Immunological effects of hybrid minimally invasive versus conventional open pancreatoduodenectomy - A single center cohort study.

BACKGROUND: Minimally invasive surgery is a field of rapid development. Evidence from randomized controlled trials in visceral surgery however still falls short of attesting unequivocal superiority to laparoscopic procedures over conventional open approaches with regard to postoperative outcome. The aim of this study was to explore the perioperative immune status of patients undergoing hybrid minimally invasive or conventional open pancreatoduodenectomy in a prospective cohort study. MATERIAL AND METHODS: Subtyping, quantification and functional analysis of circulating immune cells and determination of cytokine-levels in blood samples from patients receiving either hybrid minimally invasive (laPD) or conventional open pancreatoduodenectomy (oPD) was performed. Samples were taken from 29 patients (laPD: n = 14, oPD: n = 15) prior, during and up to six weeks after surgery. Cells were analyzed by flow cytometry, cytokines/chemokines were measured by proximity extension and enzyme-linked immunoassays. RESULTS: Open surgery induced higher levels of circulating inflammatory CD14++CD16+ intermediate monocytes. In contrast, hybrid minimally invasive resection was accompanied by increased numbers of circulating regulatory CD4+CD25+CD127low T-cells and by a reduced response of peripheral blood CD3+CD4+ T-cell populations to superantigen stimulation. Yet, rates of postoperative morbidity and infectious complications were similar. CONCLUSIONS: In summary, the results of this exploratory study may suggest a more balanced postoperative inflammatory response and a better-preserved immune regulation after hybrid minimally invasive pancreatoduodenectomy when compared to open surgery. Whether these results may translate to or be harnessed for improved patient outcome needs to be determined by future studies including larger cohorts and fully laparoscopic or robotic procedures.

Immune changes induced by periampullary adenocarcinoma are reversed after tumor resection and modulate the postoperative survival.

BACKGROUND: Tumor growth encompasses multiple immunologic processes leading to impaired immunity. Regarding cancer surgery, the perioperative period is characterized by additional immunosuppression, which may contribute to poorer outcomes. In this exploratory study, we assessed plasma parameters characterizing the perioperative immunity with a particular focus on their prognostic value. PATIENTS AND METHODS: 31 patients undergoing pancreatoduodenectomy were enrolled (adenocarcinoma of the pancreatic head and its periampullary region: n = 24, benign pancreatic diseases n = 7). Abundance and function of circulating immune cells and the plasma protein expression were analyzed in blood samples taken pre- and postoperatively using flow cytometry, ELISA and Proximity Extension Assay. RESULTS: Prior to surgery, an increased population of Tregs, a lower level of intermediate monocytes, a decreased proportion of activated T-cells, and a reduced response of T-cells to stimulation in vitro were associated with cancer. On the first postoperative day, both groups showed similar dynamics. The preoperative alterations did not persist six weeks postoperatively. Moreover, several preoperative parameters correlated with postoperative survival. CONCLUSION: Our data suggests systemic immunologic changes in adenocarcinoma patients, which are reversible six weeks after tumor resection. Additionally, the preoperative immune status affects postoperative survival. In summary, our results implicate prognostic and therapeutic potential, justifying further trials on the perioperative tumor immunity to maximize the benefit of surgical tumor therapy.