Open Surgical Repair of
Abdominal Aortic Aneurysm
What is an aortic aneurysm?
The aorta is the largest artery in the body, beginning at the aortic valve in the heart and running initially towards the head. In the upper chest it turns backwards and downwards and courses in front of the spine towards the abdomen. At the level of the umbilicus (belly button) it splits into two arteries (Iliac arteries) to provide blood supply to both legs. Along its course it gives off branches that supply all organs in the head, neck, chest and abdomen. A local dilatation of the aorta is called an aneurysm. Aortic aneurysms occur mostly in the abdominal aorta. They are generally asymptomatic but may rupture leading to an invariably fatal internal bleeding. The risk of rupture depends on the size and becomes significant once the maximum aneurysm diameter exceeds 5.5cm (see Aortic Aneurysm in Conditions).
What is open surgical repair of an abdominal aortic aneurysm?
Open surgical repair of an abdominal aortic aneurysm (AAA) is an invasive procedure aimed at treating, and thereby preventing rupture of, an AAA. It involves a laparotomy (abdominal incision) through either a midline or transverse incision. After exposure of the aorta and iliac arteries, the vessels are clamped above and below the aneurysm. The aneurysmal aorta is then replaced with a polyester graft. Depending on the extent of the aneurysm, a tubular (straight) or bifurcated (trouser) graft may be used to reconstruct the aneurysm and occasionally one or more important aortic side branches, such as the renal arteries, may also require reconstruction.
Why is this operation being offered?
Abdominal aortic aneurysm repair is a prophylactic procedure - the aim is to prevent future rupture of the aneurysm which mostly leads to a fatal internal bleeding. The risk of rupture of any aneurysm is related to its size. Below 5cm maximum diameter, the risk of rupture is very small (
What happens before surgery?
Before you undergo your operation a number of essential investigations and assessments are performed to assess your overall fitness for major arterial surgery and to decide the extent of aortic reconstruction depending on you vascular anatomy. These may include: •Blood tests •CT angiography •Cardiac Echocardiogram •Cardiopulmonary exercise test •Chest X-ray •ECG Once the decision has been made to proceed with your operation an admission date will be agreed between you and your surgeon. A pre-admission visit will be required to complete paperwork and undertake blood tests or other allied tests required prior to undergoing a general anaesthetic. Please bring all your medications to your pre-admission review.
What happens on the day of admission?
Your surgeon will visit you and go through the procedure with you once more. You will also be visited by your anaesthetist. Please do not stop any of your normal medications unless specifically instructed to by your surgeon or anaesthetist. If you smoke we strongly encourage you to stop as soon as possible to reduce the risk of peri-operative complications.
What happens during the operation?
Open surgical repair of an abdominal aortic aneurysm is a major operation performed under general anaesthesia (with you asleep). The first part of your procedure involves administering the anaesthetic. A tube will be placed into your air pipe once you have been anaesthetised and connected to a mechanical ventilator which will breathe for you during the operation. Additionally, you will have a tube (catheter) inserted into your bladder to drain your urine. This facilitates accurate assessment of your hydration status during and immediately after the operation. The anaesthetist will furthermore insert a small tube into an artery in your wrist to enable accurate measurement of your blood pressure during your operation. In order to minimise pain after the operation as much as possible, the anaesthetist may place a catheter in the epidural space of your spinal cord - an epidural. This catheter will be connected to a pump for continuous administration of pain-busting drugs during the first 4-5 days after surgery that numb the nerves supplying the area of the abdominal incision. In case of contra-indications for epidural catheter placement, your surgeon may opt to place a catheter for pain relief in your abdominal wall at the end of the procedure. Once the necessary monitoring equipment has been connected your surgeon will start the operation. At Circulation Clinic we undertake all open AAA repair procedures as a joint case with two of our experienced consultants operating together. This reduces the time taken to perform the operation and thereby the time you are under general anaesthesia. We strongly believe this improves outcomes and reduces the risk of a variety of potential complications including heart attacks, kidney failure, respiratory complications and infection rates. Through a transverse or midline laparotomy the surgeons will gain access to your abdominal cavity. After a brief inspection of the abdominal cavity (to ensure that nothing untoward is found that was not evident on pre-operative invesitgations/imaging), they will proceed to expose the aorta and both common iliac arteries. Depending on the extent of the aneurysm proximally and distally, they may have to expose the renal arteries proximally or gain access to your femoral arteries in the groin. Once adequate exposure has been achieved an aortic clamp will be placed proximally. Ideally this is placed below the renal arteries, so that the kidneys remain perfused during the operation. However, in selected cases your surgeons may deem it necessary to clamp the aorta above the renal arteries, thereby temporarily interrupting the blood flow to your kidneys. The aneurysm is then opened and replaced with a tubular or bifurcated polyester graft which is stitched onto the aorta with a non-absorbable suture. Depending on the extent of the disease, the distal anastomosis (join) is made at the level of the aortic bifurcation (tubular graft), or both iliac arteries/both common femoral arteries (trouser graft). Following the aortic reconstruction all wounds are repaired in layers with stitches. If you have not been given an epidural catheter, your surgeon will now place catheters in your abdominal wall for post-operative pain relief. Drains may be inserted into the groin wounds to drain any excess fluid that may accumulate in the immediate post-operative period. After the operation you will be transported to the Intensive Care Unit (ICU). Depending on how well you are at the end of the operation, the ICU team will try to wake you up as soon as possible. However, they may deem it necessary to keep you sedated for one day (or longer) following the operation. One or two days after the operation you should be well enough to be transferred to the ward where you will stay 4-5 more days until you are fit for discharge.
