechanical bowel preparation could be used selectively, even though no significant effect was found. Further research on patients submitted for elective rectal surgery, below the peritoneal verge, in whom bowel continuity is restored, and studies with patients submitted to laparoscopic surgeries are still warranted.

[Selective intestinal preparation in a multimodal rehabilitation program. Influence on preoperative comfort and the results after colorectal surgery]

INTRODUCTION

Despite there being no evidence of the advantages of its use, mechanical bowel preparation (MBP) continues to be routine in colorectal surgery. Our objective is to analyse the impact of its selective use, as regards patient comfort and results, comparing a perioperative multimodal rehabilitation program (MMRH) with conventional care (CC).

MATERIAL AND METHODS

A prospective study of 108 patients proposed for elective surgery, assigned consecutively 2:1 to an MMRH protocol which only included MBP in rectal surgery with low anastomosis, or to CC in whom MBP was used except in right colon surgery. We also studied two Groups (A and B) with and without the use of MBP. Their tolerance, results and postoperative recovery variables were analysed.

RESULTS

Thirty-nine patients were included in Group A, and 69 in Group B. A MMRH protocol was used in another 69 patients. The Group A patients had more abdominal pain, anal discomfort, nausea and thirst, but there were no differences as regards, death, overall or local complications, whilst there was less complications, suture failures and death in the MMRH when compared with CC Group (P<.05). There were no advantages observed in the use of MBP as regards the start of bowel movements, tolerance to diet or hospital stay, but these parameters were favourable to the MMRH when compared with CC Group.

CONCLUSIONS

The restriction of MBP is safe, and associated with an MMRH program, contributes to a faster and more comfortable recovery, without increasing complications.