Aortic Aneurysm Treatment

An aortic aneurysm is an abnormal enlargement of the main blood vessel within the abdomen. Unfortunately, a significant proportion of patients with an aortic aneurysm remain asymptomatic and do not realise they have one. Specialist vascular care aims to reduce the likelihood of the aneurysm bursting which continues to exhibit high rates of death.

What is an abdominal aortic aneurysm?
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).

Who gets an AAA?
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.

What are the risk factors for AAA?
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 .

What symptoms would I have with an AAA?
Symptoms associated with AAA include abdominal, back, groin or testicular pain. As an aneurysm stretches and enlarges this pain may increase. If the aneurysm bursts (ruptures), these symptoms are increased significantly and may cause the patient to collapse and lose consciousness.

How would I know if I had an AAA?  
Unfortunately, the majority of patients (>75%) do not know they have an AAA and as such have no symptoms at all. In some cases, patients may notice an abnormal pulse in their abdomen and seek medical care.

How are AAA diagnosed?
Many AAAs are discovered by chance during a routine clinical examination or subsequent to an X-ray or scan performed for a different reason. The majority of patients diagnosed with an AAA will have had an ultrasound scan of their abdomen. This is a quick and painless test and is similar to the scans done on pregnant women to show a picture of their baby. The scan lasts about 10 minutes and will confirm if an aneurysm is present and what size it is. AAA may also be diagnosed from attendance at the NHS Aneurysm Screening Program.

What happens if I am diagnosed with an AAA?
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.

How frequent do AAA follow-up surveillance scans occur?
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 do I need AAA surgery?
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.

What are the success rates of AAA intervention?
Planned elective AAA surgery carries a risk of death less than 5% while surgery when the AAA has ruptured has a mortality risk greater than 50%. The surgical outcomes for individual consultant vascular surgeons and vascular surgery centres throughout the UK are reported on the National Vascular Registry (Vascular Services Quality Improvement Programme-VSQIP) .

What happens if I have an AAA that isn’t large enough to require surgery?
You will continue to undergo surveillance scans.  

What happens if my aortic aneurysm ruptures?
If your AAA ruptures, this is an EMERGENCY and you should call 999 for urgent transfer to your nearest hospital. You should always advise medical personnel that you have an AAA.

Do all hospitals provide care for ruptured AAA?
In Northern Ireland, only the Royal Victoria Hospital in Belfast provides all aspects of specialised AAA care. If your ambulance transfers you to your local hospital, you will be clinically evaluated in that hospital usually followed by completion of an urgent CT scan to assess your aneurysm and to determine if urgent transfer to specialist vascular care at the Royal Victoria Hospital is warranted.  

Do aneurysms develop anywhere else in the body?
Yes, patients with AAAs may have aneurysms elsewhere in their aorta at the chest level (thoracic aorta) or in the lower limbs at groin (femoral) or knee (popliteal) level.  Other types of aneurysm not necessary linked to AAA can occur such as Berry Aneurysms within the brain.

Do I need any fitness tests prior to surgery?
You will require an anaesthetic pre-assessment a few weeks before your surgery which includes a clinical evaluation, blood work-up and some additional investigations for your heart ( Electrocardiogram-ECG and Echocardiogram-ECHO ) and your lungs (Chest X-ray and Pulmonary Function Tests-PFTS ).

It is important to inform your specialist of all your medical conditions and current medications which may be amended to optimise your recovery particularly those medications prescribed  for the treatment of diabetes, heart or lung disease.

When do I need to be admitted to hospital?
Most anaesthetic assessments and subsequent heart and lung tests can be performed during out-patient attendances prior to your planned surgery date. At the Royal Victoria Hospital, patients are usually admitted the day before surgery.

Due to the complex nature of AAA surgery, patients may require a High Dependency or Intensive Care Unit bed following your surgery. Occasionally these specialised beds may not be available on the day of your surgery leading to subsequent postponement of your surgery to a different day on the same admission or occasionally discharge from hospital and re-booking of surgery on a different admission date.

Your vascular surgeon will advise you accordingly and will wish to apologise for such an event if it happens.

Do I have to fast before my surgery?
You will be advised regarding fasting periods before surgery which is usually at least 6 hours before a general anaesthetic.

