STONE (STent Or NEphrostomy) study

Introduction & Objectives: Urolithiasis is a common disease with an increasing prevalence globally. As stones may impair urine-efflux from the kidney, they have the potential to result in a renal colic, renal impairment and infection with possible sepsis. These symptoms may be reason to take measures to ensure urinary passage. Since direct stone removal is not always an option, acute interventions such as a Percutaneous Nephrostomy (PCN) or a double J catheter (JJ), are widely applied. Globally, guidelines with regards to the choice between these two methods of treatment do not provide clearly defined statements. However, all guidelines underline the lack of evidence on this matter. As a consequence urologists might form personal preference as illustrated by an apparent practice variation. To establish an evidence based guideline prospective trials are needed. Therefore, the objective of this study is to investigate if a JJ is non-inferior to a PCN in patients with obstructive urolithiasis with regards to effectiveness, patient reported outcomes and cost. Materials & Methods: In this RCT we include and randomize patients for either PCN or JJ when the indication for drainage is set. After the procedure a daily bloodwork is drawn. Questionnaires are filled in up to 3 months after intervention (figure 1). The patient is deemed to be clinically recovered (primary outcome) from: - Infection if white blood cells decrease, are < 15.000 mm3 and the body temperature is 36-38.5 °C and/or - A renal colic if the numeric rating score is improved and < 3 points and/or - Renal impairment if creatinine/GFR is improved A sample size of 204 is needed to achieve 80% power to detect non-inferiority. Ethical Committee approval for this study has been obtained in January 2020. Results: This trial started on the 15th of June 2020. Since, 9 hospitals in the Netherlands have started their inclusion period and have included 26 participants. As there is a delay in inclusions, which to some degree could be explained by the COVID pandemic, currently more hospitals are targeted to participate. Conclusions: There is an urgent need for evidence based guidelines when it comes to choice of method of drainage in patients with obstructive urolithiasis. By means of the STONE (STent Or NEphrostomy) study we try to establish non-inferiority of JJ to PCN with regards to effectiveness, patient reported outcome measures and cost.