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.