This study documents an evaluation of trend
during the years of gaining experience on EVAR
procedure. The introduction of EVAR has provided
an opportunity for surgeons to treat non-operable
patients and patients with comorbidities at the
beginning. The satisfactory outcomes and the
long-time durability of these procedures have enabled
this treatment modality for almost all infra-renal
AAAs. In recent years, the endovascular approach for
AAAs has reached up to 75 to 80% in our clinic.[
13]
As shown in this study and previous studies, patients
with more comorbidities (such as coronary artery
disease, coronary artery bypass grafting history,
malignancy, and previous abdominal operation) and
increased ASA scores were treated endovascularly in
earlier periods of our experience.[
14] The decreased
rates of these comorbidities in later periods may
have contributed to the increased utilization of
endovascular procedures in almost all patients, even
those with no comorbidities.[
13]
The shorter periods of procedure and fluoroscopy
and decreased amounts of contrast agents used
coincided with the last period. We observed a trend
with a stabilized decrease in these parameters in
each time period; however, the significant decrease
was seen only in the latest period. This can be
attributed to the type of the stent-graft used. In
the earlier periods, we used more commonly the
unibody stent-graft (71%) which provided only onesided
femoral exploration and shorter fluoroscopy and procedure time. At the second tertile, modular
stent-grafts gained popularity in our clinic
(89%) and, currently, we implant only modular
stent-grafts. Modular stent-grafts requires more
technical procedures during deployment (such as
two-sided femoral exploration, contralateral limb
cannulation) which prolongs the procedure and
fluoroscopy time and increases the amount of
contrast agent used. An increase of these parameters
(i.e., procedure duration, fluoroscopy duration, and
amount of contrast agents) at the second tertile
may be understandable. However, with gaining
experience with a large volume of patients, we
provided a plateau phase during the first and second
tertiles and a decrease in the third tertile with
increased experience. This decrease significantly
manifested even with more use of iliac extensions
and balloons which are technically time-consuming.
The increased use of iliac extensions and balloons
can be attributed to the increased complexity of
aneurysms (angulated and elongated) over time,
as the instruction-for-use criteria of the endograft
types and technical experience have extended day
by day. Recently, the median fluoroscopy duration
of our procedures is only 12 min (IQR, 9 to 18 min),
which appears to be very convenient. There are some
reports documenting techniques for contralateral
limb cannulation and these reports particularly aim
to decrease fluoroscopy times.[15-17] In these reports,
about 12 to 15 min of contralateral limb cannulation
has been documented, indicating longer fluoroscopy
times for whole procedure. Therefore, a 12-min total fluoroscopy time is quite considerable for our
experienced team.
The ICU and hospital stays following the
endovascular procedure was significantly shorter as
of the beginning of second tertile, corresponding to
2017. The patients with less comorbidities may have
contributed to this finding, as the EVAR procedure
gained popularity for a greater population of AAAs.
The decrease at the mid-term mortality at
the latest period is quite understandable, since
the follow-up period was longer for the earlier
periods (44 months, 25 months, and 13 months,
respectively). Overall long-term mortality rate was
15.3% (2-38/249) over a median period of 26 months.
However, supporting evidence of decreasing
mid-term mortality over time was published by
Varkevisser et al.[18] who documented that four-year
survival tended to improve in recent years, due to
technical improvements and increased experience.
Nonetheless, there are some limitations. Firstly,
the groups were non-heterogenous regarding stentgrafts
used and comorbidities. Secondly, mid-term
mortality should be assessed with comparable
follow-up periods for each group.
In conclusion, technical success of the procedure
and perioperative outcomes have improved in more
recent years. We believe that the relative perioperative
outcome benefits of EVAR such as shorter ICU and
hospital stay have increased over time.
Declaration of conflicting interests
The authors declared no conflicts of interest with respect
to the authorship and/or publication of this article.
Funding
The authors received no financial support for the research
and/or authorship of this article.