Simulated<unk>  for an infrarenal<unk>  aneurysm. The clamp seen is above the aneurysm and below the renal arteries Simulated clamp placement for<unk>  repair of an infrarenal<unk>  aneurysm Simulated proximal suture line using "parachute" technique for an<unk>  infrarenal<unk>  aneurysm repair Completed proximal suture line of a simulated infrarenal<unk><unk>  repair with a dacron bifurcated graft<unk><unk>  typically involves exposure of the dilated portion of the aorta and insertion of a synthetic (Dacron or Gore-Tex) graft (tube). Once the graft is sewn into the proximal (toward the patient's head) and distal (toward the patient's foot) portions of the aorta, the aneurysmal sac is closed around the graft. Alternatively, the anastomosis can be carried out with expandable devices, a simpler and quicker procedure The aorta and its branching arteries are cross-clamped during<unk><unk> . This can lead to inadequate blood supply to the spinal cord, resulting in paraplegia, when repairing thoracic aneurysms. A 2004 systematic review and meta analysis found that cerebrospinal fluid drainage (CFSD), when performed in experienced centers, reduces the risk of ischemic spinal cord injury by increasing the perfusion pressure to the spinal cord. A 2012 Cochrane systematic review noted that further research regarding the effectiveness of CFSD for preventing a spinal cord injury is required. Approach The infrarenal aorta can be approached via a transabdominal midline or paramedian incision, or via a retroperitoneal approach. The paravisceral and thoracic aorta are approached via a left-sided posteriolateral thoracotomy incision in approximately the 9th intercostal space. For a thoracoabdominal<unk>  aneurysm, this approach can be extended to a median or paramedian abdominal incision to allow access to the iliac arteries. Sequential<unk>  clamping At medical centers with a high volume of<unk> , the fastest option for<unk>  was sequential<unk>  clamping or "clamp-and-sew", whereby the aorta was clamped proximally and distally to the diseased segment, and a graft sewn into the intervening segment. This technique leaves the branches of the aorta un-perfused during the time it takes to sew in the graft, potentially increasing the risk of ischemia to the organs which derive their arterial supply from the clamped segment. Critics of this technique advocate intra-operative<unk>  perfusion. In infrarenal aneurysms, the relative tolerance of the lower extremities to ischemia allows surgeons to clamp distally with low risk of ill effect. Techniques to limit Ischemia A number of techniques exist for maintaining perfusion to the viscera and spinal cord during<unk>  thoracoabdominal<unk>  aneurysm repair, including left heart bypass, balloon perfusion catheter placement in the visceral arteries, selective spinal drainage and cold crystalloid renal perfusion. There is limited evidence supporting these techniques. Graft configuration The abdominal aorta is anastomosed preferentially to the main limb of a tube or bifurcated graft in an end-to-end fashion to minimize turbulent flow at the proximal anastomosis. If normal aorta exists superior to the iliac bifurcation, a tube graft can be sewn distally to that normal aorta. If the distal aorta is diseased, a bifurcated graft can be used in an aorto-billiac or aorto-bifemoral configuration. If visceral vessels are involved in the diseased<unk>  segment, a branched graft can be used with branches sewn directly to visceral vessels, or the visceral vessels can be separately revascularized. Reimplantation of the inferior mesenteric artery Because of collateral blood flow from the superior mesenteric artery (SMA) via the marginal artery, the inferior mesenteric artery usually does not have to be reimplanted into the<unk>  graft when performing an<unk>  abdominal<unk>  aneurysm repair.
Open aortic surgery
Emergency bleeding control
Minimally invasive cardiac surgery
Aortic cross-clamp
Intravascular imaging
Aortography
Warren operation
Mechanical filter 