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Figure 1: CT angiogram demonstrating AAA (white arrow)
What are the risks?
All surgery is associated with risk. Open repair of an abdominal aortic aneurysm is a major procedure associated with significant risks. It poses a major stress for your heart and lungs, while manipulating the aorta. Therefore, this operation is associated with a small risk of potentially catastrophic complications including death. Complications of surgery can broadly be categorised according to when they occur (during the hospital admission - early, or following discharge - late) and whether or not they occur at the site of surgery (local) or affect the entire body (systemic). Some possible complications of open surgical AAA repair include; •Early complications: •Local oWound-related - Bleeding - Infection - Wound breakdown - Fluid collection oInjury to surrounding structures - Nerve damage causing numbness, pain or weakness in the leg - Lymphatic leak causing leakage from the wound, collection or leg swelling - Aortic, iliac and/or femoral dissection and occlusion - Iatrogenic trauma to small bowel oGraft complications: - Bleeding or blockage requiring re-operation. - Graft infection (rare) oBlood clot in leg (deep vein thrombosis) •Systemic oHeart related - Heart attack - Irregular heart rhythm oLung related - Pneumonia - Fluid on the lungs - Clot on the lung (pulmonary embolus) oKidney related - Kidney failure that may require temporary dialysis oBrain related - Stroke oUrogenital - Impotence - Retrograde ejaculation oGastrointestinal - Gastroparesis and pseudo-obstruction - Large and/or small bowel ischemia requiring bowel resection. oDeath •Late complications •Graft related: oBlockage of (a limb of) the graft is a rare occurrence. It is seen in 0-5% of open aneurysm repair cases. For patients with combined aneurysmal and occlusive disease the risk of graft occlusion is higher. The indication for treatment of the graft occlusion depends on the severity of associated symptoms, the physical condition of the patient and the vascular anatomy. If possible, endovascular (keyhole) procedures are used to restore blood flow through the graft, although occasionally the surgical team may opt for a re-laparotomy to get the graft running again. oAnastomotic pseudoaneurysms are rare late complications of aortic surgery. They represent disruption of the anastomotic suture line and as such require ideally re-intervention. However, re-interventions for anastomotic pseudoaneurysms are technically challenging and associated with increased risk for the patient. If possible, they are treated endovascularly (keyhole procedure). Occasionally, a conservative approach with frequent follow up scans is preferred, in the absence of a simple and durable reconstruction alternative. oGraft infection (<2%) oAorto-enteric fistula (
What happens after the operation?
After the operation you will be transferred to ICU. Depending on your condition, the ICU team will either try to wake you up and extubate you as quickly as possible, or may choose to keep you sedated and intubated for one or two days. Once you are awake and extubated, and under the provision that you do not require any cardiovascular or other support, you will be transferred from ICU to the vascular ward for further recuperation. The majority of patients remain in hospital for 7-10 days following aortic surgery, but this does vary on an individual basis. Patients are encouraged to mobilise as soon as possible after the procedure. With the help of a physiotherapist, patients are encouraged to get out of bed as soon as possible, to minimise the risk associated with prolonged immobility, such as chest infection, muscle wasting, and bed sores. Throughout the early period of recuperation there will be discomfort at the site of the operation which we address with a multi-targeted approach including; epidural pain relief, local abdominal wall infusion of pain medication, oral or intravenous analgesia.
What happens when I go home?
Although at the time of discharge we ensure you are safe to go home we ask that there is a responsible adult with you for the first few days following discharge. Your wounds will have sufficiently healed within a few days of surgery to allow you to have a shower. Your ability to have a shower within this time frame is primarily dictated by your overall physical recovery, with many preferring a sponge wash during the immediate post-operative period. We ask you to refrain from submersive bathing until the wounds are fully dry; normally 1-2 weeks post-surgery. For the first few weeks post-surgery there is often wound pain and discomfort. You may feel physically exhausted doing relatively minor activity, rest assured this is entirely normal and improves with time. The majority of people are not able to return to physical activity within 8 weeks of discharge, but this does depend on the nature of the activity and how well you recuperate. If in any doubt please wait until you have been reviewed in clinic by your surgeon. Patients may require anything between 3 months and one year to return to pre-operative levels of fitness.
When will I be able to drive?
You are able to drive when you can perform an emergency stop and are able to concentrate fully on driving. Overall, we advise you to not drive a car for the first 6 weeks post-surgery or until you have pain free movement of your foot and knee, and are able to stamp your foot on the ground. Different rules apply for different ‘Group’ license holders and we recommend contacting the DVLA and your car insurance company for further advice.
Will I need to see the surgeon again?
We review all aneurysm surgery patients in clinic approximately 6 weeks following discharge.