Aortic endograft complications

Background

Endovascular aneurysm repair procedure

• Patients with Endovascular Aortic Repair (EVAR) can have unique complications that are not discussed in most emergency medicine literature.
• EVAR has largely replaced open aortic repair as the gold standard for the treatment of Abdominal Aortic Aneurysm (AAA).
• Common complications including aortoenteric fistula, endoleaks, and graft thrombosis can present in a similar fashion to other common ED diagnoses.

Clinical Features

The presentation can vary based on the underlying issue with the graft. Most symptoms are non-specific and include nausea, vomiting, abdominal pain, hematochezia, and back pain.

Differential Diagnosis

EVAR Complications

• Aortoenteric Fistula (most common)- expect symptoms of GI bleeding.
• Endoleaks- Vascular flow outside of the graft that is still contained in the aortic aneurysm. This can lead to worsening AAA and ultimately rupture.
  • Type 1: the seal of the graft fails
  • Type 2: a collateral vessel leaks
  • Type 3: graft tear or failure
  • Type 4: porosity of the graft
  • Type 5: endotension/unidentifiable source
• Limb ischemia- via embolism from the graft
• Graft thrombosis
  • This usually occurs in the first 6 months following graft implantation
• Graft infection
  • A rare complication but with a mortality approaching 40%. Symptoms are non-specific.
• Renal artery occlusion
• Colonic ischemia
• Spinal cord ischemia

Evaluation

• Physical
  • There are no exam findings which reliably rule in or out these diagnoses.
• Labs
  • CBC, CMP, Lipase, Type and Screen, UA, +/- Blood cultures(graft infection), +/- Lactate(suspected mesenteric ischemia)
• Imaging
  • CT- for the highest sensitivity a triple phase CT scan (non-contrast, arterial phase, delayed phase) is required. Usually you want to talk with radiology prior to this study.
  • Ultrasound- both point of care ultrasound and duplex ultrasound do not detect EVAR complications with high enough sensitivity to be use routinely.

Management

• Coordination of care with vascular surgery is recommended when a graft issue is suspected- consult early
• Balanced resuscitation and early antibiotics if infection is suspected.

Disposition

• Knowing the unique complications of EVAR is the first and most important step in the management of these patients.
• Unfortunately, while CT is sensitive for most complications of EVAR it does NOT definitively exclude Aortoenteric Fistula, Graft infection or endoleaks. Maintain a high index of suspicion when a EVAR issue is suspected and always lean toward conservative management/early specialist consultation.

See Also

• Post-surgical complications

References

• Slama R, Long B, Koyfman A,: The Emergency medicine approach to abdominal vascular graft complications. AJEM 2016; 34: pp. 2014-2017