Objective To study the effectiveness and safety comparing Roux-en-Y versus Billroth Ⅱ alimentary canal reconstruction after pancreaticoduodenectomy (PD).Methods A computer search was conducted on PubMed,Embase,Web of Science,Science Direct,Springer Link,Cochrane Center,CBM,CNKI,Wan Fang and VIP databases before September 2017 for all RCT and CCT articles on Roux-en-Y versus Billroth Ⅱ reconstruction after PD.The quality of the included trials was studied by assessing the inclusive and exclusive criteria (the PRISMA statement) by 2 researchers independently.The data were extracted and analyzed using the RevManS.3 software.Results 9 articles (3 RCTs,6 CCTs) which involved 1 599 patients (563 Roux-en-Y patients,1 036 Billroth Ⅱ patients) were studied.Meta analysis revealed that Billroth Ⅱ patients had a lower postoperative delayed gastric emptying (DGE,grades B,C) rate (OR =3.76,95％ CI:1.32 ～ 10.68,P ＜ 0.05) and a shorter operation time (WMD =32.75,95％ CI:8.17 ～57.33,P ＜ 0.05) than Roux-en-Y patients.There were no significant differences in the rates of postoperative delayed gastric emptying (grades A,B,C),pancreatic fistula,bile leak,postoperative hemorrhage,reoperation,postoperative complications and the duration of postoperative stay (P ＞ 0.05).Conclusions The incidence of DGE (grades B,C) after PD was lower after Billroth Ⅱ than that of Roux-en-Y reconstruction.Large prospective randomized controlled trials are needed to confirm the findings of this meta-analysis.

Objective: To systematically evaluate the clinical efficacy of immunonutrition support in perioperative period of hepatectomy. Methods: Literatures were researched using CNKI，CBM，Wanfang database，VIP databases，PubMed (Medline)，Embase，Web of science，Science Direct，Cochrane Center from January 1996 to March 2018 with the key words including "肝切除术，免疫营养，hepatectomy，hepatic resection，immunonutrition，immunoenhanced nutrition" . The randomized controlled trials (RCTs) on comparison of efficacy of immunonutrition support versus routine nutritional support in perioperative period of hepatectomy. Patients in the immunonutrition group received immunonutrition support in perioperative period of hepatectomy，and patients in the routine nutrition group received routine nutritional support in perioperative period of hepatectomy. Outcome measures：overall incidence of postoperative complications，incidence of postoperative infectious complications，incidence of postoperative liver failure，perioperative mortality，hospital stay，and hospitalization expenses. Literatures screening，data extraction and quality assessment of methodology were conducted by two researchers separately. Count data were represented as risk ratio (RR) and 95% confidence interval (CI). Measurement data were represented as mean difference (MD) or weighted mean difference (WMD) and 95%CI. Heterogeneity of the included studies was analyzed with I². Funnel plot was used to test potential publication bias if the number of studies included ≥ 10，and funnel plot was used to test potential publication bias for the outcome measures with the maximum number of studies if the number of studies included <10. Results: (1) Document retrival: 12 RCTs were enrolled in the Meta analysis, and the total sample size was 1 136 patients, including 568 patients in the immunonutrition group and in the routine nutrition group, respectively. (2) Results of Meta-analysis: the that immunonutrition group had lower overall incidence of postoperative complications, incidence of postoperative infectious complications, incidence of postoperative liver failure, and hospital stay (RR=0.57, 0.49, 0.30, MD=-3.28, 95%CI: 0.46-0.71, 0.37-0.65, 0.12-0.74, -4.45 to -2.11, P<0.05), and higher hospital expenses (MD=11.86, 95%CI: 10.96-12.77, P<0.05) compared with the routine nutrition group. There was no significant difference in the perioperative mortality between the two groups (RR=0.26, 95%CI: 0.07-1.05, P>0.05). The bilateral symmetry was presented in the funnel plot based on the 9 studies comparing incidence of postoperative infectious complications between the immunonutrition group and routine nutrition group, suggesting that publication bias had little influence on results of Meta-analysis. Conclusions Perioperative immunonutrition support for hepatectomy is safe and feasible. Compared with routine nutritional support, immunonutrition support can significantly reduce overall incidence of postoperative complications, incidence of postoperative infectious complications, incidence of postoperative liver failure, and shorten the hospital stay without increasing postoperative mortality.