Is there a syndrome that causes weight loss, fatigue, and diarrhea after thoracic aortic grafting?

Yes, Prosthetic Aortic Graft Infection Should Be Strongly Suspected

In patients presenting with weight loss, fatigue, and diarrhea after thoracic aortic grafting, late prosthetic graft infection is the most critical diagnosis to exclude, as it presents with this exact constellation of symptoms and carries high mortality if untreated.

Clinical Presentation Pattern

Late graft infections (>3 months post-surgery) characteristically present with an insidious onset featuring 1:

• Fatigue and malaise (hallmark symptoms)
• Weight loss (from chronic systemic inflammation)
• Gastrointestinal symptoms including diarrhea (from graft-enteric fistula or erosion to adjacent bowel)
• Fever (may be absent in low-grade infections)
• Elevated inflammatory markers (ESR, CRP, WBC)

This contrasts sharply with early graft infections (≤3 months), which present acutely with fever and back pain 1.

Diagnostic Algorithm

Immediate workup must include 1:

1. Blood work: CBC, ESR, CRP, blood cultures (draw before antibiotics)

2. CT angiography with contrast (first-line imaging):

   • Perigraft air (>7 weeks post-procedure is pathologic) 2
   • Perigraft fluid (>3 months post-implantation is pathologic) 2
   • Perigraft abscess
   • Pseudoaneurysms
   • Signs of graft-enteric fistula to esophagus or bowel 2

3. If CT is negative but suspicion remains high:

   • PET-CT increases sensitivity from 64% to 93% for low-grade infections 1
   • MRI or tagged white blood cell scans (institution-dependent) 1

4. Endoscopy if gastrointestinal bleeding or diarrhea present to evaluate for aorto-enteric fistula 1

Critical Pitfall

CTA has only 64% sensitivity for low-grade infections despite 94% sensitivity for advanced infections 1. Do not stop at negative CT if clinical suspicion is high—proceed to PET-CT.

Alternative Diagnosis: Chronic Q-Fever Graft Infection

One case report 3 documented a patient with identical symptoms (dry cough, weight loss, fatigue) after aortic graft surgery who had chronic Coxiella burnetii infection of the prosthetic graft. This requires:

• Serologic testing for Q-fever
• Treatment with doxycycline plus hydroxychloroquine (not standard antibiotics)

Other Differential Considerations

Gastrointestinal complications occur in 5.9-7% of thoracoabdominal repairs 4, 5 and include:

• Bowel ischemia (2.5% incidence, 62% mortality)
• Hepatic dysfunction
• Pancreatitis

However, these typically present acutely perioperatively, not with chronic weight loss and fatigue months later.

Post-implantation syndrome (PIS) 6, 7 presents with fever and elevated CRP but:

• Occurs within days to weeks post-TEVAR (not months/years later)
• Does not typically cause diarrhea or significant weight loss
• Self-limited or steroid-responsive
• Not relevant to open surgical grafting

Management Priority

If graft infection is confirmed 1:

1. Infectious disease consultation (mandatory) 1
2. Minimum 6 weeks IV antibiotics targeted to culture results 1
3. Surgical evaluation for graft explant with reconstruction (definitive treatment)
4. Consider lifelong oral suppressive antibiotics if 1:
   • Extensive perigraft abscess
   • MRSA, Pseudomonas, or multidrug-resistant organism
   • In situ reconstruction performed

Bottom Line

The triad of weight loss, fatigue, and diarrhea months after thoracic aortic grafting represents late prosthetic graft infection until proven otherwise. Obtain blood cultures and contrast-enhanced CT immediately—this diagnosis carries 39.5% mortality if missed 5 but is treatable with early recognition and aggressive management 1.