Locally advanced pancreatic cancer (PDAC) with arterial infiltration of either the celiac axis (CA), hepatic artery (HA) or superior mesenteric artery (SMA) still reflects the only T4 stage of this tumor entity [1] and is considered as a sign of irresectability by most centers around the world as surgery is technically challenging and current guidelines do generally not recommend surgery in this situation [2, 3]. Despite this, arterial resection may be feasible in selected patients and with the availability of new multimodal treatment approaches it may gain increasing impact in PDAC therapy as a complete tumor removal with clear resection margins (R0, CRM-) is still the only opportunity to achieve long-term survival [4].
According to the 2014 guidelines of the International Study Group for Pancreatic Surgery (ISGPS), an infiltration of SMA or CA of more than 180 degrees are generally considered as locally advanced and should not be treated by an intended upfront resection [2] as surgery with arterial reconstruction is associated with an increased postoperative morbidity and mortality and oncological value remains unclear [5, 6].
Neoadjuvant treatment should always be considered instead of upfront surgery. The currently most promising protocol in this situation is FOLFIRINOX, which lead to resectability in a large proportion of patients [7]. After neoadjuvant treatment, a surgical exploration should always be attempted in all patients with stable disease or remission as cross-sectional imaging fails to predict the extent of remaining viable tumor. Depending on the specific intraoperative findings, a radical removal maybe achieved even without arterial resection in a considerable proportion of patients by an artery-sparing sharp dissection technique (TRIANGLE operation [8]).
In case an arterial resection is required, it has to be differentiated between resection without reconstruction which can be performed in patients with tumors of the pancreatic body and CA infiltration (modified Appleby procedure) as a distal pancreatectomy if the perfusion of the liver is sufficiently preserved via the gastroduodenal artery. This approach has recently been investigated in a multicenter analysis and seems to be feasible regarding morbidity and oncological long-term outcome when embedded in a multimodal therapy approach [9].
When HA or SMA resection require reconstruction, the restoration of perfusion can be achieved by using the splenic artery and thus avoiding allograft insertion. The splenic artery can replace the resected HA or SMA by interposition as a segmental graft or by transposition preserving the CA origin of this artery if the CA basis is not involved in the tumorous process [10]. This facilitates surgical technique and reduces the risk of vascular anastomotic complications as no separate proximal anastomosis is necessary. However, if respective extended PDAC resections are performed, a total duodeno-pancreatectomy should always be considered to avoid occurrence of postoperative pancreatic fistula as a well-known complication with potentially severe consequences in case of arrosional bleeding at the site of arterial reconstruction.
In conclusion, although arterial resections in PAC surgery are not a standard today, they are important options in individual patients and further studies should be initiated to collect more evidence on the indication and patients’ selection for these approaches.




References
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