Oncologic outcomes of minimally invasive versus open distal pancreatectomy for pancreatic ductal adenocarcinoma: A systematic review and meta-analysis.

In the absence of randomized trials, uncertainty regarding the oncologic efficacy of minimally invasive distal pancreatectomy (MIDP) remains. This systematic review aimed to compare oncologic outcomes after MIDP (laparoscopic or robot-assisted) and open distal pancreatectomy (ODP) in patients with pancreatic ductal adenocarcinoma (PDAC). Matched and non-matched studies were included. Pooled analyses were performed for pathology (e.g., microscopically radical (R0) resection and lymph node retrieval) and oncologic outcomes (e.g., overall survival). After screening 1760 studies, 21 studies with 11,246 patients were included. Overall survival (hazard ratio 0.86; 95% confidence interval (CI) 0.73 to 1.01; p = 0.06), R0 resection rate (odds ratio (OR) 1.24; 95%CI 0.97 to 1.58; p = 0.09) and use of adjuvant chemotherapy (OR 1.07; 95%CI 0.89 to 1.30; p = 0.46) were comparable for MIDP and ODP. The lymph node yield (weighted mean difference (WMD) -1.3 lymph nodes; 95%CI -2.46 to -0.15; p = 0.03) was lower after MIDP. Patients undergoing MIDP were more likely to have smaller tumors (WMD -0.46 cm; 95%CI -0.67 to -0.24; p < 0.001), less perineural (OR 0.48; 95%CI 0.33 to 0.70; p < 0.001) and less lymphovascular invasion (OR 0.53; 95%CI 0.38 to 0.74; p < 0.001) reflecting earlier staged disease as a result of treatment allocation bias. Based on these results we can conclude that in patients with PDAC, MIDP is associated with comparable survival, R0 resection, and use of adjuvant chemotherapy, but a lower lymph node yield, as compared to ODP. Due to treatment allocation bias and lower lymph node yield the oncologic efficacy of MIDP remains uncertain.
(Copyright © 2018 Elsevier Ltd, BASO ~ The Association for Cancer Surgery, and the European Society of Surgical Oncology. All rights reserved.)