Population-Based Outcomes Following Endovascular
and Open Repair of Ruptured Abdominal
Kristina A. Giles, MD1; Allen D. Hamdan, MD1; Frank B. Pomposelli, MD1;
Mark C. Wyers, MD1; Suzanne E. Dahlberg, PhD2; and Marc L. Schermerhorn, MD1
1Division of Vascular and Endovascular Surgery, Department of Surgery, Beth
Israel Deaconess Medical Center, Boston, Massachusetts, USA.2Dana-Farber
Cancer Institute, Boston, Massachusetts, USA.
Purpose: To evaluate national outcomes after endovascular and open surgical repair of
ruptured abdominal aortic aneurysms (rAAA).
Methods: The Nationwide Inpatient Sample was interrogated to identify all repairs
between 2000 and 2005 for rAAA based on ICD-9 codes. In the study period, 2323 patients
(1794 men; median age 75 years, range 45–98) with rAAAs had endovascular repair, while
26,106 patients (20,311 men; median age 73 years, range 22–99) had an open procedure.
Outcomes included in-hospital mortality, length of stay (LOS), complications, and
hospitalization charge. A secondary analysis was performed to compare outcomes from
low-, medium-, and high-volume institutions based on annual rAAA repair volume.
Results: Patients in the endovascular group were significantly older (p,0.05). Mortality
was 41% overall: 33% and 41% for endovascular versus open repair, respectively
(p,0.001). Mortality after endovascular repair was lower than open surgery for patients
$70 years (36% versus 47%, p,0.001), but not for those ,70 years (24% versus 30%,
p50.15). LOS was shorter after endovascular repair (7 versus 9 days, p,0.001). Respiratory
complications (8% versus 4%, p,0.05) and acute renal failure were more common
following open repair (30% versus 23%, p,0.01). Costs were similar (endo $73,590 versus
open $67,287, p50.15). Mortality decreased as hospital surgical volume increased (low
44%, medium 39%, high 38%; p,0.001). Over time, endovascular repair utilization
increased more rapidly at high-volume centers, and a lower mortality was seen with
endovascular repair at high-volume compared to low-volume hospitals (22% versus 44%,
p,0.001). Multivariate predictors of mortality were age, female gender, lower hospital
surgical volume, open repair, and year of surgery.
Conclusion: This population-based study found that mortality associated with rAAAs may
be improved by the performance of endovascular repair, especially in older patients.
Mortality after rAAA for both endovascular and open repairs was also lower at high-
J Endovasc Ther. 2009;16:554–564
This research was supported by Grant HL007734 (T32 Harvard-Longwood Research Training in Vascular Surgery) from the
National Institutes of Health (NIH). In accordance with the NIH Public Access Policy, this article is available for open access
at PubMed Central.
Marc L. Schermerhorn receives an unrestricted educational grant from W.L. Gore & Associates, is a consultant to Boston
Scientific Corporation, and serves on the Data and Safety Monitoring Board for Endologix. The other authors have no
commercial, proprietary, or financial interest in any products or companies described in this article.
Address for correspondence and reprints: Marc L. Schermerhorn, MD, 110 Francis Street, Suite 5B, Boston, MA 02215
USA. E-mail: email@example.com
554 J ENDOVASC THER
?2009 by the INTERNATIONAL SOCIETY OF ENDOVASCULAR SPECIALISTS
Available at www.jevt.org
Key words: abdominal aortic aneurysm, ruptured aneurysm, endovascular aneurysm
repair, open surgery, mortality, outcome analysis, population-based outcomes
Hospital mortality rates for ruptured ab-
dominal aortic aneurysms (rAAA) underesti-
mate overall death rates since a consider-
able number of patients die of free rupture
See commentary page 565
presenting acutely to hospitals, mortality
remains quite high despite rapid surgical
intervention. For the past 4 decades, there
seems to have been little progress in the
outcomes of emergently repaired rAAAs, with
inpatient mortality remaining at 40% and
60%.2The gold standard for this repair has
long been an open surgical approach. How-
ever, recently, the less invasive technique of
stent-graft repair has been gaining favor with
Endovascular aneurysm repair (EVAR) for
intact AAA was brought to worldwide notice
by Parodi et al.3in the early 1990s. The
procedure, initially held to be best utilized for
poor surgical candidates, has now achieved
widespread use, reducing hospital and inten-
sive care unit (ICU) stays, early complications,
and early mortality.4–8Randomized control
trials have documented a reduction in periop-
erative mortality compared with conventional
open repair.4–6In follow-up over 1 to 4 years,
other studies have shown that late survival is
The earliest endovascular repair for rup-
tured AAA (rEVAR), which was reported in
1994,10demonstrated the feasibility of the
procedure; 5 years later, Ohki et al.11pub-
lished a series of 12 patients. The growth of
the rEVAR technique, however, has lagged far
behind that of its non-emergent counterpart
given the vast requirements for technical
expertise, facility specialization in endovas-
cular interventions, large inventory, device
specifications, anatomical requirements, and
the need for reasonable hemodynamic stabil-
ity for appropriate preoperative imaging.