Most patients will be fasted from midnight on the day of their AAA surgery. As many other aspects can vary depending on your procedure, patients will have an individualised care plan.    

What are the treatment options for AAA?
When it has been decided that treatment is required for your AAA, the type of intervention depends on the overall shape and location of your AAA. Your consultant will discuss which of the two main forms of treatment is most appropriate for you. These procedures include “traditional” Open AAA repair and “keyhole” Endovascular Aneurysm Repair (EVAR).

All AAA patients requiring surgery are discussed at a Specialist Vascular Multi-Disciplinary Meeting where consensus opinion by all members of the vascular team regarding the type of treatment to be provided is agreed.

What does Open AAA Surgery entail?
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.

What are the Risks of Open AAA Surgery?
Open AAA Surgery is a proven treatment option to reduce risk of AAA rupture and death.

Risks of surgery may be divided into;

Local Complications

Bleeding – during your AAA surgery you will receive blood thinning medication to reduce the risk of heart complications and formation of blood clots elsewhere in your body. Your surgeon will take particular care to ensure there is no evidence of any bleeding at the end of the open AAA repair. Although bleeding following your surgery is infrequent (<5%), if it occurs you may require an additional surgery to fix the problem (<1%).

Bruising – can occur after any surgical intervention. It usually causes some localised tenderness and in most cases settles completely after 6 – 8 weeks or earlier.

Pain – it is natural to have some discomfort after any procedure. However, your anaesthetist will provide a post-operative pain relief plan after your surgery incorporating a number of different methods. Optimisation of pain relief will significantly assist your recovery.

Wound Infections – your surgeon will pay particular attention to minimising your risk of wound infections (< 3-4%) following AAA surgery. If you notice wound redness and/or discharge or develop a temperature, it is important to report this to your vascular team if you are still in hospital or your practice nurse / general practitioner if this occurs after your discharge from hospital. Most wound infections can be treated conservatively with good nursing care, dressings and antibiotics. Early treatment is vital to minimise the risk of the infection progressing deeper which can potentially affect the vascular graft itself particularly if it is a prosthetic (artificial) graft.

Open AAA Procedural Related Complications

Abdominal Wall Hernia – open operative surgery requires a skin incision which is then closed with suturing methods at the completion of the procedure. Patient healing can vary in both time and relative strength. Some patients may develop weakening in their wound over time that can lead to a protrusion called a hernia. This may be evident initially during periods of straining. Patients with AAA are at an increased risk of post-operative hernias as their tissues often have an element of weakening which is linked to AAA formation as well.  

Bowel Injury – your surgeon will be very careful during your procedure not to injure any of the structures within your abdominal cavity. Patients with previous abdominal surgery are at an increased risk of intra-abdominal adhesions which slightly increases the risk of bowel injury during open AAA surgery. It is normal for the bowels to slow down or stop functioning during your initial recovery from open AAA surgery. This is why most patients are fasted for the first few days following open AAA surgery. As you begin to recover, you may hear or feel your stomach gurgle and you will start to pass flatus (wind from your back passage) or even small amounts of formed or liquid stool. As you recover, the amount of liquid you will be allowed to take will increase up until your normal diet has been restored.  

Bowel Ischaemia – this occurs if part of the bowel does not get sufficient blood supply following your open AAA surgery. Most abdominal AAA are located close to the level of one of the gut arteries called the inferior mesenteric artery. This artery is often blocked by the atheroma within the aneurysm itself. Therefore the subsequent AAA repair does not usually cause any effects to the part of the large bowel supplied by the artery on the left side of the abdominal cavity. Although it occurs rarely (<1%), this part of the bowel may not appear healthy following open AAA repair which then warrants removal of the affected bowel segment and creation of a stoma (bag).  

Graft Occlusion (Blockage) – open AAA surgery requires the repair of your aneurysm using a prosthetic graft. As this is not going to be your own native tissue, prosthetic grafts do have a small risk of blocking over time (<1%). It is important to ensure you avoid smoking and continue to take your prescribed medications to minimise this risk.  

Graft Infection – this is a serious problem (<1%) often requiring prolonged antibiotic treatment and occasionally further surgery to clean the wound or even remove the graft.

Impotence / Sexual Dysfunction –the nerves responsible for an erection are located adjacent to the aorta. These nerves can be damaged during the AAA repair leading to erectile dysfunction.   

