Retrograd intrarenal cerrahi yapılan böbrek taşı hastalarında taş boyutu, yoğunluğu ve lokalizasyonunun; taşsızlık ve komplikasyon oranlarına etkisinin karşılaştırılması

Abstract

Amaç: Esnek üreteroskopi ile retrograd intrarenal cerrahi (RIRS) renal kalkül için birinci basamak tedavi olarak ortaya çıkmıştır. Bu çalışma, RIRS sonrası taş boyutu, yoğunluğu ve lokalizasyonunun taşsızlık oranları ve komplikasyonlar üzerindeki etkisini değerlendirmektedir. Yöntem: Bu retrospektif kohort çalışmasında, renal taş hastalığı nedeniyle RIRS uygulanan ardışık 124 hasta analiz edildi. Taş özellikleri, boyut, yoğunluk (Hounsfield Üniteleri - HU) ve anatomik lokalizasyon için kontrastsız bilgisayarlı tomografi ile değerlendirildi. Esnek üreteroskop ve holmiyum:YAG lazer litotripsi kullanıldı. Birincil sonlanım noktası, bir ayda >3 mm rezidü fragman yokluğu olarak tanımlanan taşsızlık durumuydu. Bulgular: Çalışma grubu ağırlıklı olarak erkekti (%59.7), ortalama yaş 48.48±13.976 yıl. Ortalama taş boyutu 13.54±3.692 mm ve yoğunluk 840.47±229.785 HU idi. Genel taşsızlık oranı %74.2 (92/124 hasta) idi. Taşsızlık oranı artan boyutla anlamlı olarak azaldı: <10 mm taşlar için %94.3, 10-20 mm taşlar için %71.8, >20 mm taşlar için %45.5 (p<0.001). Orta yoğunluktaki taşlar (500-1000 HU) yumuşak (<500 HU: %71.4) ve sert taşlara (>1000 HU: %62.1) kıyasla üstün taşsızlık oranları gösterdi (%85.1) (p=0.035). >60 dakika süren operasyonlar daha yüksek taşsızlık oranlarına sahipti (%85.7 vs. %68.5. p=0.045). Genel komplikasyon oranı %10.5 idi ve rezidü taşlar komplikasyon riskini anlamlı olarak artırdı (%21.9 vs. %6.5, p=0.015). Sonuç: RIRS böbrek taşlarında yüksek etkinlik gösterir ve sonuçlar taş özelliklerinden anlamlı şekilde etkilenir. Orta yoğunluktaki taşlarda gözlenen üstün sonuçlar, taş yoğunluğu ile fragmantasyon verimliliği arasındaki ilişkinin daha karmaşık olabileceğini düşündürmekte ve ileri araştırmalar gerektirmektedir. Taş boyutu birincil başarı belirleyicisi olarak ortaya çıkar ve hasta danışmanlığı için net eşik değerler sağlar. Bulgular kapsamlı preoperatif taş değerlendirmesine dayalı bireyselleştirilmiş tedavi yaklaşımlarını destekler.

Keywords

• Retrograd intrarenal cerrahi
• esnek üreteroskopi
• holmiyum lazer
• taş özellikleri
• taşsızlık oranı

Comparison of the effects of stone size, density and localization on stone-free and complication rates in kidney stone patients undergoing retrograde intrarenal surgery

Abstract

Aim: Flexible ureteroscopy with retrograde intrarenal surgery (RIRS) has emerged as a first-line treatment for renal calculi. This study evaluated the impact of stone size, density, and anatomical location on stone-free rates and complications after RIRS. Method: In this retrospective cohort study, 124 consecutive patients undergoing RIRS for kidney stones were analyzed. Stone characteristics—including size, density (Hounsfield Units; HU), and anatomical location—were assessed by non-contrast computed tomography. Flexible ureteroscopes and holmium: YAG laser lithotripsy were utilized. The primary endpoint was stone-free status at one month, defined as the absence of residual fragments >3 mm. Results: The study population was predominantly male (59.7%), with a mean age of 48.48±13.976 years. The mean stone size was 13.54±3.692 mm and the mean density was 840.47±229.785 HU. The overall stone-free rate was 74.2% (92/124 patients). Stone-free rate significantly decreased with increasing stone size: 94.3% for stones <10 mm, 71.8% for 10-20 mm, and 45.5% for >20 mm (p<0.001). Stones of intermediate density (500-1000 HU) demonstrated higher stone-free rates (85.1%) compared to soft (<500 HU: 71.4%) and hard stones (>1000 HU: 62.1%) (p=0.035). Procedures lasting over 60 minutes yielded higher stone-free rates (85.7% vs. 68.5%, p=0.045). The overall complication rate was 10.5%, and residual stones significantly increased the risk of complications (21.9% vs. 6.5%, p=0.015). Conclusion: RIRS is highly effective for renal stones, with outcomes significantly influenced by stone characteristics. The superior results observed in intermediate-density stones suggest a more complex relationship between stone density and fragmentation efficiency, warranting further investigation. Stone size emerges as the primary determinant of success, providing clear thresholds for patient counseling. These findings support individualized treatment approaches based on comprehensive preoperative stone assessment.

