Standard Open Surgery Versus Endovascular Repair of Abdominal Aortic Aneurysm (AAA)

Primary Hypothesis: All-cause mortality will differ by 25% between Endovascular repair (EVR)
and Open repair. Secondary Hypotheses: Procedure failure, short term (12-month) major
morbidity, number of hospital days, health-related quality of life and other
procedure-related abnormalities will differ between the two AAA repair strategies. Primary
Outcomes: All-cause mortality. Interventions: Patients will be randomized to one of these
repair strategies for the elective treatment of AAA: (a) Open repair or (b) Endovascular
repair (using FDA-approved devices). Study Abstract: Aortic aneurysm is the tenth leading
cause of death in older men; AAA accounts for the majority of these deaths (about 10,000
deaths per year in the United States). Since one in 22 Veterans over the age of 50 have AAA
and one in 200 have AAA with diameter greater or equal to 5.0 cm (making them candidates for
elective repair), AAA is a major disease in the VA population. Questions about the relative
safety and effectiveness of FDA approved EVR devices have been raised and remain unanswered.
To answer these questions, this multi-center, randomized clinical trial comparing EVR with
standard open surgery is proposed. Patients for whom elective repair of AAA is indicated and
who are suitable candidates for both open repair and EVR will be eligible for the study. The
anticipated duration of the study is 9 years with a proposed sample size of 900 patients.
The first planning meeting took place on March 9-10, 2000 and the second planning meeting
took place on November 6-7, 2000. The OVER protocol was submitted and reviewed by CSEC on
May 10, 2001 and approved. The kickoff was June 12, 2002. The first DSMB meeting took place
January 6, 2003. First annual meeting was held September 30, 2003; second DSMB meeting took
place September 29, 2003. Third DSMB meeting held on April 19, 2004; second annual meeting
was held on June 29, 2004. Fourth DSMB meeting was held on December 6, 2004; third annual
meeting was held on March 15, 2005. The fifth DSMB meeting was held on July 19, 2005 and the
fourth annual meeting was held March 21, 2006. The sixth DSMB meeting was held September 12,
2005. The seventh DSMB meeting was held on March 6, 2006. The eighth DSMB meeting was held
on November 6, 2006. At its November 6, 2006 meeting, the DSMB discussed and approved
unblinding of the study chair to prepare the short-term follow-up paper as specified in the
study protocol. Initially the protocol called for this analysis to include one-year
follow-up data. After discussions with the Trial Leadership, the DSMB approved use of two
year follow-up data (reflected in DSMB minutes finalized February 20, 2007). This
recommendation was subsequently approved by CSP in March 2007. The short-term outcomes
manuscript was published in JAMA on October 14, 2009. The ninth DSMB meeting was held on May
14, 2007 and the fifth annual meeting was held on June 6, 2007. The tenth DSMB meeting was
held on April 7, 2008. The eleventh DMC (name change only from DSMB to DMC) was held on June
22, 2009. The twelfth DMC meeting was held on May 24, 2010. A Site Investigator meeting was
held in Boston, MA on June 9, 2010. The thirteenth DMC meeting was held on June 3, 2011 and
a study close-out meeting was held on June 15, 2011 in Chicago, IL. The study's patient
follow-up phase ended October 15, 2011.

Inclusion Criteria:

- AAA with a maximum external diameter in any plane greater than or equal to 5 cm.

- An iliac aneurysm (associated with an AAA) with a maximum external diameter in any
plane greater than or equal to 3 cm.

- AAA greater than or equal to 4.5 cm and the AAA has increased by greater than or
equal to 0.7 cm in diameter in 6 months.

- An AAA greater than or equal to 4.5 cm and the AAA has increased by greater than or
equal to 1 cm in diameter in 12 months.

- An AAA greater than or equal to 4.5 cm and the AAA is saccular (i.e., a portion of
the circumference of the aorta at the level of the aneurysm is considered normal
based on CT scan or MRI).

- An AAA greater than or equal to 4.5 cm and the AAA is associated with distal
embolism.

- as measured from two imaging studies (ultrasound CT scan or MRI) within the
appropriate interval, the later one within 6 months of randomization.

Exclusion Criteria:

- Patient has had a previous AAA repair procedure

- Evidence of AAA rupture by imaging test

- AAA is not elective (i.e., urgent or emergent operation, usually due to suspected
rupture)

- Likelihood of poor compliance to the protocol

- Patient refused randomization

- Physician refused randomization