Retrospective series revealed that there could
be an advantage to rEVAR,12,13with early
mortality rates of 8% to 40%. Single-center
prospective trials and one multicenter trial
have shown a potential benefit for rEVAR14–21;
however, due to small patient numbers,
statistical significance has rarely been shown.
Additionally, because of the technical require-
ments of the procedure, the impact of annual
volume on outcomes of rAAA repairs is an
important factor that cannot be assessed by
single institutional series. It has been shown
that there is a significant relationship be-
tween higher surgeon and hospital volume
and improved patient outcomes after open
surgical repair for rAAA.22,23Holt et al.,24
however, found that there was no significant
relationship between volume and outcome
for rAAA repair in the UK. Existing data,
which includes rEVAR as well as open repair,
shows conflicting results and is limited by
early experience, small numbers, and varia-
tion in the volume criteria used.24–26
further expand on this work, the current study
utilized the Nationwide Inpatient Sample
(NIS) in order to analyze national outcomes
for in-hospital mortality rates after repair of
rAAAs and to assess the impact of procedural
volume specifically in the setting of aneurysm
The NIS is a database maintained through the
Healthcare Cost and Utilization Project that
captures ,20% of non-federal hospitaliza-
tions from 38 states in a stratified sample
that reflects ,90% of all hospitalizations
within the US. Data from the NIS has been
used extensively in medical research to
provide population outcome analyses in a
variety of healthcare topics; as it represents
an all-payer sample, the NIS is one of the
largest and most comprehensive datasets
100% of their discharges, which allows the
NIS to be used for volume-outcome calcula-
tions as well as population comparisons.27
Clinical data were extracted from the NIS
database using diagnosis and procedure
J ENDOVASC THER
EVAR AND OPEN SURGERY OF RUPTURED AAAS555
Giles et al.
25. Greco G, Egorova N, Anderson PL, et al.
Outcomes of endovascular treatment of rup-
tured abdominal aortic aneurysms. J Vasc
26. Holt PJ, Poloniecke JD, Gerrard D, et al. Meta-
analysis and systematic review of the relation-
ship between volume and outcome in abdom-
inal aortic aneurysm surgery. Br J Surg.
27. HCUP Tools and Software. Healthcare Cost and
Utilization Project (HCUP). April 2007. Agency
for Healthcare Research and Quality, Rockville,
MD, USA. Available at: www.hcup-us.ahrq.
28. Charlson ME, Pompei P, Ales KL, et al. A
new method of classifying prognostic com-
ment and validation. J Chron Dis. 1987;40:
29. Romano PS, Roos LL, Jollis JG. Adapting a
clinical comorbidity index for use with ICD-9-
CM administrative data: differing perspectives.
J Clin Epidemiol. 1993;46:1075–1079.
30. Visser JJ, van Sambeek MR, Hamza TH,
et al. Ruptured abdominal aortic aneurysms:
31. Rayt HS, Sutton AJ, London NJ, et al. A
systematic review and meta-analysis of endo-
vascular repair (EVAR) for ruptured abdominal
aortic aneurysm. Eur J Vasc Endovasc Surg.
32. Sadat U, Boyle JR, Walsh SR, et al. Endovas-
cular vs open repair of acute abdominal aortic
aneurysms—a systematic review and meta-
analysis. J Vasc Surg. 2008;48:227–236.
33. Dardik A, Burleyson GP, Bowman H, et al.
Surgical repair of ruptured abdominal aortic
aneurysms in the state of Maryland: actors
influencing outcome among 527 recent cases.
J Vasc Surg. 1998;28:413–421.
34. Lee RW, Rhodes JM, Singh MJ, et al. Is there a
selection bias in applying endovascular aneu-
rysm repair for rupture? Ann Vasc Surg. 2008;
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