Abstract 4373242: A Shocking Development After Peripheral Arterial Intervention

Background: Severely calcified lesions of the common femoral artery (CFA) and proximal superficial femoral artery (SFA) pose technical challenges for endovascular revascularization. Orbital atherectomy (OA) and intravascular lithotripsy (IVL) are established plaque modification techniques used to improve vessel compliance and optimize luminal gain. OA uses a diamond-coated crown rotating at variable speeds to ablate superficial calcium, while IVL delivers circumferential acoustic pressure waves to fracture deep calcium with minimal barotrauma. Case: A 78-year-old male with hypertension, stage II chronic kidney disease, and lifestyle-limiting claudication underwent elective peripheral angiography revealing >80% concentric calcific stenosis of the left CFA and ostial SFA. Lesion preparation was performed using OA (Diamondback 360, 2.0 mm solid crown, initial passes at 60,000 rpm followed by high-speed passes at 160,000 rpm, ~20 seconds per segment), followed by IVL (Shockwave M5, 7 × 60 mm balloon, inflation to 4 atm with 30 pulses in CFA and 20 pulses in ostial SFA). Drug-coated balloons were subsequently deployed. The procedure was uncomplicated, but shortly after, the patient developed dark tea-colored urine. Urinalysis showed 70 mg/dL protein, “large” blood, and 11–25 RBCs/hpf. Hemoglobin dropped from 13.9 to 11.2 g/dL. Serum creatinine remained stable at 1.3 mg/dL. The patient received IV fluids with gradual resolution of urine discoloration. Decision-Making: The described event was suspected to be a result of transient intravascular hemolysis from mechanical shearing of RBCs from sequential OA and IVL. Given improving symptoms, the patient was discharged with close outpatient follow-up, demonstrating resolution of hematuria and stable renal function. Conclusion: This case highlights an unusual but important complication, rapid-onset intravascular hemolysis following sequential OA and IVL in the femoral circulation. To our knowledge, this is among the first reports of near-black urine developing within an hour post-intervention, underscoring a rarely described hemolytic response. As calcium modification technologies become integral to complex PAD treatment, clinicians should be vigilant for this self-limited but alarming presentation.