How do you expose the aorta?

Surgical Approaches to Expose the Aorta

The surgical approach to expose the aorta depends on the specific aortic segment requiring access, with the most appropriate incision determined by anatomical location and extent of disease.

Ascending Aorta and Aortic Arch Exposure

• Median sternotomy is the standard approach for accessing the ascending aorta and aortic arch 1

  • Provides excellent exposure of the heart, ascending aorta, and proximal arch
  • Allows establishment of cardiopulmonary bypass via femoral artery and right atrium cannulation 1
  • Essential for procedures involving the aortic root, ascending aorta, and complete arch replacement

• Cannulation strategy:

  • The axillary artery should be considered as first choice for cannulation for surgery of the aortic arch and in aortic dissection (Class IIa recommendation) 1
  • Extracorporeal circulation is typically established after cannulation of femoral artery and right atrium 1

Descending Thoracic Aorta Exposure

• Left thoracotomy is the standard approach 1

  • Performed between the 4th and 7th intercostal spaces, depending on the extent of aortic pathology
  • Provides direct access to the descending thoracic aorta from the left subclavian artery to the diaphragm

• Bypass techniques during descending aortic surgery:

  • Left heart bypass technique (recommended, Class IIa) 1

    • Provides distal aortic perfusion during cross-clamping
    • Cannulation of left atrial appendage/pulmonary veins with return through distal aorta or femoral artery
    • Reduces risk of spinal cord ischemia, mesenteric and renal ischemia

  • Partial bypass technique 1

    • Uses cardiopulmonary bypass via femoral artery and vein
    • Requires full heparinization

  • Deep hypothermic circulatory arrest 1

    • Used when clamping of descending aorta is not feasible
    • Core temperature cooled to 18°C

• Avoid simple "clamp and sew" technique when cross-clamp time exceeds 30 minutes due to high risk of neurological deficit and organ ischemia 1

Thoracoabdominal Aorta Exposure

• Left thoracotomy extended to paramedian laparotomy 1

  • Provides exposure from left subclavian artery to iliac arteries
  • Essential for thoracoabdominal aneurysm repair

• Adjunctive measures to prevent paraplegia (6-8% risk):

  • Cerebrospinal fluid drainage (Class I recommendation, Level B evidence) 1
  • Permissive systemic hypothermia (34°C)
  • Re-attachment of intercostal arteries between T8 and L1
  • Continuation of CSF drainage up to 72 hours post-operatively 1

Abdominal Aorta Exposure

• Standard median laparotomy is the traditional approach 1

  • Alternative: left retroperitoneal approach

• Aortic cross-clamping can be performed:

  • Above the renal arteries
  • Below the renal arteries
  • Between the renal arteries 1

Special Circumstances

1. Combined approaches for complex cases:

   • Combined median sternotomy and posterior lateral thoracotomy can provide exposure to the heart, ascending aorta, arch vessels, and descending thoracic aorta in a single surgical field 2
   • Posterior pericardial approach through median sternotomy allows ascending-to-descending aortic bypass 3

2. For dissections involving both ascending and descending aorta:

   • Management should be guided by the location of the predominant lesion 4
   • Replacement of the arch with portion of ascending aorta via median sternotomy is recommended for patients with enlarged aortic diameter, pericardial effusion, or aortic insufficiency
   • Predominantly distal dissections with dilated descending thoracic aorta are best approached via lateral thoracotomy 4

Organ Donation Considerations (DCD)

For donation after circulatory death (DCD) organ recovery with aortic access:

• Midline incision from suprasternal notch to symphysis pubis
• Distal aorta is exposed and cannulated at approximately 5cm superior to sacral promontory
• Inferior vena cava is incised for venting blood 1

Key Pitfalls to Avoid

1. Inadequate exposure leading to poor visualization and technical complications
2. Failure to establish appropriate bypass strategy for descending aortic surgery
3. Not implementing cerebrospinal fluid drainage for thoracoabdominal procedures
4. Prolonged cross-clamp time without distal perfusion causing organ ischemia
5. Inadvertent injury to adjacent structures (e.g., ureters during retroperitoneal approach)

Remember that the surgical approach must be tailored to the specific aortic segment involved, the extent of disease, and the planned procedure to ensure optimal outcomes and minimize morbidity and mortality.