Suction sheaths in kidney stone surgery

Written and Medically Reviewed by Mr Ivo Dukic, Consultant Urologist | Last updated: 27/02/2026

Suction in Kidney Stone Surgery

For years, surgeons have treated kidney stones in tiny "snow globe" environments: they break the kidney stones with lasers, but the resulting "dust" and debris cloud the view, making it hard to ensure every last bit is gone.

There has been a significant shift in kidney stone surgery over the last few years with the introduction of suction sheaths in both Flexible Ureteroscopy (fURS) and Percutaneous Nephrolithotomy (PCNL) procedures [1-3]. Unlike traditional rigid tubes, these sheaths allow the surgeon to break a kidney stone into tiny dust pieces with a high-power laser and then "vacuum" the stone dust directly out of the kidney [4,5].

Why Suction is a "Game-Changer"

Standard stone surgery often suffers from a "snow-globe effect," where stone dust clouds the surgeon's view. Suction sheath technology solves this problem by using active suction to deliver three major clinical benefits:

• Improve Visibility: It continuously removes blood and stone "snow" so the surgeon can see the target clearly [1,6]. Continuous suction evacuates blood, debris, and small stone fragments, facilitating the passive extraction of dust and small fragments during lithotripsy [7].

• Lower Kidney Pressure: During surgery, saline is pumped into the kidney to maintain visibility. If the pressure gets too high, it can push bacteria into the blood (pyelovenous backflow) [8,9]. A systematic review of 17 studies concluded that elevated intrarenal pressure (IRP) above 40 mmHg positively correlates with infectious complications, including pyelovenous/pyelolymphatic backflow, bacteraemia, and post-operative sepsis [10]. Suction safely regulates and lowers this pressure [5,11].

• Reduce Infection: A 2025 meta-analysis of 1,816 patients (8 studies) found that patients treated with suction sheaths had a 69% lower risk of postoperative fever compared to those using traditional sheaths, alongside a 70% reduction in overall complications [1]. A second independent meta-analysis of 2,255 patients confirmed these strong safety findings [2].

Flexible Ureteroscopy (fURS): The Vacuum Highway

The use of Flexible and Navigable Suction (FANS) access sheaths represents a paradigm shift in retrograde intrarenal surgery [1,3,12].

Clinical Outcomes and Evidence:

• Superior Stone-Free Rates (SFR): A 2025 meta-analysis of 8 studies found that patients treated with FANS were four times more likely to be completely stone-free on the first day after surgery compared to those treated with traditional sheaths. This higher SFR was successfully maintained at the 30-day follow-up [1]. These results were strongly corroborated by a second meta-analysis [2].

• Laser Technology: Thulium Fiber Laser (TFL) technology enables highly efficient dusting and achieves safe, continuous lithotripsy when paired with FANS and optimized irrigation and suction settings [6]. The AFU Lithiasis Committee notes that dusting, when supported by the "vacuum cleaner" effect of suction, is the optimal indication for laser lithotripsy in mini-PCNL [13].

• Scope Choice: Early clinical data using a 6.3 Fr single-use ureteroscope with a 10/12 Fr ClearPetra suction sheath and TFL have shown highly promising outcomes [14]. Furthermore, a multicentre EAU Endourology study confirmed that smaller FANS sheaths achieve similarly high stone-free rates without increasing complication rates [15].

Suction in Percutaneous Nephrolithotomy (PCNL)

Percutaneous Nephrolithotomy (PCNL) is typically reserved for larger or more complex stones [7,16]. The advent of suction sheaths has been particularly impactful for the miniaturized "mini-PCNL" technique.

The Pressure Problem Because the "tunnels" created in Mini-PCNL are so small, the water pressure inside the kidney can spike much faster than in traditional surgery. Ex vivo data demonstrate that mini-PCNL pressures are significantly higher than conventional PCNL across all sheath and scope combinations tested [10,17]. This inherently higher pressure in mini-PCNL—caused by smaller outflow channels around a proportionally larger nephroscope—provides the strongest clinical rationale for incorporating suction to maintain low intrapelvic pressures [7,10].

A Strong Recommendation The AUA Guideline on Surgical Management of Kidney and Ureteral Stones provides a formal "Conditional Recommendation" (Evidence Level: Grade C) stating: "When performing mini-PCNL in adult patients with kidney or proximal ureteral stones, clinicians may utilize a suction sheath, when available, to improve stone-free rates and reduce the need for secondary procedures" [7]. This is backed by a meta-analysis of 1,803 patients showing suction sheaths significantly lower operative times and the need for auxiliary procedures [7].

Tailored Safety and Better Results AUA-cited evidence shows that suction is associated with a 39% lower likelihood of requiring additional stone-removing procedures, yielding statistically significantly higher stone-free rates [7]. While mini-PCNL can sometimes take longer than standard surgery, suction sheath technology helps offset these longer operative times and mitigates the inherently higher pressure associated with miniaturized tracts, resulting in lower blood loss, fewer fevers, and shorter hospital stays [7,10].

