Differance between Descending Thoracic or Abdominal Aneurysm ?
Descending Thoracic Aortic and Thoraco-Abdominal Aneurysm : The approach is through n left postero-lateral thoracotomy. After positioning the patient in the right lateral position with left leg extended and the groin exposed, cardiopulmonasy bypass is instituted by cannulalion of femoral artery and vein of the left leg. A well-lubricated venous cannula is inserted and placcd in the middle of right atleiurn. TEE can help in positioning the cannula in the right atrium. Dissection is done above and below the aneurysm 'and tapes passed for clamping the aorta. Femoro-femoral bypass is instituted to protect the spinal cord and abdominal viscera. Aorta is clamped above and below and aneurysnl is opened and clots removed. Small intercostal vessels are occluded with sutures.
Lager ones along with a cuff of aorta are anastomosed to the graft. Proximal anastomosis is done between graft and upper end of thoracic aorta. Proximal clamp is removed and it is applied on the middle of the graft. Bleeding from upper suture line is controlled. Later on distal anastomosis is done to the normal aorta below the aneurysm.
A large thoraco abdominal aneurysm will require entry into the chest at two inter costal spaces and if necessary extension into the abdomen extra peritoneally. The celiac axis, superior mesenteric and renal vessels are raised with full thickness aorta and anastomosed to the graft.