Endovascular Debranching Aortic Repair for Thoracoabdominal Aortic Aneurysms
In the past, if you had a thoracoabdominal aortic aneurysm (TAAA), treatment included traditional open surgical repair. But now, there is a new minimally invasive endovascular procedure that allows surgeons to access and repair the aneurysm through your arteries, without making any incision on your chest or abdomen. In contrast to open surgery, which involves a large incision that extends from the top of the chest to the bottom of the abdomen, endovascular TAAA repair is done via a needle stick in the groin and a small incision in the upper arm.
With each heartbeat, the heart’s left ventricle pumps blood into the aorta, the largest blood vessel in the body. The aorta, which is about an inch in diameter, is responsible for carrying oxygen-rich blood from the heart through the back of the chest and down into the abdomen. Along the way, several smaller arteries branch off to supply blood to organs and tissues in the head, arms, chest, abdomen, and legs. In short, the aorta is the main highway through which the heart pumps oxygen rich blood to every organ in the body.
A thoracoabdominal aortic aneurysm occurs when the section of the aorta that passes through the chest and the abdomen bulges and balloons outward. While a TAAA may not cause any noticeable symptoms, it tends to grow over time. And if the aneurysm gets large enough, it can rupture—or burst open—causing internal bleeding that can lead to sudden death. The ballooning of an aneurysm also increases the risk for aortic dissection, a life-threatening condition in which a tear forms in the innermost layer of the aorta’s wall.
Fortunately, with endovascular TAAA repair, patient outcomes have been outstanding, and because it’s less invasive than other surgical treatments, recovery is faster, and there are fewer complications. The Yale Aortic Center is the only institution in the east coast of the United States offering this unique endovascular platform called endovascular debranching aortic repair for patients with TAAA.
“We are excited to offer this unique, minimally invasive endovascular therapy for patients with thoracoabdominal aortic aneurysms,” says Prashanth Vallabhajosyula, MD, MS, a Yale Medicine cardiothoracic surgeon and the surgical director of the Aortic Institute at the Yale New Haven Health Heart & Vascular Center. “It has been a game-changer. We offer a team-based approach, where, unlike at other centers, every patient is cared for by a multidisciplinary group that includes a vascular surgeon, cardiac surgeon, cardiac anesthesiologists, and neurologists.”
What is a thoracoabdominal aortic aneurysm?
As blood flows through the aorta, it exerts pressure on the aorta’s wall. Normally, the wall can withstand the pressure and maintain blood flow. But when sections of the aorta’s wall are weakened through injury or disease, the pressure causes them to bulge outward.
This abnormal bulging of the aorta is known as an aneurysm. Although an aneurysm can form at any point along the aorta, a TAAA is the name for one that occurs in the portion of the aorta that descends through the back of the chest and into the abdomen. For this reason, caring for patients with TAAA requires aortic surgeons with expertise in treating aneurysms in both the chest and the abdomen.
Several arteries branch off the section of the aorta that passes through the abdomen. They supply blood to nearby organs, including the kidneys, liver, intestine, colon, and pancreas. Treatment of TAAAs that involve these arterial branches is complex because surgeons must repair the aorta while also maintaining blood flow to these arteries.
How are thoracoabdominal aortic aneurysms typically treated?
If a TAAA is small and unlikely to rupture, treatment usually involves lifestyle changes (such as quitting smoking) and medications to lower high blood pressure and cholesterol. Doctors will regularly monitor the aneurysm over time using imaging tests.
However, if the TAAA is over 5 centimeters in diameter, shows evidence of rapid growth, and/or causes symptoms, surgery is typically recommended. The traditional procedure for treating TAAAs is an open surgical repair that often requires hospital admission for weeks to months.
In this procedure, surgeons make a large incision extending from the patient’s upper back, side, and abdomen to access the aneurysm. The surgeon then removes the aneurysm and inserts a graft—a man-made fabric tube—in the aorta, which can allow for proper blood flow.
During the procedure, the patient’s heart is often connected to a heart-lung bypass machine. Surgeons also typically need to clamp parts of the aorta during the procedure to stop blood flow while they repair the aneurysm.
Open surgical TAAA repair is a lifesaving procedure that is still widely used and remains the best option for some patients. It is, however, one of the most invasive procedures that is performed on the human body, and one that often requires a long recovery period.
How does endovascular debranching aortic repair work?
During an endovascular repair procedure, patients are given general anesthesia.
