Large-Bore Aspiration Thrombectomy for Recurrent Iliofemoral DVT in Congenital IVC Interruption With Azygous Continuation.

BACKGROUND: Congenital inferior vena cava interruption with azygous continuation is an uncommon venous anomaly associated with recurrent proximal deep vein thrombosis (DVT) and challenging endovascular management. CASE SUMMARY: A 38-year-old man with congenital inferior vena cava interruption and prior unprovoked DVT presented with acute left lower extremity pain and swelling. Imaging demonstrated extensive acute iliofemoral DVT, absent conventional caval outflow, azygous continuation, and collateral venous drainage. After persistent symptoms despite anticoagulation, he underwent ultrasound-guided left popliteal access and large-bore aspiration thrombectomy using the FlowTriever system (Inari Medical), with substantial thrombus removal and improved collateral-dependent venous outflow. DISCUSSION: This case illustrates a catheter-based thrombectomy strategy when congenital caval anatomy limits conventional venous outflow. TAKE-HOME MESSAGE: Procedural success may require thrombus debulking and optimization of collateral drainage rather than restoration of normal iliocaval continuity.