TEVAR: endovascular treatment of thoracic aortic aneurysms
The aorta is the main artery of the human body. It arises directly from the heart and, with every heartbeat, receives the oxygenated blood that the left ventricle pumps out to the rest of the body.
Throughout the day, this artery continuously withstands the flow of a large volume of blood and the pressure generated by the heart’s pumping action. Its wall is designed to withstand this intense and constant mechanical load. However, when a section loses its strength and dilates abnormally, an aneurysm may form.
In the case of a thoracic aortic aneurysm, this dilation occurs in the section of the aorta that runs through the chest. It can develop silently for years and be detected incidentally during an imaging scan carried out for another reason.
As Dr Isaac Martínez, a specialist in Angiology and Vascular Surgery and head of the department, explains, “the aorta is subjected to constant pressure with every heartbeat. When an area of its wall loses strength and dilates, we are not just talking about an increase in size, but a structural abnormality that must be assessed with precision”.
Endovascular treatment of thoracic aortic aneurysms, also known as TEVAR, allows certain aneurysms to be treated from inside the artery by placing a stent graft. It is a less invasive alternative to open surgery in selected patients, particularly when the aneurysm is located in the descending thoracic aorta and the vascular anatomy allows for a safe repair.
In a nutshell
Endovascular treatment of thoracic aortic aneurysms, or TEVAR, is a technique that involves placing a stent graft inside the aorta so that blood flows through it, thereby reducing direct pressure on the dilated area. It does not physically remove the aneurysm, but helps to protect it from direct blood flow. Its suitability depends on the location of the aneurysm, the anatomy of the aorta, the available anchorage sites and the patient’s clinical condition.
What is a thoracic aortic aneurysm?
An aneurysm is an abnormal, localised and persistent dilation of an artery. In the thoracic aorta, it affects the section of the aorta located within the chest.
The aorta is neither a rigid nor a passive tube. Its wall is elastic, resilient and capable of adapting to the pulse coming from the heart. With each heartbeat, it expands slightly to receive the blood being pumped and then returns to its normal shape, helping to maintain a continuous flow of blood to the body.
When an area of this wall weakens, it may begin to dilate. This dilation may grow slowly and cause no symptoms for a long time. For this reason, some aneurysms are discovered during an X-ray, a CT scan, an MRI or a CT angiogram carried out for another reason.
“Not all aneurysms behave in the same way or pose the same risk,” notes Dr Martínez. “Size is important, but so too are the location, the rate of growth, the shape of the aneurysm and the clinical characteristics of each patient.”
The medical assessment is not based on a single figure. The specialist analyses the diameter of the aneurysm, its progression over time, the affected area of the aorta, family history, the presence of connective tissue disorders, blood pressure control and the patient’s general health.
Symptoms of a thoracic aortic aneurysm: why it can be silent
One of the main challenges with a thoracic aortic aneurysm is that it can progress without symptoms. The aorta can gradually dilate without the person experiencing pain, shortness of breath or any other obvious signs.
In some cases, as the aneurysm grows, compresses nearby structures or becomes complicated, symptoms such as chest or back pain, a feeling of pressure, a persistent cough, difficulty swallowing or changes in the voice may appear. However, the absence of symptoms does not always mean there is no risk.
As the specialist warns, “the fact that an aneurysm does not cause symptoms should not lead us to underestimate it. In many cases, the key lies precisely in detecting it, measuring it accurately and monitoring its progression before a complication arises”.
For this reason, once an aneurysm has been identified, medical monitoring is essential. The aim is to determine whether it remains stable or whether it exhibits characteristics that might make surgery advisable.
When is treatment for a thoracic aortic aneurysm indicated?
For small, stable aneurysms, it may be sufficient to carry out regular checks using imaging tests and to optimise medical management, particularly blood pressure control.
However, when the aneurysm reaches a certain size, grows rapidly, causes symptoms or exhibits high-risk anatomical features, repair may be recommended. The aim of the procedure is to protect the weakened segment and prevent the pressure generated by blood flow from continuing to act directly on the aneurysmal wall.
