Urology Annals

: 2016  |  Volume : 8  |  Issue : 3  |  Page : 400--401

RE: Semi-rigid ureteroscopy – Proximal versus distal ureteral stone

Mohd Nazli Kamarulzaman 
 Department of Surgery, Urology Unit, Kulliyyah (Faculty) of Medicine, International Islamic University ,25100 Kuantan, Pahang, Malaysia

Correspondence Address:
Mohd Nazli Kamarulzaman
Department of Surgery, Urology Unit, Kulliyyah (Faculty) of Medicine, International Islamic University Malaysia, 25100 Kuantan, Pahang

How to cite this article:
Kamarulzaman MN. RE: Semi-rigid ureteroscopy – Proximal versus distal ureteral stone.Urol Ann 2016;8:400-401

How to cite this URL:
Kamarulzaman MN. RE: Semi-rigid ureteroscopy – Proximal versus distal ureteral stone. Urol Ann [serial online] 2016 [cited 2022 Jan 28 ];8:400-401
Available from: https://www.urologyannals.com/text.asp?2016/8/3/400/184903

Full Text


I read with great interest the article “Semi-rigid ureteroscopy: Proximal versus distal ureteral stone” by Alameddine et al.[1] This article highlights important findings regarding common endourology procedure which is ureteroscopy. Since development of semi-rigid ureteroscope, various studies had been done to evaluate the safety and efficacy of ureteroscopy. In this study, the authors found that stone-free rate was comparable between proximal (89%) and distal (98.2%) ureteric stone with insignificant difference in complication rate.

This study was retrospective in nature which had some limitations. The limitation found in this study was the selection of ureteroscope size. The authors stated that the ureteroscope size used ranged between 8 and 11 French.[1] These ranges were including almost all sizes of available ureteroscopes. Whereas, in other study by Molina Escudero et al., the ureteroscope size used was only 7 French.[2] These created a bias in this study. Without precise selection of the ureteroscope size, the author concluded that the use of smaller caliber semi-rigid ureteroscopy combined with holmium-yttrium-aluminum-garnet laser for proximal ureteral calculi is safe.[1] In my opinion, the conclusion made by the authors was not proved by this study.

Upon detailed review of this paper, I found conflicting results between published result in [Table 1] and conclusion made by the authors. In [Table 1], the number of patients was 103 in Group I and 88 in Group II. Whereas the documented complication was 69 patients (67%) in Group I and 67 patients (76%) in Group II.[1] However, the authors mentioned that only a total of 8 intraoperative and postoperative complications occurred (5.8%). Further elaboration is required to avoid confusion, thus not created any doubt for the readers.{Table 1}

Besides that, in the same table, the authors had published the number of patients who had stone clearance was 64 patients and 57 patients in Group I and Group II, respectively.[1] Together with the “no success” cases, the total number of patients who undergone the procedure was only 129 patients. Whereas in result section, the authors clearly documented that the total number of patients was 191 patients. These give another doubt to me because the published stone-free rate in discussion section were 89% for Group I and 98.2% for Group II.[1] If we use the figures from [Table 1], the stone clearance rate was only 62.1% in Group I and 64.8% for Group II which was remarkably low compared to other available international data. In most of other studies, there was clear elaboration regarding number of patients and number of procedures done. As an example, Zargar-Shoshtari et al. had published data regarding 285 patients with 499 ureteroscopy procedures.[3] These clearly showed that majority of their patients had bilateral ureteroscopy. In view of this, any possible conflicting results should be discussed in detailed by the authors.

In my opinion, this paper had very interesting results. However, the presentation was not straight forward which can confuse the readers.

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Conflicts of interest

There are no conflicts of interest.


1Alameddine M, Azab MM, Nassir AA. Semi-rigid ureteroscopy: Proximal versus distal ureteral stones. Urol Ann 2016;8:84-6.
2Molina Escudero R, Gonzalez Avila N, Alvarez Ardura M, Egui Rojo MA, Ripalda Ferretti E, Crespo Martinez L, et al. Predictors of success and hospitalization in semi-rigid ureteroscopy for lithiasis as an outpatient procedure. Arch Esp Urol 2013;66:865-72.
3Zargar-Shoshtari K, Anderson W, Rice M. Role of emergency ureteroscopy in the management of ureteric stones: Analysis of 394 cases. BJU Int 2015;115:946-50.