Mechanical bowel preparation and antibiotics in elective colorectal surgery: network meta-analysis

Abstract

Background The use of intravenous antibiotics at anaesthetic induction in colorectal surgery is the standard of care. However, the role of mechanical bowel preparation, enemas, and oral antibiotics in surgical site infection, anastomotic leak, and other perioperative outcomes remains controversial. The aim of this study was to determine the optimal preoperative bowel preparation strategy in elective colorectal surgery. Methods A systematic review and network meta-analysis of RCTs was performed with searches from PubMed/MEDLINE, Scopus, Embase, and the Cochrane Central Register of Controlled Trials from inception to December 2022. Primary outcomes included surgical site infection and anastomotic leak. Secondary outcomes included 30-day mortality rate, ileus, length of stay, return to theatre, other infections, and side effects of antibiotic therapy or bowel preparation. Results Sixty RCTs involving 16 314 patients were included in the final analysis: 3465 (21.2 per cent) had intravenous antibiotics alone, 5268 (32.3 per cent) had intravenous antibiotics + mechanical bowel preparation, 1710 (10.5 per cent) had intravenous antibiotics + oral antibiotics, 4183 (25.6 per cent) had intravenous antibiotics + oral antibiotics + mechanical bowel preparation, 262 (1.6 per cent) had intravenous antibiotics + enemas, and 1426 (8.7 per cent) had oral antibiotics + mechanical bowel preparation. With intravenous antibiotics as a baseline comparator, network meta-analysis demonstrated a significant reduction in total surgical site infection risk with intravenous antibiotics + oral antibiotics (OR 0.47 (95 per cent c.i. 0.32 to 0.68)) and intravenous antibiotics + oral antibiotics + mechanical bowel preparation (OR 0.55 (95 per cent c.i. 0.40 to 0.76)), whereas oral antibiotics + mechanical bowel preparation resulted in a higher surgical site infection rate compared with intravenous antibiotics alone (OR 1.84 (95 per cent c.i. 1.20 to 2.81)). Anastomotic leak rates were lower with intravenous antibiotics + oral antibiotics (OR 0.63 (95 per cent c.i. 0.44 to 0.90)) and intravenous antibiotics + oral antibiotics + mechanical bowel preparation (OR 0.62 (95 per cent c.i. 0.41 to 0.94)) compared with intravenous antibiotics alone. There was no significant difference in outcomes with mechanical bowel preparation in the absence of intravenous antibiotics and oral antibiotics in the main analysis. Conclusion A bowel preparation strategy with intravenous antibiotics + oral antibiotics, with or without mechanical bowel preparation, should represent the standard of care for patients undergoing elective colorectal surgery.

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

“…Multiple studies indicate that the incidence of postoperative complications, such as ALs and SSIs, remains unchanged when using preoperative antibiotic bowel preparation, regardless of whether it is administered with or without MBP. These findings prompt a reassessment of the standard preoperative regimen and suggest that preoperative oAB alone should be considered as the new standard of care [43][44][45][46][47].…”

Morbidity After Mechanical Bowel Preparation and Oral Antibiotics Prior to Rectal Resection

“…Several retrospective studies from the American College of Surgeons National Surgical Quality Improvement Program reignited the debate almost a decade ago and suggested that mechanical and oral antibiotic bowel preparation (MOABP) is associated with lower rates of SSIs in colorectal surgery compared with only mechanical bowel preparation (MBP) or no bowel preparation . A recent meta-analysis of randomized clinical trials (RCTs) found an approximately 50% reduction in SSIs when oral antibiotics are added to bowel preparation regimens . However, a crucial limitation of the RCTs included in the meta-analysis is that outcomes were not reported separately for rectal surgery.…”

“…[8][9][10][11][12] A recent meta-analysis of randomized clinical trials (RCTs) found an approximately 50% reduction in SSIs when oral antibiotics are added to bowel preparation regimens. 13 However, a crucial limitation of the RCTs included in the meta-analysis is that outcomes were not reported separately for rectal surgery. Rectal surgery is often preceded with neoadjuvant radiotherapy or chemoradiotherapy and, due to higher rates of anastomotic dehiscence especially in low anastomoses, a protective stoma is often used.…”

Colorectal surgery in 2023: BJS Open highlights and editors’ choices

“…Another area of coloproctology that divides opinion is the use of mechanical bowel preparation and preoperative oral and intravenous antibiotics. A network meta-analysis comprising 60 RCTs and 16 314 patients 4 aimed to determine the optimal bowel preparation strategy. The authors concluded that oral and intravenous antibiotics with or without mechanical bowel preparation reduced surgical site infection and anastomotic leaks and should be the standard of care.…”