This finding was consistent among 220 patients who underwent pancreaticoduodenectomy ( 10 % vs. 21 % ; relative risk , 0.49 ; 95 % CI , 0.25 to 0.95 ) and 80 patients who underwent distal pancreatectomy ( 7 % vs. 23 % ; relative risk , 0.32 ; 95 % CI , 0.10 to 0.99 ) , as well as among 136 patients with a dilated pancreatic duct ( 2 % vs. 15 % ; relative risk , 0.11 ; 95 % CI , 0.02 to 0.60 ) and 164 patients with a nondilated pancreatic duct ( 15 % vs. 27 % ; relative risk , 0.55 ; 95 % CI , 0.29 to 1.01 ) .