“The main indication for endovascular treatment of the thoracic aorta is the diameter of the aneurysm. We treat the aneurysm when the risk of allowing it to progress outweighs the risk of intervention,” explains Dr Martínez. “The decision must be highly individualised: it is not based solely on a single figure, but on the behaviour of the aneurysm and the patient’s clinical condition.”
Clinical evidence has reinforced the role of endovascular treatment in selected aneurysms of the descending thoracic aorta. A study published in the *Journal of the American College of Cardiology* analysed Medicare patients with unruptured aneurysms of the descending thoracic aorta treated by endovascular repair or open surgery.
After matching patient groups with similar characteristics, the study included 1,235 patients treated with open surgery and 2,470 treated with TEVAR. The authors found that open surgery was associated with higher perioperative mortality, particularly in centres with a lower volume of procedures.
In contrast, endovascular treatment showed better overall survival outcomes during the period analysed, although open surgery was associated with a lower risk of reintervention during follow-up. The clinical takeaway is balanced: TEVAR may offer a significant initial advantage, but it should be indicated after assessing the anatomy, surgical risk, the team’s experience and the need for long-term follow-up.
In some patients, open surgery remains the most appropriate option. In others, particularly when the aneurysm is located in the descending thoracic aorta and there are safe sites for stenting, endovascular treatment may be considered.
What is endovascular treatment of thoracic aortic aneurysms (TEVAR)?
TEVAR stands for thoracic endovascular aortic repair. It is a procedure in which a stent graft is placed inside the aorta to treat certain aneurysms without the need to open the chest.
Endovascular treatment allows the affected area to be repaired from inside the blood vessel. Unlike open surgery, it does not require the chest to be opened to directly replace the diseased segment of the aorta.
The procedure is carried out by accessing the arterial system, usually via the femoral artery in the groin. From this point, the medical team inserts catheters and guidewires which are advanced through the blood vessels until they reach the thoracic aorta.
Once in the correct position, a vascular endoprosthesis or stent graft is deployed. This device consists of a metal framework covered with a prosthetic material. As it expands within the aorta, it creates a new internal channel through which blood flows.
“Endovascular treatment allows us to repair certain aneurysms from inside the artery,” explains Dr Martínez. “Through a vascular access point, usually in the groin, we insert a stent graft which is positioned in the affected area so that blood flows through it, thereby reducing the direct pressure on the aneurysm.”
The stent graft does not physically remove the aneurysm. Its function is to create a stable internal pathway for blood within the aorta. In this way, blood flow circulates mainly through the stent graft and no longer impacts the dilated wall of the aneurysm directly.
In vascular medicine, it is said that the aneurysm is ‘excluded’, but for the patient it may be easier to understand it this way: the aorta continues to carry blood, but the dilated area is protected from direct blood flow and from some of the pressure it previously received with every heartbeat.
For this to be possible, the stent graft must be anchored to healthy or sufficiently strong segments of the aorta, located above and below the aneurysm. These areas are known as anchorage sites. When the device is correctly positioned, it acts as an internal conduit that helps to protect the weakened wall.
Planning for TEVAR: CT angiography, anatomy and anchorage sites
The safety of endovascular treatment begins before the procedure. To determine whether a patient is a candidate for TEVAR, it is necessary to study the anatomy of the aorta and the access vessels in detail.
CT angiography is usually a key test. It allows assessment of the aneurysm’s diameter, its length, the shape of the aorta, the presence of thrombus or calcification, the relationship with major arterial branches, and the calibre of the arteries through which the device must be inserted.
This planning helps answer crucial questions: whether the patient can be treated endovascularly, what type and size of stent graft is required, where it should be anchored, what anatomical risks exist, and whether additional procedures may be necessary.
“Planning is a critical part of treatment,” emphasises the specialist. “Before placing a stent graft, we need to know the exact anatomy of the aorta, the anchorage sites and the vascular access points. The safety of the procedure begins long before we enter the operating theatre.”
