Endovascular Aneurysm Repair
This procedure has now usurped the role of open repair, and is performed in over 80% of patients undergoing elective AAA repair.
The workup is similar to that of patients undergoing open repair, but with some changes. In order to prepare for this procedure, it is vital that a full medical work-up be obtained to confirm fitness for anaesthesia.
This will involve a number of blood tests, and an assessment of the heart with an ECG, thallium scan, and referral to a cardiologist if there are any concerns about your heart.
A CT scan is necessary for planning the procedure.
It would be fair to say that this procedure has broadened the scope of elective AAA repair, as many patients previously unfit for open repair, can now be offered EVAR
Day of procedure
You may be admitted on the morning of the procedure if your work-up has been completed. You will be required to bring ALL of your usual medications.
It is important to fast for at least 6 hours prior to the procedure. For a morning procedure, you will need to fast from midnight, whereas for an afternoon procedure, this will mean fasting from 7am.
Your anaesthetist will consult you prior to the operation, and explain the anaesthetic and its risks to you.
A full general anaesthetic is administered, and a tube inserted into your windpipe (trachea) to help with your breathing while you are asleep. A catheter is also inserted into your bladder to help in monitoring your fluid status. This will remain in-situ for the first 48 hours.
The operation is performed under sterile conditions in an operating theatre with x-ray facilities (Endovascular suite or catheter lab).
The femoral (groin) arteries are punctured and sheaths inserted into these arteries. The device (endoluminal graft) is delivered into the aorta via the sheaths. The device is modular, consisting a main body and two extension limbs. When deployed it resembles a pair of trousers. As long as we can achieve a satisfactory seal at the top and bottom, the AAA is thereby excluded from the circulation. As the AAA is no longer subjected to pressure is will gradually shrink, but more importantly, the risk of rupture disappears.
As you can appreciate, the sheaths are fairly sizable to accommodate the graft, and would leave a substantial hole in the artery. In order to seal the hole, we use a closure device, which in most cases is successful. Where the femoral artery is very diseased with calcification, an open exposure may be more appropriate
All patients return to ward for observation. Diet and gentle ambulation is readily resumed. Most patients are fit for discharge within 48 hours.
It is imperative that all patients remain under close scrutiny, and to that end you will enter a program of regular scans to rule out any endoleak.
What is an Endoleak?
An endoleak occurs when there is still some blood flow in the aneurysm sac. If this creates pressure in the sac, the sac may expand and could potentially rupture.
A type 1 endoleak will occur if we have not been able to achieve a seal at the top or bottom, or if following what appeared to be a good seal, this has not been maintained and a new leak has emerged.
Persistent flow in arteries emerging from the AAA (lumbar arteries or inferior mesenteric) can cause a type 2 endoleak.
Disruption of the components of the graft can cause a type 3 endoleak