Discussion
DFAA is rare and difficult to diagnose in the early stage(1). DFAA often progresses asymptomatically and is found in large size at presentation because they are located deeply and covered by several muscles(2). DFAA can cause complicated conditions such as rapid expansion, rupture, and acute lower limb ischemia due to distal embolism of thrombus, particularly if there is concomitant superficial femoral artery occlusive disease(3). All symptomatic femoral aneurysms should be treated to prevent rupture, embolization and worsening local compression. Reslan and colleagues suggested that repair is always recommended for DFAA because of the possibility of those complications(3).
Treatment of true femoral aneurysms including DFAA is usually open repair consisting of exclusion of aneurysm and interposition of graft so that the treatment resolves local compression and maintains lower extremity perfusion. The prosthetic grafts are better size matches and patency rates than vein grafts in the femoral artery region(4). As mentioned in the report of case 1, during open repair, gentle dissection of the branches of femoral nerve and vein is necessary to protect from injury and perioperative venous thrombosis. Preoperative assessment of ipsilateral SFA patency and other regions including iliac artery, popliteal artery, and contralateral side is very important because femoral artery aneurysms are often associated with different aneurysms and bilateral aneurysms.(5,6)
Although aneurysmectomy and graft replacement are preferred, simple ligation may be reasonable treatment in challenging cases such as ruptured aneurysms, elder patient with poor general condition e.g. case 3.(3) Coil embolization has been reported as useful non-surgical alternative if the aneurysm involves distal branches of DFA.(7,8) In the presented case 2, ruptured right DFAA was treated by hybrid repair with proximal direct ligation and distal embolization using Amplatzer vascular plug because the distal artery of DFAA was large measuring 5mm in diameter. When distal branches are large in diameter, prompt embolization is possible by using vascular plugs even in emergency case of ruptured aneurysm. Although embolization has been a successful treatment, the patients are at risk for limb ischemia because DFA is an important collateral source to the lower extremity, especially in cases of femoropopliteal artery diseases.(1)
Endovascular management of DFAA using stent-grafts may be effective approach for the preservation of distal perfusion. There are some reports of successful deployment of stent-grafts to treat DFAA with good short-term results.(5,6,9). In case 2, we successfully deployed 7mm stent- graft because DFAA was short in length with enough both proximal and distal landing zone. Endovascuolar treatments are attractive for stable patients as well as frail patients because of their less invasiveness. However, contralateral femoral access or groin incision is often required to deliver stent-grafts. There are no officially approved covered stents for peripheral artery aneurysms and appropriate length of landing zone was unknown to completely exclude aneurysm sac. Further size discrepancy between proximal and distal arteries of DFAA is assumed if aneurysm is large and long, so preoperative assessment using CTA or magnetic resonance angiography is essential. Postoperatively, careful follow-up of graft patency and local compressive and ischemic symptoms is necessary.