In this analysis, we included 10 articles to
determine the possibility of renal failure risk between
EVAR and OSR in elderly patients older than
80 years. The results demonstrated that there was a
significant difference for the development of renal
failure. The heterogeneity among the studies was
very high, but the possibility of publication bias was
not statistically significant. The main reason for
the presence of heterogeneity was the retrospective
design of the studies.
In their study, Bagia et al.[20] showed that elective
AAA repair caused higher treatment costs in patients
over 80 years of age. However, the opposite result was obtained in the emergency surgery setting.
Nevertheless, as a result of analyzing the ratio of
treatment cost to survival, emergency AAA repair
caused an eight-fold increase over 80 years.
In a recent meta-analysis of 15,580 patients and
13 studies, patients who underwent thoracic aortic
aneurysm repair were examined.[21] In this study,
OSR was applied to younger patients and EVAR
was chosen for mostly elderly. According to this
meta-analysis, the rate of renal failure development
was higher in the OSR (p=0.01). On the other hand,
the age difference between the groups appeared to be
an important issue in this analysis. However, Scheer
et al.[22] concluded that the development of renal
insufficiency did not show a significant difference
between the octogenarian and younger patients.
In another study, Grant et al.[23] examined the
risk factors of renal failure in patients undergoing
elective OSR with a logistic regression model. As a
result, age >75 years, symptomatic AAAs, respiratory
disease, hypertension, juxta-/supra-renal AAAs, and
a serum creatinine level of >150 ?mol/L were found
to be risk factors. According to the data obtained
from this study, for the renal insufficiency in the
scoring system, the age of >75 years was 1.5 and
serum creatinine >150 ?mol/L was 2.5, while the
other factors were evaluated with 2 points.
Geriatric patients and renal failure are two
important issues for aortic aneurysm repair. Egorova
et al.[24] evaluated 66,943 patients who underwent
EVAR and recommended a scoring system for 30-day
mortality risk. In this scoring system, age and renal
failure were the factors which increased the risk. For
age between 75 and 79 years one point, 80 and 84 years
two points, and ?85 years four points were determined.
On the other hand, the highest risk factor was renal
failure (7 points) requiring dialysis. A recent study
by Saratzis et al.[7] investigated the development of
renal insufficiency due to EVAR in 146 patients, and
demonstrated that the rate of renal insufficiency was
significant (18.8%) and was associated with mortality.
Wald et al.[25] also compared EVAR and OSR in terms
of renal failure in their retrospective study including
6,516 patients. Renal failure developed in 6.7% of the
patients. However, the authors observed that EVAR had
a lower probability (OR: 0.42, 95% CI: 0.33-0.53). In
addition, EVAR was more advantageous, as it reduced
renal failure requiring dialysis (OR: 0.30, 95% CI:
0.15-0.63). Our analysis and results were an update of a previous meta-analysis performed with only three
studies.[26] This current meta-analysis applied with
10 versus three studies in 9,027 versus 2,159 patients.
According to these results, retrospective studies have
more weight. The total weight of prospective studies
was 16.99%.[13,16,17] The weight of four studies with a
high sample size was 64.39%.[12,15,18,19] Also, these were
retrospective studies. Among the studies we included
in the quantitative analysis, there was no study with a
randomized-controlled design.
In their research, Hagiwara et al.[27] retrospectively
examined 350 patients and 25.7% had chronic renal
failure. After 30 months of follow-up, the rate of
chronic renal failure increased to 33.4%. On the
other hand, 27.5% of them had acute renal failure
postoperatively. In this study, the authors concluded
that being over 65 years of age was a risk factor for
chronic renal failure development, but not for acute
renal failure. In another study, Patel et al.[28] examined
the effect of renal failure on clinical outcomes in
8,701 patients with chronic renal failure. They
analyzed the patients by classifying them as mild,
moderate, and severe renal insufficiency and EVAR
or OSR. When the groups with mild and severe renal
insufficiency were compared, a significant relationship
was observed between renal failure severity and 30-day
mortality, prolongation of ventilation, and acute renal
failure in both EVAR and OSR groups. However,
an increased amount of blood transfusion and
cardiac arrest differed only in the EVAR group. The
development of renal insufficiency in the aneurysm
repair may increase the risk for morbidity, leading to
an increase in the cost of treatment and mortality due
to secondary causes.
There are some limitations to the present research.
The lack of randomized-controlled trials which
fulfilled the inclusion criteria are the main limitation.
On the other hand, although many studies included
patients over 80 years of age, the fact that the
age variable for renal failure development was not
examined by age subgroups reduced the number of
studies we analyzed.
In conclusion, our study results suggest that repair
of aortic aneurysms with both techniques carries a
risk for renal failure development, and the risk is
higher with open surgical technique in patients over
the age of 80 years. However, further large-scale,
randomized-controlled studies are needed to confirm
these results.
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.