In general, endovascular aortic aneurysm repair works as follows: Surgeons make a small needle puncture in the skin to access an artery in the groin. They then insert a catheter—a long, flexible tube—into the artery. A folded stent-graft—a metal tube covered with fabric—is attached to the end of the catheter. The catheter and stent-graft are threaded through the artery, into the aorta, and guided to the aneurysm. Once it’s in place, the surgeon deploys the stent-graft, which then opens and expands. One end of the stent-graft extends to a section of the aorta above the aneurysm; the other extends below the aneurysm. Blood can then flow through the stent-graft.
At Yale, a team of cardiac and vascular surgeons use a recently developed endovascular technique to repair TAAAs. Called endovascular debranching aortic repair, it uses a device called the unitary manifold, and the procedure is performed in one setting, in three main stages.
- Stage 1. In the first stage, surgeons repair the portion of the aneurysm located in the chest. To do so, they access the femoral artery in the groin, insert a stent-graft, guide it to the aneurysm in the chest, then deploy and open it.
- Stage 2. In the second stage, surgeons implant what’s called a four-branch endograft (endograft is another name for a stent-graft) into the part of the aneurysm located in the abdomen. There are four blood vessels that branch off the abdominal aorta to supply blood to the kidneys, liver, intestines, and other organs. As the name suggests, the four-branch endograft contains four branches, each of which corresponds to one of the four blood vessels that branch off the abdominal aorta.
The four-branch endograft is inserted into the femoral artery via a needle puncture in the groin. It is then guided to the aneurysm in the abdomen. At the same time, a one-inch incision is made on the inside of the upper left arm to access the brachial artery. Surgeons insert wires through the brachial artery and thread them down the aorta to the aneurysm in the abdomen. Using the wires, they individually engage each of the four limbs of the endograft, directing them to the four arteries that branch off the abdominal aorta. The endograft is then deployed and opened.
The four-branch endograft allows surgeons to repair the aneurysm while maintaining blood flow to the abdominal organs, thereby lowering the risk of complications.
- Stage 3. In the third stage, the surgeons endovascularly implant a stent-graft in the lower portion of the aneurysm in the abdomen. This is usually done via the femoral artery, which is accessed in the groin.
What happens after endovascular debranching aortic repair?
After the procedure, patients will recover in the intensive care unit (ICU), where they will be given a low-dose blood thinner to prevent blood clots.
Most patients spend two days in the ICU and a few more in the hospital. By the day after the surgery, patients can eat and walk on their own. Within a week, patients can go home.
What are the risks associated with endovascular debranching aortic repair?
Like all surgical procedures, endovascular TAAA repair comes with certain risks. Complications can include:
- Paraplegia (paralysis of the lower body and legs)
- Kidney failure
- Bowel ischemia (restricted blood flow to the intestines)
- Heart attack
- Respiratory failure
Most of these complications occur due to ischemia, which occurs when blood flow to an organ or part of the body is restricted, resulting in tissue or organ damage.
These complications can also occur with open surgical repair. In general, though, the risk is lower for endovascular TAAA repair than it is for open surgical repair.
What are the advantages of endovascular repair of thoracoabdominal aortic aneurysms?
Compared to open surgical repair, endovascular TAAA repair is less invasive, involves a shorter hospital stay, and typically recovery is much quicker. Because endovascular repair does not require a large incision in the chest or abdomen, there is usually less blood loss, which means that blood transfusions are less likely to be necessary. There is also no need to put a patient on the heart-lung bypass machine. The risk of complications from endovascular TAAA repair tends to be lower than for open surgical repair.
It’s important to note that open surgical TAAA repair may not be suitable for all patients. Some people, for example, are too unwell to undergo the procedure. In these cases, minimally invasive endovascular repair may be an option. Ultimately, a multidisciplinary team of cardiac and vascular surgeons will work with patients who have TAAAs to determine the best course of treatment.
What makes Yale Medicine unique in its approach to treating thoracoabdominal aortic aneurysms?
“We are the only institution in the east coast of the United States offering this endovascular platform for patients with thoracoabdominal aneurysms,” says Dr. Vallabhajosyula. “At several centers, this operation is done either by the vascular surgeons or the cardiac surgeons, but at Yale, it is done by the vascular and cardiac surgeons together. This means that our patients are always cared for by two surgeons, working together, to provide the best care possible in treating this very complex disease.”