A Case of Renal Artery Restenosis in a Patient with Alagille Syndrome

Introduction: Alagille syndrome is an autosomal dominant multisystem disorder affecting the liver, heart, eyes, skeleton, and kidneys. Renal involvement occurs in over 40% of cases, with renal artery stenosis being a rare but important cause of secondary hypertension in these patients. Case Description: The patient is a 40 year-old male with Alagille syndrome who developed HTN at age 17. Initial renal ultrasound showed left renal atrophy, and renal arteriogram showed severe right renal artery stenosis, treated with angioplasty and stenting. His BP remained well controlled with two medications until 2022, when he developed accelerated HTN again. Repeat arteriogram showed severe intra-stent stenosis, treated with angioplasty and a stent within the stent. He was monitored with serial renal Doppler studies, including one in March 2025 that showed 50-70% right renal artery stenosis. In April 2025, he presented with SOB and was found to be severely hypertensive, with BP as high as 310/120 mm/Hg. Attempts to lower BP further were complicated by AKI. Despite stable BP at around 170/90 mm/Hg for several days, his creatinine continued to worsen, peaking at 7.24 mg/dL. He became anuric, developed uremic symptoms, and was initiated on HD. Repeat renal Doppler showed 50–70% renal artery stenosis, stable compared to the prior study. The unexplained AKI, in the setting of a solitary functioning kidney, prompted consideration of an occluded renal artery stent, despite stable imaging. He underwent CO2 angiography, which revealed severe in-stent restenosis, treated successfully with balloon angioplasty. He immediately became non-oliguric, with UOP of 1.8 L over the next 24 hours with improved creatinine. He was discharged five days post-procedure with no further dialysis needs. His creatinine at outpatient clinic a week after discharge was 1.4 mg/dL. Discussion: Renal artery restenosis led to hypertensive emergency and AKI in a patient with Alagille syndrome, ultimately requiring dialysis. Initial intervention was deferred due to stable imaging, but clinical deterioration prompted further multidisciplinary discussion, resulting in angioplasty and subsequent renal recovery. This case highlights the need to balance imaging with clinical context and to reassess early when renal perfusion is threatened. Prompt intervention can reverse dialysis-dependent AKI.