Danilovic A. et al., 2020: Residual stone fragments after percutaneous nephrolithotomy: shockwave lithotripsy vs. retrograde intrarenal surgery
Danilovic A, Torricelli F, Marchini GS, Batagello C, Vicentini FC, Traxer O, Srougi M, Nahas WC, Mazzucchi E.
Department of Urology, Hospital das Clinicas, University of Sao Paulo Medical School, Sao Paulo, Brazil.
Sorbonne Université, GRC n 20 Lithiase Renale, AP-HP, Hôpital Tenon, Paris, France.
Abstract
Background: Despite technology incorporation to percutaneous nephrolithotomy (PCNL), residual stone fragments (RSF) may still persist after PCNL and need to be addressed to avoid re-growth or ureteral obstruction. The objective of this study was to compare the outcomes of retrograde intrarenal surgery (RIRS) to shock wave lithotripsy (SWL) for treating patients with residual stone fragments after a previous standard PCNL.
Material and methods: Adult patients with RSF after a standard PCNL submitted to RIRS or SWL in our Institution from January 2017 to January 2020 were retrospectively studied. Stone-free rate (SFR) was evaluated on POD 90 by non-contrast computerized tomography (NCCT) or ultrasound and kidney-bladder-ureter radiography (KUB) for each renal unit. Surgical complications based on Clavien-Dindo classification during the 90 days of follow-up were recorded. Sample size was calculated for a power of 80% and a significance level of 0.05, assuming SFR of 20% for SWL and 50% for RIRS.
Results: Thirty-three patients treated by SWL were compared to 36 patients treated by RIRS. Hospitalization time was longer in the RIRS group (4.18h vs. 12.33h, p=0.001). SFR and success rate were lower in SWL than RIRS group (24.2% vs. 58.3%, p=0.007 and 30.3% vs. 72.2%, p=0.004, respectively), using POD 90 NCCT in 81.8% and ultrasound and KUB in 18.2% of the SWL group and using POD 90 NCCT in 100% of the RIRS group. Minor complications (Clavien-Dindo < III) occurred in 11/36 (30.6%) patients submitted to RIRS and in 2/33 (6.1%) patients submitted to SWL group (p=0.025). Two patients (6.1%) of the SWL group had Clavien-Dindo IIIb complication due to steinstrasse and were submitted to ureteroscopy. Emergency room visits were similar between groups (6.1% vs. 8.3%, p=1.0).
Conclusions: RIRS has better SFR, higher minor complications and lower major complications than SWL for the treatment of RSF after standard PCNL.
J Endourol. 2020 Oct 23. doi: 10.1089/end.2020.0868. Online ahead of print. PMID: 33096975
Comments 1
In study a comparison was carried out between SWL and RIRS for removal of residual fragments after PCNL.
Stones measured 5-15 mm and the study was made retrospectively without randomisation.
Of the 115 patients that initially were identified, 60 had been treated with SWL and 55 with RIRS, but only 69 patients met the inclusion criteria.
SWL was in all patients completed with general anaesthesia! Shockwaves were administered at 1.5Hz with energy levels up to 18kV. It is not mentioned how many of these patients that were monitored by ultrasound and no further details of SWL are given.
Hans-Göran Tiselius