title: A low or high BMI is a risk factor for renal hematoma after extracorporeal shock wave lithotripsy for kidney stones.
abstract: The purpose of this study was to evaluate risk factors for renal hematoma after extracorporeal shock wave lithotripsy (SWL) for kidney stones in a matched case-control analysis of a subgroup of patients recruited from a prospective randomized cohort. Between 06/2010 and 03/2013, 418 patients underwent SWL with the MODULITH®-SLX-F2-lithotripter for kidney stones. In 39/418 patients (9 %), ultrasound at post-treatment day 1 revealed renal hematomas. For 37 of these patients, a matched group without hematoma could be selected according to the following matching criteria: age, gender, number and energy of shock waves, stone burden and localization. Risk factors for renal hematoma after SWL were compared between the two groups. The rates of diabetes, stopped anticoagulant/antiplatelet medications and arterial hypertension were not different between the two groups (p > 0.2). The skin-kidney distance was virtually the same in both groups (p = 0.5). In the hematoma group, significantly more patients had a high (>30: n = 16) as well as a low (<21.5: n = 4) BMI when compared to the control group (n = 4; n = 0; p < 0.001). Importantly, all patients with BMI <21.5 developed renal hematomas after SWL. Patients with a high (>30) or low (<21.5) BMI had a higher risk for renal damage after SWL. Therefore, alternative endoscopic treatment options should be considered in these patients.
authors: Department of Urology, University of Bern, Freiburgstrasse, 3010, Bern, Switzerland.
authors: Fabio
authors: F
authors: Nussberger
authors: Department of Urology, University of Bern, Freiburgstrasse, 3010, Bern, Switzerland.
authors: Beat
authors: B
authors: Roth
authors: Department of Urology, University of Bern, Freiburgstrasse, 3010, Bern, Switzerland.
authors: Tobias
authors: T
authors: Metzger
authors: Department of Urology, University of Bern, Freiburgstrasse, 3010, Bern, Switzerland.
authors: Bernhard
authors: B
authors: Kiss
authors: Department of Urology, University of Bern, Freiburgstrasse, 3010, Bern, Switzerland.
authors: George N
authors: GN
authors: Thalmann
authors: Department of Urology, University of Bern, Freiburgstrasse, 3010, Bern, Switzerland. r_seiler@gmx.ch.
authors: Roland
authors: http://orcid.org/0000-0002-3529-2088
authors: R
authors: Seiler
mesh_terms: D000328:Adult; D000368:Aged; D015992:Body Mass Index; D016022:Case-Control Studies; D005260:Female; D006406:Hematoma / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000209:etiology; D019220:High-Energy Shock Waves / Q000009:adverse effects; D006801:Humans; D007668:Kidney / Q000473:pathology / Q000528:radiation effects*; D007669:Kidney Calculi / Q000000981:diagnostic imaging / Q000601:surgery*; D008096:Lithotripsy / Q000009:adverse effects* / Q000295:instrumentation; D008297:Male; D008875:Middle Aged; D000074642:Nephrolithotomy, Percutaneous / Q000009:adverse effects / Q000706:statistics & numerical data; D011183:Postoperative Complications / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000209:etiology; D011446:Prospective Studies; D012086:Reoperation / Q000706:statistics & numerical data; D012307:Risk Factors; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D014463:Ultrasonography; D018666:Ureteroscopy / Q000009:adverse effects / Q000706:statistics & numerical data; D055815:Young Adult
keywords: BMI; Case–control analysis; Extracorporeal shock wave lithotripsy; Renal hematoma; Stones