Aortic aneurysm repair
Elective and Urgent Operations
Before the operation starts the anaesthetist will insert a number of lines for monitoring your heart, lungs and kidneys. The operation is carried out under a general anaesthetic. The monitoring used is as follows:
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A - line |
This is an arterial line and is inserted into the artery at the wrist (the one where many doctors feel the pulse). It allows very accurate monitoring of your blood pressure. In this picture the A-line is red. The orange object is a cannula into a vein to allow the rapid infusion of fluids. |
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Central line |
This is inserted into the jugular vein in the neck. It allows for monitoring of blood volume. In this picture the big white plastic tube leading to a green connection is the tube from the ventilator. This does the breathing for you whilst you are asleep. |
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Epidural |
This is inserted into the back and positioned near the nerves. It helps during the operation by taking some of the stress off the heart and is used for post-operation pain control. The ECG lead can be seen on the right shoulder. This displays your heart tracing on monitor. |
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Urinary catheter |
This is inserted into the bladder and monitors the amount of urine produced. It indicates if the kidneys are working. |
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Trans-oesophageal doppler |
This is inserted via the gullet and positioned behind the heart. It allows for continuous monitoring of how well the heart is working. |
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| Pulse oximeter | This peg is clipped onto a finger and allows monitoring of the amount of oxygen in your blood. |
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The operation is carried out through a long up and down cut in the abdominal wall or through a sideways cut. The choice depends on personal preference, the patient's build and the extent of the aneurysm.
Once the bowels are moved out of the way, dissection is carried out to identify the aneurysm, the normal aorta above, the renal vein (this is the vein draining the left kidney and it usually crosses in front of the aorta) and the iliac arteries at the lower end:
So that the operation can proceed without undue blood loss, clamps are put on the aorta above the aneurysm and on the iliac arteries below. The aneurysm sac is then opened and any atheroma inside removed. The picture below shows some of the nerves that may be damaged during this procedure - this can cause impotence in men (see complications). Some small arteries at the back (called 'lumbar arteries') bleed and have to be stitched shut:
Depending on the size of the normal aorta, an appropriately sized graft is chosen. The graft is made of polyester ('Dacron'). It is available sterile, pre-packed in a box. It is stitched to the aorta with a permanent suture:
Once the top end has been stitched into place and tested to ensure it does not leak, the graft is cut to length and stitched at the bottom end:
Once the graft is stitched in and the clamps removed, any leaks are controlled with extra stitches. To stop the bowel sticking to the graft, the wall of the aneurysm is stitched over the graft:
The bowels are then returned to their normal position and the abdominal wound closed.
The patient is then transferred to the Intensive Treatment Unit (ITU) for careful monitoring whilst warming up. During the operation the body temperature drops by 3 or 4 degrees. Once normal body temperature has been achieved the patient is woken up and the ventilating tube removed.
For another 24 - 48 hours the patient is closely monitored on the High Dependency Unit (HDU) before the various lines are removed and the patient returned to the ward. If everything progresses to plan the patient is discharged 7 - 10 days after the operation.
Another new, minimally invasive and experimental method of aneurysm repair has been developed over the last few years - endovascular aneurysm repair.
Emergency Operation
This is essentially the same as the elective procedure except that the anaesthetist may not have time to insert an epidural. Dissecting down to the aorta and the renal vein can be difficult as the area is usually full of blood. Sometimes the aorta has to be clamped above the level of the arteries to the kidneys. Once the bleeding has been controlled the operation is essentially as for the elective case. The outcome, however, is often much worse.
Compare this photograph to the one above showing the dissection in an elective operation