Potentiality of dissection of the lymph nodes with preservation of the nerve plexus around the superior mesenteric artery.
Periampullary cancer frequently metastasizes to the lymph nodes around the superior mesenteric artery. Simultaneous dissection of the nerve plexus around the SMA, however, often results in intractable diarrhea. This study was performed to examine the extent to which regional lymph nodes may be dissected while preserving the superior mesenteric nerve plexus during radical surgery for periampullary cancer. The pancreas and surrounding tissue from ten adult autopsied subjects were sectioned at 5 mm intervals. The structure of the nerve plexus and the distribution of the lymph nodes were analyzed, and the anatomical relationship between the nodes and the nerve plexus was investigated. The average thickness of the PLsma was 4.2 +/- 1.3 mm, becoming thinner from the root to the periphery. The lymph nodes were distributed uniformly on the right and left hemicircles of the superior mesenteric artery and along its longitudinal axis. The average number of lymph nodes was 14.2 +/- 7.5 per subject, and the average maximum node diameter was 3.3 +/- 2.3 mm. The distance from the adventitia of the superior mesenteric artery to the node was 5.5 +/- 2.0 mm. Of a total of 142 lymph nodes, 134 (94.4%) were located outside of the nerve plexus. Dissection of the superior mesenteric lymph nodes while preserving the superior mesenteric nerve plexus is theoretically possible.