Conclusion

Suction sheath technology represents a meaningful evolution in endoscopic stone management [1-3,7]. By enabling active fragment retrieval while maintaining stable intrarenal pressures, it directly addresses the two most persistent challenges in urology: residual fragments and infectious complications [1,2,7,10].

Mr Ivo Dukic is one of the UK's premier complex stone surgeons and top kidney stone specialists, offering world-class urological care in Birmingham. Recognised as the leading PCNL expert in the West Midlands, Mr Dukic delivers cutting-edge minimally invasive treatments, including:

• Mini-PCNL for optimal outcomes.

• Ultra-mini PCNL for reduced recovery times.

• Advanced endoscopic removal and complex renal stone surgery.

Mr Dukic combines years of specialist experience with the latest innovations, such as suction sheaths and LASER technology in both mini PCNL and flexible ureterorenoscopy, to provide superior treatment outcomes.

You can schedule an appointment with him for expert, bespoke advice through his Top Doctors profile or book an appointment through Harborne Hospital, HCA Healthcare, the Priory Hospital, Edgbaston, Circle Health Group or Droitwich Spa, Circle Health.

References

1. Gonçalves ABV, Carvalho-Neto RR, Ribeiro Júnior DR, Moraes FC, de Figueiredo GF, Costa LMP, et al. Flexible and navigable suction ureteral access sheath versus traditional ureteral access sheath in flexible ureteroscopy: a systematic review and meta-analysis. BMC Urol. 2025;25:86.

2. Carvalho-Neto RR, Gonçalves ABV, de Figueiredo GF, Costa LMP, Sit NKK, Navarro-Sanchez JC, et al. Enhanced stone-free rates with suctioning ureteral access sheath vs traditional ureteral access sheath in flexible ureteroscopy: a systematic review and meta-analysis. BMC Urol. 2025;25.

3. Gauhar V, Traxer O, Castellani D, Seitz C, Chew BH, Fong KY, 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):975-82.

4. Li H, Chen Y, et al. A comparative study of flexible and navigable suction ureteral access sheath combined with su-fURS for the treatment of kidney stones > 2.5 cm. BMC Urol. 2025;25.

5. Wu S, Xie H, et al. High stone-free rate immediately after suctioning flexible ureteroscopic lithotripsy with intelligent pressure-controlled irrigation (SFUI) in adults with renal stones. BMC Urol. 2022;22:188.

6. Ventimiglia E, Talso M, et al. Optimization of laser, irrigation and suction settings for automated laser lithotripsy in impacted ureteral stones. Sci Rep. 2026;16.

7. Ziemba JB, Moreno-Avarado RE, et al. Surgical management of kidney and ureteral stones: AUA Guideline (2026). J Urol. 2026. DOI: 10.1097/JU.0000000000004842.

8. Kottooran C, Twum-Ampofo J, Lee J, Saunders J, Franco M, Budrewicz J, et al. Evaluation of fluid absorption during flexible ureteroscopy in an in vivo porcine model. BJU Int. 2022;131(2):213-8. DOI: 10.1111/bju.15858.

9. Hong A, du Plessis J, Browne C, Jack G, Bolton D. Mechanism of urosepsis: relationship between intrarenal pressures and pyelovenous backflow. BJU Int. 2023;132(5):512-9. DOI: 10.1111/bju.16095.

10. Tokas T, Tzanaki E, Nagele U, Somani BK. Role of intrarenal pressure in modern day endourology (mini-PCNL and flexible URS): a systematic review of literature. Curr Urol Rep. 2021;22:52.

11. Castellani D, et al. Continuous intrarenal pressure monitoring during endourological procedures. Urol Int. 2025;109(6):641.

12. Ding X, et al. Utilization of flexible ureteroscopy in conjunction with FANS for treatment of complex lower calyceal stones. BMC Urol. 2025.

13. Association Française d'Urologie (AFU). 2022 Recommendations of the AFU Lithiasis Committee: Laser utilization and settings. Prog Urol. 2023;33:854-63.

14. Ventimiglia E, et al. Early clinical outcomes using a 6.3 Fr single use ureteroscope with a flexible and navigable suction ureteral access sheath and thulium fiber laser. Sci Rep. 2025;15.

15. Kwok JL, Somani B, Sarica K, Yuen SKK, Zawadzki M, Castellani D, et al. Multicenter outcome analysis of different sheath sizes for flexible and navigable suction ureteral access sheath (FANS) ureteroscopy: an EAU Endourology collaboration with the global FANS study group. Urolithiasis. 2024;52(1):162.

16. Assimos D, Krambeck A, Miller NL, Monga M, Murad MH, Nelson CP, et al. Surgical management of stones: American Urological Association/Endourological Society Guideline, Part I. J Urol. 2016;196(4):1153-60.

17. Nagele U, et al. Intrarenal pressure during PCNL: influence of sheath diameter, irrigation height and outflow conditions. Ex vivo porcine kidney model. ISU. 2.