Usefulness of Preoperative Mechanical Bowel Preparation in Patients with Colon Cancer who Undergo Elective Surgery: A Prospective Randomized Trial Using Oral Antibiotics

Efficacy of a 1 day Rifaximin and Metronidazole Regimen and Mechanical Bowel Preparation for Preventing Surgical Site Infection in Minimally Invasive Colorectal Cancer Surgery: A Prospective Observational Study

BACKGROUND

A combination of oral antibiotics and mechanical bowel preparation is recommended for patients scheduled to undergo elective colorectal surgery on the basis of recent large trials that have reported the superiority of this approach in preventing surgical site infections (SSIs). However, there are no standard recommendations for this approach. Therefore, in this study, we evaluated the efficacy of rifaximin and metronidazole and mechanical bowel preparation for preventing SSIs in cases of minimally invasive surgery for colorectal cancer.

METHODS

This single-arm prospective observational study included 256 individuals. The primary end point was the rate of SSI. Rifaximin 400 mg and metronidazole 500 mg were administered twice daily (10 am and 10 pm), and mechanical bowel preparation was administered the day before the operation.

RESULTS

After excluding 15 patients, 241 were enrolled. No adverse event occurred following the administration of oral antibiotics and mechanical bowel preparation; there was 100% compliance. The total SSI rate was 2.9%; the rates of incisional and organ/space SSIs were 1.2% and 1.7%, respectively. All patients were treated conservatively. Univariate analyses revealed preoperative anemia, hypoalbuminemia, and transfusion and postoperative transfusion were significantly associated with SSIs.

DISCUSSION

A 1 day rifaximin and metronidazole regimen with mechanical bowel preparation for elective minimally invasive surgery for colorectal cancer was associated with a favorable SSI rate of 2.9%, safety, and high compliance. This approach is appropriate for inclusion in the current guidelines for perioperative management of patients scheduled to undergo minimally invasive surgery for colorectal cancer.

Oral Antibiotics Alone versus Oral Antibiotics Combined with Mechanical Bowel Preparation for Elective Colorectal Surgery: A Propensity Score-Matching Re-Analysis of the iCral 2 and 3 Prospective Cohorts

The evidence regarding the role of oral antibiotics alone (oA) or combined with mechanical bowel preparation (MoABP) for elective colorectal surgery remains controversial. A prospective database of 8359 colorectal resections gathered over a 32-month period from 78 Italian surgical units (the iCral 2 and 3 studies), reporting patient-, disease-, and procedure-related variables together with 60-day adverse events, was re-analyzed to identify a subgroup of 1013 cases (12.1%) that received either oA or MoABP. This dataset was analyzed using a 1:1 propensity score-matching model including 20 covariates. Two well-balanced groups of 243 patients each were obtained: group A (oA) and group B (MoABP). The primary endpoints were anastomotic leakage (AL) and surgical site infection (SSI) rates. Group A vs. group B showed a significantly higher AL risk [14 (5.8%) vs. 6 (2.5%) events; OR: 3.77; 95%CI: 1.22-11.67; p = 0.021], while no significant difference was recorded between the two groups regarding SSIs. These results strongly support the use of MoABP for elective colorectal resections.

The Impact of Mechanical Bowel Preparation and Oral Antibiotics in Colorectal Cancer Surgery (MECCA Study): A Prospective Randomized Clinical Trial

