Incidence and risk factors of renal hematoma: a prospective study of 1,300 SWL treatments

Abstract

Shock wave lithotripsy (SWL) is the gold standard for the treatment of upper urinary tract stones. Despite being relatively non-invasive, SWL can cause renal hematoma (RHT). The aim of this study was to determine incidence and risk factors for RHT following SWL. 857 patients were included in a prospectively maintained database. The observation period spans from 2007 to 2012. 1,324 procedures were performed due to kidney stones. Treatment protocol included power ramping and shock wave frequency of 60-90 per minute as well as an ultrasound check within 3 days of SWL for all patients. Patients with RHT were analyzed, and treatment characteristics were compared with the complete population in a non-statistical manner due to the low event count. RHTs after SWL, sized between 2.6 × 0.6 cm and 17 × 15 cm, were verified in seven patients (0.53%). In four patients, the RHT was asymptomatic. Three patients developed pain after SWL treatment due to a RHT. In one patient surgical intervention was necessary due to a symptomatic RHT, the kidney was preserved. The risk of RHT following SWL treatment of kidney stones is about 0.5%. Clinically relevant or symptomatic RHTs occur in 0.23%, RHTs requiring surgical intervention are extremely rare. Older age and vascular comorbidities appear to be risk factors for the development of RHT. The technical characteristics of SWL treatment and intake of low-dose acetylsalicylic acid due to an imperative cardiologic indication do not appear to influence the risk. Prospective studies are warranted.

Hypovolemic Shock Caused by Massive Renal Hematoma After a Third Consecutive Extracorporeal Shockwave Lithotripsy Session: A Case Report

“…1,2 In rare cases, patients with this latter complication present with life-threatening hemodynamic instability. 1,3 Hematomas after SWL are attributed to the tissue damaging effect of the administered pulses. Several factors may contribute.…”

“…First, there are process-specific factors, for example, the properties and settings of the lithotripter, the process of cavitation inherent to SWL, or respiratory movements of the patient. 2,3 Other factors are patient-specific, for example, bleeding diathesis, antiplatelet activity, diabetes mellitus, and hypertension. 1 In the present case, elevated blood pressure might be considered a contributing factor caused by elevated mechanical stress on the blood vessel walls.…”

Sudden onset of a huge subcapsular renal hematoma following minimally invasive ureteroscopic holmium laser lithotripsy: A case report

“…When patients are without signs for active bleeding, a conservative manner should be used to treat the SRH (1,9). With the exception of contrast-enhanced CT, CT scan, ultrasound, routine blood tests and coagulation status, creatinine levels, blood urea nitrogen levels, electrolyte balance and urine tests should be included in diagnostics (1).…”

“…Shock wave lithotripsy (SW L), trauma and renal angiographic procedures are all known to cause renal hematoma (1). However, a renal hematoma may also occur spontaneously in patients with a malignancy or in patients receiving anticoagulation therapy.…”

What should be the ideal time interval between repeated extracorporeal shock wave lithotripsy sessions for renal stone treatment?

“…We have read the article by Schnabel et al [1] with great interest. The authors aimed to determine the incidence of and risk factors for renal hematoma (RHT) after extracorporeal shock wave lithotripsy (SWL).…”