Subcapsular renal hematoma following shock wave lithotripsy

OBJECTIVES: The present study analyzed the incidence of subcapsular hematoma of the kidney (SH) following extracorporeal shock wave lithotripsy (ESWL), its management and the possible risk factors that influence the development of this condition. METHODS: We received the records of 1600 patients submitted to 2250 ESWL sessions. SH was evaluated according to the following parameters: clinical features, diagnostic methods, management, follow up and the patient -and ESWL- related factors that influence the development of this condition. RESULTS: Five cases of SH were found (0.22% incidence), which had been diagnosed by ultrasound (US). Eighty per cent had sustained lumbar pain and a fall in hemoglobin values. The patients were managed conservatively and US follow up evaluation was done. At six months, resolution was almost complete with no sequelae. No patient had any of the risk factors described in the literature (hypertension, concomitant urinary tract infection or coagulation disorders) or changes in the ESWL unit standards. CONCLUSIONS: Although SH following ESWL is uncommon, sustained lumbar pain and a fall in hemoglobin values are risk factors that should be taken into account and corroboration and follow up by US should be done. Unless complications present, the patients should be managed conservatively.