Systematic review and Meta-analysis of intraoperative lymphadenectomy in pancreatic cancer

Objective To compare the incidence of postoperative complications and long-term survival rates in pancreatic head cancer with extended and standard lymphadenectomy, and conclude an appropriate cleaning range. Methods Published randomized controlled trials about pancreatoduonectomy with extended lymphadenectomy (ELPD) vs standard lymphadenectomy (SLPD)in pancreatic cancer patients on Pubmed, Embase and the Cochrane library were retrieved from database building to October 1st 2017 with the keywords including "pancreatoduonectomy" "pancreatic adenocarcinoma" "whipple" "lymphadenectomy" "extended" and "standard" . Obtained literatures were screened independently by two researchers(the PRISMA statement). After included literatures reviewed and data extracted, a meta-analysis was carried out using Revman 5.3 software. Results A total of 7 RCTs were included in the analysis, and the total number of cases was 850, of which 426 cases were extended lymph node dissection and 424 were standard. The results showed that the ELPD group had longer operation time (373.1 min and 318.4 min, respectively, P=0.003), increased intraoperative bleeding and blood transfusion (681.5 ml and 556.2 ml, respectively, P= 0.03). The incidence rate of postoperative complications (40.8% and 28.9%, respectively, P=0.0006) and the delayed gastric emptying (16.2% and 10.0%, P= 0.02), postoperative hospitalization time (19.7 d and 15.0 d, P<0.05) also increased in ELPD group. At the same time, the 1-、3-、5-year survival rate (66.0% and 70.8%, P=0.17; 24.7% and 27.5%, P=0.41; 16.6% and 14.3%, respectively, P=0.45) was not improved in pancreatic cancer patients. Conclusion ELPD increase the postoperative complications and prolong the hospital stay of pancreatic cancer patients and did not improve postoperative survival rate at the same time, SLPD should be preferred during the operation. By summarizing the latest research progress. Key words: Pancreatic neoplasms; Pancreaticoduodenectomy; Lymph node excision; Meta-analysis