Aortic Dissection

Aortic DissectionAn aortic dissection is a tear in the inner lining of the aorta. This tear allows blood to flow through the walls of the aorta rather than remaining in the central channel (lumen). The two major types of aortic dissection, type A and type B, are defined by the location of the tear.

  • Type A dissection—The tear begins in the ascending aorta and progresses throughout the vessel, often extending as far as the arteries in the leg.
  • Type B dissection—The tear is located only in the descending aorta, but may extend into the abdomen.

The distinction between the two types is important, as it guides the management of the disease. Type A requires immediate surgery, to prevent death from stroke, heart attack, congestive heart failure, or bleeding. Type B dissection is considered a medical condition that can be initially treated with aggressive control of blood pressure. Additional treatments are generally reserved for complications resulting from the tear.

Symptoms of Aortic Dissection

Patients often feel as though they are having a heart attack. Specific symptoms may include:

  • Sudden and severe "tearing" or "crushing" pain between the shoulder blades or behind the sternum
  • Inability to find a comfortable position
  • Extremely high blood pressure
  • Loss of consciousness
  • Shortness of breath
  • Weakness
  • Stroke
  • Sense of doom (extreme anxiety)

Complications Associated with Aortic Dissection

Type A dissection is associated with many acute and chronic complications, if untreated. The dissection may cause:

  1. Exsanguinating hemorrhage: aortic rupture causing extreme blood loss
  2. Aortic valve incompetence: failure of the aortic valve leading to rapid heart failure
  3. Coronary artery dissection: loss of blood from the coronary arteries to the heart muscle causing a heart attack (myocardial infarction)
  4. Cardiac tamponade: accumulation of blood in the pericardium (the sac that contains the heart) leading to an inability of the heart to pump blood.
  5. Stroke: interruption of blood flow to the brain may cause a debilitating or fatal stroke

Aortic dissection can also cause a process known as malperfusion syndrome. Because blood flows in the walls of the aorta rather than through the vessel itself, not enough blood may reach its intended destination. This condition may cause organ failure, most frequently involving the kidneys and intestines. The result may be temporary or permanent kidney failure and intestinal injury, which may necessitate extensive bowel resection.

Treatment of Type A Aortic Dissection

Before and after surgery to correct Type A dissectionType A Dissection is an emergency that requires rapid diagnosis and surgical intervention.

At NewYork-Presbyterian/Columbia University Medical Center (NYP/Columbia), the Aortic Surgery Center provides immediate triage, direct transfer to the operating room, medical stabilization, and definitive repair with innovative procedures involving surgery, stents, and transcatheter valves.

NYP/Columbia surgeons and cardiologists work as a multidisciplinary team to ensure excellent outcomes and 100% long-term follow up. When treating patients with type A dissection, antegrade selective perfusion is used to provide enhanced protection of the brain. Valve sparing root replacements may be performed to replace the entire ascending aorta without leaving residual dissection behind. The center's operative mortality rate is less than 3% for all patients undergoing valve sparing root replacement surgery.

Treatment of Type B Aortic Dissection

The traditional therapy for type B aortic dissections is aggressive control of blood pressure, with the hope the dissection will not progress. Surgery is generally reserved for patients with complications including malperfusion syndrome or active hemorrhage. Open surgical repair is often associated with unacceptably high risks of paralysis, lung dysfunction, and fatal hemorrhage. Medical therapy (blood pressure and pain control) provides palliative care, but does not protect the patient from the later development of large aneurysms, kidney dysfunction, and death from aortic complications.

With endovascular stent grafting clearly established as a therapy for other aortic aneurysms, minimally invasive repair is now evolving as a treatment for type B aortic dissection. The Aortic Surgery Program is currently participating in two trials to compare endovascular repair to medical management. Four fabric covered metal stents are available, the Medtronic Talent™ Stent Graft, GORE TAG® Thoracic Endoprosthesis (for the descending thoracic aorta), the Cook Medical TX2 graft,  and Bolton Medical Relay Graft. Inserted through a catheter in the groin, the devices close the dissected aorta and effectively redirect the flow of blood. Patients receiving the stents receive maximal medical therapy as well. The Aortic Surgery Program is the largest center north of Philadelphia to participate in these trials.