Background: Colorectal cancer surgery has been associated with surgical site infections (SSIs), leading to an increase in postoperative morbidity, length of stay and total cost. The aim of the present randomized study was to investigate the relationship between the preoperative administration of oral antibiotic therapy and SSI rate, as well as other postoperative outcomes in patients undergoing colorectal cancer surgery. Material and Methods: Patients who underwent colorectal cancer surgery in a university surgical department were included in the present study. Patients were randomized into two groups using the "block randomization" method. The intervention group received three doses of 400 mg rifaximin and one dose of 500 mg metronidazole per os, as well as mechanical bowel preparation the day before surgery. The control group underwent only mechanical bowel preparation the day before surgery. The study has been registered in ClinicalTrials.gov (NCT03563586). Results: Two hundred and five patients were finally included in the present study, 97 of whom received preoperative antibiotic therapy per os (intervention group). Patients of this group demonstrated a significantly lower SSI rate compared with patients who did not receive preoperative antibiotic therapy (7% vs. 16%, p = 0.049). However, preoperative antibiotic administration was not correlated with any other postoperative outcome (anastomotic leak, overall complications, readmissions, length of stay). Conclusions: Preoperative antibiotic therapy in combination with mechanical bowel preparation seemed to be correlated with a lower SSI rate after colorectal cancer surgery.

Effect of preoperative oral antibiotics and mechanical bowel preparation on the prevention of surgical site infection in elective colorectal surgery, and does oral antibiotic regime matter? a bayesian network meta-analysis

PURPOSE

Surgical site infection (SSI) impacts 5-20% of patients after elective colorectal surgery. There are varying reports on the effectiveness of oral antibiotics (OAB) with preoperative mechanical bowel preparation (MBP) in preventing SSI. We aim to determine the role of OAB and MBP in preventing SSI after elective colorectal surgery. We also determine if a specific OAB regimen will be more effective than others.

METHODS

This study investigated the impact of OAB and MBP in patients undergoing elective colorectal surgery. PubMed, MEDLINE, Ovid, Cochrane Central Register of Controlled Trials, ACP Journal Club, and Embase databases were searched for randomized clinical trials (RCTs) published by June 2022. All RCTs comparing various preoperative bowel preparation regimens, including pairwise or multi-intervention comparisons, were included. To establish the role of OAB and MBP in preventing SSI, we conducted a Bayesian network meta-analysis on all RCTs. We further performed subgroup analysis to determine the most effective OAB regimen.

RESULTS

Among included 46 studies with a total of 12690 patients, patients in the MBP + OAB group were less likely to have SSI than those having MBP-only (OR 0.55, 95% CrI 0.39-0.76), and without MBP and OAB (OR 0.52, 95% CrI 0.32-0.84). OAB regimen C (kanamycin + metronidazole) and A (neomycin + metronidazole) demonstrated a significantly reduced incidence of SSI, compared to regimen B (neomycin + erythromycin) with OR 0.24 (95% CrI 0.07-0.79) and 0.26 (95% CrI 0.07-0.99) respectively.

CONCLUSIONS

OAB with MBP reduces the risk of SSI after elective colorectal surgery. Providing adequate aerobic and anaerobic coverage with OAB may confer better protection against SSI.

Is There a Role for Mechanical and Oral Antibiotic Bowel Preparation for Patients Undergoing Minimally Invasive Colorectal Surgery? A Systematic Review and Meta-analysis

INTRODUCTION

To date, all meta-analyses on oral antibiotic prophylaxis (OA) and mechanical bowel preparation (MBP) in colorectal surgery have included results of both open and minimally invasive approaches. Mixing both procedures may lead to false conclusions. The aim of the study was to assess the available evidence of mechanical and oral antibiotic bowel preparation in reducing the incidence of surgical site infection (SSI) and other complications following minimally invasive elective colorectal surgery.

METHODS

We searched PubMed, Science Direct, Google Scholar and Cochrane Library from 2000 to May 1, 2022. Comparative randomized and non-randomized studies were included. We reviewed the use of oral OA, MBP and combinations of these treatments. The methodological quality of the included studies was assessed using the Rob v2 and Robins-I tools.

RESULTS

We included 18 studies (7 randomized controlled trials and 11 cohort studies). Meta-analysis of the included studies showed that the combination of MBP + OA was associated with a significant reduction in SSI, AL and overall morbidity compared with the other options no preparation, MBP only and OA only.  CONCLUSION: Adding OA with MBP has a positive impact in reducing the incidence of SSI, AL and overall morbidity after minimally invasive colorectal surgery. Therefore, the combination of OA and MBP should be encouraged in this selected group of patients undergoing minimally invasive surgery.

