There are discrepancies in the guidelines on preparation for colorectal surgery. Although intravenous (IV) antibiotics are generally administered, the use of mechanical bowel preparation (MIP), enemas, and/or oral antibiotics (OC) is controversial.
We aimed to summarize all data from randomized clinical trials (RCTs) that met the selection criteria using network meta-analysis (NMA) to determine the classification of different bowel preparation treatment strategies by their associations with postoperative outcomes. .
| Methods |
Randomized studies of adults undergoing elective colorectal surgery with appropriate aerobic and anaerobic antibiotic protection that reported surgical incisional site infection (SSI) or anastomotic leak were selected for inclusion in the analysis. These were selected by several reviewers and adjudicated by an independent principal investigator. A total of 167 of 6833 selected studies met the initial selection criteria.
Data sources included MEDLINE, Embase, Cochrane and Scopus databases without language restrictions, including abstracts and articles published before 2021.
The use of IV antibiotics, OCs, PIMs, enemas, and combinations of these treatments was reviewed. Exclusion criteria included studies that were not RCTs, studies that looked at pediatric patients, and studies in which the results of different bowel preparation interventions were combined.
The treatment options were:
1. PIM + IV
2. IV antibiotics alone (IV)
3. IV antibiotics with enema (IV + E)
4. IV and OA antibiotics with or without enema (IV + OA ± E)
5. PIM + IV + AO
- with good aerobic and anaerobic IV antibiotic coverage and additional OA (PIM + IVA + OA)
- with incomplete IV antibiotic coverage, but by adding OC, good aerobic and anaerobic coverage was achieved (PIM + IVB + OC)
6. PIM and AO (MBP + OA)
7. AO alone (AO)
| Results |
A total of 35 RCTs including 8377 patients were identified. Treatments compared IV antibiotics (2762 patients [33%]), IV antibiotics with enema (222 patients [3%]), IV antibiotics with OC with or without enema (628 patients [7%]), PIM with IV antibiotics (2712 patients [32%]), PIM with IV antibiotics with OA (with good IV antibiotic coverage in 925 patients [11%] and with good overall antibiotic coverage in 375 patients [4%]), PIM with OA (267 patients [ 3%] ), and OA (486 patients [6%]).
The likelihood of incisional surgical site infection (SSI) was significantly lower for those receiving IV antibiotics with OC with or without enema (range 1) and PIM with appropriate IV antibiotics with OC (range 2) compared to all other treatment options. treatment. The addition of OCs to IV antibiotics, with and without PIM, was associated with a reduction in incisional SSI by more than 50%.
| Discussion |
The main finding of this NMA was that adding IV + OC resulted in a significant reduction in SSI by more than 50% compared to other options.
This was the case with and without PIM. The finding that IV + AO ± E is an excellent (perhaps the best) option in colorectal surgery is interesting from 2 perspectives.
First, it avoids the potential adverse effects of full PIM and has the benefit of combining IV and OA antibiotics. Second, this option has not been widely used, and therefore requires further evaluation.
Large database studies, summarizing data on PIM + OA, PIM alone, OA alone, and none (neither PIM nor OA), although they do not evaluate intravenous antibiotic use and differences in aerobic and anaerobic antibiotic coverage, also provide some evidence supporting the use of IV + OC.
With respect to anastomotic leaks, there was no significant advantage in favor of either option. However, AO was associated with a non-significant reduction.
> Limitations
One possible criticism of this article is that it is too complex and compares too many bowel preparation options (the choice of bowel preparation options was determined by the data from the RCTs).
Regarding the potential impact of changes in practice over time on NMA, the results for SSI and anastomotic leaks were consistently the same, indicating that changes, such as the introduction of laparoscopic surgery, equally impacted the results. different bowel preparation options that were compared.
The main weakness of the NMA is the limited number of studies and patients included, with less than 500 patients for 4 of the bowel preparation options.
These shortcomings demonstrate the need for more research, including larger studies with standardized methods for diagnosing endpoints.
| Conclusions |
A review of all RCT evidence demonstrated that the addition of OCs to IV antibiotics was associated with a reduction in incisional SSI by more than 50%. The results support the addition of OCs to IV antibiotics to reduce incisional SSI among patients undergoing elective colorectal surgery.
While there were no significant differences in favor of any option for anastomotic leaks, options associated with reductions in SSI were also ranked favorably in terms of reduction.
