Extracorporeal shock wave lithotripsy for lower calyx stones: predicting treatment success

The use of extracorporeal shock wave lithotripsy (ESWL) for lower calyx stones is associated with a high rate of residual fragments. Our aim is to analyse the effectiveness and complications of ESWL for lower calyx stones. Retrospective review of patients with lower renal calyx stones treated with ESWL between January-2014 and December-2020. Measurement of infundibular length, infundibular width and infundibulopelvic angle in lower renal pole to determine favourable anatomy. ESWL failure: fragments >3 mm detected in plain abdominal film, CT scan and/or renal ultrasound 3 months after treatment. Complications after ESWL, auxiliary procedures along with risk factors associated with perirenal haematoma were analysed. SPSS statistical software was used. 512 patients with lower calyx stones were treated with ESWL. 80.3% of patients had a favourable anatomy. Overall stone-free rate was 70.5%. Regarding main complications after ESWL, stainstrasse was described in 5 patients and urinary tract infection in 3 patients. 10 perirenal haematomas (2%) were reported. Statistical association was found between antiplatelet treatment and the risk of perirenal haematoma (p = 0.004). Logistic binary regression proved the association between unfavourable anatomy of the lower renal pole (p = 0.000), size of the stone (p = 0.001), number of shock waves (p = 0.003), energy applied (p = 0.038) and the need for additional treatment after ESWL. ESWL can still be considered as the initial treatment option for lower renal pole stones. The size of the stone, an unfavourable anatomy of the lower renal calyx, number of shock waves and energy applied can help predict the need for additional treatment. El uso de la litotricia extracorpórea por ondas de choque (LEOCh) en litiasis de grupo calicial inferior (GCI) se asocia con una alta tasa de fragmentos residuales. Nuestro objetivo es analizar la efectividad y complicaciones del tratamiento con LEOCh en litiasis de GCI. Revisión retrospectiva de pacientes con litiasis en GCI tratadas con LEOCh entre enero 2014 y Diciembre 2020. Se determina anatomía favorable del GCI mediante longitud infundibular, ancho infundibular y ángulo infundibulopélvico. Se considera fracaso de LEOCh la presencia de fragmentos >3 mm en radiografía simple, TC o ecografía a los 3 meses del procedimiento. Análisis de complicaciones, procedimientos auxiliares y factores de riesgo asociados con hematoma perirrenal. Análisis estadístico mediante software SPSS. En total, 5