The appropriate dissection of the nerve plexus of the SMA, which means circumferential dissection, semicircle dissection, or no dissection, is controversial. The nerve plexus dissection of the SMA could cause postoperative severe diarrhea and may delay the start of the adjuvant therapy [36, 37]. Furthermore, it is reported that the semicircle dissection of the nerve plexus of the SMA could not improve the survival for the patients with resectable pancreatic cancer [36]. Therefore, the nerve plexus of the SMA may not be necessary for pancreatic cancer without invasion to the nerve plexus around the SMA. However, borderline resectable pancreatic cancer sometimes needs semicircle or circumferential dissection of the SMA to obtain the negative margins (R0). If the nerve dissection is necessary, the nerve plexus of the SMA is also dissected outside of the SMA adventitial during dissection of the connective tissues around the SMA (Fig. 17.3).

The connective tissues around the SMV also are dissected, and the inferior pancreaticoduodenal vein, first jejunal vein, Henle’s gastrocolic trunk, and middle colic vein (if necessary) are ligated and divided. Mesenteric approach is finished at the time of completion of dissection around the SMA and SMV (Fig. 17.4).