Current clinical guidelines also reinforce this need to tailor the indication to the individual. The 2022 ACC/AHA guidelines for the diagnosis and management of aortic disease set out recommendations on medical treatment, surgical repair, endovascular repair and long-term monitoring in different scenarios of aortic disease.
In the case of descending aortic aneurysms, the recommendations emphasise that the decision must take into account the diameter, the presence of symptoms, the rate of growth, the anatomy and the patient’s risk profile. This approach is consistent with current clinical practice: it is not simply a matter of having an advanced technique at one’s disposal, but of knowing for which patients and at what stage it can provide the greatest benefit.
Not all thoracic aortic aneurysms can be treated with TEVAR. When they affect the ascending aorta, the aortic arch or areas close to critical arterial branches, they may require open surgery, hybrid techniques or more complex strategies. For this reason, the decision to proceed must be made within a specialised setting.
Advantages and limitations of endovascular treatment compared with open surgery
In selected patients, endovascular treatment can offer significant advantages over open surgery. As it is performed from within the blood vessels, it avoids a large thoracic incision and reduces the initial surgical trauma.
This can result in less post-operative pain, a shorter initial recovery time and a shorter hospital stay in certain patients. It may also be a particularly relevant alternative for people at higher surgical risk due to age, lung disease, heart disease or other associated conditions.
A systematic review and meta-analysis published in the *Journal of the American College of Cardiology* pooled 43 studies involving 5,888 patients to compare endovascular treatment with open surgery for diseases of the descending thoracic aorta. In the comparative studies, patients treated with TEVAR had lower mortality over the first 30 days and a lower risk of serious neurological complications, such as paraplegia or paraparesis.
Fewer renal complications, fewer reinterventions due to bleeding, fewer transfusions, fewer cases of pneumonia and a shorter hospital stay were also observed, with an average reduction of approximately seven days.
These findings help to explain why the endovascular approach has gained prominence in selected patients: it can reduce the initial invasiveness of treatment and promote a faster recovery. However, the authors themselves noted that the evidence came from non-randomised studies and that no sustained benefit in long-term survival was demonstrated.
Therefore, the value of TEVAR should not be presented as a universal substitute for open surgery, but rather as a highly relevant option when the indication is appropriate. Less invasive does not mean less complex.
“The fact that it is less invasive does not make it a minor procedure,” clarifies Dr Martínez. “We are working on the thoracic aorta, a vital structure. That is why it is essential to select patients carefully, plan the technique and have an experienced team.”
Risks, safety and follow-up after TEVAR
Like any procedure on the aorta, endovascular treatment may be associated with risks. These include bleeding, injury to the access vessels, contrast-related complications, kidney problems, stroke, spinal ischaemia, stent displacement, endoleaks or the need for further interventions.
A specific complication of endovascular repairs is endoleak. This occurs when blood continues to enter the aneurysmal sac after the stent graft has been placed. Put simply, an endoleak means that the dilated area has not been completely protected from direct blood flow or is once again receiving blood via some route. Not all endoleaks are equally serious, but some require close monitoring or further treatment.
The less invasive nature of TEVAR does not eliminate the need for rigorous planning or subsequent monitoring. A national analysis published in the *Journal of Vascular Surgery* evaluated 11,473 thoracic endovascular repair procedures and found an overall rate of spinal ischaemia of 3.7 per cent, equivalent to 422 cases.
Although this is a rare complication, it can have significant neurological consequences. This finding clearly illustrates that the procedure is performed on a critical structure and requires experienced teams, protective protocols and subsequent imaging follow-up.
Following endovascular repair, follow-up is not usually carried out in the operating theatre where the stent graft was implanted, but rather through scheduled clinical check-ups and imaging tests. These checks ensure that the stent graft remains correctly positioned, that blood flows through it, that there are no significant endoleaks, and that the aneurysm is not continuing to grow.
