Background: Endoscopic papillary balloon dilatation (EPBD) is generally considered a safe and effective technique for removal of common bile duct (CBD) stones. However, some reports have prompted concern about the risk of pancreatitis following the procedure, and it seems to be more difficult and to require adjunctive procedures more frequently in patients with large stones.
Aims: To analyse the factors influencing pancreatitis after the procedure, and to examine which is the more suitable adjunct for treating large stones, mechanical lithotripsy (ML) or extracorporeal shockwave lithotripsy (ESWL).
Patients and methods: EPBD was performed in 92 patients, including 40 with large stones (> or = 12 mm). These 40 patients were randomly assigned to two groups receiving ML or ESWL to fragment stones (20 patients each).
Results: Complete ductal clearance was obtained in all 92 patients. Significant elevation of the serum amylase level compared with the prior value (> 300 IU/l) was observed in 26 (28%), and eight (8.7%) developed clinical pancreatitis. To assess the influence of various factors on the amylase level, multivariate analysis was used. The number of stones and the time required for treatment had a significant influence on the incidence of increased amylase level (P < 0.05), and ML also significantly increased it (P < 0.05). On the other hand, the amylase level remained low in the ESWL group. ML caused elevation of amylase level in 11 patients (55%), while three (15%) had elevation after ESWL.
Conclusions: In patients with multiple stones, elevation of the amylase level is more frequent. This seems to be because repeated cannulation and much time is required for treatment. In patients with large stones, the rate was also high if ML was used, but was low when ESWL was used. ESWL may reduce the incidence of pancreatitis.