Different Ideas of Nodal Grouping in Standard and Extended Lymphadenectomy During Pancreaticoduodenectomy for Pancreatic Head Cancer
We wonder why the lymph node station 14 [superior mesenteric artery (SMA) lymph nodes] has been included in the extended lymphadenectomy during pancreaticoduodenectomy for pancreatic head cancer by Jang et al 1 in their recently published randomized controlled trial. Considering the anatomical location of station 14, it seems almost impossible for us not to include these lymph nodes in the standard resection, at least those located to the right side of the SMA (what the authors call “14b” in their Table 1). Looking back at the 4 randomized controlled trials on the same topic previously published, 2–5 Pedrazzoli et al 2 and Nimura et al 5 did the same grouping as that of Jang et al, whereas the other 2 US-based randomized controlled trials cited the dissection of the lymph nodes located to the right side of the SMA during a standard lymphadenectomy. 3,4
At our institution, we routinely and necessarily dissect the right side and the anterior surface of station 14 during a standard pancreaticoduodenectomy for pancreatic head cancer. We believe that the clearance of the posterior pancreatic margin, with freeing of the mesentericoportal axis, leads to the retroportal lamina and compulsory to the right side of the SMA where some lymph nodes are located and harvested during a standard pancreaticoduodenectomy. The authors show a total number of lymph nodes retrieved during standard lymphadenectomy of 17.3 ± 10.6. This means that in some cases, they reached a total number of nodes insufficient to properly assess pN-status to avoid understaging. Our approach to the SMA would compulsorily add some nodes of the SMA area to the total nodal count. Finally, because station 14, after stations 13 and 17, is one of the most frequently involved by metastatic spread, we assume that our approach might be able to strike a balance between standard and extended lymphadenectomy during pancreaticoduodenectomy for pancreatic head cancer.
Hence, which is the surgical technique adopted by these Korean authors? Would the inclusion of some subgroups of station 14 have changed the results shown in oncological and surgical terms? This answer would probably be negative, but this different interpretation of nodal grouping demonstrates that maybe we are not all talking the same surgical language yet.