What is the surgical management of arterial dissection?

Surgical Management of Arterial Dissection

Immediate surgical repair is recommended for all patients with Type A aortic dissection, while endovascular approaches are preferred for complicated Type B dissections. 1, 2

Type A Aortic Dissection Management

Indications for Surgery

• All patients with Type A dissection require emergency surgical intervention
• Immediate surgery is especially critical with:
  • Malperfusion syndromes (cerebral, mesenteric, lower limb, renal) 1
  • Pericardial tamponade
  • Aortic rupture
  • Aortic regurgitation 1

Surgical Approach for Type A Dissection

1. Aortic Root Management:

   • For patients with extensive aortic root destruction, root aneurysm, or genetic aortic disorders: complete root replacement with mechanical or biological valved conduit 1
   • For partially dissected root without significant valve pathology: aortic valve resuspension 1
   • Valve-sparing root repair may be considered in selected patients when performed by experienced surgeons 1
   • GRF adhesive or Teflon felt strips are used to fortify dissected layers 1

2. Distal Anastomosis Technique:

   • Open distal anastomosis is recommended to improve survival and increase false lumen thrombosis rates 1
   • For dissection without intimal tear in the arch: hemi-arch repair is preferred 1
   • For secondary intimal tear in arch or proximal descending thoracic aorta: extended repair with stenting of proximal descending thoracic aorta (frozen elephant technique) may be considered 1

3. Cannulation Strategy:

   • Double arterial cannulation (typically femoral and axillary arteries) is effective for both prevention and management of intraoperative malperfusion 3
   • Single cannulation options include femoral artery, axillary artery, left ventricular apex, or ascending aorta

4. Management of Malperfusion:

   • For cerebral, mesenteric, lower limb, or renal malperfusion: immediate aortic surgery 1
   • For mesenteric malperfusion: consider angiographic diagnostics to evaluate percutaneous repair before or after aortic surgery 1, 4
   • For severe visceral ischemia: consider visceral arterial revascularization before aortic repair to prevent irreversible ischemic damage 4

Type B Aortic Dissection Management

Uncomplicated Type B Dissection

• Medical therapy is first-line treatment 2
• TEVAR (Thoracic Endovascular Aortic Repair) should be considered in the subacute phase (14-90 days) for patients with high-risk features 1

Complicated Type B Dissection

• Emergency intervention is recommended 2
• TEVAR is the preferred first-line therapy 2
• Surgical indications include:
  • Intractable pain
  • Rapidly expanding aortic diameter
  • Periaortic or mediastinal hematoma
  • Dissection in a previously aneurysmatic aorta 1
  • Malperfusion syndromes

Surgical Approach for Type B Dissection

• Replacement of affected portions with appropriately sized tubular graft 1
• Standard approach: posterolateral chest incision for access to descending aorta 1
• Most surgeons use extracorporeal circulation via left heart bypass 1
• Moderate hypothermia with equalized perfusion pressures during graft implantation 1

Chronic Aortic Dissection Management

Chronic Type A Dissection

• Surgical approach similar to acute dissection but with more emphasis on valve repair/replacement 1
• Catheter-guided fenestration may be considered for decompressing true lumen 1

Chronic Type B Dissection

• Intervention recommended for descending thoracic aortic diameter ≥60 mm 1
• Intervention should be considered for diameter ≥55 mm in low-risk patients 1
• Fenestrated/branched stent grafts may be considered for chronic post-dissection thoracoabdominal aneurysms 1

Interventional Techniques

• Stenting of obstructed branch origin for static obstruction 1
• Balloon fenestration of dissecting membrane plus stenting of aortic true lumen for dynamic obstruction 1
• Stenting to keep fenestration open 1
• Fenestration to provide re-entry tear for dead-end false lumen 1
• Stenting of true lumen to seal entry or enlarge compressed true lumen 1

Perioperative Considerations

• Maintain hemodynamic stability with beta-blockers targeting heart rate ≤60 bpm and systolic BP between 100-120 mmHg 2
• Monitor cerebral oxygenation during surgery 5
• Use transesophageal echocardiography for diagnostic support 5
• Address coagulation abnormalities which are common during these procedures 5

Postoperative Follow-up

• After open surgery: imaging by CCT and TTE within 6 months, then CCT at 12 months and yearly if stable 2
• For medically treated Type B AAS or IMH: imaging at 1,3,6, and 12 months after onset, then yearly if stable 2

Pitfalls and Caveats

• Delayed diagnosis and treatment significantly increases mortality
• Malperfusion syndromes may persist after proximal repair and require additional interventions
• Extremity malperfusion frequently requires revascularization even after central aortic repair 6
• Intestinal ischemia carries particularly poor outcomes and may require prioritizing abdominal surgery before aortic repair 4
• Coagulation abnormalities are common and require thorough management 5