Small caliceal stones: is extracorporeal shock wave lithotripsy justified?

Of 446 patients treated by extracorporeal shock wave lithotripsy 22 had small nonobstructive caliceal stones associated with lumbar or flank pain. Size (less than 1 cm.) and location of the stone did not explain the severity of the symptoms, nor would they have been an indication for open or percutaneous stone removal. Followup consisted of a sonogram and a film of the kidneys, ureters and bladder on postoperative day 1, a film of the kidneys, ureters and bladder 2 weeks after treatment, and a film of the kidneys, ureters and bladder and/or excretory urography after 3 months for patients with residual stone fragments. All patients were interviewed 3 to 15 months after treatment to ascertain the resolution or persistence of the symptoms. After extracorporeal shock wave lithotripsy, 3 of 22 patients had persistent stone fragments for more than 3 months: 2 reported no change and 1 had marked improvement of the symptoms. Of the remaining 19 patients 15 (79 per cent) had complete resolution of the pain and 4 (21 per cent) had significant symptomatic improvement. Thus, 20 of 22 patients (91 per cent) achieved complete or significant relief of pain. The only complication was a perirenal hematoma that resolved spontaneously. These results indicate that small, nonobstructive caliceal stones can be responsible for persistent, severe flank pain. Extracorporeal shock wave lithotripsy is an effective, noninvasive treatment for caliceal stones and it can be justified as therapeutic treatment when the correlation between a small caliceal stone and persistent flank pain is indeterminable.