Supplementary Material for: The role of ERAS in pancreaticoduodenectomy: A systematic review and meta-analysis.

Introduction
This study aimed to compare the safety and short-term outcomes of ERAS with standard care for patients undergoing pancreatoduodenectomy (PD) based on literature published following the first publication of ERAS guidelines for PD.
Methods
Five medical databases were searched for studies that compared ERAS to standard care in adults undergoing PD. Data on postoperative complications, length of hospitalization, readmissions, and time to chemotherapy were analyzed using either a fixed- or random-effects model meta-analysis. Meta-regressions were conducted to investigate the role of operative technique, study origin, and study design.
Results
Our analysis included 22 studies involving 4043 patients. ERAS was associated with fewer complications (RR: 0.83; 0.75 to 0.91), particularly Clavien-Dindo (CD) grade 1 and 2 complications (RR: 0.82; 0.72 to 0.92), delayed gastric emptying (RR: 0.69; 0.52 to 0.93), and postoperative fistula (POPF) (RR: 0.76; 0.66 to 0.89), and a shorter time to chemotherapy (SMD: -0.68; 95% CI: -0.88 to -0.48). ERAS did not affect the risk for CD grade 3 and 4 complications (RR: 1.00; 0.72 to 1.38), post-pancreatectomy hemorrhage (RR: 0.88; 0.67 to 1.14), length of stay (SMD: -0.56; 95% CI: -1.12 to 0.01), readmission (RR: 1.01; 0.84 to 1.21), and mortality (RR: 0.81; 0.54 to 1.22). The continent of origin was an effect moderator in the role of ERAS in CD grade 1 and 2 complications (p= 0.047) and POPF (p=0.02).
Conclusion
Implementing ERAS principles in PD improves surgical outcomes without compromising safety. ERAS may also accelerate time to chemotherapy, an essential issue for future research.