THE USE OF EUS TO DIAGNOSE MALIGNANT PORTAL VENOUS SYSTEM INVASION BYPANCREATIC-CANCER

Background: CT scanning and mesenteric angiography are insensitive tes ts for diagnosing vascular invasion by pancreatic cancer. Endoscopic u ltrasound (EUS) has been proposed as an alternative. The sensitivity, specificity, and accuracy of specific EUS criteria for diagnosing mali gnant invasion of the branches of the portal venous system have not be en determined. Methods: This is a prospective blinded evaluation of EU S and angiography to diagnose malignant invasion of the portal venous system by pancreatic cancer in 45 patients, 28 of whom underwent surge ry. Surgical staging was used as the gold standard for determining the accuracy of EUS and angiography. Results: Four EUS criteria were stud ied and the overall accuracy rates were as follows: irregular venous w all (87%), loss of interface (78%), proximity of mass (73%), and size (39%). Although ''irregular venous wall'' was the most accurate, it su ffered from a low sensitivity rate (47%) because of its relative inabi lity to detect superior mesenteric vein invasion (sensitivity of 17%). The angiographic criteria had accuracy rates of 73% to 90% with low s ensitivity rates (20% to 77%). The clean resection rate was 86% when a ll tests were used, 78% if EUS was used without angiography, and 60% i f only angiography was used.Conclusion: EUS is highly sensitive far de tecting portal and splenic vein invasion by pancreatic cancer, but may be insensitive for superior mesenteric vein involvement.