Clinical trial NCT05046496: Transplant Renal Artery Stenosis: Observation Versus Stenting
Official title: Transplant Renal Artery Stenosis: Observation Versus Stenting - a Feasibility Study
Study type: INTERVENTIONAL
Overall status: RECRUITING
Phase: NA
Conditions: Transplant Renal Artery Stenosis
Keywords: Kidney transplant
Transplant renal artery stenosis
Lead sponsor: Imperial College Healthcare NHS Trust
Sponsor class: OTHER
First posted: 2021-09-16
Enrollment: 36
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: TREATMENT

Brief summary: Transplant renal artery stenosis (TRAS) is abnormal narrowing of the main blood vessel to the kidney transplant and has historically been considered a surgical complication. In heart transplantation, it has long been recognised that rejection can cause narrowing of the heart's blood vessels, and that this complication is the leading cause of heart transplant failure. It is reasonable to assume that this process may also occur in kidney transplantation, which could contribute to premature transplant failure. However, in kidney transplantation it is also likely that other factors, such as surgical factors, traditional cardiovascular risk factors and immunological factors, contribute to the development of TRAS. Given that the disease processes that cause TRAS are not fully understood, at present there is no consensus among kidney doctors on the best means of treating patients diagnosed with TRAS. The aim of the proposed study is to investigate the involvement of these different processes in the development of TRAS, and investigate the optimal way to diagnose and manage TRAS.

At present, there is no standard recommendation for how to treat patients with TRAS. This is partly due to the fact that patients with TRAS may have a broad array of symptoms: Some may have no symptoms, other may have problems with high blood pressure or fluid accumulation, and others may have severe transplant dysfunction. In most transplant centres, patient TRAS and severe symptoms will undergo IADSA and a stent will be placed to open the narrowing. However, it is not clear how best to manage patients with TRAS who have mild to moderate symptoms. We propose to recruit 36 such patients to a clinical study and split them into two groups: One group to undergo IADSA with possible stent placement, and one group to be closely observed. We will then compare transplant function, and other outcomes, after one year between the two groups.

Detailed description: Transplant renal artery stenosis (TRAS) is abnormal narrowing of the main blood vessel to the kidney transplant and has historically been considered a surgical complication. In heart transplantation, it has long been recognised that rejection can cause narrowing of the heart's blood vessels, and that this complication is the leading cause of heart transplant failure. It is reasonable to assume that this process may also occur in kidney transplantation, which could contribute to premature transplant failure. However, in kidney transplantation it is also likely that other factors, such as surgical factors, traditional cardiovascular risk factors and immunological factors, contribute to the development of TRAS. Given that the disease processes that cause TRAS are not fully understood, at present there is no consensus among kidney doctors on the best means of treating patients diagnosed with TRAS. The aim of the proposed study is to investigate the involvement of these different processes in the development of TRAS, and investigate the optimal way to diagnose and manage TRAS.

At present, there is no standard recommendation for how to treat patients with TRAS. This is partly due to the fact that patients with TRAS may have a broad array of symptoms: Some may have no symptoms, other may have problems with high blood pressure or fluid accumulation, and others may have severe transplant dysfunction. In most transplant centres, patient TRAS and severe symptoms will undergo IADSA and a stent will be placed to open the narrowing. However, it is not clear how best to manage patients with TRAS who have mild to moderate symptoms. We propose to recruit 36 such patients to a clinical study and split them into two groups: One group to undergo IADSA with possible stent placement, and one group to be closely observed. We will then compare transplant function, and other outcomes, after one year between the two groups.

Eligibility criteria: Inclusion Criteria:

- 1. Renal transplant recipient with a diagnosis of TRAS by radiological imaging, and an MDT decision to proceed with diagnostic IADSA.

2. Aged 18 years and over 3. Able to give informed consent

Exclusion Criteria:

- 1. Estimated GFR \<10mls/min/1.73m2 or dialysis dependence 2. Contraindication to angiography (e.g. allergy to radiological contrast) 3. Patients with clinical features of severe TRAS (eg. resistant hypertension, pulmonary oedema and/or rapidly deteriorating function).

4. Any condition or co-morbidity which in the investigator's opinion would make the patient ineligible for the trial or unlikely to adhere to trial procedures.

Primary outcomes:
measure: Change in eGFR between both arms
timeFrame: 1 year
Secondary outcomes:
measure: Change in estimated glomerular filtration rate (eGFR)
timeFrame: at baseline, then 1, 3, 6 and 12-months following diagnosis
measure: Change in mean arterial blood pressure (BP), systolic BP and diastolic BP
timeFrame: at baseline, then 1, 3, 6 and 12-months following diagnosis
measure: Average number of anti-hypertensive medications
timeFrame: at baseline, then 1, 3, 6 and 12-months following diagnosis
measure: Urinary protein : creatinine ratio (UPCR) measurement
timeFrame: at baseline, then 1, 3, 6 and 12-months following diagnosis
measure: Donor-specific antibody (DSA) free survival
timeFrame: 1 year
measure: Rejection free survival
timeFrame: 1 year
measure: Renal allograft failure
timeFrame: 1 year
measure: Patient survival
timeFrame: 1 year
measure: Requirement for intervention (primary angiogram in observational group, secondary angiogram in interventional group)
timeFrame: 1 year
Other outcomes:
measure: Adverse event reporting
timeFrame: 1 year
Locations:
city: London
country: United Kingdom
facility: Imperial College Healthcare NHS Trust
state: England
Study officials:
affiliation: Imperial College London
name: Michelle Willicombe
role: PRINCIPAL_INVESTIGATOR
References: