Chung DY et al., 2019: Comparison of stone-free rates following shock wave lithotripsy, percutaneous nephrolithotomy, and retrograde intrarenal surgery for treatment of renal stones: A systematic review and network meta-analysis
Chung DY, Kang DH, Cho KS, Jeong WS, Jung HD, Kwon JK, Lee SH, Lee JY.Department of Urology, Severance Hospital, Urological Science Institute, Yonsei University College of Medicine, department of Urology, Inha University School of Medicine, Gangnam Severance Hospital, Urological Science Institute, Yonsei University College of Medicine, Kwangju Christian Hospital, Gwangju, Yongin Severance Hospital, Yonsei University Health System, Severance Check-Up, Yonsei University Health System, Department of Nursing Science, Gachon University College of Nursing, Korea.
Abstract
OBJECTIVES: To perform a systematic review and network meta-analysis comparing stone-free rates following retrograde intrarenal surgery (RIRS), extracorporeal shock wave lithotripsy (SWL), and percutaneous nephrolithotomy (PCNL) treatments of renal stones. MATERIALS AND METHODS: Clinical trials comparing RIRS, SWL, and PCNL for treatment of renal stones were identified from electronic databases. Stone-free rates for the procedures were compared by qualitative and quantitative syntheses (meta-analyses). Outcome variables are shown as risk ratios (ORs) with 95% credible intervals (CIs). RESULTS: A total of 35 studies were included in this network meta-analysis of success and stone-free rates following three different treatments of renal stones. Six studies compared PCNL versus SWL, ten studies compared PCNL versus RIRS, fourteen studies compared RIRS versus SWL, and five studies compared PCNL, SWL, and RIRS. The quality scores within subscales were relatively low-risk. Network meta-analyses indicated that stone-free rates of RIRS (OR 0.38; 95% CI 0.22-0.64) and SWL (OR 0.12; 95% CI 0.067-0.19) were lower than that of PCNL. In addition, stone-free rate of SWL was lower than that of RIRS (OR 0.31; 95% CI 0.20-0.47). Stone free rate of PCNL was also superior to RIRS in subgroup analyses including ≥ 2 cm stone (OR 4.680; 95% CI 2.873-8.106), lower pole stone (OR 1.984; 95% CI 1.043-2.849), and randomized studies (OR 2.219; 95% CI 1.348-4.009). In rank-probability test, PCNL was ranked as No. 1 and SWL was ranked as No. 3. CONCLUSIONS: PCNL showed the highest success and stone-free rate in the surgical treatment of renal stones. In contrast, SWL had the lowest success and stone-free rate.
PLoS One. 2019 Feb 21;14(2):e0211316. doi: 10.1371/journal.pone.0211316. eCollection 2019. FREE ARTICLE
Comments 1
The outcome of this meta-analysis of treatment results in terms of stone-free rates reported in the literature after PCNL, RIRS and SWL is in accordance with the expectations based on what has been published over the years. The current extensive study summarizes data from comparative retrospective and randomized studies up to 2016 and includes a total of 1205 patients treated with PCNL, 1281 patients treated with RIRS and 2342 patients treated with SWL.

Following demonstration of the fact that stone-free rates were highest with PCNL and lowest with SWL, the authors conclude that selection of the most appropriate treatment for an individual patient is a delicate matter given the advantages and disadvantages of the three treatment modalities.
In the Table below, that can be useful as a reference, I have extracted the mean and range of stone-free rates reported with PCNL, RIRS and SWL and extracted from the different studies. It is of note that despite the therapeutic achievements there is a considerable variation of treatment results recorded for the three methods. In the different studies patients have stones in different parts of the kidney. Stone-free rates were not expressed in the same way or not at all stated. Some authors included residual fragments up to 4 mm and the final examination was carried out at different times after the procedure.
Moreover, it is important to keep in mind that all studies referred to in this report were obtained from comparative studies in which the operator expertise at least for PCNL and RIRS can be expected to be at the top level. How successful theses methods were or are in the everyday urological practice is unknown, but it can be assumed that the overall variation in both endourological and SWL procedures is much more pronounced than what can be read out in this report. The outcome of SWL in several centers is hampered by the erroneous assumption that little expertise is required and that the basic prerequisite for success only is a competent lithotripter.
Nevertheless, the lower stone-free rates obtained with SWL have to be considered in view of the obvious advantages of this method and the disadvantages of invasive procedures, together with a reasonable judgment of how residuals will affect the further course of the disease.