TREATMENT OF THORACAL AORTIC ANEURYSMS-DISECTIONS WITH STENT-GRAFT (TEVAR)
What is TEVAR?
The aorta is the largest artery emerging from the heart. The part in the chest is called the thoracic aorta. A thoracic aortic aneurysm is an abnormal enlargement of this vessel. Dissection is the rupture of this vessel. Stent-graft treatment, which is an alternative to surgical treatment, is the treatment of aneurysm-dissection by inserting a prosthesis called stent-graft into the diseased vascular area by entering an appropriate superficial vein. The stent-graft is a wire cage covered with a special fabric. It creates a new vessel opening limited by the stent-graft in the vessel where it is placed.
The procedure is performed in the operating room (HYBRID OPERATING ROOM) or in the radiology department of the hospital. Depending on the patient's condition, it is performed by anesthetizing with or without general anesthesia, by preventing the pain sensation with epidural or local anesthesia methods.
The artery called the femoral artery in the groin area is surgically exposed. Catheters loaded with the stent graft to be placed for angiography and for treatment are entered through these vessels and delivered to the appropriate places. A stent-graft is placed on the part where the aneurysm-dissection is located. Catheter systems are withdrawn and the opening in the access vessel is surgically closed. The average process takes 3-6 hours. If the femoral arteries are so thin that they do not allow the entry of stent-graft catheters, the operation can be performed by opening the veins above these veins. In some cases, a catheter must be inserted into the arm artery. With this catheter, angiography or manipulations to facilitate the procedure are performed. After the stent-graft is placed and, if necessary, during the procedure, angiography is taken if necessary. In order for the stent graft to settle well in the vessel and to eliminate the leakage from the ends and the junctions of the stent-grafts, expansion is performed with a special balloon. The incisions in the inguinal region are closed with surgical sutures.
After the procedure, the patient is sent to the intensive care unit. Here is a close follow-up. It is necessary to stay in the hospital for about 3 days.
Risks and Complications:
1- Leaks into the aneurysm.
These leaks are caused by the inability of the stent-graft ends to completely close the vessel (type 1), the arteries coming out of the aneurysm sac (type 2), the stent-graft junctions added to the end, or the punctured stent-graft opening (type 3) and the pores of the stent graft fabric (type 4). It is possible. These leaks increase the risk of an aneurysm bursting. Especially type 1 and type 3 leaks should be treated early. Type 2 leaks have a low risk of explosion, they can heal spontaneously, and are followed by imaging. Type 4 leaks are very rare, and resolve spontaneously or with re-administration of the medication taken by the patient.
The risk of leakage is 15-25% in the first month.
2-Occlusion in the vessels leading to the spinal cord and nerve roots (3%). Paralysis can occur in both legs. The risk increases if the stent-graft covers most of the aorta or if aortic surgery has been performed before.
3- Inflammation may develop in the stent graft (0,2-0,6%)
4- Secondary treatments are required for stent graft defects caused by delayed leaks, bending of the stent graft, etc.
5- systemic complications. It develops due to the general medical condition of the patient and their current illness.
Heart: heart failure, infarction (heart attack)
Digestive system: bleeding, intestinal bleeding disorder.
Kidney: Kidney failure.
6- Entry site complications:
a) Due to infection at the incision site; redness, pain, discharge or abscess may occur.
b) Dissection (separation in vessel wall layers)
c) Vascular occlusion or narrowing. Malnutrition may occur that requires treatment through surgery or angiography.
ç) Aneurysm (sac occuring in the weakened area of the vessel wall), pseudoaneurysm (posing that occurs around the vessel due to the inability to close the entrance in the artery), bleeding, nerve damage.
d) Arteriovenous fistula (the formation of a connection between the artery and the vein) may result in malnutrition and swelling in the inserted limb, which requires treatment through surgery or angiography.
e) Temporary or permanent damage to the area fed by the vessels as a result of the catheter causing the interruption of the flow in the vessel due to a previous narrowing in the vessel through which the catheter passes, or dissection, spasm or coagulation or rupture of the clot by catheter or wire manipulation. In this case, treatment through emergency surgery or angiography may be required.
7- Perforation, tearing, occlusion of the vessels in the entry site and path.
8- Obstruction due to coagulation in the stent graft
9- Occlusion in the kidney vessels with clots or plaques that break off in the vessel.
10- Aneurysm burst. It can happen during the procedure (very rare). It can happen even after successful treatment (due to the inability of the stent graft to adhere to the vessel wall)
11- Occlusion in the leg arteries.
12- In the vascular area where the stent graft is attached (aneurysm length)