Title
Percutaneous closure of a large saphenous vein graft pseudoaneurysm
Introduction
Aortocoronary saphenous vein graft (SVG) aneurysms and pseudoaneurysms are rare with an estimated incidence of 0.07%
1. We describe a case of an incidentally found, large SVG pseudoaneurysm closed percutaneously using an Amplatzer vascular plug.
Clinical Case
This is a 74 year-old male with a history of hypertension, hyperlipidemia, supra-renal aortic aneurysm, and coronary artery disease who underwent coronary artery bypass grafting in 1999. In 2021, lung cancer screening with a low-dose CT chest incidentally noted a pseudoaneurysm of a proximal saphenous vein graft (SVG) to left circumflex artery measuring 5.5 x 3.3 cm. He deferred intervention and was lost to follow-up. In 2024, he underwent a second screening CT scan which triggered a CTA of the chest due to a noted ‘mediastinal mass’. His pseudoaneurysm had grown to 8.3 x 5.2 cm with a 1cm x 1cm neck and appeared to be occluded distal to the pseudoaneurysm. After a multidisciplinary discussion, it was determined that his surgical risk was high and the patient declined surgery. Due to concern for spontaneous rupture, he was offered attempted percutaneous closure. Coronary and graft angiography confirmed occlusion of the SVG. It was engaged with an 8F LCB guide. Pseudoaneurysm neck measurement was confirmed and we proceeded with a 14 mm AVP 2 plug. On initial deployment the positioning was not satisfactory; it was recaptured and again deployed so the mid-portion was fully occupying the neck of the pseudoaneurysm. There was minimal persistent leak, and the decision was made to deploy the device. After deployment, final angiography showed no leak into the pseudoaneurysm. The patient was discharged the next day without complications and repeat CT evaluation one month later showed a stable pseudoaneurysm with no contrast opacification. Fenestrated endovascular aortic repair of his infrarenal aneurysm was completed three months later.
Discussion
Aneurysmal dilation is defined as focal enlargement of the vessel 1.5x the expected normal diameter. True aneurysms involve all three vessel wall layers while pseudoaneurysms disrupt the vessel wall, leading to a hematoma contained by adventitia or surrounding soft tissue. While rare, SVG pseudoaneurysms pose a high mortality risk with a risk of rupture of 17% (compared to an estimated 7% for SVG aneurysms)
2. They are often found incidentally on chest imaging or present with cardiopulmonary symptoms >15 years after CABG, most commonly in males (84%) at an average age of 67. While there are no formal guidelines, it is reasonable to discuss surgical or percutaneous closure when they are >4cm in size
2. Percutaneous options that have been described include coiling, Amplatzer vascular plugs
3-6, covered stenting, endoluminal grafts, or thrombin injection. In this case, the pseudoaneurysm was large, thrombotically occluded distally, and enlarging on serial scans. Due to the smaller neck, it was felt the Amplatzer vascular plug was the most appropriate method of closure. When choosing a vascular plug, it is recommended to size the plug 1.3-1.5x the diameter of the intended vessel
3. In this case the aneurysm was successfully excluded utilizing the AVP 2 plug.