What is the outcome of Thoracic Endovascular Aortic Repair (TEVAR) for a tubercular (TB) mycotic aneurysm?

TEVAR for TB Mycotic Aneurysm: Outcomes and Management

Direct Answer

TEVAR combined with prolonged anti-tuberculosis therapy is a reasonable initial treatment for tuberculous mycotic aneurysms of the thoracic aorta, with 0% in-hospital mortality and 95% one-year survival in reported cases, though infection-related complications remain a significant concern requiring lifelong surveillance. 1, 2

Mortality and Survival Outcomes

Short-term outcomes with TEVAR are excellent:

• 0% in-hospital/30-day mortality in TB mycotic aneurysm cases treated with TEVAR 1
• 92% survival at 30 days and 88% at 3 months for all mycotic thoracic aortic aneurysms treated with TEVAR 2
• Overall mortality of 5% in the TEVAR group versus 10% in open surgery group (not statistically different) 1

Long-term survival remains acceptable but requires vigilance:

• 78% survival at one year and 71% at five years for mycotic thoracic aortic aneurysms treated with TEVAR 2
• Two-year survival comparable between TEVAR and open surgery approaches 1

Critical Management Principles

The fundamental concern with TEVAR for TB mycotic aneurysm is placing a foreign body in an infected field without debridement. 3 However, this theoretical disadvantage has not translated into worse outcomes compared to open surgery in reported series. 1

Essential treatment components include:

• Minimum 15 weeks of anti-tuberculosis medications (median duration in successful cases) 2
• Some experts recommend lifelong suppressive antimicrobial therapy when endovascular devices are retained in infected fields 3
• Pre-operative antibiotic therapy for at least 1 week before TEVAR improves outcomes 3
• Image-guided drainage of periaortic collections before TEVAR is associated with favorable outcomes 3

Infection-Related Complications

Infection-related complications (IRC) occur in 17% of patients and are the primary cause of late mortality:

• Graft infection (3 cases) 2
• Recurrent mycotic aneurysm (1 case) 2
• Aorto-esophageal or aortobronchial fistula (2 cases) 2
• Sepsis despite treatment (3 cases) 2

80% of infection-related complications occur within the first year, and 67% are fatal. 2 This underscores the need for intensive early surveillance.

Risk Factors Predicting Poor Outcome

Specific factors associated with treatment failure include:

• Persistent signs of sepsis preoperatively despite appropriate antimicrobial therapy 3
• Presence of aortoenteric or aortobronchial fistula 3
• Rupture at presentation 3
• Undrained periaortic infection preoperatively 3

When these high-risk features are present, mortality with device retention ranges from 36% to 100%. 3

Surveillance Protocol

Rigorous imaging follow-up is mandatory:

• Contrast-enhanced CT at 1 month, 3 months, 6 months, 12 months, then annually for life 4, 2
• More frequent imaging if endoleak or infection-related abnormality detected 4
• Mean follow-up duration in survivors should extend to at least 45 months 2

CTA findings suggesting persistent or recurrent infection include:

• Enhancing perigraft fluid or soft tissues 3
• Visible gas bubbles around the graft 3
• Persistent or enlarging periaortic soft tissue mass 5
• Aneurysm sac enlargement (>2% increase suggests device failure) 3

Comparison to Open Surgery

TEVAR offers advantages over open repair:

• Lower perioperative morbidity and shorter hospitalization 3
• 0% versus 7% in-hospital mortality (though not statistically significant in small series) 1
• Can serve as life-saving bridge procedure in acute rupture 3

However, open surgery may have lower late complication rates:

• Late mortality and complication rates were 20% with TEVAR versus 3-14% with open surgery in one literature review 3
• Freedom from aneurysm recurrence is comparable between approaches 1

Clinical Pitfalls to Avoid

Do not proceed with TEVAR if:

• Active sepsis persists despite 1 week of appropriate antibiotics 3
• Large undrained periaortic abscess is present 3
• Aortobronchial or aortoenteric fistula is identified (consider open repair or hybrid approach) 3

Do not discontinue antibiotics prematurely:

• Minimum 15 weeks of anti-TB therapy is required 2
• Consider lifelong suppressive therapy given retained foreign body in previously infected field 3
• Relapse can occur months after initial treatment, as demonstrated by miliary TB developing 6 weeks post-TEVAR 5

Special Considerations for TB Etiology

TB mycotic aneurysms have unique characteristics:

• Often present with adjacent soft tissue mass or vertebral osteomyelitis 5
• May be associated with miliary tuberculosis requiring extended treatment 5
• Culture positivity occurs in only 56% of mycotic aneurysms, so empiric TB treatment may be necessary based on clinical context 2
• Staphylococcus aureus (31%) is more common than TB in mycotic thoracic aneurysms overall, so broad-spectrum coverage until cultures finalize is prudent 2

The combination of TEVAR with anti-tuberculosis medications has revolutionized management and improved prognosis for this previously uniformly fatal condition. 6