Keywords

• Retrograde intrarenal surgery
• flexible ureteroscopy
• holmium laser
• stone characteristics
• stone-free rate

References

1. Zyoud SH, Abushamma F, Shahwan M, et al. Visualizing the landscape of urolithiasis research from 1979-2023: a global bibliometric analysis of randomized clinical trials. Urolithiasis 2024;52(1):153.
2. Han S, Zhao S, Zhong R, et al. An analysis of the burden of urolithiasis: differences between the global, China, India and the United States, with projections through 2050. Urolithiasis 2025;53(1):32.
3. Wu J. Temporal trends and projections of urolithiasis in China and globally from 1990 to 2030: insights from the global burden of disease study 2021. Urolithiasis 2025;53(1):118.
4. Kamal WK, Alghamdi MM, Azhar RA, et al. The impact of urolithiasis on urology services in a high-prevalence region: A multicenter study. Asian J Urol 2025;12(1):59-65.
5. Man MY, Somani B, Pietropaolo A. Does surgical removal of kidney stones help prevent the recurrence of urinary tract infections? A systematic review. Curr Opin Urol 2026;36(1):103-111.
6. Teke K, Çınar NB, Çınar Ö, et al. "Virgin ureter" vs. "non-virgin ureter"? A comparative analysis on complications and failure of retrograde intrarenal surgery: a multicentre case-control study from RIRSearch Group. Urolithiasis 2025;53(1):83.
7. Simsekoglu MF, Özman O, Cakir H, et al. Lower Pole Stones Are Associated with Low Stone-Free Rates in Retrograde Intrarenal Surgery: A Myth or Fact? - A Matched Case-Control Study from the RIRSearch Group. Urol Int 2025;109(1):52-60.
8. Kaygısız O, Aydın YM, Çiçek MÇ, et al. The predictive factors that total laser energy consumed during retrograde intrarenal surgery (RIRS): stone area and density. Lasers Med Sci 2023;38(1):128.

9. Başaranoğlu M, Kuş O, Tek M, Akbay E. The impact of normalized energy utilization on clinical outcomes and complications in endourological stone surgery: a prospective study. Urolithiasis 2025;53(1):209.
10. Alnadhari I, Abdeljaleel O, Ali O, et al. Comparison between flexible and navigable suction ureteral access sheath and standard ureteral access sheath during flexible ureteroscopy for the management of kidney stone: systematic review and meta-analysis. BMC Urol 2025;25(1):115.
11. Hsieh TY, Chang SJ, Chueh JS, Lee YJ. The mayo adhesive probability score predicts postoperative fever and sepsis in retrograde intrarenal surgery. Urolithiasis 2024;52(1):80.
12. Noah K, Shaher H, Hamdy M, Diab T, Farag M. Comparative analysis of STONE, TOHO, and ITO stone scoring systems for predicting stone-free status following flexible ureteroscopy in patients with renal stones: a prospective study. Int Urol Nephrol 2026;58(1):15-23.
13. Soderberg L, Ergun O, Ding M, et al. Percutaneous nephrolithotomy vs retrograde intrarenal surgery for renal stones: a Cochrane Review. BJU Int 2024;133(2):132-140.
14. Tang X, Wu S, Li Z, et al. Comparison of Thulium Fiber Laser versus Holmium laser in ureteroscopic lithotripsy: a Meta-analysis and systematic review. BMC Urol 2024;24(1):44.
15. Rico L, Blas L, Ramos LB, et al. Thulium Fiber Laser versus Vapor Tunnel HO:YAG laser in retrograde intrarenal surgery: which one has better laser ablation performance? World J Urol 2025;43(1):472.
16. Ito H, Kuroda S, Kawahara T, et al. Clinical factors prolonging the operative time of flexible ureteroscopy for renal stones: a single-center analysis. Urolithiasis 2015;43(5):467-475.
17. Ito H, Fukuda T, Yamamichi F, et al. Factors influencing operative time for mini-endoscopic combined intrarenal surgery for renal stones. Sci Rep 2024;14(1):27857.
18. Gauhar V, Traxer O, Castellani D, et al. Could Use of a Flexible and Navigable Suction Ureteral Access Sheath Be a Potential Game-changer in Retrograde Intrarenal Surgery? Outcomes at 30 Days from a Large, Prospective, Multicenter, Real-world Study by the European Association of Urology Urolithiasis Section. Eur Urol Focus 2024;10(6):975-982.
19. Kayano S, Matsukawa A, Laukhtina E, et al. Impact of suction ureteral access sheath in ureteroscopy/retrograde intrarenal surgery: a systematic review and meta-analysis. Transl Androl Urol 2025;14(5):1315-1326.
20. Belkovsky M, Passerotti CC, Maia RS, et al. Comparing outcomes of single-use vs reusable ureteroscopes: a systematic review and meta analysis. Urolithiasis 2024;52(1):37.
21. Zhang F, Xu J, Liang H. Single-use flexible ureteroscope provides an alternative treatment for upper urinary calculi: A systematic review and meta-analysis. Medicine (Baltimore) 2023;102(36):e34829.
22. Gauhar V, Traxer O, Sabnis RB, et al. The reused-disposable scope in flexible ureteroscopy for stones as a cost-conscious approach: Reporting the outcomes of a real-world practice multicenter study of 2183 patients by the team of worldwide endourological researchers group. Indian J Urol 2024;40(4):235-241.
23. Lykkegaard EG, Jung H. Intrarenal Pressure During Ureteroscopy. Eur Urol Focus 2025;11(5):709-711.
24. Tokas T, Gauhar V, Yuen SKK, Somani BK. Current clinical evidence in intrarenal temperature, pressure and suction during retrograde intrarenal surgery: a review of literature. Curr Opin Urol 2025;35(4):390-398.
25. Bonzagni AF, Hall TL, Marom R, Ghani KR, Roberts WW. Ureteral Tissue Temperature During Ureteroscopy With Ho:YAG Laser Activation in an In Vivo Porcine Model. Urology 2025;200:11-17.
26. Guo Z, Wen Z, Qiu J, et al. A comparative analysis of tip-bendable suction ureteral access sheath versus traditional sheath in retrograde intrarenal stone surgery: a systematic review and meta-analysis of comparative studies. Int J Surg 2025;111(11):8493-8502.