Gallstones that obstruct the ampulla are responsible for initiating and maintaining biliary pancreatitis. The duration of the ampullary obstruction is directly linked to the severity of the illness. Endoscopic retrograde cholangiopancreatography (ERCP) has been suggested as the appropriate diagnostic and therapeutic tool for use in patients with acute gallstone pancreatitis. In most patients, gallstones migrate spontaneously within 48 hours, resolving the problem and making ERCP unwarranted. Acosta and associates evaluated the value of ordinary clinical and laboratory data in establishing the diagnosis of acute gallstone pancreatitis and in predicting the course of the obstruction during the initial phases of the disease.

Patients were eligible for the study if they presented with the appropriate clinical picture of acute pancreatitis and if cholelithiasis was evident on ultrasonogram at the time of admission, or if the patient had undergone prior cholecystectomy for cholelithiasis. Other inclusion criteria included admission within 48 hours after onset of symptoms, bile-free gastric aspirate, increased serum amylase and bilirubin levels, and no history of alcohol abuse. The severity of the pancreatitis was established by applying the Ranson criteria at the time of admission, before treatment and again at 48 hours after admission. Monitoring of ampullary obstruction was conducted by using three parameters: (1) the severity of the disease, particularly the severity of abdominal pain, which was checked every four to six hours; (2) the presence of bile in the gastric aspirate, which was checked every six hours; and (3) serial bilirubin levels determined at admission and every six hours thereafter. The clinical diagnosis was confirmed by surgical exploration with intraoperative cholangiography or ERCP.

After admission, 132 patients were assumed to have acute gallstone pancreatitis. Of these patients, 109 (83 percent) showed signs of ampullary decompression (e.g., rapid relief of pain, the appearance of bile in the gastric aspirate and a falling bilirubin level). Eleven of these 109 patients underwent successful treatment by conservative measures only and were excluded from the study. The remaining 98 patients formed the elective surgery group (group A). The 23 patients (17 percent) in the other group showed signs of persistent ampullary gallstone obstruction. These patients comprised the urgent surgery group (group B). Surgical and endoscopic findings revealed gallstones in 93 patients and cholesterolosis in two patients in group A. The remaining three had undergone prior cholecystectomy. Common duct stones were detected in 17 (17 percent) patients in this group. In group B, gallstones were found in 21 patients and cholesterolosis in one patient. The remaining patient had undergone a previous cholecystectomy. Common duct stones were detected in 17 patients (74 percent), 14 (61 percent) of whom had a stone impacted at the ampulla. The clinical impression using the three parameters previously mentioned had high sensitivity and specificity in predicting those with or without ampullary obstruction. When tests were positive for acute gallstone pancreatitis and patients underwent surgery, 95 percent showed clear signs of the suspected condition.

The authors conclude that the diagnosis of acute gallstone pancreatitis can be made using clinical evaluation and easily obtainable laboratory data. In addition, using these criteria can identify patients with persistent signs and symptoms who will require ERCP or surgical intervention to decompress the ampullary obstruction but spare those in whom the procedures are unnecessary.