Multicenter randomized phase II trial of prophylactic right-half dissection of superior mesenteric artery nerve plexus in pancreatoduodenectomy for pancreatic head cancer.

Aim: Right-half dissection of the superior mesenteric artery (SMA) nerve plexus in pancreatoduodenectomy for pancreatic cancer was initiated to accomplish R0 resection; however, subsequent refractory diarrhea was a major concern. This study aimed to evaluate the necessity of this technique.

Methods: From April 2014 to June 2018, 74 patients with pancreatic head cancer were randomly allocated to either Group A, in which right-half dissection of the SMA nerve plexus was performed (n = 37), or Group B, in which total preservation of the nerve plexus was performed (n = 37). Short-term, long-term, and survival outcomes were prospectively compared between the groups.

Results: The patient demographics, including the R0 resection rate, were not significantly different between the groups. Postoperative diarrhea occurred in 26 (70.3%) patients in Group A and 18 (48.6%) patients in Group B. There was a tendency for the development of severe diarrhea in Group A within 1 year postoperatively, and the frequency of diarrhea gradually decreased within 2 years, although that did not affect tolerance to adjuvant chemotherapy. There was no difference in either locoregional recurrence (27.0% vs 32.4%) or systemic recurrence (46.0% vs 46.0%). The median overall survival time in Groups A and B was 37.9 and 34.6 months, respectively ( = 0.77).

Conclusion: We did not demonstrate a clinical impact of right-half dissection of the SMA nerve plexus on locoregional recurrence or survival. Therefore, the prophylactic dissection of the SMA nerve plexus is unnecessary given that refractory diarrhea could be induced by this technique (UMIN000012241).