A ten-year prospective study on gallbladder stone recurrence after successful extracorporeal shock-wave lithotripsy

Objective. The risk of recurrence has limited the acceptability of conservative therapies of gallbladder stones. The aim of the present study was to determine the long-term rate of stone recurrence and its risk factors after successful extracorporeal shock-wave lithotripsy ( ESWL). Material and methods. The study comprised a prospective ultrasound follow-up at yearly intervals or whenever biliary pain was reported. A total of 192 consecutive patients ( primary single stones, n = 159; primary 2 or 3 stones, n = 33) were followed for up to 11.2 years after becoming stone-free and after termination of adjuvant treatment with ursodeoxycholic acid ( UDCA). Results. Eighty-four patients developed recurrent stones after a median of 2.6 years ( maximum = 8.8 years). The 108 patients without recurrence were followed for a median of 6.7 years ( maximum = 11.2 years). By actuarial analysis, the cumulative recurrence rates for these 192 stone-free patients were 27% +/- 3%, 41% +/- 4% and 54% +/- 4% ( observed +/- SE) at 3, 5 and 10 years, respectively. Cox's regression analysis was used to identify the presence of slight calcification in the primary stone(s) as a protective feature against recurrence ( p = 0.03). Conclusions. 1) The risk of recurrence continues to increase over time, and although it rises less steeply after 5 years, it does not reach a plateau until at least 10 years. 2) Having had slightly calcified stone( s) seems to be associated with a reduced risk of recurrence and might signal a "burnt out'' lithogenic process. 3) The long-term results are unsatisfactory and ESWL of gallbladder stones should be offered only in special cases.