Kruck S et al, 2012: Minimally invasive percutaneous nephrolithotomy: an alternative to retrograde intrarenal surgery and shockwave lithotripsy
Kruck S, Anastasiadis AG, Herrmann TR, Walcher U, Abdelhafez MF, Nicklas AP, Hölzle L, Schilling D, Bedke J, Stenzl A, Nagele U.
Department of Urology, University of Tuebingen, Tübingen, Germany.
Abstract
PURPOSE: There is a lack of studies comparing shock wave lithotripsy (SWL), retrograde intrarenal surgery (RIRS) and minimally invasive percutaneous nephrolithotomy (MIP) in renal stone treatment. This study compared treatment outcome, stone-free rate (SFR) and stone-free survival (SFS) with regard to stone size and localization.
METHODS: This analysis included 482 first-time-treated patients in the period 2001–2007. Detailed clinical information, stone analysis and metabolic evaluation were evaluated retrospectively. Outcome, SFR and SFS were analyzed with regard to size (\1 vs. C1 cm) and localization (lower vs. non-lower pole).
RESULTS: Higher SFRs in lower and non-lower pole stones C1 cm were confirmed for RIRS and MIP (p\0.0001). A regression model confirmed a higher risk of non-lower pole stone persistence for SWL versus RIRS (OR: 2.27, p = 0.034, SWL vs. MIP (OR: 3.23, p = 0.009) and larger stone burden C1 versus\1 cm (OR: 2.43, p = 0.006). In accordance, a higher risk of residual stones was found in the lower pole for SWL versus RIRS (OR: 2.67, p = 0.009), SWL versus MIP (OR: 4.75, p\0.0001) and stones C1 cm versus \1 cm (OR: 3.02, p = 0.0006). In RIRS and MIP patients, more complications, stenting, prolonged disability, need/duration of hospitalization and analgesia were noticed (p\0.05). Overall SFS increased from SWL, RIRS, to MIP (p\0.001). SWL showed lower SFS for non-lower pole (p = 0.006) and lower pole stones (p = 0.007).
CONCLUSIONS: RIRS and MIP were shown to have higher stone-free rates and SFS compared to SWL. The price for better outcome was higher, considering tolerable complication rates. Despite larger preoperative stone burden, MIP achieved high and long-term treatment success.
World J Urol. 2012 Oct 11. [Epub ahead of print]
PMID: 23064981 [PubMed - as supplied by publisher]
Comments 1
That stone-free rates following SWL were lower than those obtained following MIP and RIRS, was an expected finding. These results are in agreement with other reports. The only exception was a better outcome of RIRS compared with SWL than that found in some other reports. The differences in stone-free rates were most obvious for stones with a diameter ≥ 10 mm in the lower calyx. Also this outcome was expected. For smaller stones and for stones in other parts of the kidney there were no significant differences. All these observations were recorded after one treatment session and a different and better SWL-result might have been obtained if more than ones SWL session had been carried out.
There are, however, two other features in this article that need attention. The first notation is that there was a higher risk of complications associated with the invasive procedures: 8% and 12%, respectively for RIRS and MIP compared with 5% for SWL. Although this problem is well recognized, two of the complications following invasive treatment were of Clavien grade III!
The stone-free survival would have been of definite interest, but, unfortunately, the authors defined the survival as the time to repeated intervention or ≥ 7 mm growth of residuals. A significantly higher incidence of recurrent stone formation was then seen in patients treated with SWL (following one session). Unfortunately the authors provide no information on how the recurrence prevention affected the outcome. It seems as if the earlier signs of recurrence after SWL can be explained by insufficient initial treatment of that group? If not, why did the SWL treated patients had earlier signs of recurrence? As I can see there was no specific follow-up of patients rendered completely stone-free after the procedures. Neither is it clear what the authors mean by excluding "patients with high risk of stone recurrence".
Prospective studies on the course of stone disease in patients with or without residuals in the kidney and its relation to the stone composition are highly important and desirable in future reports of this kind.
Hans-Göran Tiselius