Intra-abdominal Adhesions – any surgery entering the abdominal cavity can create a potential for intra-abdominal adhesions which can form early or many months after the surgery and may never cause any problems. However, some patients may need to attend their clinician with bowel obstruction secondary to these adhesions which may be initially treated conservatively with bowel rest but can occasionally require a second operation.  

Limb Loss – the aorta branches out lower down to form the blood vessels that supply the lower limbs. Occasionally some debris from within the AAA can break off during the repair and lodge in the very small arteries at the foot level. This is called “Trashing” and can lead to some pain in the toe and may cause an ulcer. This does not usually require surgery but can take many weeks or months to fully settle. Limb loss following AAA surgery remains rare (<1%). Sometimes the aorta and iliac arteries are very diseased at the start of the operation and the surgeon may have to alter their surgery type to include groin incisions with the AAA repair extending to the femoral arteries at this level.

Spinal Cord Ischaemia and Paralysis – this complication is associated more in patients who have more extensive aneurysms affecting both the thoracic (chest level) and abdominal aorta. This is a rare complication following elective open AAA repair (<1%).

Systemic Complications

Cardiac (Heart Attack) – any major surgery can stress the heart. This is why your surgeon will have requested an anaesthetic pre-assessment to minimise these risks and ensure your medications are optimised.  

Renal Impairment – open AAA surgery is a major operation that can cause slight reductions in your kidney function during your initial recovery. Your surgeon will try to minimise any actual harmful effects during the surgery itself as open AAA surgery is performed in the immediate area just below your kidney (renal) arteries.  

Respiratory (Chest Infection) – any abdominal surgery can increase lung complications particularly when a patient does not breathe deeply enough due to pain. Your anaesthetist will optimise your pain relief and you will also see a chest physiotherapist as you recover. It is very important to have considered smoking cessation prior to any procedure.

Thromboembolic (Vein Clots) – All patients requiring major surgery are placed on a preventive care plan to minimise clots in your legs and clots that can also affect the lungs. This may include light compression stocking combined with mechanical lower limb compression during your surgery and injection of blood thinning medication throughout your hospital admission.  

Mortality – All major surgery carries a mortality risk. This is why your surgeon will be extremely particular about all facets of your care during open AAA repair. All surgeons within the UK submit their outcome data to the National Vascular Registry.

Local Complications

Bleeding – during your AAA surgery you will receive blood thinning medication to reduce the risk of heart complications and formation of blood clots elsewhere in your body. Your surgeon will take particular care to ensure there is no evidence of any bleeding at the groin wounds after completion of the endovascular AAA repair. Although bleeding following your surgery is infrequent (<5%), if it occurs you may require an additional surgery to fix the problem (<1%).

Bruising – can occur after any surgical intervention. It usually causes some localised tenderness and can occasionally travel to the penis/ scrotal or vaginal areas. Please do not worry about this as most bruising settles after a few weeks.

Numbness – some patients may describe numbness at the groin wound or further down the inside of the thigh. This can occur following any groin wound as the femoral nerve can occasionally be stretched during the procedure by a surgical retractor (device used to keep groin open so the vessels can be accessed during the procedure). This normally settles.

Pain – it is natural to have some discomfort after any procedure. However, your anaesthetist will provide a post-operative pain relief plan after your surgery usually involving pain relief tablets. Optimisation of pain relief will significantly assist your recovery.

Wound Infections – your surgeon will pay particular attention to minimising your risk of wound infections (< 3-4%) following AAA surgery. If you notice wound redness and/or discharge or develop a temperature, it is important to report this to your vascular team if you are still in hospital or your practice nurse / general practitioner if this occurs after your discharge from hospital. Most wound infections can be treated conservatively with good nursing care, dressings and antibiotics. Early treatment is vital to minimise the risk of the infection progressing deeper.  

Endovascular AAA Procedural Related Complications

Bowel Ischaemia – this occurs if part of the bowel does not get sufficient blood supply following your endovascular AAA surgery. Although most abdominal AAA are located close to the level of one of the gut arteries called the inferior mesenteric artery, this artery is often blocked by the atheroma within the aneurysm itself. Endovascular repair does not specifically block this artery if it is still open and as such bowel ischaemia is rare after endovascular AAA repair. However, severe left sided abdominal pain following endovascular AAA repair may suggest a reduction in bowel blood flow which will warrant an urgent CT scan and emergency bowel surgery if the bowel is not healthy and formation of a stoma (bag). This fortunately is a rare event (<1%). 
 

