Wide Applicability and Various Advantages of Supracolic Anterior Artery-first Approach in Pancreatoduodenectomy
We read the Letter to the Editor titled, “Which Is the Best Surgical Approach for the Pancreatic Cancer? A Classification of Pancreatic Cancer to Guide Operative Decisions Is Needed” with great interest, and we appreciate the enthusiasm of Wang et al in having a constructive discussion on systematic mesopancreas dissection with staging of the extent of dissection during pancreatoduodenectomy (PD). 1 We have some concerns, however, regarding their interpretation of our grading system of the extent of dissection. For example, they assume that the superior mesenteric vein (SMV) should always be preserved in level (LV)-2 dissection, whereas LV-3 includes coresection of SMV. Although we have presented a representative case for each dissection in the “Method” section of our article, it was not our intention to suggest that all cases in each LV stage are the same. Our classification is oriented to dissection toward the superior mesenteric artery (SMA), and coresection of other structures such as the mesocolon, transverse colon, portal vein, and the SMV would depend on each individual case. As shown in Table 2 of our article, our LV-3 dissection included many patients in whom the SMV was not coresected. On the contrary, coresection of the SMV was performed if necessary even in LV-1 patients (we do not assume LV-3 dissection for benign lesions). Ease of intraoperative adjustment and choice of the extent of dissection before the point-of-no-return procedure is one of the strongest points of our technique. We apologize for the insufficient description of our principle due to the limited space availability and hope that this letter will provide a clear interpretation.
Establishment of a classification of pancreatic tumors and resection procedures based on the location and extent of invasion requires an open discussion among expert pancreatic surgeons with the same interests. The classification by Wang et al seems like a very interesting attempt, but we feel that classification into 8 categories is somewhat too complicated. Moreover, the details of their strategy for each classification differ substantially from the artery-first principle described in previous reports, including ours. 1–4 For example, their “total arterial devascularization-first” technique includes preceding ligation and transection of the pancreas before the dissection around the SMA. 5 According to their method, the unnecessary R1 or 2 resection due to cancer invasion to the SMA would be difficult to avoid in borderline resectable pancreatic cancers corresponding to their category IV. So-called artery-first approach is aimed not only at the safety of dissection but also at prompt judgement of the tumor resectability in relation to the SMA before the point-of-no-return procedure. 3,6 Although Wang et al recommend the SMV-first approach proposed by Hirota et al 7 for pancreatic cancers without SMA invasion, even in such cases, the systematic mesopancreas dissection-PD with anterior artery-first approach is applicable and has many additional advantages in addition to the safety of the procedure.
We again advocate our technique for even type I or III cancers in categorization by Wang et al. Although our principle is that all potentially invasive cancers should be treated by LV-3 dissection, this point needs further discussion. Therefore, LV-2 dissection for type I or II might be acceptable. Because PD is also indicated for a variety of lesions other than pancreatic cancer, the classification should be simple and applicable to all candidate diseases. Tumors that constitute indications for distal pancreatectomy should be dealt with separately. Now, we are also considering a novel classification of pancreatic tumors on the basis of “relation to surrounding arteries.”
Anyway, the categories proposed by Wang et al have inspired us to determine solutions for many unsolved points in PD.