This article is part of the operation script for grafting an abdominal aortic aneurysm. The article can be used on its own, or to go to the next part of the operation, click on NEXT PART OF THE OPERATION at the bottom of this page.
AORTIC ANEURYSM 240 SECTION 12.00 - CHECKING THE ILIAC ARTERIES
STEP 12.01 INTRODUCTION
- The iliac arteries and more distal vessels may be occluded by atheroma, thrombus or embolus.
- Thrombosis and embolism may have occurred before the operation or since the operation started.
- Thrombus and emboli can usually be cleared with a balloon catheter.
- Atheroma may indicate a modification to the operation plan or additional surgery, immediately or later.
STEP 12.02 CHECK THE ILIAC ARTERIES ARE PATENT
- Part open the iliac artery clamp on each side in turn to confirm that there is back bleeding.
- The peripheral vessels are usually patent, and even larger than normal, since the aneurysmal condition often affects all arteries to some degree
- If there is back bleeding from each iliac artery:
- Anticoagulate the iliac arteries again.
- Use the 20ml. syringe with a blunt bulb adapter (blob) containing heparin saline.
- Temporarily open each iliac clamp in turn to flush 3 syringefuls of heparin saline down each iliac artery.
- Go to Section 14.00 CHOOSING A STRAIGHT OR Y GRAFT.
- If there is no back bleeding from one or both iliac arteries:
- Squeeze the quadriceps to force blood from branches of the external iliac back up the common iliac artery into the aorta.
- If there is no back flow from quadriceps compression:
- Pass a Fogarty catheter down the blocked iliac artery from inside the aneurysm.
STEP 12.03 CHECK THE FOGARTY CATHETER
- Check it is a No 4 French Gauge catheter.
- I.e Balloon 4mm. in circumference.
- Check you have a spare No 4 catheter available.
- Have the catheter brought to the operating table.
- Make sure it does not flip onto unsterile areas.
- Remove the central wire.
- Test the balloon at the tip of the catheter.
- Have 0.75ml of heparin saline inserted into a 2ml. syringe.
- Check that there is no air in the syringe.
- Air in the syringe would upset the feel of the catheterisation.
- Push the syringe onto the catheter until any creaking at the joint stops.
- Inflate the balloon with the 0.75ml. of the heparin solution.
- Check that the balloon does not burst and the balloon is a regular sphere shape.
- Replace the catheter if substandard.
STEP 12.04 PASS THE FOGARTY CATHETER DOWN THE LEFT COMMON ILIAC ARTERY
- Open the left iliac artery clamp fully, but leave it in place.
- Pass the Fogarty catheter down the artery.
- The catheter usually passes easily down to about 40cm.
- i.e down the superficial femoral artery and its extension, the popliteal artery, to the popliteal trifurcation.
- The catheter will pass through thrombus and embolus material.
- If the catheter meets an obstruction at less than 20cm:
- This may be due to a kink in a tortuous vessel.
- Bend the distal 2cm.of the catheter.
- Repass the catheter and rotate it to negotiate any kink.
- Try to pass a narrower catheter.
- If the catheter will still not pass:
- The iliac arteries are probably blocked with atheroma.
- You will need to perform a Y aorto-bifemoral graft.
- If the catheter encounters a blockage at 40cm. or so:
- There is probably atheroma at the femoro-popliteal junction.
- Concentrate on clearing the femoral artery of any thrombus or embolus more proximally
- Reassess the blood flow to the limb at the end of the aortic operation.
- A femoro-popliteal bypass may be needed immediately or later.
- If the catheter passes to more than 40cm.:
- There is probably no atheromatous blockage of the femoral or popliteal artery.
- There may be a poor run off more distally.
- This may not be amenable to further surgery.
- Assess this in the recovery period.
STEP 12.05 CLEAR OUT ANY THROMBUS OR EMBOLUS
- At best, this will be from the iliac, femoral and popliteal arteries.
- Push the heparin saline into the balloon until you feel a resistance.
- The resistance is the wall of the artery.
- If you push too hard:
- You can rupture the arterial wall, especially when it is healthy.
- This will most likely be in the vessels below the inguinal ligament.
- The balloon will suddenly inflate easily.
- This sudden inflation can happen also if the balloon bursts.
- Withdraw the balloon.
- If the balloon has burst:
- Replace it.
- Be more gentle with the new balloon.
- If you think you have ruptured the vessel:
- Plan to examine the limb at the end of the operation.
- Explore and repair the vessel as needed.
- Pull the catheter steadily out of the artery with your left hand.
- At the same time, with your right hand, increase or decrease the amount of liquid in the balloon.
- The aim is to match the diameter of the vessel being swept clear of the thrombus or embolus.
- You will probably feel the narrowing of the superficial femoral artery at the adductor hiatus (about 35cm. from the aortic bifurcation).
- You will feel the roughness of atheromatous plaques on the arterial wall.
- As the balloon of the catheter approaches the mouth of the common iliac artery, get the first assistant ready with a vascular sucker to remove thrombus or emboli.
- If you bring up thrombus or emboli:
- Repeat passing the catheter until no more material is obtained.
- You should have a steady stream of back bleeding if the blockage is relieved.
- Flush 60ml of heparin saline down the left iliac artery.
- Reclamp the left iliac artery.
- If there is no back bleeding and the catheter passes to 40cm. or more::
- The limb may not be viable below the knee.
- Flush 60ml of heparin saline down the left iliac artery as above.
- Reclamp the left iliac artery.
- Continue the operation with a straight graft in anticipation of improvement in the distal limb when the aortic flow is reestablished.
- However, the patient may eventually lose part of the left limb from ischaemia.
STEP 12.06 REPEAT THE CATHETERISATION PROCEDURE ON THE RIGHT COMMON ILIAC ARTERY
- Use the same technique as for the left iliac artery
