LETTER TO EDITOR
|Year : 2021 | Volume
| Issue : 1 | Page : 102-103
Author reply Re: Guler Y, Erbin A. Comparison of extracorporeal shockwave lithotripsy and retrograde intrarenal surgery in the treatment of renal pelvic and proximal ureteral stones ≤2 cm in children. Indian J Urol 2020;36:282-7
Yavuz Guler1, Akif Erbin2
1 Department of Urology, Private Safa Hospital, Istanbul, Turkey
2 Department of Urology, Haseki Training and Research Hospital, Istanbul, Turkey
|Date of Submission||19-Oct-2020|
|Date of Acceptance||20-Nov-2020|
|Date of Web Publication||1-Jan-2021|
Department of Urology, Haseki Training and Research Hospital, Istanbul
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Guler Y, Erbin A. Author reply Re: Guler Y, Erbin A. Comparison of extracorporeal shockwave lithotripsy and retrograde intrarenal surgery in the treatment of renal pelvic and proximal ureteral stones ≤2 cm in children. Indian J Urol 2020;36:282-7. Indian J Urol 2021;37:102-3
|How to cite this URL:|
Guler Y, Erbin A. Author reply Re: Guler Y, Erbin A. Comparison of extracorporeal shockwave lithotripsy and retrograde intrarenal surgery in the treatment of renal pelvic and proximal ureteral stones ≤2 cm in children. Indian J Urol 2020;36:282-7. Indian J Urol [serial online] 2021 [cited 2022 Jun 26];37:102-3. Available from: https://www.indianjurol.com/text.asp?2021/37/1/102/306054
We would like to thank the readers for their interest in our paper and for taking the time to express their concerns. In their letter, they state that the difference in family preference and the number of stones between the groups reduced the strength of the study as this resulted in more sessions in the retrograde intrarenal surgery – RIRS patients. Second, they ask that although the stone was completely fragmented in RIRS, why 3–4 sessions were needed in all patients. Third, they ask whether the procedural time specified in RIRS (43.5 ± 12 min) included only one session. Fourth, they asked how the cutoff values of 16 mm and 11.5 mm were reached. Fifth, they stated that the infundibular width had no impact on stone clearance rate and infundibulopelvic angle cutoff was established as 40° in the study cited by us. Finally, they stated that it could be a reasonable first-line treatment for impacted upper ureteral stones <2 cm in a study cited in our article.
Our study was a retrospective analysis, and family preference was a factor in the selection of the procedure. We agree with the authors that it would be more valuable if the study were randomized in nature. In our study, the mean procedural time was 43.5 ± 12 min and the mean anesthesia number was 3.09 ± 0.3 (3–4) for the RIRS group. The mean procedural time and mean anesthesia sessions included preoperative stenting, RIRS, and postoperative stent removal times and numbers. Therefore, the main factor that increased the number of sessions was not the multiplicity of the stones, but taking prestenting and stent removal into account as anesthesia sessions. Two sessions of RIRS were performed for only 8.7% of the patients. These patients were accepted as four sessions (two; RIRS, one: for placement of stent , and one; stent removal). One session of RIRS was performed in 91.2% of the patients. Similarly, these were counted as three procedures. Two (presenting and stent removal) of these 3–4 procedures were very short procedures, so the mean procedure time was not affected much. In addition, our clinic is a tertiary stone center. Many complicated stone cases are referred to our clinic. This accumulated experience was another factor in the short operation times.
On binary logistic regression analysis, receiver operating characteristic analysis was performed for “stone size,” which is the predictive factor in treatment success, and the result was given as area under the curve (AUC) and 95% confidence interval. The cutoff point for the “stone size” variable, which was found to be significant in terms of AUC, was calculated according to the Youden index.
For both adults and pediatric patients, steep infundibular-pelvic angle, long calyx, and narrow infundibulum are factors that adversely affect the clearance rates during treatment of lower pole stones with extracorporeal shockwave lithotripsy (SWL). A narrow infundibular width will make it difficult for fragments to pass.
We stated that SWL was less successful for impacted stones in the upper ureter probably due to the associated edema-polyposis burying the stone in the ureteric wall In the study mentioned in our article, Ghoneim et al. reported an overall SFR of 88.3% (<1 cm; 95.7% and >1 cm; 83.8%). This figure can be considered low despite the multiple-session treatment in 71.7% of patients. Stone size greater than 1 cm and impaction of the stone are thought to influence the success of fragmentation during SWL. Impacted ureteral calculi can be more difficult to fragment with SWL because of the lack of natural expansion space for stones. It is a controversial issue to apply SWL as the first choice for impacted ureteral stones between 1 and 2 cm. To clarify this, randomized controlled studies with high patient volume are needed.
| References|| |
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Ghoneim IA, El-Ghoneimy MN, El-Naggar AE, Hammoud KM, El-Gammal MY, Morsi AA. Extracorporeal shock wave lithotripsy in impacted upper ureteral stones: A prospective randomized comparison between stented and non-stented techniques. Urology 2010;75:45-50.
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