Impact of enhanced recovery after surgery protocol on pancreaticoduodenectomy: a meta-analysis of non-randomized and randomized controlled trials

Background: Enhanced recovery after surgery (ERAS) has been widely applied in many surgical spe-cialties. However, with respect to the impact of ERAS on pancreaticoduodenectomy (PD), there still exist some controversies. Methods: Literature search was performed in PubMed, Web of Science and the Cochrane Library from January, 1990 to July, 2019. A meta-analysis was performed using fixed-effects or random-effects models. Results: Twenty-two studies containing 4147 patients were identified. The entire pooled data showed that ERAS significantly reduced overall and minor morbidity (RR: 0.80, 95% CI: 0.72-0.88, p < 0.001; RR: 0.78, 95% CI: 0.69-0.88, p < 0.001, respectively), but didn't affect major morbidity (RR: 0.97, 95% CI: 0.84-1.13, p = 0.72). ERAS markedly reduced the incidences of delayed gastric emptying (DGE) (RR: 0.69, 95% CI: 0.55-0.88, p = 0.002), incisional infection (RR: 0.75, 95% CI: 0.60-0.94, p = 0.01) and intra-abdominal infection (RR: 0.79, 95% CI: 0.63-1.00, p = 0.05), but didn't influence clinically-relevant postoperative pancreatic fistula (CR-POPF) (RR: 0.86, 95% CI: 0.73-1.01, p = 0.07). Shorter length of stay (LOS) (WMD: -5.07, 95% CI: -6.71 to -3.43, p < 0.001) was noted in ERAS group, without increasing 30-day readmission (RR: 1.03, 95% CI: 0.86-1.24, p = 0.71) and mortality (RR: 0.70, 95% CI: 0.41-1.21, p = 0.20). Conclusion: ERAS significantly reduced overall and minor morbidity, incidences of DGE, incisional and intra-abdominal infections, and shortened LOS in PD, without increasing 30-day readmission and mortality. However, more large-scale randomized controlled trials are still needed to confirm the findings.