Vascular Complications After Kidney Transplantation

Inclusion Criteria20

• \. 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:
• -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.