Effect of Early vs Late Start of Oral Intake on Anastomotic Leakage Following Elective Lower Intestinal Surgery: A Systematic Review

Background Experimental and clinical studies have demonstrated a beneficial effect of early enteral nutrition (EN) on anastomotic leakage following colorectal surgery. Early oral intake is a common form of early EN with various clinical benefits, but the effect on anastomotic leakage is unclear. This systematic review investigates the effect of early vs late start of oral intake on anastomotic leakage following lower intestinal surgery. Methods Results A systematic literature search was performed using the PubMed, Embase, Medline, and Cochrane databases. Randomized controlled trials were included that compared early (within 24 hours) vs late start of oral intake following elective surgery of the small bowel, colon, or rectum. Meta-analysis was performed for anastomotic leakage, overall complications, length of stay, and mortality. Sensitivity analysis was performed in which studies of inferior methodological quality were excluded. Nine studies including 879 patients met eligibility criteria. Early start of oral intake significantly reduced overall complications (odds ratio [OR], 0.65; 95% confidence interval [CI], 0.46-0.93; P = .02), length of stay (mean difference, -0.89; 95% CI, -1.22 to -0.57; P <.001), and anastomotic leakage (OR, 0.40; 95% CI, 0.17-0.95; P = .04) compared with late start of oral intake. However, in the sensitivity analysis only the overall reduction of length of stay remained significant. Conclusion The effect of early oral intake on anastomotic leakage is unclear as existing studies are heterogeneous and at risk of bias. High-quality studies are needed to study the potential benefit of EN on anastomotic healing.