Aortic Aneurysm Treatment

An abdominal aortic aneurysm (AAA) is an abnormal dilation or swelling of the major artery within the abdomen that supplies the body with blood. An aneurysm is diagnosed when the blood vessel is 50% greater (> 3cm) than the normal diameter of the aorta (<2cm) .

Approximately 5% of people over the age of 60 will have an aortic aneurysm. This rate increases further in patients over the ages of 70 and 80 years respectively. AAAs are 4 to 6 times more common in males.

Smoking is the biggest risk factor for AAA development and enlargement. The presence of high blood pressure, coronary heart disease (angina, heart attack), cerebrovascular disease (TIA, stroke), peripheral arterial disease, chronic respiratory (lung) disease, diabetes, kidney dysfunction and high cholesterol (dyslipidaemia) increase the risk of patients developing an AAA. Certain genetic conditions also pre-dispose to aneurysms such as Marfan syndrome .

The majority of AAAs do not require immediate treatment. All patients diagnosed with an AAA less than 5.5cm in diameter will be enrolled in an AAA surveillance program with completion of another ultrasound scan at a specific time period depending on the size of your AAA.

Patients with an AAA greater than 5.5cm will require a more specialised scan called a CT scan which is usually performed within 2 weeks. This will determine if a procedure to fix the AAA is required.

If you are recently diagnosed with a small AAA less than 4.5cm, most vascular clinicians will request a further ultrasound scan in 6 months to determine your AAA growth rate.

For patients with an already known AAA between 3cm and 4.4cm, an annual ultrasound scan is arranged. If the AAA is between 4.5cm and 4.9cm, an ultrasound scan is arranged every six months and if between 5cm and 5.4cm the time frame for repeat ultrasound scan is 3 months. These time-scales and frequency of ultrasound scans can vary between specialist vascular centres.

When an AAA reaches 5.5cm or greater, surgery is normally considered. At this size, the enlarged AAA can weaken the aortic vessel wall leading to an increase in tension which subsequently increases the risk of the AAA bursting (rupturing).

Research has further demonstrated that the risk of a 5.5cm aortic aneurysm rupturing now becomes greater than the risk of having the AAA repaired in the majority of patients. In certain circumstances, patients with slightly smaller AAAs may be considered for surgery if they have pain or if the AAA has significantly increased in size over a short period of time (> 1cm in one year). Female patients may occasionally be considered for intervention when their AAA is below 5.5cm in size.

Alternatively, if a patient is thought to be very high risk for AAA intervention due to significant medical co-morbidities, their threshold for intervention may be higher than normal. Your surgeon will discuss all these factors with you.

This traditional surgical treatment for an AAA is performed under general anaesthetic. Once you are asleep, a large incision is performed on the front of your abdomen from just below your ribs extending to below your umbilicus (belly button). Occasionally two smaller incisions are completed in your groin depending on the shape and extent of your AAA.

When the surgeon enters your abdominal cavity parts of the bowel are retracted away (moved aside) to allow the surgeon to gain access to the area at the back of the abdominal cavity where the major blood vessels are located. The aorta and iliac arteries are then exposed and clamps are subsequently applied at these levels to lie just above and below the AAA to minimise blood loss when the aneurysm is opened during the repair. Once the aneurysm is opened, an artificial graft is then sutured to healthy artery just below and above where the previously applied clamps are located. Once the suturing is completed the clamps are removed to ensure that the suture line is intact without any leaks. The wound is then carefully closed in multiple layers. A dressing is then applied. The procedure may take between 1 to 4 hours depending on the complexity of repair required.

Endovascular AAA surgery utilises a combination of wires, tubes (sheaths) and stents placed in an area just above and below your AAA to ensure that blood flow passes through the stents and not the AAA anymore thereby reducing pressure within the AAA and the subsequent risk of rupture. It is important to realise that keyhole AAA surgery is still a significant procedure and it can still take time to fully recover after. Careful case planning based on the size and shape of your AAA, by your vascular specialist, ensures an individualised treatment plan to provide the best outcome for you.

A team based approach commences with access to your femoral artery in the groin. This is usually performed with a small vertical surgical incision followed by careful dissection down to the arterial vessels themselves. Alternatively if deemed appropriate, your vessels can be accessed directly without the need for an incision using endovascular devices to close the opening in your artery where the endovascular sheaths and stents pass through.

Once access to your femoral arteries on both sides is obtained, the endovascular stent system is inserted and placed inside your aorta to just below the renal (kidney) arteries. X-ray pictures are then taken with contrast (dye) to ensure accurate positioning of the stent prior to careful deployment of the stent within the aorta to ensure blood flow passes through the stents avoiding the aneurysm itself. The procedure may take between 1 to 4 hours depending on the complexity of repair required.

Most people do not describe significant pain after the procedure. However, positional changes from lying to sitting and sitting to standing can cause slight discomfort as if you have had groin hernia repairs on both sides.

Although your surgeon will have discussed aspects of your AAA intervention during your initial out-patient clinic attendance, they will also meet you before the operation and go through all the required information regarding your planned intervention. The surgeon will then ask you to sign a consent form for your AAA procedure after they have explained the procedure to you.

You will have all aspects of surgery discussed with you ensuring you are aware of why the surgery is required and what risks and complications are associated with the surgery.

You will have an opportunity to meet your anaesthetist before your surgery who will advise accordingly what type of anaesthesia will be required. For open AAA repair, this will include general anaesthesia where you are put to sleep. For endovascular repair, general, spinal or local anaesthesia can be used.

