Objective: The newer flexible ureteroscopes, 150-200-microm holmium YAG laser fibres and superflexible Dormia baskets have made it possible to reach and treat stones in all parts of the kidney. The object of this evaluation was to study the outcome of retrograde intrarenal stone surgery (RIRS) for extracorporeal shock-wave lithotripsy (ESWL)-resistant kidney stones.
Material and methods: A total of 38 consecutive patients (18 males, 20 females) participated in the study. All patients had undergone ESWL prior to RIRS without success. In all cases the stones could be reached with the endoscope. Calculi ranged in size from 3 to 20 mm (mean 9 mm). In 32 cases the stones were fragmented using a holmium YAG laser and in six the stones could be extracted using zero-tip Dormia baskets without fragmentation. Sixteen patients had lower calyceal calculi and eight had an abnormal anatomy of the upper urinary tract. Intravenous pyelography was performed 6-8 weeks after the treatment.
Results: In all cases the stones could be reached and fragmented to some extent. After a single RIRS procedure, 22/38 patients (58%) were completely stone-free at follow-up, and four (11%) had residual fragments < or = 4 mm in size that were expected to pass spontaneously. Of the remaining 12 patients, who initially had larger stones (mean 11.3 mm), the residual fragments ranged in size from 5 to 15 mm. Three patients underwent an additional RIRS procedure, after which they were all completely stone-free, resulting in an overall success rate of 76%. There were no major complications.
Conclusions: RIRS is a safe procedure with a high success rate and a low complication rate for ESWL-resistant renal stones. Patients with larger stones (> 10 mm), those with stones in the lower pole and those with an abnormal renal anatomy may require more than one procedure.