Purpose: Shock wave lithotripsy (SWL) is a widely utilized treatment for renal and ureteral stones due to its noninvasive approach.
Although minor complications arise in most patients, a relatively severe complication, perirenal or subcapsular hematoma, may also occur. We evaluate the possible risk factors for perirenal hematoma following SWL.
Material and Methods: Between 2001 and 2011, a total of 10,887 urolithiasis performed SWL treatments. All SWL procedures were performed using a Siemens Lithostar multiline lithotripter at a frequency of 2/sec under intermittent fluoroscopic guidance. All these cases underwent outpatient treatment without general anesthesia but pethidine was applied for pain control. Treatment episodes were retrospectively reviewed for medical history, patient age, gender, body mass index, mean arterial pressure at induction, location of stone, total number of shock waves and peak shock wave intensity. We also compared the hematoma group with the control group (no hematoma formation after SWL under matched age and sex) in various factors.
Results: Following 10,887 treatment episodes on a total of 6,177 patients during this time period, subcapsular or perirenal hematoma developed in 20 cases for a total incident rate of 0.32%. Eighteen patients had the symptom of flank pain and two patients were diagnosed accidently without symptoms. Four patients had blood transfusion due to low hemoglobulin concentration. All of them received conservative and supportive treatment without surgical exploration. Ten patients (50%) had a past history of hypertension. Eleven cases developed renal hematoma after the 2nd or 3rd SWL treatment. Hypertension is a predisposing risk factor (p=0.022) for the renal hematoma.
Conclusions: Renal hematoma is a rare (incidence rate 0.32 %) but severe complication. The most common symptoms of renal hematoma are severe flank pain and hematuria. Past history of hypertension is an important predisposing factor to perirenal hematoma.
Written by:
Lee HY, Juan YS. Are you the author?
No.100 , Tzyou 1st Road Kaohsiung 807 , Taiwan, Kaohsiung, Taiwan, 807.
Reference: J Endourol. 2012 Dec 31. Epub ahead of print.
doi: 10.1089/end.2012.0619
PubMed Abstract
PMID: 23272952
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