Preoperative combined mechanical and oral antibiotic bowel preparation for preventing complications in elective colorectal surgery

BACKGROUND

The success of elective colorectal surgery is mainly influenced by the surgical procedure and postoperative complications. The most serious complications include anastomotic leakages and surgical site infections (SSI)s, which can lead to prolonged recovery with impaired long-term health.  Compared with other abdominal procedures, colorectal resections have an increased risk of adverse events due to the physiological bacterial colonisation of the large bowel. Preoperative bowel preparation is used to remove faeces from the bowel lumen and reduce bacterial colonisation. This bowel preparation can be performed mechanically and/or with oral antibiotics. While mechanical bowel preparation alone is not beneficial, the benefits and harms of combined mechanical and oral antibiotic bowel preparation is still unclear.

OBJECTIVES

To assess the evidence for the use of combined mechanical and oral antibiotic bowel preparation for preventing complications in elective colorectal surgery.

SEARCH METHODS

We searched MEDLINE, Embase, CENTRAL and trial registries on 15 December 2021. In addition, we searched reference lists and contacted colorectal surgery organisations.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) of adult participants undergoing elective colorectal surgery comparing combined mechanical and oral antibiotic bowel preparation (MBP+oAB) with either MBP alone, oAB alone, or no bowel preparation (nBP). We excluded studies in which no perioperative intravenous antibiotic prophylaxis was given.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures as recommended by Cochrane. Pooled results were reported as mean difference (MD) or risk ratio (RR) and 95 % confidence intervals (CIs) using the Mantel-Haenszel method. The certainty of the evidence was assessed with GRADE.

MAIN RESULTS

We included 21 RCTs analysing 5264 participants who underwent elective colorectal surgery. None of the included studies had a high risk of bias, but two-thirds of the included studies raised some concerns. This was mainly due to the lack of a predefined analysis plan or missing information about the randomisation process. Most included studies investigated both colon and rectal resections due to malignant and benign surgical indications. For MBP as well as oAB, the included studies used different regimens in terms of agent(s), dosage and timing.  Data for all predefined outcomes could be extracted from the included studies. However, only four studies reported on side effects of bowel preparation, and none recorded the occurrence of adverse effects such as dehydration, electrolyte imbalances or the need to discontinue the intervention due to side effects. Seventeen trials compared MBP+oAB with sole MBP. The incidence of SSI could be reduced through MBP+oAB by 44% (RR 0.56, 95% CI 0.42 to 0.74; 3917 participants from 16 studies; moderate-certainty evidence) and the risk of anastomotic leakage could be reduced by 40% (RR 0.60, 95% CI 0.36 to 0.99; 2356 participants from 10 studies; moderate-certainty evidence). No difference between the two comparison groups was found with regard to mortality (RR 0.87, 95% CI 0.27 to 2.82; 639 participants from 3 studies; moderate-certainty evidence), the incidence of postoperative ileus (RR 0.89, 95% CI 0.59 to 1.32; 2013 participants from 6 studies, low-certainty of evidence) and length of hospital stay (MD -0.19, 95% CI -1.81 to 1.44; 621 participants from 3 studies; moderate-certainty evidence). Three trials compared MBP+oAB with sole oAB. No difference was demonstrated between the two treatment alternatives in terms of SSI (RR 0.87, 95% CI 0.34 to 2.21; 960 participants from 3 studies; very low-certainty evidence), anastomotic leakage (RR 0.84, 95% CI 0.21 to 3.45; 960 participants from 3 studies; low-certainty evidence), mortality (RR 1.02, 95% CI 0.30 to 3.50; 709 participants from 2 studies; low-certainty evidence), incidence of postoperative ileus (RR 1.25, 95% CI 0.68 to 2.33; 709 participants from 2 studies; low-certainty evidence) or length of hospital stay (MD 0.1 respectively 0.2, 95% CI -0.68 to 1.08; data from 2 studies; moderate-certainty evidence). One trial (396 participants) compared MBP+oAB versus nBP. The evidence is uncertain about the effect of MBP+oAB on the incidence of SSI as well as mortality (RR 0.63, 95% CI 0.33 to 1.23 respectively RR 0.20, 95% CI 0.01 to 4.22; low-certainty evidence), while no effect on the risk of anastomotic leakages (RR 0.89, 95% CI 0.33 to 2.42; low-certainty evidence), the incidence of postoperative ileus (RR 1.18, 95% CI 0.77 to 1.81; low-certainty evidence) or the length of hospital stay (MD 0.1, 95% CI -0.8 to 1; low-certainty evidence) could be demonstrated.

