T. Nakamoto et al., LONG-TERM RESULTS OF ENDOUROLOGICAL TREATMENT OF URINARY CALCULI - INVESTIGATION OF RISK-FACTORS FOR RECURRENCE OR REGROWTH, Journal of endourology, 7(4), 1993, pp. 297-301
To evaluate the risk factors related to the long-term outcome of endou
rologic treatment of urinary calculi, we examined rates of recurrence
and regrowth in 167 renal units. The following risk factors were exami
ned: age; previous stone; location, number, size, and composition of s
tone; and procedures. In our study sample, the overall recurrence and
regrowth rates were 17 % and 10 %, respectively. The earliest recurren
ce and regrowth appeared at 3 months after treatment, and 71 % occurre
d within 2 years. In 22 % of renal units that were estimated to be sto
ne-free, stones appeared later, and 45 % of inadequately fragmented st
ones enlarged. Stones located in a renal calix and pelvis, multiple st
ones, large stones (more than 20 mm), stones composed of calcium oxala
te or calcium phosphate or both, and struvite stones were likely to be
risk factors, but there were no significant differences statistically
. Although the possibility of several risk factors was suggested in ou
r study, thorough fragmentation of stones and complete removal of frag
ments, combined with extracorporeal shock wave lithotripsy or chemolys
is if needed, is ultimately responsible for successful treatment of ur
inary calculi.