Patients are normally taken to the operating department in their own vascular ward beds. All staff members will introduce themselves to you as we know you will be very nervous pending your procedure.

After you are checked into the theatre environment you will meet your anaesthetic team. Once your anaesthesia is complete, various tubes will be inserted into your bladder, arm veins and wrist artery. This will allow you to be accurately monitored and can facilitate administration of medications, fluid or blood products during your procedure. Some patients will also have a tube placed into their stomach which is more common for patients undergoing open AAA repair compared to endovascular AAA repair.

Not necessarily.

During open AAA surgery, we use a cell-salvage machine which sucks up your own blood during the surgery and subsequently prepares it for re-administration to you. Occasionally you may still require additional blood products from donors during your open AAA repair or in the post-operative period. It is quite rare to require a blood transfusion during endovascular AAA surgery.

Please make your vascular specialist aware as early as possible if you have personal or religious concerns regarding the administration of donor blood products.

Prior to your surgery, the anaesthetic team will have discussed post-operative pain relief which can be provided using an epidural (positioned in your back), rectus sheath catheter (placed either side of an abdominal wound) or a patient-controlled anaesthesia where you, the patient, press a button to provides pain relief at given intervals. Oral pain relief tablets will also be administered.

Most patients will experience some discomfort after any major procedure. However, your specialist vascular team will do their best to try and minimise any pain you may have during your post-operative recovery. It is well researched that optimisation of your pain relief after your procedure affords you a better outcome which is exactly what your vascular team wish for you.

All patients are transferred to the Operating Theatre Recovery Area immediately following surgery for a period of time to ensure you have stabilised after your procedure. Following this period which is normally at least a few hours, you may be transferred back to the vascular ward. This usually occurs after endovascular AAA surgery and often after open AAA surgery if you have minimal medical problems and were relatively fit and healthy prior to your procedure.

Alternatively, your vascular team will have decided during your pre-assessment that a high dependency or critical care bed was required for your initial post-operative recovery period. When you are subsequently deemed stable and require no additional breathing or heart support, you will be transferred back to the vascular ward. Unfortunately, when a high dependency or critical care bed is unavailable in the hospital, your surgery may be postponed or re-scheduled.

Following your admission the day before your AAA surgery, most patients are discharged home after 1 or 2 days following endovascular AAA repair whereas a longer admission between 5 and 10 days is required following open AAA surgery.

Open AAA surgery is a more invasive procedure most often indicated in patients with an AAA not suitable for endovascular repair. Following your abdominal incision, your bowel is moved inside your abdomen to allow access to the aorta at the back of the abdomen. Due to this movement, your gut function can take a number of days to gradually start and normalise. Therefore, you will receive intravenous fluids only for the first few days after your surgery followed by gradual increase in oral fluids prior to consideration of solid food. Patients with a larger incision will also require additional assistance for even simple activities such as sitting up in bed or getting out of bed in the initial period following surgery. Your specialist vascular team will be fully aware of these factors and will assist you every part of the way.

Within 2 to 5 days, the drip (intravenous fluids), epidural and bladder catheter will be removed. The physiotherapists will visit you after your operation. They will help you with your breathing to prevent you developing a chest infection and with your mobilisation to get you walking again. You will become gradually more mobile until you are fit enough to go home.

Most skin wounds can be closed with an invisible suture layer (subcuticular) and you will only require a dressing over the wound for the first few days. If your surgeon uses external sutures or skin staples (clips), these remain for between 10 and 14 days after your procedure. Some patients will have sutures removed in hospital if they are still an in-patient while the majority will have removal arranged by their district nurse following their discharge who will also complete a wound check.

You may feel tired for many months after the operation but this should gradually improve over time. Most patients comment that they return to normal approximately 6 months after open AAA repair. Patients also comment that endovascular AAA repair still takes a similar time to fully recover back to normal.

You should be shower lightly whilst your wounds are healing. It is not advised to fully immerse non-healed wounds in a bath until they are fully healed. You should avoid heavy lifting for at least 6 weeks after the operation to protect the wound and minimise the risk of hernia formation.

You should be able to resume normal sexual activity as soon as you feel comfortable to do so. If you are experiencing problems in this area you should seek advice from your GP or discuss with your vascular specialist at your post-operative follow up consultation. Impotence is a recognised problem of open aneurysm repair and you should ask more about this if you are concerned.

You should refrain from driving for at least for 6 weeks after open AAA repair. Following endovascular AAA repair you may be able to drive sooner provided you can competently perform an emergency stop under controlled conditions. It is suggested for you to advise your car insurance of your recent AAA surgery and clarify matters with your vascular surgeon prior to recommencing driving activities.

You must tell DVLA if your aortic aneurysm is 6 centimetres or more in diameter despite treatment. You must not drive if your aortic aneurysm is 6.5 centimetres or more in diameter.

Most people undergoing AAA repair are retired. If you are still working, you will need a minimum of at least 4 to 6 weeks recuperation or sometimes slightly longer depending on your occupational duties.

Your consultant will organise a follow–up appointment with you approximately 6 to 12 weeks after your procedure to discuss your treatment and assess your recovery.

Following open AAA surgery, most vascular specialists do not organise any routine follow-up scans. However, after endovascular AAA surgery, you will have been advised previously regarding the requirement for long-term surveillance follow-up scans which will be arranged 1 month, 12 months and annually thereafter following your endovascular AAA repair. These scans normally involve a CT scan initially converted to ultrasound scanning if your post-operative CT scans are satisfactory. Occasionally, more frequent scans are warranted if your vascular specialist needs to keep a closer check on your AAA.