Defying the Clock: Restoring Renal Function After 72 Hours of Subacute Renal Thrombosis.

Introduction: Acute renal artery occlusion, especially of thrombotic origin, is rare and often challenging to diagnose. Although early revascularisation is generally recommended, the optimal timing of intervention, especially beyond six hours, remains uncertain. Report: A 51 year old man, an active smoker, with a history of ST elevation myocardial infarction and previous triple coronary artery bypass grafting, hypertension, and dyslipidaemia, developed subacute renal artery thrombosis. He presented to the emergency department, with non-specific symptoms, >72 hours after symptom onset. Computed tomography angiography confirmed right renal artery occlusion with preserved distal arterial patency and contrast enhancement of the renal parenchyma, except in the lower third of the kidney. Endovascular revascularisation was performed with primary placement of a covered stent (Advanta 5×22 mm), resulting in improved estimated glomerular filtration rate (eGFR) from 30 to 77 mL/min/1.73 m2. At the six month follow up, there were no recurrent symptoms, and laboratory results showed eGFR >90 mL/min/1.73 m2. Discussion: A thrombotic aetiology was presumed, based on the patient's cardiovascular history, smoking status, atherosclerotic changes in the renal arteries, and absence of dysrhythmias. While standard practice favours revascularisation within six hours, this case supports that delayed intervention may still be effective in thrombotic occlusions. This aligns with emerging evidence from fenestrated endovascular aortic repair related renal artery thrombosis, which shows favourable outcomes despite delayed treatment. Clinical decisions should therefore consider factors such as preserved renal parenchyma perfusion and distal arterial patency. Timing of revascularisation should be individualised, rather than strictly time dependent.