Ampullary obstruction monitoring in acute gallstone pancreatitis: a safe, accurate, and reliable method to detect pancreatic ductal obstruction.

OBJECTIVE: The aim of this study was to determine the value of ordinary clinical and laboratory data, including the monitoring of ampullary gallstone obstruction in the early phases of the disease, in the diagnosis of acute gallstone pancreatitis (AGP).
METHODS: One hundred and thirty-two patients were studied. The inclusion criteria were admission within 48 h from the onset of symptoms, clinical presentation compatible with AGP, bile-free gastric aspirate, elevation of serum amylase and bilirubin, and ultrasonographic demonstration of cholelithiasis. Monitoring of ampullary obstruction included severity of pain, presence of bile in the gastric aspirate, and serial serum bilirubin determinations. The clinical diagnosis of AGP was confirmed or excluded by surgical exploration, and that of ampullary obstruction by intraoperative cholangiography (IOC) or endoscopic retrograde cholangiopancreatography (ERCP).
RESULTS: The overall accuracy of the diagnostic tests for AGP was high: sensitivity, 0.94; specificity, 0.99; positive predictive value, 0.95; and negative predictive value, 0.99. Detection of spontaneous ampullary decompression was correct in 100% of the patients, and that of ampullary obstruction, in 61%. The accuracy of this test was sensitivity, 1.0; specificity, 0.92; positive predictive value, 0.61; and negative predictive value, 1.0.
CONCLUSIONS: Clinical criteria and ordinary laboratory determinations are sufficiently accurate to discriminate between patients with AGP and those with other acute abdominal pathologies. Careful monitoring of patients' pain, quality of nasogastric aspirate, and serum bilirubin level can accurately identify the few cases with persistent ampullary obstruction. Those patients can then be selected for intervention to restore the ampullary patency and prevent progression of acute pancreatitis.