The Impact of Inferior Vena Cava Anomalies on Deep Vein Thrombosis: A Case Report.

Inferior vena cava (IVC) anomalies are rare congenital pathologies related to variations of agenesis, hypoplasia, or atresia, predisposing patients to thromboembolic events secondary to an alteration in venous drainage with resultant stasis. This is a case report of a 27-year-old male without significant medical history presenting for a fall after playing recreational basketball with associated pain and swelling in his left lower extremity. After his symptoms progressively worsened, he came to the emergency room for an evaluation where an ultrasound (US) of the extremity showed extensive deep vein thromboses (DVT). Despite anticoagulation therapy, his pain increasingly worsened and thus catheter-directed thrombectomy was considered. A diagnostic venogram in the cardiac catheterization lab was obtained showing an occlusive left iliofemoral DVT with thrombosis of superficial veins along with an IVC anomaly. After a dedicated abdominal computed tomography (CT) venogram, there was no evidence of any IVC anomalies. After repeat cardiac catheterization, an IVC atresia was noted on the cath lab venogram with venous drainage occurring through the azygos vein and partial contributions from the hepatic veins. This case underscores the importance of detailed imaging and consideration of rare anatomical anomalies in diagnosing unexplained or recurrent thrombotic events especially in younger patients.