Minimally Invasive Versus Open Pancreatectomy for Right-Sided and Left-Sided G1/G2 Nonfunctioning Pancreatic Neuroendocrine Tumors: A Multicenter Matched Analysis with an Inverse Probability of Treatment-Weighting Method

Background: Limited evidence exists for the safety and oncologic efficacy of minimally invasive surgery (MIS) for nonfunctioning pancreatic neuroendocrine tumors (NF-PNETs) according to tumor location. This study aimed to compare the surgical outcomes of MIS and open surgery (OS) for right- or left-sided NF-PNETs. Methods: The study collected data on patients who underwent surgical resection (pancreatoduodenectomy, distal/total/central pancreatectomy, duodenum-preserving pancreas head resection, or enucleation) of a localized NF-PNET between January 2000 and July 2017 at 14 institutions. The inverse probability of treatment-weighting method with propensity scores was used for analysis. Results: The study enrolled 859 patients: 478 OS and 381 MIS patients. A matched analysis by tumor location showed no differences in resection margin, intraoperative blood loss, or complications between MIS and OS. However, MIS was associated with a longer operation time for right-sided tumors (393.3 vs 316.7 min; P < 0.001) and a shorter postoperative hospital stay for left-sided tumors (8.9 vs 12.9 days; P < 0.01). The MIS group was associated with significantly higher survival rates than the OS group for right- and left-sided tumors, but survival did not differ for the patients divided by tumor grade and location. Multivariable analysis showed that MIS did not affect survival for any tumor location. Conclusion: The short-term outcomes offered by MIS were comparable with those of OS except for a longer operation time for right-sided NF-PNETs. The oncologic outcomes were not compromised by MIS regardless of tumor location or grade. These findings suggest that MIS can be performed safely for selected patients with localized NF-PNETs.