The case for primary endoscopic management of upper urinary tract calculi: I. A critical review of 121 extracorporeal shock-wave lithotripsy failures.

OBJECTIVES: To define those patients with upper urinary tract calculi who are more likely to have an unsuccessful outcome from extracorporeal shock-wave lithotripsy (ESWL).
METHODS: A critical prospective analysis of 121 patients, referred to two university centers after ESWL had been exhausted as a treatment modality for upper urinary tract calculi, was performed. Patients were subdivided into the following groups: failure to clear fragments, failure to fragment, difficulty in calculus localization, and failure due to inherent upper urinary tract obstruction. Other important variables include the type of extracorporeal lithotriptor used, number of treatment sittings before referral, calculus location, calculus composition, patient body habitus, and the imaging leading to and associated with extracorporeal therapy.
RESULTS: Large renal calculi (mean, 22.2 mm) and those within dependent or obstructed portions of the collecting system were frequently referred for endoscopic management after failed ESWL. Steinstrasse can be an extremely morbid complication from ESWL and in this series was associated with irreversible loss of renal function and ureteral stricture disease. Extracorporeal lithotripsy of infectious calculi can be associated with severe septic complication. Inadequate preoperative and intraoperative imaging and morbid obesity were also associated with failure. Second- and third-generation lithotriptors were represented in greater numbers than the Dornier HM-3 in this group of ESWL failures.
CONCLUSIONS: ESWL remains the treatment of choice for moderately sized, uncomplicated renal calculi. Large calculi, those within obstructed or dependent portions of the collecting system, and those composed of calcium oxalate monohydrate, frequently fail ESWL. Training in the more technically challenging aspects of endoscopic lithotripsy must be encouraged.