Etiology and pathogenesis of acute biliary pancreatitis.

Abstract

In 78 patients withacute pancreatitis associated with gallstones, anatomic inspection (operation or autopsy) was performed during the acute stage of the disease. The patients presented with typical clinical signs and with concomitant biliaty obstruction. Sixty-three percent had a history of dietary abuse prior to the crisis. Thirty-three percent had a concomitant biliary tract infection. Impacted gallstones at the ampulla were found in 49 of the 78 patients (63%). According to the cholangiographicjndings four types of obstruction were seen: (1) total low obstruction (43%), (2) total low obstruction with reflux to the Wirsung duct (23%), (3) total high obstruction (I3%), and (4) partial obstruction (21%). In each patient the gallstones removed from the ampulla were identical to those found in the gallbladder. The pathologic changes found in the pancreas were grouped under four dtxerent grades according to the degree of lesion found: grade Z, edema (n = 36); grade ZZ, fat necrosis and peritoneal exudate (n = 16) grade ZZZ, hemorrhage (n = 1 I); and grade ZV, massive necrosis, abscess, or pseudocyst (n = 15). The degree of pancreatic lesion directb correlated with the duration of ampullary obstruction in 49 patients in whom a stone was still impacted at the time of anatomic inspection (x’ = 55.13, P < 0.001, contingency coeficient = 0.73). The dietary excess prior to the pancreatitis and the cholangiographic evidence of rejbx to the Wirsung duct were not found to correlate with the severity of pancreatitis. Patients with biliary tract infection presented with more severe pancreatitis. The relief of obstruction obtained through operation within thejrst 48 hours was followed by complete and immediate recovery in 98% of the patients. The present study proves that acute biliary pancreatitis is caused by ampullary obstruction due to migration of gallstones. Rapid remission occurs tfpatency of the ampulla is restored before 48 hours. Following more prolonged ampullary obstruction, irreversible lesions are formed.