Successful weaning from hemodialysis by percutaneous transluminal renal angioplasty in a patient with a solitary kidney and acute kidney injury caused by renal artery occlusion.

There is no clear consensus on the indication for percutaneous transluminal renal angioplasty (PTRA) in cases of acute kidney injury caused by renal artery stenosis or occlusion in patients with a solitary kidney. A 79-year-old man with a solitary kidney presented with right back pain and anuria and was admitted to our hospital with a diagnosis of acute kidney injury. Because of progressive renal impairment and worsening fluid overload, hemodialysis was initiated the day after admission. Magnetic resonance angiography and ultrasonography indicated severe stenosis at the right renal artery ostium, and renal scintigraphy showed markedly reduced blood flow to the right kidney. Although the outcome was uncertain, PTRA was performed on day 8 because renal viability was suspected. Abdominal aortography revealed occlusion at the origin of the right renal artery, and a bare-metal stent was placed to restore blood flow. Following PTRA, renal function gradually improved, and the patient was successfully weaned from hemodialysis 1 week later. This case demonstrates that assessing renal blood flow with multimodality imaging and performing reperfusion therapy can be effective, even when there is a delay in treatment following the onset of renal ischemia. Learning objective: Early revascularization is typically recommended for acute renal ischemia due to renal artery stenosis or occlusion in patients with a solitary kidney because delayed intervention may lead to irreversible renal function loss. However, the present case highlights that even when revascularization is delayed, renal viability can be assessed using multimodality imaging to evaluate blood flow, and revascularization may restore renal function in select cases.