AUTHORS' CONCLUSIONS

Based on moderate-certainty evidence, our results suggest that MBP+oAB is probably more effective than MBP alone in preventing postoperative complications. In particular, with respect to our primary outcomes, SSI and anastomotic leakage, a lower incidence was demonstrated using MBP+oAB. Whether oAB alone is actually equivalent to MBP+oAB, or leads to a reduction or increase in the risk of postoperative complications, cannot be clarified in light of the low- to very low-certainty evidence. Similarly, it remains unclear whether omitting preoperative bowel preparation leads to an increase in the risk of postoperative complications due to limited evidence. Additional RCTs, particularly on the comparisons of MBP+oAB versus oAB alone or nBP, are needed to assess the impact of oAB alone or nBP compared with MBP+oAB on postoperative complications and to improve confidence in the estimated effect. In addition, RCTs focusing on subgroups (e.g. in relation to type and location of colon resections) or reporting side effects of the intervention are needed to determine the most effective approach of preoperative bowel preparation.

A Network Meta-Analysis and GRADE Assessment of the Effect of Preoperative Oral Antibiotics with and Without Mechanical Bowel Preparation on Surgical Site Infection Rate in Colorectal Surgery

Objective

To compare the effect of different methods of bowel preparation on the incidence of surgical site infections (SSI), anastomotic leakage (AL), and mortality in patients undergoing elective colorectal surgery.

Background

Recent guidelines advise mechanical bowel preparation with oral antibiotics (MBP-OA) for the prevention of SSI in colorectal surgery. Recent trials suggest oral antibiotics (OA) alone may be sufficient.

Methods

PubMed, MEDLINE, and Embase were searched from inception until 10-08-2021. We included randomized controlled trials (RCTs) comparing multiple methods of bowel preparation (mechanical bowel preparation [MBP], OA, MBP-OA, or no preparation) with regards to clinical outcomes such as incidence of SSI, AL, and mortality rates. A frequentist random-effects network meta-analysis was conducted to estimate the network effects of the different treatment options.

Results

We included 48 studies with 13,611 patients. Compared to no preparation, combined direct and indirect network estimates showed a relative risk (RR) for SSI of 0.57 (95% confidence interval [CI], 0.45-0.72) for MBP-OA, 0.68 (95% CI, 0.49-0.95) for OA, and 1.05 (95% CI, 0.87-1.26) for MBP. The RR for MBP-OA compared to OA was 0.84 (95% CI, 0.60-1.19); in sensitivity analysis of mainly laparoscopic procedures this effect of MBP-OA was more profound (RR, 0.56; 95% CI, 0.31-0.99).

Conclusions

This network meta-analysis of RCTs finds that both mechanical bowel preparation with oral antibiotics and oral antibiotics alone are comparably effective in the prevention of SSI. The evidence is uncertain about the relative benefit of MBP-OA compared to OA alone. Therefore, it seems justified to use either of the 2 for the prevention of SSI in colorectal surgery.

Postoperative paralytic ileus following debulking surgery in ovarian cancer patients

Aim

This study aims to evaluate the incidence of postoperative ileus (POI) following cytoreductive surgery in epithelial ovarian cancer (EOC) patients and its impact on anastomotic leakage occurrence and postoperative complications.

