Pancreaticoduodenectomy with combined superior mesenteric vein resection without reconstruction is possible: A case report and review of the literature

Revascularization techniques for complete portomesenteric venous occlusion in patients undergoing pancreatic resection

INTRODUCTION

Pancreatic pathologies causing portomesenteric occlusion complicate extirpative pancreatic resection due to portomesenteric hypertension and collateral venous drainage.

METHODS

Patients with portomesenteric occlusion undergoing pancreatectomy were identified between 2007 and 2020 at Stanford University Hospital. Demographic and clinical data, technique and perioperative factors, and post-operative outcomes were analyzed.

RESULTS

Of twenty-seven (27) patients undergoing venous revascularization during pancreatectomy, most (15) were for pancreatic neuroendocrine tumor. Occlusions occurred mostly at the portosplenic confluence (15). Median occlusion length was 4.0 cm [3.1-5.8]. Regarding revascularization strategy, mesocaval shunting was used in 11 patients, in-line venous revascularization with internal jugular conduit in three patients, traditional venous resection and reconstruction in 9 patients, and thrombectomy in two patients. Median cohort operative time and estimated blood loss were 522 min [433-638] and 1000 mL [700-2500], respectively. Median length of stay was 10 days [8-14.5] with overall readmission rate of 37%. Significant complications occurred in 44% of patients despite only one (4%) perioperative mortality.

DISCUSSION

Despite the technical complexity for managing portomesenteric occlusions, early revascularization strategies including mesocaval shunting or in-line venous revascularization are feasible and facilitate a safe pancreatic resection for surgically fit patients.

Pancreatectomy with En Bloc Superior Mesenteric Vein and All Its Tributaries Resection without PV/SMV Reconstruction for "Low" Locally Advanced Pancreatic Head Cancer

The "vein definition" for locally advanced pancreatic ductal adenocarcinoma (LA PDAC) assumes portal-to-superior mesenteric vein (PV/SMV) unreconstructability due to tumor involvement or occlusion. Radical pancreatectomies with SMV resection without PV/SMV reconstruction are scarcely discussed in the literature. Retrospective analysis of 19 radical pancreatectomies for "low" LA PDAC with SMV and all its tributaries resection without PV/SMV reconstruction has shown zero mortality; overall morbidity-56%; Dindo-Clavien-3-10.5%; R0-rate-82%; mean operative procedure time-355 ± 154 min; mean blood loss-330 ± 170 mL; delayed gastric emptying-25%; and clinically relevant postoperative pancreatic fistula-8%. In three cases, surgery was associated with superior mesenteric (n2) and common hepatic artery (n1) resection. Surgery was completed without vein reconstruction (n13) and with inferior mesenteric-to-splenic anastomosis (n6). There were no cases of liver, gastric, or intestinal ischemia. A specific complication of the SMV resection without reconstruction was 2-3 days-long intestinal edema (48%). Median overall survival was 25 months, and median progression-free survival was 18 months. All the relapses, except two, were distant. The possibility of successful SMV resection without PV/SMV reconstruction can be predicted before surgery by CT-based reconstructions. The mandatory anatomical conditions for the procedure were as follows: (1) preserved SMV-SV confluence; (2) occluded SMV for any reason (tumor or thrombus); (3) well-developed inferior mesenteric vein collaterals with dilated intestinal veins; (4) no right-sided vein collaterals; and (5) no varices in the upper abdomen. Conclusion: "Low" LA PDACs involving SMV with all its tributaries can be radically and safely resected in highly and specifically selected cases without PV/SMV reconstruction with an acceptable survival rate.

Distal pancreatectomy with superior mesenteric vein resection without reconstruction for pancreatic neuroendocrine tumor

Mesenteric and portal vein involvement is seen frequently in pancreatic neoplastic disease and requires venous resection to obtain clear surgical margins. If sufficient collateral circulation is present, venous resection can be performed without reconstruction and without substantial impact on venous drainage.

Vein resection without reconstruction (VROR) in pancreatoduodenectomy: expanding the surgical spectrum for locally advanced pancreatic tumours

PURPOSE

Pancreatic malignancy with mesenterico-portal venous involvement can be safely managed with en bloc vein resection with comparable survival outcomes. Non-constructible venous encasement is regarded as criteria of unresectability in pancreatic cancer. In long-standing extra-hepatic venous obstruction, hepatopetal blood flow is established by collateralization in the hepatoduodenal and mesenteric region. Their importance in pancreatic malignancies is being recently acknowledged.

METHODS

The records of patients undergoing pancreatoduodenectomies were retrospectively evaluated from 2012 to 2019. Pre and intraoperative records of patients undergoing concomitant vein resection were evaluated for the presence of venous collaterals, and its impact on oncological management was studied.

RESULTS

Over a period of 7 years, 947 pancreatoduodenectomies were performed, of which 56 patients underwent concomitant vein resection. Among these, six patients had significant collaterals due to venous obstruction. They had pancreatic adenocarcinoma (2), neuroendocrine tumour (2) and solid pseudopapillary epithelial neoplasm (2) respectively. All these patients successfully underwent pancreatoduodenectomy with vein resection without vascular reconstruction. Superior mesenteric vein (SMV) was resected in four patients, whereas spleno-portal junction was resected in two patients. Dominant collaterals were preserved in all, without compromising oncological safety. Bowel congestion was checked by tolerability to 20-minute mesenteric venous clamping test. There was no major morbidity or hospital mortality following this surgical approach.

CONCLUSION

We recommend vein resection without reconstruction (VROR) as a novel approach in locally advanced pancreatic tumours (due to non-constructible vein involvement) with significant venous collaterals and emphasize the need to assess venous collateralization pre and intraoperatively.