4560 Assessment of chronic pancreatitis by using endoscopic ultrasonography and fine-needle aspiration cytology compared with ercp and pancreatic function tests.

Abstract

Background: Previous studies showed that endoscopic ultrasonography (EUS) can sensitively detect structural inflammatory changes of the pancreas. However, little is known about the specificity and clinical impact of EUS findings in chronic pancreatitis (cP). Therefore, we studied the morphology of the pancreas in patients with cP by using EUS techniques and fine-needle aspiration cytology (FNA), and we compared the EUS results to ERCP and pancreatic function tests. Materials/Methods: 37 patients with clinical symptoms and laboratory tests suggestive of cP (48±13 years) were prospectively studied. Patients with malignancy or major concomitant disease were excluded. EUS was carried out 10±3 days after the resolution of clinical signs of pancreatitis, and FNA was performed during EUS in 24 patients. EUS criteria for cP included the presence of echointense septae and echoreduced foci (=pseudolobularity), ductal irregularities, and calcifications. ERCP served as reference in all patients using the Cambridge classification. The clinical work-up also included fecal elastase and urine pancreolaureate tests. Results: 31 patients had cP, while 6 had normal findings during ERCP. EUS showed morphologic abnormalities in 32 patients, while ERCP revealed pathologic findings in only 31 patients. The combination of EUS/FNA versus ERCP reached a sensitivity of 100% with a specificity of 83%. Based on the presence of pseudolobularity alone, EUS reached a sensitivity of 96% with a specificity of only 72% for the presence of chronic pancreatitis, while the positive predictive value (PPV) was 93%, and the negative predictive value (NPV) was 83%. Based on 3 EUS criteria including ductal irregularities, the specificity decreased to 46%, while the sensitivity reached 97%. Compared with pancreatic function tests, EUS reached a sensitivity of only 86% with a specificity of 73%. EUS was in agreement with the severity of chronic pancreatitis in 6/8 patients with grade I, in 11/13 patients with grade II, and in 10/10 patients with grade III. Conclusions: EUS is a highly sensitive tool to detect morphologic abnormalities of the pancreas. However, the EUS findings are unspecific, which is probably due to postinflammatory organ abnormalities that may resolve completely over time. FNA improves the specificity and should thus be performed routinely during EUS. The association between morphologic findings and pancreatic function is poor.