Larger Stones Increase Post-SWL Steinstrasse Risk in Children
Stone size is the only predictor of the development of steinstrasse after shock wave lithotripsy (SWL) in children, according to researchers in Turkey.
Bulent Onal, MD, and collaborators at the University of Istanbul Cerrahpasa Medical Faculty studied 341 renal units (RUs) in 341 children treated with SWL for urolithiasis. The researchers placed the children into three groups based on stone size: 1 cm2 or less (group 1), 1.1-2.0 cm2 (group 2) and greater than 2.0 cm2 (group 3). Steinstrasse developed in 26 RUs (7.6%), an incidence similar to that observed in adult series, Dr. Onal's team reported online ahead of print in Urology. Stone burden was the only factor significantly associated with steinstrasse formation. The rate of steinstrasse formation in groups 1, 2, and 3 was 1.9%, 15.4%, and 19.5%, respectively.
Of the 26 RUs with steinstrasse, 17 (65.4%) were successfully managed with repeat SWL alone, four (15.4%) were managed with ureteroscopy after SWL failure, and one (3.8%) was managed by ureteroscopy alone. Four patients (15.4%) were managed conservatively with an antispasmodic drug plus hydration therapy.
In 20 (77%) of the 26 RUs, steinstrasse was localized in the lower ureter, five (19%) were localized in the upper ureter, and one (4%) occurred in multiple locations.