Is extracorporeal shockwave lithotripsy (SWL) still suitable for >1.5 cm intrarenal stones? Data analysis of 1902 SWLs

Abstract

Purpose

According to the American Urological Association and European Association of Urology guidelines, shockwave lithotripsy (SWL) is the least-invasive treatment option for kidney stones smaller than 2 cm. However, it is well known that SWL stone-free rates (SFR) decline as stone size increases. We sought to evaluate whether the size limit of 1.5 cm could be a better predictor of success after a single SWL session than current recommendations.

Methods

Data from an SWL-dedicated center were prospectively scrutinized according to stone locations and sizes. Information on patients’ demography, lithotripsy parameters, and outcomes was evaluated by multivariate analysis among 1902 SWLs.

Results

The overall SFR was 70.8% (1347/1902). SFRs according to stone size were <1 cm: 73.8% (825/1118), 1–1.5 cm: 70.4% (401/569) and >1.5 cm: 56.2% (121/215); and according to calculi location were lower pole (LP) 64.4% (398/618), mid pole 73.8% (339/459), upper pole 73.8% (273/370) and renal pelvis 74.1% (337/455). Multivariate analysis revealed better SFR independent better SFR in <1.5 cm (p < 0.01), and non-LP stones (p < 0.01).

Conclusion

SWL is an effective treatment modality for kidney stones. The single session reached up to 74.8% SFRs (range 70.8%–74.8%) when indicated for intrarenal non LP stones smaller than 1.5 cm. Patients with stones >1.5 cm or >1 cm located in the LP should be counseled on the lower SFRs after a single SWL session.

Keywords:

• SWL
• kidney stones
• minimally invasive treatment
• lithotripsy
• shockwave lithotripsy
• urolithiasis
• endourology

Acknowledgments

To the involved institution(s), the patients, and those that provided and cared for study patients.

Ethical approval

Research involving Human Participants: The authors certify that the study was performed under the ethical standards as laid down in the 1964 Declaration of Helsinki and its later amendments or comparable ethical standards.

Author contributions

All authors have made a substantial contribution to the information or material submitted for publication. All authors have read and approved the final manuscript. No author has direct or indirect commercial or financial incentives associated with the publishing of this manuscript. There was no extra-institutional funding for this project. The manuscript, or portions thereof, is not under consideration for publication by any other journal or electronic publication and has not been published previously.

Disclosure statement

No potential conflict of interest was reported by the author(s).