Pancreatic endocrine tumors with major vascular abutment, involvement, or encasement and indication for resection

Abstract

Background: Surgery for pancreatic endocrine tumors (PETs) with blood vessel involvement is controversial.

Hypothesis: Resection of PETs with major blood vessel involvement can be beneficial.

Design: The combined databases of the National Institutes of Health and Stanford University hospitals were queried.

Main outcome measures: Operation, pathologic condition, complications, and disease-free and overall survival.

Results: Of 273 patients with PETs, 46 (17%) had preoperative computed tomography evidence of major vascular involvement. The mean size for the primary PET was 5.0 cm. The involved major vessel was as follows: portal vein (n = 20), superior mesenteric vein or superior mesenteric artery (n = 16), inferior vena cava (n = 4), splenic vein (n = 4), and heart (n = 2). Forty-two of 46 patients had a PET removed: 12 (27%) primary only, 30 (68%) with lymph nodes, and 18 (41%) with liver metastases. PETs were removed by either enucleation (n = 7) or resection (n = 35). Resections included distal or subtotal pancreatectomy in 23, Whipple in 10, and total in 2. Eighteen patients had concomitant liver resection: 10 wedge resection and 8 anatomic resections. Nine patients had vascular reconstruction: each had reconstruction of the superior mesenteric vein and portal vein, and 1 had concomitant reconstruction of the superior mesenteric artery. There were no deaths, but 12 patients had complications. Eighteen patients (41%) were immediately disease free, and 5 recurred with follow-up, leaving 13 (30%) disease-free long term. The 10-year overall survival was 60%. Functional tumors were associated with a better overall survival (P < .001), and liver metastases decreased overall survival (P < .001).

Conclusion: These findings suggest that surgical resection of PETs with vascular abutment/invasion and nodal or distant metastases is indicated.

Figure 1

Computed tomography (CT) scans of 2 different patients with pancreatic endocrine tumor (PET) in the head of the pancreas abutting the mesenteric vessels. In panel A, the PET is in the uncinate portion of the pancreatic head and lies abutting the posterior surface of the superior mesenteric vein (SMV) and superior mesenteric artery (SMA). In panel B, the PET is in the anterior portion of the head of the pancreas abutting the anterior and lateral wall of the SMV. These patients could have the PET dissected off the SMV.

Figure 2

Coronal planar reformation (panel A) and axial tomogram (panel B) of a computed tomography of the same patient with a locally invasive non-metastatic pancreatic endocrine tumor (PET) obstructing the proximal portal vein. The PET has calcifications. There are extensive collateral veins because of the portal vein obstruction. This patient had the portal vein resected and reconstructed with autologous femoral vein.

Figure 3

Gadolinium enhanced magnetic resonance imaging (MRI) (panel A) and selective arteriogram (panel B) of a pancreatic endocrine tumor (PET) that was in the wall of the right hepatic duct. The tumor was abutting the right portal vein. There is a second liver tumor shown on the hepatic arteriogram (panel B) as a liver hemangioma. The PET was locally resected with the right hepatic duct. The tumor was dissected off the portal vein.

Figure 4

Kaplan Meier plot of total survival (upper panel) and disease-free survival (lower panel) of the 44 patients with pancreatic endocrine tumors (PET) involving major vascular structures who had the tumor removed surgically. The 10-year total survival was 60 % and the 10-year disease-free survival was 33%.

Figure 5

Kaplan Meier plot of total survival (upper panel) and disease-free survival (lower panel) based on the clinical production of a hormone (gastrin and glucagon); that is, defined as functional vs non-functional pancreatic endocrine tumor (NF-PET). Functional PET had a significantly better total survival than NF-PET (p<0.001, upper panel), but there was no difference in disease-free survival (lower panel).