Subcapsular renal hematoma after retrograde ureterorenoscopic lithotripsy: our experience

BACKGROUND: Ureterorenoscopy is the current standard treatment for ureteral and kidney stones, also stones greater than 2 cm can be removed. Complications linked to infectious processes or ureteral damage are the most frequently reported. Subcapsular renal hematoma is an extremely rare complication following this procedure. METHODS: We report the retrospective experience of two urological referral units for stones disease by analyzing incidence, risk factors and management of subcapsular renal hematoma. RESULTS: Between May 2011 and December 2017, 2497 consecutive ureteroscopies for urolithiasis were performed by 8 skilled endourologists. A subcapsular renal hematoma was diagnosed in four cases (0.12%). Symptoms appeared few hours after intervention in two patients and after 14 postoperative days in the remaining two. In all cases CT scan revealed a subcapsular renal hematoma without signs of active bleeding. Conservative treatment was successful. Two patients required blood transfusion. One patient developed renal hypotrophy. CONCLUSIONS: Subcapsular renal hematoma represents a rare but potentially serious complication after ureterorenoscopic lithotripsy. Its real incidence and etiology still need to be clarified. The elevated intrarenal pressures play an important role. Persistent hematuria, flank pain and hemoglobin drop should guide prompt investigation to reach an early diagnosis. In most cases a conservative management is sufficient.