How do the outcomes of open and EVAR repair of abdominal aortic aneurysm (AAA) compare?

Updated: Jan 08, 2019
  • Author: Saum A Rahimi, MD, FACS; Chief Editor: Vincent Lopez Rowe, MD  more...
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Answer

In a randomized study of 1252 patients (EVAR-1 UK trial) with large AAAs (5.5 cm in diameter), EVAR was associated with a significantly lower perioperative mortality than open surgical repair was. [25]  However, no long-term differences in total mortality or aneurysm-related mortality were reported. EVAR was associated with increased rates of graft-related complications and reinterventions and was more costly. The 15-year follow-up data from EVAR-1, published in late 2016, also did not show significant differences in mortality. [26]

In a study of more than 2200 patients with small AAAs (4-5.4 cm), no significant survival difference was observed between patients who underwent immediate open repair for these lesions and those for whom surveillance, rather than surgery, served as first-line treatment. [27]

In a randomized trial involving 404 patients who were physically ineligible for open repair, endovascular repair of AAA was associated with a significantly lower rate of aneurysm-related mortality than no repair was. [28]  However, endovascular repair was not associated with a reduction in the rate of death from any cause. The rates of graft-related complications and reinterventions were higher with endovascular repair, and this approach was more costly.

In a 6-year, multicenter, randomized, controlled trial (DREAM trial) involving 351 patients with an AAA at least 5 cm in diameter who were considered suitable candidates for both open repair and EVAR, the two techniques were found to yield similar survival rates. [29]  The primary outcomes were mortality from any cause and rate of reintervention. The rate of secondary interventions was significantly higher for EVAR.

In a study of 106 patients with ruptured AAAs (75 treated with open repair and 31 with EVAR), minimally invasive EVAR was associated with significantly better aneurysm-related survival at 30 days than open surgical repair was (70% vs 33%). [30]  EVAR was also associated with a shorter hospital stay, fewer complications and interventions, less pneumonia, and fewer transfusions. At 5 years, however, mortalities in EVAR and open surgical repair were similar, with death occurring primarily from cardiovascular complications.

In a study by Mehta et al involving 136 patients undergoing EVAR for ruptured AAAs, mortality was greater in those with hemodynamic instability. [31]  The 136 patients were divided into two groups: (1) hemodynamically stable (systolic blood pressure ≥80 mm Hg; n = 92 [68%]) and (2) hemodynamically unstable (systolic blood pressure 10 min; n = 44 [32%]). The 30-day mortality, postoperative complications, need for secondary reinterventions, and midterm mortality were recorded.

The two groups were found to be similar with respect to comorbid conditions, mean maximum AAA diameter (6.6 cm vs 6.4 cm), need for on-the-table conversion to open repair (3% vs 7%), and incidence of nonfatal complications (43% vs 38%) and secondary interventions (23% vs 25%). [31]  Intraoperative need for aortic occlusion balloon, mean estimated blood loss, incidence of abdominal compartment syndrome, and mortality were all increased in the hemodynamically unstable group (40% vs 6%, 744 vs 363 mL, 29% vs 4%, and 33% vs 18%, respectively).

Perioperative use of beta blockers is associated with an overall reduction in postoperative cardiac events in patients undergoing infrarenal aortic reconstruction. In most patients with low perioperative bleeding, beta-blockers are protective; however, patients with severe bleeding who are treated with perioperative beta blockers have higher mortality and an increased risk of multiple organ dysfunction syndrome (MODS). [32]

Endovascular methods are used in the majority of infrarenal AAA repairs performed in the United States. Preoperative baseline aortoiliac anatomic characteristics were reviewed for each patient in a study by Schanzer et al, for which the primary outcome was post-EVAR AAA sac enlargement. [33]  The study results suggested that adherence to EVAR device guidelines was considered low and that post-EVAR aneurysm sac enlargement was high; this raises concerns regarding the long-term risk of aneurysm rupture.

In conclusion, when outcomes after open repair are compared with those after EVAR, perioperative mortality (30 days or inpatient) is significantly lower for EVAR. Outcome at 2 years also favors EVAR, but the difference between the two approaches is not statistically significant. [34]

A 2012 Cochrane review indicated that in comparison with systemic opioid-based drugs, epidural analgesia provided better pain relief and reduced tracheal tube use after abdominal aortic surgery. [35]


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