The endourological treatment of renal matrix stones.

OBJECTIVE To report our experience with the endourological treatment of renal matrix stones, an infrequent form of urinary calculi whose diagnosis and treatment are often difficult. METHODS From 1990 to 2010 we treated 9 female patients with matrix calculi using the endourological approach; 4 presented with renal colics, 3 with symptomatic urinary tract infection and 2 with asymptomatic bacteriuria. Six patients underwent percutaneous lithotripsy and 3 retrograde intrarenal surgery as first-line therapy. Three cases needed a multidisciplinary approach. RESULTS The six percutaneous procedures were successful after a single session, while the retrograde approach required multiple treatments; a single case needed a shock wave session to complete the fragmentation, in another one a percutaneous lithotripsy was necessary after the first procedure, and a third case needed multidisciplinary treatment. CONCLUSIONS Percutaneous lithotripsy has been confirmed as the first option for matrix stones. The retrograde approach - by confirming the suspected diagnosis and being minimally invasive - may be employed to treat either lower-size stones or stones at high risk of recurrence.