The relationship between the stone-free status after extracorporeal shockwave lithotripsy (ESWL) treatment in different patient and kidney stone characteristics: A single center experience in Saudi Arabia

Abstract

Purpose: The objective was to unveil the relationship between different relevant patient and kidney stone characteristics and the stone-free status post extracorporeal shockwave lithotripsy (ESWL) treatment. Materials and methods: Kidney stones cases referred for ESWL from October 2019 to January 2020 were collected. A total of 225 adult patients who met the criteria of being new cases of single radio-opaque kidney stones measuring 5 to 20 mm were included. We were looking for disintegrated stones down to 4 mm or less as a marker for stone-free (SF) status. The studied parameters were gender, laterality (right or left kidney), location of the stone within the kidney, stone’s density measured in Hounsfield units (HU), stone’s size, and stone-to-skin distance (SSD). Results: Out of the 225 cases treated, only 175 (77.8%) became SF after or during the study timeframe. SF status was achieved after the first session in 131 cases (58.2%). The bivariate analysis of the factors associated with higher SF rates found to be statistically significant were left kidney ( p-value of < 0.01), low stone density ( p-value of < 0.01), short stone–skin distance ( p-value of < 0.01), and small stone size ( p-value of < 0.01). On the other hand, gender and stone location within the kidney showed no association with ESWL outcomes. Conclusion: Kidney laterality, SSD, stone density, and size are influencing parameters on ESWL outcomes and achievement of stone-free status.