Follow-up is usually carried out using CT angiography or other imaging techniques, depending on the clinical situation, renal function, the patient’s age and the medical team’s judgement. The Society for Vascular Surgery recommends monitoring using contrast-enhanced computed tomography following TEVAR, with initial scans followed by periodic checks if the patient’s condition remains stable.
The 2022 ACC/AHA guidelines also highlight the need for imaging surveillance following thoracic endovascular repair. In practice, the specific protocol should be tailored to the individual patient based on the type of aneurysm, the device used, imaging findings and the patient’s characteristics.
In addition to imaging follow-up, monitoring of cardiovascular risk factors continues. The treatment of high blood pressure is particularly important. So too are giving up smoking, managing cholesterol levels, physical activity tailored to the patient’s condition, and ongoing medical supervision.
Personalised treatment of thoracic aortic aneurysms
Endovascular treatment of thoracic aortic aneurysms represents one of the most significant advances in the modern management of aortic disease. It allows certain aneurysms to be repaired from within the artery, reducing the initial surgical burden in selected patients.
However, its use requires precision. Not all patients are suitable candidates. Not all aneurysms have the same anatomy. And not all cases benefit from the same strategy.
“In aortic disease, there are no automatic decisions,” concludes Dr Martínez. “Each case must be analysed in detail to choose the safest option: monitoring, medical treatment, open surgery or endovascular repair.”
In a condition that can progress silently, timely diagnosis, rigorous planning and close monitoring are just as important as the technique used.
What patients need to bear in mind
A thoracic aortic aneurysm may not cause any symptoms. TEVAR is a less invasive option for certain aneurysms, particularly those of the descending thoracic aorta, but it is not suitable for all cases. Planning using CT angiography and subsequent follow-up are essential to ensure that the stent graft remains in position, that blood flows through it, and that there are no significant endoleaks.
The information contained in this article is for informational purposes only and is not a substitute for a personalised medical assessment or the individual recommendation of diagnostic tests.
Frequently asked questions about endovascular treatment of thoracic aortic aneurysms
What does TEVAR stand for?
TEVAR stands for thoracic endovascular aortic repair. It is a technique that involves placing a stent graft inside the aorta to treat certain aneurysms from within the blood vessel.
Does endovascular treatment remove the aneurysm?
It does not physically eliminate it. The stent graft creates a new internal channel through which the blood flows. This means that the blood flow no longer impacts the dilated wall of the aneurysm directly, thereby reducing the direct pressure on that weakened area.
What does it mean for the aneurysm to be ‘excluded’?
In vascular medicine, ‘excluding’ the aneurysm means isolating it from direct blood flow. Blood continues to circulate through the aorta, but does so mainly through the stent graft. Therefore, from the patient’s perspective, this can be understood to mean that the aneurysm is protected from direct blood flow.
Can all thoracic aortic aneurysms be treated with stents?
No. Endovascular treatment depends on the location of the aneurysm, its size, its shape, the available anchorage sites and the condition of the access vessels. In some cases, open surgery, a hybrid technique or medical management may be more appropriate.
What tests are used to plan treatment?
CT angiography is one of the most important tests for planning the procedure. It allows the anatomy of the aorta to be studied, the aneurysm to be measured, the endoprosthesis fixation sites to be assessed and the vascular access sites to be analysed.
Why are follow-up checks necessary after TEVAR?
Because the stent graft must be monitored over time. Follow-up checks ensure that it remains in the correct position, that blood is flowing through it, that there are no significant endoleaks and that the aneurysm is not continuing to grow.
Is the follow-up carried out in the same room where the procedure took place?
Usually not. The procedure is carried out under image guidance in a specialised surgical or endovascular setting. Subsequent follow-up is usually carried out through scheduled consultations and imaging tests, such as CT angiography or other investigations, depending on the individual case.
Does endovascular treatment always replace open surgery?
No. TEVAR is a very important option for selected patients, particularly for aneurysms of the descending thoracic aorta, but it does not replace open surgery in all cases. The best strategy must be decided on a case-by-case basis.
The information in this article is provided for general awareness and does not replace an individualised medical assessment.
