TISU

Urinary stone disease is very common with an estimated prevalence among the general population of 2–3% (1.8 million people in the UK) and is a major burden on the NHS. Urinary tract stones, and ureteric stones, in particular, are associated with severe pain as they pass through the urinary tract and can have a significant impact on patients’ quality of life due to the detrimental effect on their ability to work and the need for hospitalisation. Between a fifth and a third of cases require an active intervention (stone removal) because of failure to pass the stone, continuing pain, infection or obstruction to urine drainage.  The two standard active intervention options are extracorporeal shockwave lithotripsy (ESWL) and ureteroscopic stone retrieval

TISU was a multicentre randomised controlled trial, funded by the NIHR HTA Programme, of ESWL as first treatment option compared with direct progression to ureteroscopic treatment for ureteric stones. The clinical and cost-effectiveness of ESWL, as the first treatment option, compared with ureteroscopic treatment was determined with respect to the primary outcomes of:

1. clinical stone clearance, defined as no further intervention required to facilitate stone passage

2. incremental cost per quality adjusted life years (QALYs) and

3. disease or treatment-related harms up to 6 months after randomisation.

Six hundred and thirteen adults (≥ 16 years old), presenting with a unilateral ureteric stone within any segment of the ureter, confirmed by computed tomography scan of the kidneys, ureters, and bladder (CTKUB), were recruited into the trial and randomised to one of the treatment options. 

In the ESWL arm, 67 out of 302 (22.2%) participants needed further treatment compared to 31 out of 302 (10.3%) participants in the ureteroscopic treatment arm.  The overall costs of for those receiving ESWL were lower than those receiving ureteroscopic treatment. The absolute risk difference between the two clinical pathways (11.4%) was lower than expected and at a level that is acceptable to clinicians and patients. The shockwave lithotripsy pathway is more cost-effective in an NHS setting, but results in lower quality of life.

The TISU trial was led by Professor Sam McClinton based at the University of Aberdeen.