Graft Occlusion (Blockage) / Migration – your vascular specialist will complete x-ray pictures at the end of your procedure to ensure the blood flow through the stent is satisfactory. Occasionally the stents can bend or kink during your initial surgery or even many years later particularly if your own blood vessels were very bendy at the start. Your aorta can remodel with time after endovascular repair leading to stent movement called migration. Such processes may warrant the insertion of further stents to reinforce an area at the same time as your initial surgery or during a second procedure.   

Graft Infection – this is a serious problem (<1%) often requiring prolonged antibiotic treatment and occasionally further surgery to remove the graft.

Impotence / Sexual Dysfunction –the nerves responsible for an erection are located adjacent to the aorta. It is rare for endovascular AAA stents to affect their function.  

Limb Ischaemia / Loss – the aorta branches out lower down to form the blood vessels that supply the lower limbs. Sometimes these vessels are very diseased at the start of the operation and there is a risk of the blood vessels blocking over time or debris breaking off and affecting the lower blood vessels during stent insertion. This is called “Trashing” and can lead to some pain in the toe and may even cause an ulcer. This does not usually require surgery but can take many weeks or months to fully settle. Limb loss following AAA surgery remains rare (<1%).

Seroma – Any incision in the groin area can sometimes disrupt vessel channels called lymphatics. Such disruption can lead to the collection of sterile fluid below the skin leading to the impression of a small soft “golf-ball” appearance in the groin. This is usually a benign process and resolves spontaneously. However, full resolution can take many months. If the swelling starts to affect the skin or cause pain due to pressure, the seroma may require sterile aspiration drainage using a needle and syringe. Very rarely is re-exploration of the groin wound required.   

Spinal Cord Ischaemia and Paralysis – this complication is associated more in patients who have more extensive aneurysms affecting both the thoracic and abdominal aorta. This is a rare complication following elective endovascular AAA repair where the aneurysm is located below the kidney (renal) arteries (<1%).

Requirement for follow-up imaging – Although not a complication of endovascular AAA repair, it is important to comply with follow-up scans to ensure your endovascular AAA stent repair still remains satisfactory. The use of CT for these scans does carry a risk of x-ray radiation exposure which your endovascular specialist will reduce as much as possible by converting your follow-up scans to ultrasound if your AAA repair remains stable.    

Systemic Complications

Cardiac (Heart Attack) – any major surgery can stress the heart. This is why your surgeon will have requested an anaesthetic pre-assessment to minimise these risks and ensure your medication is optimised.  

Renal Impairment – endovascular AAA surgery is a still major operation that can cause slight reductions in your kidney function during your initial recovery. Your surgeon will also try to minimise any actual harmful effects during the surgery itself as endovascular AAA surgery is performed in the immediate area just below your kidney (renal) arteries. Endovascular AAA surgery also uses intra-arterial x-ray dye (contrast) to identify parts of the AAA anatomy during the surgery. This can lead to transient kidney dysfunction which usually settles.  

Respiratory (Chest Infection) – although it avoids an abdominal incision, endovascular AAA surgery can lead to lung complications particularly when a patient does not breathe deeply enough due to pain. Your anaesthetist will optimise your pain relief and you will also see a chest physiotherapist as you recover. It is very important to have considered smoking cessation prior to any procedure.

Thromboembolic (Vein Clots) – All patients requiring major surgery are placed on a preventive care plan to minimise clots in your legs and clots that can also affect the lungs. This may include light compression stocking combined with mechanical lower limb compression during your surgery and injection of blood thinning medication throughout your hospital admission.  

Mortality – All major surgery carries a mortality risk. This is why your surgeon will be extremely particular about all facets of your care during your endovascular AAA repair. All surgeons within the UK submit their outcome data to the National Vascular Registry.

What happens following my surgery?
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 intensive 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 intensive care bed is unavailable in the hospital, your surgery may be postponed or re-scheduled.

How long do I stay in hospital for AAA repair?
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.

Why do I have to stay longer for 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.

Do I need any stitches removed?  
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.   

What is my projected post-operative recovery period like following hospital discharge?
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.