PUrE

PUrE stands for the Percutaneous nephrolithotomy, flexible Ureterorenoscopy and Extracorporeal shockwave lithotripsy for lower pole kidney stones.

About 10% of people will have kidney stones in their lifetime and these commonly develop in the lower part (pole) of the kidney.  About half of these people will experience symptoms, typically kidney pain, and about a quarter of patients with stones will require active treatment.

Active treatments break up the stone into small fragments.  Active treatments in the NHS include shockwave therapy (called ESWL or extracorporeal shockwave lithotripsy), flexible ureteroscopic treatment (FURS, flexible ureterorenoscopy) and keyhole surgery (PCNL, Percutaneous Nephrolithotomy).

The aim of the PUrE study was to determine the clinical effectiveness and cost effectiveness of using flexible ureterorenoscopy, (FURS, flexible ureterocopic treatment) compared to shockwave therapy (ESWL) or keyhole surgery (PCNL) to treat lower pole kidney stones. 

PUrE comprised two multi centre randomised controlled trials (RCTs) funded by the NIHR HTA programme.

• PUrE RCT1 for people with smaller stones (≤ 10mm):

We compared flexible ureteroscopic stone treatment (flexible ureterorenoscopy ,(FURS)) with shockwave therapy (extracorporeal lithotripsy, (ESWL)).

• PUrE RCT2 for people with larger stones (> 10 and ≤ 25 mm):

We compared flexible ureteroscopic stone treatment (flexible ureterorenoscopy, (FURS)) with keyhole surgery (percutaneous nephrolithotomy, (PCNL)).

The primary outcome measure was health status ‘area under the curve’, measured weekly to 12 weeks after treatment using the EQ-5D. The primary economic outcome was the incremental cost per QALY up to 12 months after randomisation.

In RCT1, we recruited 461 participants from 48 UK NHS hospitals and randomised 231 to treatment with FURS and 230 to shockwave lithotripsy.

In RCT2, we recruited 159 participants from 39 UK NHS hospitals and randomised 73 to treatment with FURS and 86 to keyhole surgery.

In RCT1, we found that shockwave lithotripsy was more cost-effective than FURS treatment, with no meaningful difference in patient health status even though complete stone-free rates were higher with FURS.

In RCT2, we found keyhole surgery was marginally beneficial for health status with higher complete stone-free rate compared to treatment with FURS. Keyhole surgery was more cost-effective than FURS on a micro-costing basis.

PUrE was led by Prof Sam McClinton of Aberdeen Royal Infirmary NHS Grampian.

PuRE Statistical Analysis Plan (SAP)

Contacts

• Ruth Thomas; r.e.thomas@abdn.ac.uk
• Victoria Bell; victoria.bell@abdn.ac.uk

Status

Publications

The PUrE protocol is published in Trials 

McClinton S, Starr K, Thomas R, MacLennan G, Lam T, Hernandez R, Pickard R, Anson K, Clark T, MacLennan S, Thomas D, Smith D, Turney B, McDonald A, Cameron S, Wiseman O. (2020) The clinical and cost effectiveness of surgical interventions for stones in the lower pole of the kidney: the percutaneous nephrolithotomy, flexible ureterorenoscopy and extracorporeal shockwave lithotripsy for lower pole kidney stones randomised controlled trial (PUrE RCT) protocol. Trials, 21,479. http://doi.org/10.1186/s13063-020-04326-x

Smith, D., Wiseman, O., Starr, K., Aucott, L., Hernández, R., Thomas, R., MacLennan, S., Clark, C. T., MacLennan, G., McRae, D., Bell, V., Cotton, S., Gall, Z., Turney, B., McClinton, S. (2025). PUrE Randomised Controlled Trial 2: Clinical and Cost Effectiveness of Flexible Ureterorenoscopy and Percutaneous Nephrolithotomy for Lower-pole Stones of 10–25 mm. European Urology Focus, 11 (5), 684-694. https://doi.org/10.1016/j.euf.2025.08.010

MacLennan, S., Wiseman, O. J., Smith, D., Starr, K., Aucott, L., Hernández, R. A., Manson, P., Thomas, R., Clark, C. T., MacLennan, G., McRae, D., Bell, V., Cotton, S., Gall, Z., Turney, B., McClinton, S. (2025). Updated Systematic Review and Meta-analysis of Extracorporeal Shock Wave Lithotripsy, Flexible Ureterorenoscopy, and Percutaneous Nephrolithotomy for Lower Pole Renal Stones.European Urology, 88 (3), 231-239. https://doi.org/10.1016/j.eururo.2025.01.020.

Wiseman, O., Smith, D., Starr, K., Aucott, L., Hernández, R. Thomas, R., Maclennan, S., Clark, C. T., Maclennan, G., McRae, D., Bell, V., Cotton, S., Gall, Z., Turney, B., McClinton, S. (2025). Clinical and cost-effectiveness of percutaneous nephrolithotomy, flexible ureterorenoscopy and extracorporeal shockwave lithotripsy for lower pole stones: the PUrE RCTs. Health Technology Assessment, 29 (40). https://doi.org/10.3310/WFRE6844

Wiseman, O. J., Smith, D., Starr, K., Aucott, L., Hernández, R. A., Thomas, R., MacLennan, S., Clark, C. T., MacLennan, G., McRae, D., Bell, V., Cotton, S., Gall, Z., Turney, B., McClinton, S. (2025). The PUrE Randomised Controlled Trial (RCT) 1: Clinical and cost-effectiveness of Flexible Ureterorenoscopy and Extracorporeal Shockwave Lithotripsy for lower pole stones ≤10mm. 2025. European Urology, 88 (2),179-189. https://doi.org/10.1016/j.eururo.2025.02.002