Aortic Aneurysm Opening the aneurysm

Aortic Aneurysm

SECTION 7.00 OPENING THE ANEURYSM

7.01 DISPLAY THE ANTERIOR SURFACE OF THE ANEURYSM

Reflect the peritoneal cover using a pledget.
This may be the site of an enormous haematoma and infiltration from blood from a leaking aneurysm.

7.02 LOOK FOR THE INFERIOR MESENTERIC ARTERY

Dissect with a pledget.
Look on the left lateral wall of the aneurysm.
If you find the artery, ligate it at two sites 10mm apart.
Use 3/0 Vicryl (Ethicon W 9125).
Cut the artery between the sutures.
If you cannot find the artery:
Continue with the dissection.
Be prepared to stitch it off from inside the aorta if it has not thrombosed.

7.03 LET THE ANAESTHETIST CATCH UP WITH BLOOD LOSS

If the bleeding has been controlled with the aortic clamp:
The anaesthetist has time to replace blood loss with blood or colloid.
If the bleeding is not controlled with the clamp:
Compress the aorta with an aortic compressor in the lesser sac. The exploration has to continue very quickly.
Open the aneurysm sac and control the suprarenal aorta with a Foley catheter balloon.

7.04 CHECKS BEFORE OPENING THE ANEURYSM

Check there is a large bowl available for the blood clot and platelet thrombus from the aneurysm.
Check the scrub nurse has:
   A 16 F G Foley catheter:
   Balloon checked by inflating to 30ml with saline.
   Artery clamp across the distal end of the catheter.
   A 50ml Luer lock syringe of saline.
Two spare Foley catheters, in case the balloon on the first one bursts, or the iliac vessels need control with the catheters
Three stitches of 3/0 Vicryl (Ethicon W9136) on the scrub table, one mounted on a long needle holder.
These stitches will be to underrun any bleeding lumber arteries in the back wall of the aneurysm.
There may be as many as six or more. They may bleed very near the planned anastomosis at the upper end of the aneurysm.
Be prepared to underrun the rarer median sacral artery.

7.05 OPEN THE ANEURYSM

Use a scalpel with a No 15 blade.
Make a longitudinal incision into the front wall of the aorta.
Start 5 cm above the bifurcation to 5 cm. below the aortic clamp.
Be prepared for:
    Some blood loss from the aneurysm itself.
    Blood loss from the upper aorta.
If the aortic clamp is not clamped tightly enough:
    Tighten the clamp.
If this controls the bleeding:
    Continue the operation.
If not:
    Apply a second clamp higher than the first.
    Press the second clamp even more firmly onto the vertebral column than the first, before closing the jaws.
If the second clamp has controlled the bleeding:
    Remove the first clamp
If not:
    Compress the aorta in the lesser sac with an aorta compressor.
    Insert a Foley catheter into the aorta through the aneurysmal incision.
    Inflate the balloon to control the bleeding.
Continue the operation.

7.06 REMOVE THE ANEURYSM CONTENTS

Scoop out blood clots, yellow platelet thrombus and blood with your hand.
Have a large pack available to pack into the lower part of the aneurysm while you deal with any serious bleeding from above.
If there is obvious uncontrolled bleeding from the upper end:
   Tighten or readjust the aortic clamp.
If this fails:
    Insert the Foley catheter 10cm up the aorta.
    Inflate the balloon with up to 30ml of saline to control the upper end of the aneurysm.
    Clip off the filling tube with an artery forcep.
    Make sure the catheter is clamped with another artery clamp.
If there is serious bleeding from below:
    Tighten the iliac clamps.
    Check that they are clamping the common iliacs completely.
    Check that they are not clamping the internal or external iliac arteries only.
    Check that the iliac arteries are not torn.
If they are torn:
   Double clamp and repair the tear with a continuous suture of 4/0 Polypropylene (Ethicon W8935).
If that does not work:
    Consider tying the iliac arteries off and use a trouser graft
   Stitch off the iliac artery with a continuous 4/0 Polypropylene stitch (Ethicon W8935).

7.07 INSERT A RETRACTOR INTO THE ANEURYSM

Use a Travers self-retaining retractor.
Place the handles to distally, so that they do not impede the upper anastomosis.
Open the jaws to display the inside of the aneurysm.

7.08 ANTICOAGULATE THE ILIAC ARTERIES AGAIN

Use the 20ml syringe with a bulb adaptor (blob) containing heparin saline.
Temporarily open the iliac clamps in turn to flush 3 syringefuls of heparin saline down each common iliac artery.

7.09 CONTROL THE LUMBAR ARTERIES

The lumbar arteries, if not blocked, will be bleeding from the back wall of the aneurysm.
The vessels are arranged in pairs – up to 6 pairs, corresponding to the vertebrae. The aortic clamp my compress the lining of the aorta and hide the uppermost two.
Complete control of bleeding is essential to prevent blood obscuring the suturing of the anastomoses as well as causing hypovolaemia.

7.10 UNDER-RUN THE LUMBAR ARTERIES

Excise flaps of atheroma holding the arterial orifices open, before stitching the vessels off.
Use crisscross stitches of 3/0 Vicryl (Ethicon W1936).
You should now have a relatively bloodless field inside the aneurysm sac.
A minute of two controlling minor bleeders at this point is well worth the extra effort.