Deep Venous Thrombosis Within a Complete Duplication of the Left Femoral Vein

Venous duplications, particularly in the femoral vein, are rare anatomical variations that can complicate the clinical presentation and management of deep venous thrombosis (DVT). This case describes an elderly female who was diagnosed by her primary care physician with a left lower extremity DVT one week prior to her presentation and had been prescribed Xarelto. Despite strict adherence to therapy, her left leg pain, swelling, and discoloration worsened, prompting her hospital admission. On physical examination, her left leg was markedly swollen, violaceous, and tender. A repeat compression ultrasound upon admission revealed an occlusive thrombus within the left common femoral vein. Given the diagnosis of phlegmasia, cerulea dolens, the patient was at risk for irreversible venous gangrene and possible limb loss. Therefore, she was taken to the operating room for venography and a mechanical thrombectomy. Venography of the left lower extremity uncovered an extensive thrombus within a complete duplication of the left femoral vein, as well as in the left common femoral and iliac veins. Thrombosis in a duplicated femoral vein, though rare, is a significant clinical entity. This case highlights the importance of considering anatomical anomalies in patients with refractory symptoms and emphasizes the role of detailed imaging for accurate diagnosis and tailored treatment.