SECTION 6.00 CONTROLLING THE LOWER END OF THE ANEURYSM

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6.01 INCISE THE PERITONEUM OVER THE ANEURYSM

Use dissecting scissors and a pledget.
Run the dissection down the mid line of the aorta.
Start at the site of opening the peritoneum at the lower border of the duodenum.
Finish at the bifurcation of the aorta. This may run to one side or another if the aneurysm distorts the anatomy.

6.02 DIVIDE THE INFERIOR MESENTERIC ARTERY

Look out for the inferior mesenteric artery running downwards on the left side of the sac. If you cannot find it, it may be thrombosed.
Dissect out the mesenteric artery, double ligate it with 2/0 Vicryl (Ethicon W9125) and divide it.

6.03 DISSECT OUT THE COMMON ILIAC ARTERIES

Use a mixture of finger and blunt dissection.
The common, the external and internal iliac arteries may be displaced from their usual positions and directions.
This can be caused by the aneurysm and a large haematoma.
Also, any dilatation of the iliacs is usually associated with lengthening and tortuosity of the vessels.
Make sure you have dissected the common iliac arteries, and not the others.
Concentrate on the displaying the front and the sides of the iliac arteries to allow a right angled clamp to occlude the vessel.
It is unnecessary to dissect behind the back of the common iliac artery. It is also very dangerous because of the risk of damaging the iliac veins.
Control abnormal branches of the iliac arteries with sloops, double wrapped around and clipped with artery forceps.
If the iliac veins bleed:
   Control them with 5 minutes of pressure.
If this fails:
   Repair the defects with 4/0 Prolene (Ethicon W8935) .
If this fails:
   Tie the veins off using 2/0 Vicryl (W9025).

6.04 CLAMP THE LEFT COMMON ILIAC ARTERY

Use a right angled De Bakey clamp (3 clicks).
Arrange the handles to lie down towards the thigh so as to be out of the way of the anastomoses.
If the vessel is too deep:
   Use a straight vascular clamp. Beware of knocking it during the anastomosis.

6.05 LOCALLY ANTI-COAGULATE THE DISTAL LEFT ILIAC ARTERY

Use 20 ml of Heparinised Saline, a 20 ml. syringe and a green topped 21 SWG needle.
Check the needle is pressed onto the syringe until it has stopped creaking.
Squeeze the artery distal to the clamp to find an uncalcified area of wall.
This squeezing will also help check whether the artery is thrombosed.
Push the needle into the anterior wall at right angles to the vessel.
Avoid pushing the needle through the posterior wall.
Aspirate blood into the syringe before injecting, to confirm you are in the lumen of the artery.
If blood does not aspirate:
   You may have gone through the posterior wall.
Choose another site on the artery.
If blood still does not aspirate:
   The artery may contain blood clot, aneurysmal debris or be blocked by atheroma. (Your initial clinical examination of the    patient should have suggested any arterial blockage).
Continue with the operation, but be prepared to perform an embolectomy or to eventually use a straight graft.

6.06 CLAMP THE RIGHT COMMON ILIAC ARTERY

Use a right angled De Bakey clamp (3 clicks).
Arrange the handles to lie down towards the thigh so as to be out of the way of the anastomoses.
If the vessel is too deep, use a straight De Bakey clamps. Beware of knocking it during the anastomosis.

6.07 LOCALLY ANTI-COAGULATE THE DISTAL RIGHT ILIAC ARTERY

As for the left common iliac artery:
Use 20 ml of Heparinised Saline, a 20 ml. syringe and a green topped 21 SWG needle.
Check the needle is pressed onto the syringe until it has stopped creaking.
Squeeze the artery distal to the clamp to find an uncalcified area of wall.
This squeezing will also help check whether the artery is thrombosed.
Push the needle into the anterior wall at right angles to the vessel.
Avoid pushing the needle through the posterior wall.
Aspirate blood into the syringe before injecting, to confirm you are in the lumen of the artery.
If blood does not aspirate:
   You may have gone through the posterior wall.
Choose another site on the artery.
If blood still does not aspirate:
   The artery may contain blood clot, aneurysmal debris or be blocked by atheroma. (Your initial clinical examination of the    patient should have suggested any arterial blockage).
Continue with the operation, but be prepared to perform an embolectomy or to eventually use a straight graft.