Effect of preoperative oral antibiotics in combination with mechanical bowel preparation on inflammatory response and short-term outcomes following left-sided colonic and rectal resections

Influence of additional prophylactic oral antibiotics during mechanical bowel preparation on surgical site infection in patients receiving colorectal surgery

BACKGROUND

Prophylactic antibiotics (PAs) are standard for preventing surgical site infections (SSIs) post-colorectal surgery. This study aims to compare the effect of additional empiric oral antibiotics (OAs) alongside routine PAs to identify SSI risk factors.

METHODS

A retrospective observatory analysis was conducted from January 2019 to December 2022 at Asan Medical Center, Seoul, Korea. The cohort was divided into two groups: PA given 1 h before surgery and discontinued within 24 h, and OA administered empiric OAs during mechanical bowel preparation in addition to PA.

RESULTS

From a total of 6736 patients, 3482 were in the PA group and 3254 in the OA group. SSI incidence showed no significant intergroup difference (p = 0.374) even after propensity score matching (p = 0.338). The multivariable analysis revealed male sex [odds ratio (OR): 2.153, 95% confidence interval (CI): 1.626-2.852, and p = 0.001], open surgery (OR: 3.335, 95% CI: 2.456-4.528, and p = 0.001), dirty wound (OR: 2.171, 95% CI: 1.256-3.754, and p = 0.006), and an operation time of more than 145 min (OR: 2.110, 95% CI: 1.324-3.365, and p = 0.002) as SSI risk factors. In rectal surgery subgroup, OA demonstrated a protective effect against SSI (OR: 0.613, 95% CI: 0.408-0.922, and p = 0.019) and in laparoscopic approach (OR: 0.626, 95% CI: 0.412-0.952, and p = 0.028).

CONCLUSIONS

OA did not affect SSI incidence in colorectal surgeries. Male sex, open surgery, dirty wounds, and longer operation time were risk factors for SSI. However, for rectal and laparoscopic surgery, OA was a protective factor for SSI.

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.

Mechanical bowel preparation with or without oral antibiotics for rectal resection for cancer (REPCA trial): a study protocol for a multicenter randomized controlled trial

BACKGROUND

There is still a lack of randomized trials assessing the clinical value of mechanical bowel preparation (MBP) and oral antibiotics (OA) before rectal surgery. Existing studies are inconsistent regarding OA. The aim of this study is to examine the role of MBP with or without OA (using Alfa Normix^®) on postoperative complications in patients undergoing rectal resection for cancer.

METHODS

We are conducting a prospective multicenter randomized controlled trial comparing MBP (Moviprep^®) with OA (Alfa Normix^®) versus MBP alone in patients undergoing elective rectal resection for cancer. Patients with rectal or rectosigmoid cancer are randomized in a 1:1 allocation ratio. The primary endpoint is incisional surgical site infection (SSI) assessed within 30 days after surgery. Secondary endpoints are anastomotic leakage (AL), organ/space SSI, other postoperative complications, intraoperative complications, operation time, bowel preparation quality, bowel preparation adherence. Intention-to-treat and per protocol analyses will be performed.

CONCLUSIONS

The results of the REPCA trial will demonstrate whether MBP + OA is superior to MBP alone in rectal cancer surgery. This trial might influence current preoperative practice and improve postoperative outcomes.

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.

Perioperative nutrition: Recommendations from the ESPEN expert group

BACKGROUND & AIMS

Malnutrition has been recognized as a major risk factor for adverse postoperative outcomes. The ESPEN Symposium on perioperative nutrition was held in Nottingham, UK, on 14-15 October 2018 and the aims of this document were to highlight the scientific basis for the nutritional and metabolic management of surgical patients.

METHODS

This paper represents the opinion of experts in this multidisciplinary field and those of a patient and caregiver, based on current evidence. It highlights the current state of the art.

RESULTS

Surgical patients may present with varying degrees of malnutrition, sarcopenia, cachexia, obesity and myosteatosis. Preoperative optimization can help improve outcomes. Perioperative fluid therapy should aim at keeping the patient in as near zero fluid and electrolyte balance as possible. Similarly, glycemic control is especially important in those patients with poorly controlled diabetes, with a stepwise increase in the risk of infectious complications and mortality per increasing HbA1c. Immobilization can induce a decline in basal energy expenditure, reduced insulin sensitivity, anabolic resistance to protein nutrition and muscle strength, all of which impair clinical outcomes. There is a role for pharmaconutrition, pre-, pro- and syn-biotics, with the evidence being stronger in those undergoing surgery for gastrointestinal cancer.

CONCLUSIONS

Nutritional assessment of the surgical patient together with the appropriate interventions to restore the energy deficit, avoid weight loss, preserve the gut microbiome and improve functional performance are all necessary components of the nutritional, metabolic and functional conditioning of the surgical patient.

A Review of Bowel Preparation Before Colorectal Surgery

Infectious complications are the biggest problem during bowel surgery, and one of the approaches to minimize them is the bowel cleaning method. It was expected that bowel cleaning could facilitate bowel manipulation as well as prevent infectious complications and further reduce anastomotic leakage. In the past, with the development of antibiotics, bowel cleaning and oral antibiotics (OA) were used together. However, with the success of emergency surgery and Enhanced Recovery After Surgery, bowel cleaning was not routinely performed. Consequently, bowel cleaning using OA was gradually no longer used. Recently, there have been reports that only bowel cleaning is not helpful in reducing infectious complications such as surgical site infection (SSI) compared to OA and bowel cleaning. Accordingly, in order to reduce SSI, guidelines are changing the trend of only intestinal cleaning. However, a consistent regimen has not yet been established, and there is still controversy depending on the location of the lesion and the surgical method. Moreover, complications such as Clostridium difficile infection have not been clearly analyzed. In the present review, we considered the overall bowel preparation trends and identified the areas that require further research.