S5881 Use of Dual Watchman for Congenital Portosystemic Shunt Occlusion in a Patient With Klippel-Trenaunay Syndrome: A Case Report

Introduction: Congenital portosystemic shunts (CPSS) are rare vascular anomalies in which portal blood bypasses the liver and drains directly into the systemic circulation. Abernethy malformations are distinct CPSS subtypes with unique management challenges. Klippel-Trenaunay Syndrome (KTS) is a congenital vascular disorder characterized by capillary malformations, venous varicosities, and limb overgrowth. Coexistence with CPSS, especially Abernethy type II, is exceedingly rare. We present a case of KTS and a large Abernethy type II shunt who underwent successful transvenous embolization using dual watchman (left atrial appendage occluder devices). Case Description/Methods: A 32-year-old man with lifelong history of left lower extremity swelling, superficial varicosities, and recurrent thromboembolic episodes, consistent with KTS, presented with recurrent spontaneous hemorrhage from varicosities requiring multiple aspiration and suture control which started 4 years ago. Computed tomography (CT) abdomen and pelvis with contrast revealed extensive pelvic and lower limb varicosities and a large congenital portosystemic shunt (CPSS) arising from the confluence of the portal and splenic veins and draining into the left internal iliac vein. After multidisciplinary planning, endovascular shunt closure with 2 left atrial appendage occluder devices was performed. Post-procedurally, the patient reported no further episodes of bleeding. Venography demonstrated immediate cessation of shunt flow and improved portal venous perfusion with a follow-up CT scan confirming a reduction in the caliber of abdominal and pelvic varicosities and improved portal venous flow. Discussion: The patient’s large Abernethy type II shunt, draining from the portal-splenic confluence into the left internal iliac vein, posed challenges for closure. Traditional devices were unsuitable due to the shunt size and complexity. The use of dual watchman devices successfully occluded the shunt, improving portal venous flow without complications. This case demonstrates the feasibility and safety of endovascular closure of large CPSS in KTS using such novel approach, offering a potential strategy for similarly complex cases.