Thoracic Endovascular Aortic Repair (TEVAR) is a minimally invasive technique designed to address issues within the aorta in the chest area. The procedure involves accessing the artery system through a small incision, typically in the groin, and navigating a delivery system to the diseased section. Once in position, a specialized device called a stent-graft is deployed to reinforce the weakened aortic wall from the inside. The stent-graft acts as a new lining, diverting blood flow away from the damaged area to prevent complications.
Conditions That Require TEVAR
A patient may require TEVAR for several conditions that compromise the structural integrity of the thoracic aorta. The primary indication is a Thoracic Aortic Aneurysm (TAA), a localized bulging of the vessel wall caused by chronic weakening. If a TAA continues to expand, it can rupture, leading to catastrophic internal bleeding. Repair is often recommended when the diameter reaches a threshold, typically around 5.5 to 6 centimeters.
Another reason for the procedure is an Aortic Dissection, where a tear occurs in the innermost layer of the aortic wall, allowing blood to flow between the layers and separate them. TEVAR is primarily used for Type B dissections, which affect the descending aorta, sealing the initial tear to redirect blood back into the true channel and relieve pressure. Acute traumatic aortic injuries, such as a tear or transection resulting from forceful chest trauma, are also addressed with this endovascular approach. Quick repair of these injuries is necessary to prevent immediate rupture and stabilize the patient.
How the Endovascular Repair is Performed
The TEVAR procedure is conducted in a specialized operating suite using real-time imaging guidance, often under general anesthesia. The surgeon makes a small incision, usually in the groin, to access the femoral artery. A guidewire is then inserted and threaded up the arterial system until it reaches the diseased segment of the thoracic aorta.
A collapsed stent-graft, a tube made of fabric supported by a metal mesh frame, is loaded onto a delivery catheter. This catheter system is guided over the wire to the precise location of the aneurysm or dissection. Continuous fluoroscopy, a type of X-ray imaging, is used to ensure accurate placement.
Once positioned correctly, the stent-graft is deployed, expanding to fit snugly against the inner walls of the aorta. This expansion seals off the damaged area, creating a new, reinforced channel for blood flow and excluding the compromised section. Finally, the delivery catheter and guidewire are withdrawn, and the incision is closed, leaving the stent-graft permanently in place.
TEVAR Versus Open Surgical Repair
The development of TEVAR offered an alternative to the traditional Open Surgical Repair (OSR) for thoracic aortic disease. OSR requires a large incision, typically a thoracotomy that involves opening the chest, which is a significantly more invasive approach. The procedure also requires temporary clamping of the aorta, which increases the risk of complications due to interrupted blood flow to organs.
In contrast, TEVAR is a minimally invasive technique that avoids a major chest opening, resulting in less trauma. Patients undergoing TEVAR experience less blood loss and pain than those who have OSR. This difference in invasiveness translates to a shorter hospital stay, often reducing it by several days, and a faster overall recovery period.
While TEVAR offers superior short-term outcomes, including lower perioperative mortality, OSR may still be necessary in certain anatomical situations. For instance, if the diseased segment is too close to major branch arteries supplying the head and arms, or if the patient’s existing arteries are too narrow or tortuous to accommodate the catheter, open surgery may be the only option. OSR historically offered a lower risk of needing a second intervention, though the initial mortality advantage of TEVAR often makes it the preferred treatment.
Recovery and Long-Term Surveillance
Recovery following TEVAR is quicker than traditional surgery, with a typical hospital stay ranging from a few days to about a week. Patients are monitored closely in an intensive care unit immediately after the procedure to manage blood pressure and ensure the new graft is functioning. Upon discharge, patients are advised to limit physical activities, such as avoiding lifting anything heavier than 10 pounds, for one to four weeks.
Long-term surveillance is a component of post-TEVAR care used to monitor the integrity and positioning of the stent-graft. This involves regular follow-up imaging, most commonly with contrast-enhanced Computed Tomography (CT) scans. Follow-up scans are often scheduled at frequent intervals, such as one, six, and twelve months, with annual scans continuing indefinitely.
Imaging studies are performed to detect complications, most notably an endoleak, which is blood flow persisting outside the stent-graft but within the aneurysm sac. Endoleaks can cause the aneurysm to continue growing and risk rupture, necessitating further intervention. Patients who received TEVAR for an aortic dissection often require stricter surveillance due to a higher risk of long-term aorta-specific complications.