Reply to “Different Ideas of Nodal Grouping in Standard and Extended Lymphadenectomy During Pancreaticoduodenectomy for Pancreatic Head Cancer”
We appreciate Paiella, Butturini, and Bassi for their letter and interest in our study. We are delighted to share and describe our ideas on some issues with regard to the extent of pancreatoduodenectomy (PD).
Our trial was designed and carried out to verify the positive impact of extended PD in comparison with standard PD on overall survival in patients with pancreatic ductal adenocarcinoma. 1 Although there have been 4 other RCTs on this issue, each study used different definitions for standard and extended PD. 2–5
Grouping the lymph nodes around the peripancreatic area and superior mesenteric artery (SMA) is sometimes very difficult. #14LN is defined as the LNs at the root of the mesenteric artery. It is subclassified into 4 groups according to the level of the LN (origin of the SMA, inferior pancreaticoduodenal artery, middle colic artery, and 1st jejunal branch of the SMA). For standard resection, all or most of the #14 LNs are preserved because the level of the transaction between the pancreatic uncinate process and SMA is closer to the pancreas, preserving the pancreatic head nerve plexus, #14LN can be barely moved. Very small pieces of #14LNs could be included, but #14LN is not intentionally removed. I think the LNs of that area are sometimes confusing and it can be categorized #13b instead of #14b. I am sure all the #14a, b, and c LNs were preserved during standard resections in this Korean study.
Paiella et al might use the SMA approach seeing their letter, which inevitably included more dissection around the SMA, including #14LN. In the standard group of our trial, we did not dissect the soft tissues near the SMA and cut off the pancreas head at the left side, so as not to dissect most of #14LN to minimize the LN dissection around the pancreas head, unlike in the extended group.
Paiella et al stressed that a part of the #14LN should be removed to do curative or R0 surgery in both standard and extended surgery. In the beginning of our study, many of the surgeons participating in this study also worried about not having enough dissection around the SMA, followed by poor overall survival and early recurrence. This was because many Korean pancreatic surgeons usually carried out a nerve plexus dissection of the SMA and a complete LN#14 dissection, similar to Japanese surgeons.
However, our RCT showed that extended lymphadenectomy with nerve plexus excision has no significant survival benefit in patients with pancreatic head cancer when compared with the standard lymphadenectomy. There was no difference in local recurrence around the surgical margin between the 2 groups. Most recurrences were distant metastasis in both groups, which showed that systemic therapy is more important than the extent of LN and nerve plexus dissection. So, we could conclude that standard resection is the proper operative method for the management of pancreatic head cancer, considering oncologic radicality and the quality of life after pancreatectomy.
After this study, we changed our surgical strategy for pancreatic head cancer. Although dissection of LN#14 is not a major issue, routine dissection around the SMA dissection is not needed, except cases adjacent to the SMA, to pursue R0 resection.