What are the mortality rates for abdominal aortic aneurysm repair under various anesthetic techniques (open versus endovascular, elective versus ruptured, general anesthesia versus neuraxial anesthesia) and which journal articles provide these data?

Mortality Data for Anesthetic Management of Abdominal Aortic Aneurysm

For ruptured AAA, overall mortality remains 80-90% with most deaths occurring before hospital arrival, but among those reaching the hospital alive, endovascular repair under local anesthesia achieves the lowest mortality (18.5-21%) compared to open repair (29-50%) or EVAR under general anesthesia. 1, 2

Mortality by Clinical Scenario

Ruptured AAA (rAAA)

The mortality profile for ruptured AAA is dramatically different from elective repair and represents a true surgical emergency:

• Pre-hospital mortality: 80-90% of patients die before reaching the hospital 1, 2
• In-hospital mortality (all-comers): 75-90% despite treatment 1
• Contemporary surgical mortality: 18.5-50% depending on repair technique and institutional protocols 1

Mortality by repair modality for ruptured AAA:

• Endovascular repair (EVAR): 18.5-23% in contemporary series 1, 2
• Open surgical repair: 29-50% 1, 3
• Historical open repair: Approximately 50% for patients surviving to hospital presentation 1

The IMPROVE trial demonstrated that EVAR provides a late survival advantage, with hazard ratio of 0.57 (95% CI 0.36-0.9) between 90 days and 3 years compared to open repair 4. Propensity-matched registry data from the Vascular Quality Initiative showed 30-day mortality of 21% for EVAR versus 34% for open repair (P<0.001) 4, 2.

Elective AAA Repair

For non-ruptured aneurysms, mortality is substantially lower but varies significantly by patient age and comorbidities:

• 30-day mortality for EVAR: 1.7% 4
• 30-day mortality for open repair: 4.7% 4
• Overall elective repair mortality: 5.1% (30-day) 5

The DREAM trial showed initial 30-day operative mortality favoring EVAR (1.7% vs 4.7%, RR 3.9,95% CI 0.9-32.9) 4. However, 2-year cumulative survival rates were not significantly different (89.6% for open repair vs 87.7% for EVAR) 4.

Age-stratified mortality for elective repair:

• 28-day mortality ranges from 3.3% to 27.1% in men and 3.8% to 54.3% in women depending on age 6
• 5-year mortality ranges from 12.9% to 78.1% in men and 24.3% to 91.3% in women 6

Anesthetic Technique and Mortality

Local vs General Anesthesia for EVAR

Local anesthesia is strongly preferred for endovascular repair of ruptured AAA because it significantly reduces perioperative mortality. 4, 1, 2

The IMPROVE trial subanalysis demonstrated that patients with rAAA who underwent EVAR with only local anesthesia had dramatically lower mortality compared to general anesthesia (adjusted OR 0.27,95% CI 0.1-0.7) 4. This finding has been corroborated by large registry studies 4.

Mechanism of harm with general anesthesia in rAAA:

• Loss of catecholamine response leads to circulatory collapse 4
• Anesthetic agents directly depress blood pressure 4
• Deleterious effects on inflammatory and temperature regulation 4

Anesthetic Agent Comparison for Open Repair

For elective open AAA repair, a randomized trial comparing fentanyl versus sufentanil-oxygen anesthesia found no significant mortality difference between opioid-based general anesthetic techniques 4.

Critical Anesthetic Management Factors Affecting Mortality

Permissive Hypotension Strategy

Maintain systolic blood pressure between 60-90 mmHg (sufficient for mentation) until definitive aortic control is achieved. 4, 1, 2

This strategy reduces ongoing bleeding while preserving end-organ perfusion 4, 1. Aggressive fluid resuscitation before aortic control is associated with excess mortality 4.

Hemodynamic Status and Imaging

• Hemodynamically unstable patients (SBP <90 mmHg): Immediate operating room transfer without imaging to avoid fatal delays 4, 1
• Hemodynamically stable patients: Emergent CT angiography to determine EVAR suitability 4, 1

The IMPROVE trial established that obtaining preoperative imaging in stable patients does not increase mortality risk and enables appropriate repair selection 4.

Long-Term Mortality Considerations

While EVAR has superior early mortality, this advantage dissipates over time with higher rates of late rupture and aneurysm-related death after 8 years. 7, 8

Meta-analysis of long-term RCT data found:

• Early mortality (<6 months): EVAR superior (HR 0.62,95% CI 0.42-0.91 for all-cause death; HR 0.42,95% CI 0.24-0.75 for aneurysm-related death) 8
• Late mortality (>8 years): Open repair superior (HR 5.12,95% CI 1.59-16.44 for aneurysm-related death after EVAR) 8
• Overall long-term mortality: No significant difference (HR 1.02,95% CI 0.93-1.13) 8

EVAR carries significantly higher risk of secondary intervention (HR 2.13,95% CI 1.69-2.68), aneurysm rupture (OR 5.08,95% CI 1.11-23.31), and death due to rupture (OR 3.57,95% CI 1.87-6.80) 8.

Institutional and Surgeon Volume Effects

Surgeon experience significantly impacts mortality in elective AAA repair, with clear dependence on both total vascular case load (p<0.01) and number of operated elective aneurysms (p<0.01) 5. However, no association was found between hospital volume and mortality in AAA surgery 5.

For non-ruptured aneurysm repair, absolute mortality differences between very-low-volume and very-high-volume hospitals were 2-5% 4.

Critical Pitfalls to Avoid

• Do not delay operative intervention for extensive preoperative optimization in unstable patients; time to hemorrhage control is the decisive survival factor 1, 2
• Do not use general anesthesia for EVAR when local anesthesia is feasible; general anesthesia increases perioperative mortality 4, 1, 2
• Do not perform aggressive fluid resuscitation before aortic control; maintain permissive hypotension 4, 1, 2
• Do not default to open repair when EVAR is anatomically feasible; EVAR reduces mortality from 33% to 19% in ruptured cases 1, 2

Optimal Anesthetic Protocol for Ruptured AAA

Implement a structured "rupture protocol" that achieves mortality as low as 18.5%: 1, 2

• Rapid imaging for hemodynamically stable patients
• Permissive hypotension strategy (SBP 60-90 mmHg)
• Endovascular-first approach when anatomically suitable
• Local anesthesia for EVAR (not general anesthesia)
• Immediate operating room availability with coordinated multidisciplinary team
• Avoid rapid infusion systems and aggressive resuscitation

Independent risk factors for 5-year mortality after elective repair include higher age, congestive heart failure, cerebrovascular disease, and diabetes mellitus 6.