Aortic Aneurysms: OSR, EVAR, Stent-Grafts, Migration and Endoleak—Current State of the Art and Analysis - Cardiovascular and Cardiac Therapeutic Devices - page 81

mortality of up to 13 %, after a median follow-up of about 2 years. They also
identified that successful hemostat sealing was achieved in 97.40 % of cases and
cumulative vessel patency after about 4 years was 92 %. For finding outcomes of
implanting fenestrated and branched endografts, for the patients suffered from
thoraco-abdominal aortic aneurysm (TAAA), Bakoyiannis et al. [ 99 ] reviewed the
English literature available between 2000 and 2009. By statistical analysis of the
data, they found that overall mortality was 16.1 % with mean follow up of
11.8 months, and identified that technical success was achieved in 94.2 % of the
cases; among other complications the incidence of renal failure was 5.8 %. Their
results are encouraging in the use of EVAR with fenestrated and branched stent
grafts as an alternative therapeutic treatment option. Greenberg [ 100 ] has reported
in a clinical case study that introduction of fenestrated and branched stent graft has
led one to believe that almost all patients can now be treated by EVAR, regardless
of anatomical restrictions.
5.4 Suprarenal and Infrarenal Fixation
Excluding the cases repaired with fenestrated and branched stent grafts, about
55 61 % of the patients suffering from AAAs are currently treated endoluminally
with bifurcated and aortouniiliac endografts [ 52 , 101 ]. Among postprocedural
complications, migration and type-I endoleak are largely associated with short
proximal aortic neck deployment and aortic neck dilation [ 57 , 88 ]. It has been
reported that suprarenal aortic neck is more stable to postoperative dilatation and
resistant to atherosclerosis formation, thus is an ideal site for fixation [ 102 ].
Suprarenal fixation can provide patients with an alternative landing zone for
anchoring and secure attachment, especially to those having adverse anatomical
restrictions in terms of short and angulated neck with severe calcification and
thrombus lining [ 52 ]. Suprarenal fixation has widened the spectrum of EVAR
applications by offering it now to 70 % of patients suffering from AAA [ 75 , 103 ].
However, implantation of suprarenal stents may result in partial occlusion of renal
arteries by stent struts, thereby raising concerns of renal dysfunction. Numerous
investigators have carried out comparative studies of EVAR with suprarenal
versus infrarenal fixations, and identified that different patients have faced post-
procedural renal dysfunction irrespective of the landing zone. However, it is
documented that suprarenal fixation does not play any role in the progression of
renal artery stenosis and acute renal events [ 103 - 107 ]. Malina et al. [ 108 ] have
carried out a short term trial with a mean follow up of 6 months, after deploying
Gianturco Z-stent across renal arteries. They reported that suprarenal fixation does
not lead to any renal complication. It has been observed that suprarenal and
infrarenal fixations are not even associated with proximal neck dilatation after
EVAR, instead it is governed by morphology and remodelling of the aneurysm
[ 109 ]. However, larger studies with longer postprocedural outcomes are required
to correlate suprarenal fixation with incidence of renal complication if there is any.