Small Gallstones Are Associated with Increased Risk of Acute Pancreatitis: Potential Benefits of Prophylactic Cholecystectomy?

OBJECTIVES: Pancreatitis is a severe complication of gallstone disease with considerable mortality. Small gallstones may increase the risk of pancreatitis. Our aims were to evaluate potential association of small stones with pancreatitis and potential beneficial effects of prophylactic cholecystectomy. METHODS: Stone characteristics were determined in patients with biliary pancreatitis (115), obstructive jaundice due to gallstones (103), acute cholecystitis (79), or uncomplicated gallstone disease (231). Sizes and numbers of gallbladder and bile duct stones were determined by ultrasonography and endoscopic retrograde cholangiopancreatography, respectively. Effects of prophylactic cholecystectomy were assessed by decision analyses with a Markov model and Monte Carlo simulations. RESULTS: Patients with pancreatitis or obstructive jaundice had more and smaller gallbladder stones than those with acute cholecystitis or uncomplicated disease (diameters of smallest stones: 3 +/- 1, 4 +/- 1, 8 +/- 1, and 9 +/- 1 mm, respectively, p < 0.01). Bile duct stones were smaller in case of pancreatitis than in obstructive jaundice (diameters of smallest stones: 4 +/- 1 vs 8 +/- 1, p < 0.01). Multivariate analysis identified old age and small stones as independent risk factors for pancreatitis. Decision analysis in a representative group of patients with small (<or=5 mm) gallstones (5,000 patients, 67% females, 45 yr old, 10-yr follow-up) indicates that life-years may be gained or lost by cholecystectomy, depending on incidence and mortality of pancreatitis. CONCLUSIONS: Small gallstones are associated with pancreatitis. Prophylactic cholecystectomy may lead to gain or loss of life-years in patients with small stones, depending on incidence and mortality of pancreatitis.