Beatriz Oliveira et al., 2024: Extracorporeal shock wave lithotripsy: retrospective study on possible predictors of treatment success and revisiting the role of non-contrast-enhanced computer tomography in kidney and ureteral stone disease
Beatriz Oliveira 1 , Bernardo Teixeira 2 , Martinha Magalhães 2 , Nuno Vinagre 2 , Avelino Fraga 2 , Vítor Cavadas 2
1Unidade Local de Saúde de Santo António, Porto, Portugal.
2Unidade Local de Saúde de Santo António, Porto, Portugal.
Abstract
Extracorporeal shock wave lithotripsy (ESWL) is a safe and efficient treatment option for urinary stone disease. The overall stone-free rate (SFR) varies significantly. This study aimed to assess the influence of stone size, location, stone density, and skin-to-stone distance (SSD), on the outcome of ESWL. We assessed whether pre-treatment non-contrast-enhanced CT scan (NCCT) confers significant advantages compared to kidney-ureter-bladder film (KUB) only. We reviewed the medical records of 307 cases (165 men, 142 women) with renal and ureteral stones treated consecutively at our institution with ESWL between 2020 and 2023. 44 of these underwent a NCCT. The outcome of ESWL was defined in two ways: visible stone fragmentation on KUB, and the need for further treatment. Overall success of fragmentation was 85% (261 patients). 61% of patients (n = 184) didn't need any further treatment. Stone size and location correlated significantly with treatment outcomes regarding the need for further treatment (p = 0.004) and stone fragmentation (p = 0.016), respectively. Unlike mean SSD (p = 0.462), the mean attenuation value (MAV) significantly correlated with the need for retreatment (p = 0.016). MAV seems to be a better predictor of treatment success (AUC of the ROC curve: 0.729), compared to stone size (AUC: 0.613). The difference between groups (with and without NCCT) in both treatment outcomes did not reach statistical significance. During decision-making, information regarding SSD and MAV can be useful in more dubious scenarios. However, it appears that their inclusion doesn't provide substantial advantages when compared to relying solely on KUB.
Urolithiasis. 2024 Apr 17;52(1):65. doi: 10.1007/s00240-024-01570-7. PMID: 38630281
PMCID: PMC11024041
Comments 1
Like many other articles, this report deals with predictors of SWL success. In that regard the presented information is very similar to what already is well documented in the literature.
However, the authors should be complemented for two reasons. First that they in addition to the extensive literature review have added their own new research data. Unfortunately, too many reports today only summarize in systematic reviews what others have achieved, but without adding any significant research efforts!
It is of note that 84% of the patients were successfully managed with SWL.
The other point that needs attention is that the authors compared KUB and NCCT, with the conclusion that there was no important difference in treatment prediction or outcome when a CT had been carried out. That conclusion is not surprising because successful stone disintegration was achieved also when NCCT-examinations were not applied clinically. The latter imaging modality has been possible only during the past 20-25 years. Before that KUB was the standard procedure.
Hans-Göran Tiselius