Surgery for Locally Advanced Pancreatic Cancer: Oncological Landmarks for Venous and Arterial Reconstruction.

[BACKGROUND] According to the National Comprehensive Cancer Network (NCCN) guidelines, pancreatic cancer is classified as borderline resectable (BR-PC) on the basis of three criteria: (1) anatomical-the involvement of major vessels such as the celiac axis, hepatic artery (HA), superior mesenteric artery (SMA), or the mesenterico-portal venous axis; (2) biological-an elevated CA19-9 level exceeding 500 kU/L; and (3) conditional-patient unfitness for surgery due to general health status. The extensive involvement of major vessels is classified as locally advanced pancreatic cancer (LAPC). In such cases, neoadjuvant therapy is recommended. Importantly, for pancreatic vascular surgeons working at the edge of technical feasibility in high-volume centers of excellence, surgical decision-making today must go beyond anatomical considerations. Increasingly, biological markers and the patient's overall condition have become key factors in determining surgical eligibility. In addition to patient selection, surgeons often contend with significant anatomical variations. One such challenge is a completely replaced common hepatic artery (CHA) originating from the superior mesenteric artery (SMA), known as Michels type IX. Though rare-occurring in approximately 1% of the population-this variation can complicate resection. The preservation of the HA in this setting may result in an R1 resection or vascular injury, making arterial reconstruction essential. Various techniques are available for this purpose. We present here a case involving the reconstruction of the superior mesenteric vein (SMV) at the mesenteric root, SMA divestment, and HA reconstruction, to illustrate the standardized oncologic approach used at the Paoli-Calmettes Institute for BR-PC and LAPC.

[PATIENTS AND METHODS] We present the case of a 74-year-old patient with biopsy-confirmed pancreatic ductal adenocarcinoma of the pancreatic head, involving a completely replaced CHA with abutment of the SMA and encasement of the SMV (see Fig. 1 and video) with the tumor considered locally advanced. Fig. 1 Preoperative assessment of reconstructability and vascular anatomy is essential. Pancreatic phase CT scan A Axial view. Tumor encasement of the SMV, and RHA Michels IX. RHA take-off from the SMA is free; it is essential to ensure that a stump is available to avoid SMA resection B Coronal view showing RHA Michels IX encasement but SMA abutment. Evaluation for divestment as there is no disparity in caliber of the SMA C CC Coronal view. It is essential to target venous inflow in the root of the mesentery, as this is the cornerstone of reconstructabilit. CT, computed tomography; SMA, superior mesenteric artery artery; SMV, superior mesenteric vein; RHA, right hepatic artery PERIOPERATIVE MANAGEMENT: At our institution, surgical indication for BR-PC and LAPC is guided primarily by oncologic principles. We implement an extended neoadjuvant regimen-typically a minimum of eight cycles of FOLFIRINOX-aiming for normalization of CA19-9 levels. Para-aortic lymph node sampling is routinely performed, and arterial reconstruction is undertaken only if a frozen section analysis confirms the absence of metastasis. The preoperative planning includes a high-resolution computed tomography (CT) angiography with three-dimensional (3D) reconstruction performed within 3 weeks of surgery to assess vascular involvement. This imaging is critical for evaluating the feasibility of arterial divestment and for planning potential vascular reconstructions. The key intraoperative strategies include the precise identification of vascular segments suitable for reconstruction (the "suitable target" concept), an artery-first approach for HA reconstruction and SMA divestment, selective preservation of SMV branches, and, when feasible, end-to-end venous reconstruction with conservation of the splenic vein (see Fig. 2 and video). Fig. 2 Intraoperative steps for double vascular reconstruction in pancreatic cancer surgery. Selective and sequential clamping A Targeting the inflow for SMV reconstruction is essential. One branch (the ileal branch) must be spared. Test clamp for the other one (jejunal branch) B Artery-first approach for SMA divestment and HA reconstruction C HA is reconstructed through the inverted splenic artery. Clamping time: 25 min. Retroportal lamina is done with the hanging technique D In case of pancreatoduodenectomy, if the LGV or the IMV cannot be spared, preservation or reconstruction of the SV should be discussed. Vein reconstruction is performed last. Clamping time: 17 min. IMV, inferior mesenteric vein; LGV, left gastric vein; SMA, superior mesenteric artery artery; SV, splenic vein; SMV, superior mesenteric vein; RHA, right hepatic artery CONCLUSIONS: Prioritizing tumor biology, meticulous preoperative planning, and attention to key vascular technical details to ensure radical resection represent our three core oncologic landmarks. Further international, multicenter studies are needed to validate and promote the standardization of surgery for BR-PC and LAPC.