Accuracy of Endoscopic Ultrasound for Vascular Invasion and Vascular Adhesion in Pancreatic Cancer: A single center experience

Introduction: Endoscopic Ultrasound (EUS) has emerged as an accurate tool to diagnose and stage pancreatic cancer. The reported accuracy of EUS to detect vascular adhesion or invasion in pancreatic cancer is variable. Aim: To asses the accuracy of EUS to diagnose vascular invasion and vascular adhesion in patients with pancreatic malignancy. Methods: Patients with pancreatic cancer who underwent EUS and surgery at one hospital were identified in a retrospective manner. EUS criteria for vascular adhesion was loss of echoplane alone. Vascular invasion was defined as tumor in the lumen or abnormal vessel contour or the presence of collateral vessels in the absence of a main vascular structure. Surgical definition for vascular adhesion was – tumor adherence but not precluding complete tumor resection and vascular invasion was defined as tumor encasing the vessel or vascular unresectability. Results: Total of 77 patients with pancreatic cancer and vascular involvement on EUS were identified. 41 out of 77 patients had surgery at our institution and were included in the analysis. EUS showed vascular invasion in 15 patients, vascular adhesion in 10 patients and no involvement in 16 patients. Superior mesenteric vessels were involved in 11 patients, portal vein in 12 patients, and splenic vein in 2 patients. The accuracy of EUS for vascular invasion and vascular adhesion is shown in table 1.

Table 1: Accuracy of EUS to diagnose vascular involvement in patients with pancreatic cancer.

	Sensitivity	Specificity	Positive Predictive Value	Negative Predictive Value
Vascular Invasion	63.64%	94.44%	93.33%	68%
Vascular Adhesion	20.00%	87.88%	20.00%	87.88%

Conclusion: EUS is a good test to diagnose vascular invasion but it performs poorly when it comes to diagnosing vascular adhesion. Better EUS diagnostic criteria or technologies are needed to diagnose vascular adhesion.