Methods

A total of 357 surgeries were performed on 346 ovarian cancer patients between 1/2010 and 12/2020 at our institution. The postoperative course regarding paralytic ileus, anastomotic leakage, and postoperative complications was analyzed by Fisher's exact test and through ordinal logistic regression.

Results

A total of 233 patients (65.3%) returned to normal gastrointestinal functions within 3 days after surgery. A total of 123 patients (34.5%) developed POI. There were 199 anastomoses in 165 patients and 24 leakages (12.1%). Postoperative antibiotics (p 0.001), stoma creation (p 0.0001), and early start of laxatives (p 0.0048) significantly decreased POI, while anastomoses in general (p 0.0465) and especially low anastomoses (p 0.0143) showed increased POI rates. Intraoperative positive fluid excess >5,000 cc was associated with a higher risk for POI (p 0.0063), anastomotic leakage (p 0.0254), and severe complications (p 0.0012).

Conclusion

Postoperative antibiotics, an early start with laxatives, and stoma creation were associated with reduced POI rates. Patients with anastomoses showed an increased risk for POI. Severe complications, anastomotic leakages, and POI were more common in the case of intraoperative fluid balance exceeding 5,000 cc.

Preoperative oral antibiotics with versus without mechanical bowel preparation to reduce surgical site infections following colonic resection: Protocol for an international randomized controlled trial (ORALEV2)

AIM

Surgical site infections (SSIs) are common after colonic surgery. SSIs can cause relevant morbidity and increase costs of care. Preoperative oral antibiotics can reduce the incidence of SSIs after resection of the colon, but the role of mechanical bowel preparation (MBP) is debated. This study aims to assess the impact of a combined regimen of oral antibiotics and MBP on SSIs after colonic surgery.

METHODS

An international, multicentre, pragmatic, adaptive, parallel-group, randomized controlled trial will be conducted across Europe. Adult patients scheduled to undergo elective colonic resection will be assessed for inclusion. Patients will be randomized into one of two treatment arms: (1) preoperative oral antibiotics without MBP (control); (2) preoperative oral antibiotics with MBP (experimental). All patients will receive intravenous antibiotics at anaesthetic induction. The primary aim will be 30-day SSI, assessed by a blinded nurse. Additional end-points include safety, morbidity and mortality, satisfaction with the preparation, time to return of bowel function, time to complete recovery and time to discharge, long-term results. Analyses will be performed with a modified intention-to-treat approach. Interim analyses are planned.

DISCUSSION

This will be the first randomized clinical trial to assess the efficacy and safety of preoperative oral antibiotics plus MBP versus preoperative oral antibiotics only, before colonic surgery. The knowledge obtained could help to establish the ideal preparation for patients scheduled to undergo resection of the colon. Full protocol NCT04161599.

Oral neomycin and bacitracin are effective in preventing surgical site infections in elective colorectal surgery: a multicentre, randomized, parallel, single-blinded trial (COLORAL-1)

Several regimens of oral and intravenous antibiotics (OIVA) have been proposed with contradicting results, and the role of mechanical bowel preparation (MBP) is still controversial. This study aims to assess the effectiveness of oral antibiotic prophylaxis in preventing Surgical Site Infections (SSI) in elective colorectal surgery. In a multicentre trial, we randomized patients undergoing elective colorectal resection surgery, comparing the effectiveness of OIVA versus intravenous antibiotics (IVA) regimens to prevent SSI as the primary outcome (NCT04438655). In addition to intravenous Amoxicillin/Clavulanic, patients in the OIVA group received Oral Neomycin and Bacitracin 24 h before surgery. MBP was administered according to local habits which were not changed for the study. The trial was terminated during the COVID-19 pandemic, as many centers failed to participate as well as the pandemic changed the rules for engaging patients. Two-hundred and four patients were enrolled (100 in the OIVA and 104 in the IVA group); 3 SSIs (3.4%) were registered in the OIVA and 14 (14.4%) in the IVA group (p = 0.010). No difference was observed in terms of anastomotic leak. Multivariable analysis indicated that OIVA reduced the rate of SSI (OR 0.21 / 95% CI 0.06–0.78 / p = 0.019), while BMI is a risk factor of SSI (OR 1.15 / 95% CI 1.01–1.30 p = 0.039). Subgroup analysis indicated that 0/22 patients who underwent OIVA/MBP + vs 13/77 IVA/MBP- experienced an SSI (p = 0.037). The early termination of the study prevents any conclusion regarding the interpretation of the data. Nonetheless, Oral Neomycin/Bacitracin and intravenous beta-lactam/beta-lactamases inhibitors seem to reduce SSI after colorectal resections, although not affecting the anastomotic leak in this trial. The role of MBP requires more investigation.

