EVAR-Endovascular aneurysm repair
The intended benefits: to prolong life by preventing rupture of your aneurysm.
Alternative treatments: 1.some patients live on without rupture for some time, especially with smaller aneurysms and some may survive emergency surgery after rupture; only 10-20% do survive though. Once aortic aneurysms reach 5-6 cm in diameter, they are safest mended for most patients. The risk of surgery for you will be carefully assessed with several tests and Consultant Anaesthetist review and will be discussed with you. 2. Open repair will also already have been considered and discussed with you but is not preferable in some patients for medical fitness reasons, especially if older, and has a higher risk of death and complications. It may be a better option for younger and fit patients.
Serious or frequently occurring risks: while repairing the aneurysm, blood flow through it to the lower half of the body is disturbed, more so to the legs. This puts strain on the heart, lungs and kidneys and can cause one or more of them to fail, e.g. a heart attack, together with a small risk of stroke. Dye is injected to allow us to see the arteries on X-ray and this can also affect the kidneys. We monitor these functions carefully and can usually treat them, but severe failures are occasionally fatal despite treatment. These are less common with EVAR than with open aneurysm repair. Prolonged recovery or not returning to your former level of fitness and functions can occur and is more likely after a serious complication. Bleeding in the abdomen is rare but it is dangerous if rupture occurs and may require an emergency open operation. Circulation to the legs or feet can occasionally become blocked after the operation and we must operate to try to restore the circulation. Uncommonly this leads to loss of toes or rarely a leg. Sometimes we need to block a branch artery on purpose, this can lead either to loss of a small area of a kidney, or to the pelvis and buttock resulting in some usually temporary discomfort on walking. Rarely circulation to one or both kidneys is accidentally lost which may cause permanent kidney damage; patients with pre-existing poor kidney function may then develop kidney failure and require dialysis but most patients with previously normal kidney function carry on as normal without treatment with the remaining good kidney. Even more rarely, circulation to the bowel is lost and this needs surgery to remove the affected bowel as it quickly dies with no blood supply which results in peritonitis, sepsis and death if not treated successfully. This may leave you with a stoma, where the bowels empty into a bug on your tummy. Very rarely the circulation to the spinal cord is lost, leading to paraplegia. Impotence can also occur, with or without paraplegia. Infection can rarely affect the stent graft but is both dangerous and difficult to treat. Rarely it is impossible to introduce or fix the stent properly requiring open surgery. All major operations carry general risks, including heart problems. Many requiring this surgery are older or already have a background of heart disease. The risk of heart attack is low in EVAR surgery and lower than with the open repair.
Deep vein thrombosis (DVT) is uncommon as you are usually up and about next day after the operation but extra precautions (heparin injections) are taken for all patients. Around 1 in 10 of those who develop a DVT get clots in the lungs(pulmonary embolism or PE) , only 1 in 10 again of these are life-threatening but this is why we take the extra precautions. Overall, death or major complications each occur in around only 2% of patients.
The surgery requires small cuts in each groin. Early on, the wound may ooze or bleed and a collection of blood or tissue fluid may need removal or bleeding can usually be stopped by further minor surgery if required. Alternatively the wound may become inflamed and infected needing antibiotics and dressings. Rarely a nerve (femoral nerve) next to the artery may be injured causing numbness or weakness of the thigh or leg. In some patients further problems can develop after EVAR, such as the aneurysm coming back or occurring beyond the previous repair, leaking of blood around the stent (endoleak), or loss of circulation to a leg. For this reason we monitor younger patients after treatment with annual CT scans for a few years to check that all remains well. These problems are less likely in older patients who are just scanned once over 80 years. Additional procedures may be needed for these problems, most commonly with more stents for the new aneurysms and leaks.
Modern anaesthetics are generally very safe and you will have the opportunity to discuss this in detail with your Anaesthetist. In most patients, injections in your back to numb the lower half of your body (epidural or spinal anaesthetic) are preferable as this avoids any complications from general anaesthesia. Commoner side effects of an epidural or spinal anaesthetic include:
- Inability to pass urine which resolves as the epidural wears off
- Low blood pressure
- Itching, feeling sick and vomiting or headache
- Inadequate pain relief for which other methods to deal with pain will be offered
Uncommon complications include fits, permanent disabling nerve damage, epidural infection, epidural blood clot and cardiac arrest.
Commoner side effects of a general anaesthetic (1 in 10-100) include: pain during drug injection, aches, pains and backache. Uncommon problems (1 in 1000) include: bladder problems, muscle pains, awareness during surgery or worsening of an existing medical condition. Rare complications (1 in 10,000-100,000) include; bleeding, nerve damage, serious allergy to drugs, equipment failure and death.
Any extra procedures which may become necessary during the operation:
- Blood transfusion is rarely needed unless you are already anaemic but transfusions can result in severe allergic reactions or infections despite careful screening of the blood for you
- Photographs and images X-rays are a usual part of this operation but if we want images for teaching or research purposes, we would always ask your special permission
Other procedures, except for those listed above, are not often required during this operation unless planned in advance , the problems listed above can lead to additional procedures as described.