Blood Vessel Problems After Kidney Transplantation and Balloon Treatment

Trial details

Who runs it

University of Aarhus

Trial code

NCT07531966

Record updated

16 October 2026

Original description

* To determine the incidence of arterial inflow problems and venous outflow problems as causes of impaired renal function and/or treatment-resistant hypertension after kidney transplantation, when all kidney-transplant recipients in Denmark are evaluated according to uniform, well-defined clinical criteria. * To investigate the efficacy and safety of catheter-based balloon treatment (percutaneous transluminal angioplasty, PTA) for these vascular complications, of which transplant renal artery stenosis is by far the most common. * To assess whether novel imaging and functional diagnostic methods can predict treatment response.Read full original descriptionShow less

Vascular Complications After Kidney Transplantation: A Prospective National Multicenter Study - The DAN-PTRAIII Study

* To determine the incidence of arterial inflow problems and venous outflow problems as causes of impaired renal function and/or treatment-resistant hypertension after kidney transplantation, when all kidney-transplant recipients in Denmark are evaluated according to uniform, well-defined clinical criteria. * To investigate the efficacy and safety of catheter-based balloon treatment (percutaneous transluminal angioplasty, PTA) for these vascular complications, of which transplant renal artery stenosis is by far the most common. * To assess whether novel imaging and functional diagnostic methods can predict treatment response.

Inclusion: At least one of the following clinical criteria (1 or 2) must be fulfilled:; Graft dysfunction, defined by at least one of the following:; Acute reduction in estimated glomerular filtration rate (eGFR) >15% on two consecutive measurements at least 2 weeks apart, with other causes excluded (rejection, obstruction, infection); eGFR <50% of the expected value 30 days after kidney transplantation of unknown cause; Decline in eGFR >30% after initiation of an angiotensin-converting enzyme inhibitor or angiotensin II receptor blocker; Persistent resistant hypertension for more than 6 weeks after kidney transplantation, defined as:; 24-hour ambulatory systolic blood pressure >130 mmHg despite treatment with at least three classes of antihypertensive medication at maximally tolerated doses (including diuretics, if tolerated); Together with at least one of the following radiological criteria:; CT or MR angiography demonstrating a lumen reduction ≥50%; Doppler ultrasound showing:; Peak systolic velocity in the renal artery ≥200 cm/s and a renal-renal ratio (velocity at stenosis / velocity in distal artery) >4; Acceleration time >70 ms in intrarenal arteries; In cases of strong clinical suspicion of a vascular complication where CT or MR angiography cannot reliably exclude graft artery or vein stenosis, patients may be referred for confirmatory invasive investigations; Before PTA, catheter-based angiography and translesional pressure measurements are performed to confirm whether the patient meets the radiological eligibility criterion for PTA:; Stenosis ≥70%; Stenosis 50-69% if at least one of the following criteria is met:; Mean translesional pressure gradient ≥10 mmHg; Systolic pressure gradient ≥20 mmHg; Renal Pd/Pa ≤0.8; If pressure measurements cannot be obtained, treatment is based on the operator's clinical judgement.

Exclusion: Concurrent biopsy demonstrating rejection requiring treatment; Previous PTA of the same vessel; Patients unable to tolerate any form of antithrombotic therapy and therefore not eligible for stent placement; Inability to provide informed consent; Pregnancy.

ClinicalTrials.gov NCT07531966