Infections after elective intestinal surgery remain a significant burden for patients and for the health care system. The cost of treating a single surgical site infection is estimated at approximately $27,000. In adult patients, there is good evidence that the combination of oral antibiotics and mechanical bowel preparation is effective at reducing infections after intestinal surgery. In children, the body of evidence is much weaker. In this population, little evidence exists for oral antibiotics reducing infections and no data exists as to the effect of combining antibiotics with mechanical bowel preparation (such as polyethylene glycol (PEG)). The goal of the proposed study is to examine the effects of oral antibiotics with and without the combined use of mechanical bowel preparation on the rate of post-operative infectious complications in children aged 6 months to 18 years. This will be compared to the institution's current standard of care, which is to abstain from any type of mechanical bowel preparations or oral antibiotic administration before intestinal surgery.

Background:

A Cochrane review of randomized controlled trials of MBP use in adults showed no difference in the rate of wound infection or anastomotic leak in colon or rectal procedures with MBP compared to no preparation (Guenaga, Matos, & Wille-Jorgensen, 2011). Two recent systematic reviews and meta-analyses support those findings. Lok and colleagues (2018) identified two randomized controlled trials and four retrospective reviews for patient <21 years, looking at preoperative MBP and its effect on the incidence postoperative complications, including anastomotic leak, wound infection, and intra-abdominal infection (Janssen Lok M 2018). Overall, MBP before colorectal surgery did not significantly decrease the incidence of post-operative outcomes. This was consistent with findings from a systematic review in mechanical bowel preparation in pediatric population. The review showed that the risk of developing a post-operative infection was 10.1% in patients who received MBP compared to 9.1% in patients who did not receive MBP, resulting in no statistically significant difference difference (risk difference of -0.03% (95% CI, -0.09% - 0.03%)) (Zwart 2018).

With regards to OA alone, the adult literature showed promising results in favour of the OA. In a Cochrane review on antimicrobial prophylaxis in colorectal surgery, the addition of OA to the intravenous antibiotics was found to reduce surgical wound infection (RR 0.56, 95% CI 0.43 to 0.74) (Nelson, Gladman, & Barbateskovic, 2014).

There are fewer studies in the pediatric population on the subject, they contain fewer patients and are mainly retrospective in nature. In a multi-center retrospective study, Serrurier et al. (2012), reviewed outcomes in children who underwent colostomy closure, and found higher rates of wound infection (14% vs. 6%, p=0.04) and a longer hospital length of stay in children who received MBP. In a retrospective cohort study including 1581 pediatric patients from PHIS database, post-operative complications were found to be highest in the no preparation group compared to combination prep and OA alone (23.3%, 15.9%, and 14.2% respectively; p=0.002) (Ares 2018). One study compared MBP alone versus MBP with OA in children undergoing colostomy closure post anorectal malformation repair and found no difference in overall SSI rates (MBP+OA: 13% (7/53) versus MBP alone: 17% (7/12) p=0.64) (Breckler, Rescorla, & Billmire, 2010). The authors found that the use of MBP alone was associated with a greater risk of wound infection (14% vs. 6%, p=0.04) and a longer hospital stay. Evidence to support the sole use of oral antibiotics versus in combination with MBP is lacking, particularly in the pediatric literature, with more studies being required to address this question.

One recent meta-analysis including adults assessed 8458 adult patients (38 clinical trials), comparing 4 groups of different bowel preparation: MBP with OA, OA only, MBP only, and no preparation. The primary outcome was the total rate of incisional and organ/space SSIs. Results showed that only MBP with OA versus MBP alone was associated with a statistically significant reduction in SSI rates. The use of OA without MBP was not associated with a statistically significant reduction in SSI rates when compared to any other group. The authors concluded that MBP with OA was associated with the lowest risk of SSI, followed by OA only (Toh et al., 2018).

It remains unclear whether the addition of MBP to OA in pediatric population affects the rate of post-operative infectious complications positively or negatively. The current study is therefore needed to build on the work conducted in the adult literature to determine best practices for the pediatric population.

Purpose:

This is a pilot study to check the feasibility of conducting a randomized controlled trial to assess the efficacy of oral nonabsorbable antibiotics, with or without mechanical bowel preparation, in reducing the rate of post-operative infectious complications occurring within 30 days post-operatively in children and adolescents (aged 6 months to 18 years) undergoing elective colon or rectal surgery.

Post-operative complications include: surgical site infections (incisional, organ-space, and anatomic leak), length of hospital stay, readmission, post-operative use of therapeutic antibiotics, re-operation, occurrence of electrolyte disturbances (in case MBP was used), and occurrence of C. difficile infection.

Inclusion Criteria:

1. Pediatric patients aged three months to eighteen years being treated by the Pediatric General Surgery service at McMaster Children's Hospital.
2. Undergoing elective colorectal surgery.
3. Parents or legal guardian able to give free and informed consent.

Exclusion Criteria:

1. Non-elective surgery

2. Procedures that would not require mechanical bowel preparation:

   1. Colorectal resection with an existing diverting small bowel ostomy.
   2. Completion proctectomy - Ileal Pouch Anal Anasotmosis (IPAA)
   3. Closure of small bowel ostomy (e.g. ileostomy)

3. Mechanical bowel obstruction

4. Known hypersensitivity to laxatives or oral antibiotics (neomycin and metronidazole)

5. Contraindication to oral antibiotics

6. Patients on long-term antibiotics for other reasons

7. Congestive heart failure

8. Renal insufficiency

9. Other medical conditions precluding the use of either oral antibiotics or mechanical bowel preparation

10. Co-enrolment in another intervention trial

The patient's records will mention he/she is part of a study and will mention the study number, while the actual medications received (group allocation) will not be mentioned. The outcome detector, assessing the patient from day 1 in the hospital to the end of the study, will not have access to information on the study group allocation. The statistician analyzing the data will have a coded and de-identified version, and will be blinded to study groups to ensure unbiased analysis.

For the purpose of blinding the data analyst, data on bowel prep diary will be withheld until analysis for all other outcomes is done and finalized.

The principle investigators and the research coordinator will be involved in prescribing the prep regimen preoperatively and will not be blinded. The patient and family will be aware of the medications used and will not be blinded either. Also, the pharmacist will have access to the treatment allocation list, and cannot be blinded.