Schregel C et al, 2017: Influence of acetylsalicylic acid and low-molecular weight heparins on the formation of renal hematoma after shock wave lithotripsy.
Schregel C, John H, Randazzo M, Keller I.
Department of Urology, Kantonsspital Winterthur, Brauerstrasse 15, 8401, Winterthur, Switzerland.
Abstract
PURPOSE: To investigate the risk of renal hematoma (RHT) after shock wave lithotripsy (SWL) among patients on acetylsalicylic acid (ASA) or low-molecular-weight heparin (LMWH).
PATIENTS AND METHODS: Retrospective analysis of 434 patients treated with SWL for nephrolithiasis and ureterolithiasis of the proximal ureter. Primary endpoint was detection of RHT by ultrasound the day after SWL. Secondary outcome variables included transfusion of erythrocyte concentrate(s), interventions, hospital readmission or death due to RHT within 30 days of SWL. Binary logistic regression analysis was used including a post hoc one-way analysis.
RESULTS: Of 434 patients, 33 (7.6%) and 67 (15.4%) patients were medicated with ASA and LMWH, respectively. RHT was detected in 20 of 434 (4.6%) patients. Of those, 3 (20%) were on ASA, 6 (35%) were on LMWH, 1 (5%) was on ASA and LMWH, and 10 (50%) had no anticoagulation. Univariate analysis showed a statistically significant higher risk for RHT among patients on ASA (p = 0.04) and LWMH (p = 0.02) with an untreated urinary tract infection (UTI) (p = 0.008) and history of cardiovascular disease (p = 0.028). On multivariate analysis, ASA medication, untreated UTI (OR 4.4, 95% CI 1.31-14.75, p = 0.016 and OR 5.79, 95% CI 1.65-20.32, p = 0.03) and a therapeutic dose of LMWH (OR 10.4, 95% CI 1.74-62.27, p = 0.01) were independent predictors for RHT.
CONCLUSIONS: Before SWL, a patient risk profile should be evaluated. If feasible, LMWH in therapeutic dosing should be avoided, and ASA should be discontinued. UTI should be treated before SWL in any case.
TRIAL REGISTRATION: http://www.clinicaltrials.gov ; Identifier NCT02875717.
World J Urol. 2017 Jul 12. doi: 10.1007/s00345-017-2070-0. [Epub ahead of print]
Comments 1
The basis of this publication is very week and does not allow any sound conclusions regarding the frequency of renal hematomas after ESWL.
In this retrospective study ”ultrasound control was performed the day after SWL in all patients by a urologist, regardless of symptoms. A differentiation between symptomatic and asymptomatic hematoma was not possible.” Obviously the patient files did not include reproducible data on symptoms.
”Any perirenal fluid collection detected by ultrasound was classified as RHT. The RHT size was not evaluated.”
If only perirenal changes were classified as hematomas after ESWL, all intrarenal hematomas were disregarded.
My own experience with sonography after ESWL with the HM3 in the early 80s showed that perirenal fluid collections seen with sonography were frequently not hematomas when controlled by CT. Clinical studies and animal experiments on CT findings after ESWL were done in our department together with the radiologists (Schaub T et al. Computed tomography following extracorporeal shockwave lithotripsy (ESWL) of the kidneys. I: Correlation with acute histopathological findings in experimental animals. Rofo. 1991 Mar;154(3):231-7;
Schaub T et al. Computed tomography following extracorporeal shockwave lithotripsy of the kidneys. III. A prospective CT study of 105 patients and a 3-year follow-up of 23 patients using CT and 99mTc-MAG3 clearance. Rofo. 1993 Feb;158(2):121-6) . ESWL was done with the Siemens Lithostar. In the patient series CT was done within two days after ESWL. In these 105 patients the CT showed very varying pathological findings in 36:
(Modified from: Schaub T et al. Computed tomography following extracorporeal shockwave lithotripsy of the kidneys. III. A prospective CT study of 105 patients and a 3-year follow-up of 23 patients using CT and 99mTc-MAG3 clearance. Rofo. 1993 Feb;158(2):121-6)
Even though in this study CT and sonography findings were not compared, the CT findings suggest that sonography must have missed some lesions and misinterpreted others.
Complications in the present series were seen in only three patients but they were impressive:
”All adverse events occurred in patients with continued application of LMWH in therapeutic dosing or with LMWH in combination with ASA. One patient died eight days after SWL (complication Clavien Grade V). Autopsy revealed a myocardial rupture with pericardial tamponade due to myocardial infarction, potentially triggered by postoperative anemia. In two patients with symptomatic anemia after SWL, a selective embolisation of a segmental renal artery in interventional angiography was performed. One of the two patients received red cell concentrates and needed treatment in the intensive care unit (complication Clavien Grade IIIa and IVa).”