Background <p>Cholesterol crystal embolism syndrome (CCES) represents a catastrophic complication of endovascular procedures. While mechanical trauma during left atrial catheter ablation acts as a known trigger, the specific embolic risks associated with Vein of Marshall ethanol infusion (VOM-EI) remain unexplored.</p> Case presentation <p>A 66-year-old male with severe atherosclerosis and chronic kidney disease underwent persistent atrial fibrillation ablation involving VOM-EI (8 mL of ≥ 99.7% dehydrated ethanol). Six hours post-procedure, he developed extensive, non-pruritic livedo reticularis. He remained hemodynamically stable (lowest blood pressure 111/78 mmHg) but rapidly progressed to anuric acute kidney injury (creatinine peaking at 542 µmol/L) and severe systemic inflammation. Diagnostic evaluation effectively ruled out contrast-induced nephropathy, hypotensive acute tubular necrosis, and autoimmune vasculitis. Given the rapid deterioration, specific eosinophiluria testing and renal biopsy were deferred; however, sterile pyuria, classic skin lesions, and recent vascular intervention established a highly probable clinical diagnosis of CCES. Treatment with intermittent hemodialysis and high-dose intravenous methylprednisolone (40 mg/day) rapidly suppressed the inflammatory storm and facilitated substantial renal recovery.</p> Conclusions <p>In patients with severe aortic plaque burden, VOM-EI, alongside established factors like transseptal catheter manipulation and systemic anticoagulation, may act as a potential trigger for CCES. Although a definitive diagnosis via biopsy was not feasible, we believe that early recognition and prompt corticosteroid therapy contributed substantially to the patient’s clinical recovery.</p>