Mechanical plus oral bowel preparation with paromomycin and metronidazole reduces infectious complications in elective colorectal surgery: a matched case-control study

PURPOSE

Infectious complications are as high as 30% in elective colorectal surgery. In recent years, several studies have discussed the topic of preoperative bowel decontamination prior to colorectal surgery in order to reduce postoperative infectious complications and have found significant effects of oral antibiotic administration with a large variety of drugs used. No study has evaluated the combination of oral paromomycin and metronidazole in this context.

METHODS

We performed a prospective single-center study with a matched-pair retrospective cohort to evaluate postoperative infectious complications (superficial site infections, organ space abscess, anastomotic leakage) in elective colorectal surgery.

PATIENTS

A total of 120 patients were available for study inclusion; 101 gave informed consent and were included. A total of 92 patients were matched and subsequently analyzed. We could show a reduction in overall infectious complications in the intervention group (15.2% vs 30.8%, p = 0.018; odds ratio 0.333, 95% CI 0.142-0.784) as well as a reduction in superficial surgical site infections (8.7 vs 19.6%, p = 0.041, OR 0.333, 95% CI 0.121-0.917). The frequency of the other infectious complications such as intraabdominal abscesses and anastomotic leakage showed a tendency towards decreased frequencies in the intervention group (OR 0.714, 95% CI 0.235-2.169 and OR 0.571; 95% CI 0.167-1.952, respectively). Finally, the oral antibiotic administration led to an almost significantly reduced length of stay (12.24 days vs 15.25 days; p = 0.057).

CONCLUSIONS

Oral paromomycin and metronidazole with intravenous ertapenem effectively reduce infectious complications in elective colorectal surgery.

TRIAL REGISTRATION

The study was registered at Clinicaltrials.gov (NCT03759886) December 17, 2018.

Italian multi-society modified Delphi consensus on the definition and management of anastomotic leakage in colorectal surgery

INTRODUCTION

The incidence of anastomotic leak (AL) has not decreased over the past decades and some important grey areas remain in its definition, prevention, and management. The aim of this study was to reach a national consensus on the definition of AL and to identify key points to be applied in clinical practice.

METHODS

A 3-step modified Delphi method was used to establish consensus. Ten representative members of the major Italian surgical scientific societies with proven colorectal expertise were selected after a call to action. After a comprehensive literature search, each expert drew a list of evidence-based statements which were voted in round one by the scientific board. Panel members were asked to mark "totally disagree", "partially agree" or "totally agree" for each statement and provide comments. The same voting method was used for round 2. Round 3 consisted of a final face-to-face meeting.

RESULTS

Thirty-three statements (clustered into 14 topics) were included in round 1. Following the third voting round, a final list of 16 items was formulated, which encompass the following 9 topics: AL definition, patient- and operative-related risk factors, prevention measures, bowel preparation, surgical technique, intraoperative assessment, early diagnosis, radiological diagnosis and management of specific patterns of AL. The overall response rate was 100% for all items in all the three rounds.

CONCLUSIONS

This Delphi survey identified items that expert colorectal surgeons agreed were important to be applied in the prevention, diagnosis, and management of AL. This represents the first consensus involving all relevant national scientific societies, defining important and shared concepts in the diagnosis and management of AL.