Many of these are complex procedures, and precise measurements of the aortic aneurysm or dissection before procedure facilitates planning and ensures appropriate device availability at the time of procedure [9,65] Inclusion of the pelvis in the study also aids in procedure planning by allowing evaluation of the iliofemoral access vessels. Femoral access is typically preferred for endovascular repair, although access vessels must typically be suitable in size, tortuosity, and calcification of the iliac vessels to permit device delivery to the aorta. In patients with inappropriate iliofemoral vessels, groin cutdown with conduit, direct aortoiliac access, or brachial access can be used. Before open or endovascular repair of a thoracoabdominal aneurysm or dissection, some authors have advocated for imaging for identification of the artery of Adamkiewicz because preoperative identification could potentially reduce the risk of spinal cord ischemia [68]. Given the variability of the origin of this artery, preoperative identification of the origin of this vessel allows for operative planning that minimizes risk of damage. Multiple studies evaluating the ability of CT and MRI to identify the artery of Adamkiewicz show that the artery can be identified and traced in >75% of patients, with identification rates typically higher in MRA compared with CTA [68,70-73]. MRA Chest, Abdomen, and Pelvis Without IV Contrast A 2012 study by Shaida et al [63] compared aortic measurements in 20 patients undergoing both CTA and noncontrast MRI before EVAR. The study measured vessel diameter at multiple points as well as several vessel lengths and found small discrepancies between MRI and CTA, typically <1 mm for diameters or 5 mm for lengths [63]. The authors concluded such measurements were unlikely to alter planning of the repair but favored CTA in most patients [63].
Thoracoabdominal Aneurysm or Dissection Treatment Planning and Follow Up. Many of these are complex procedures, and precise measurements of the aortic aneurysm or dissection before procedure facilitates planning and ensures appropriate device availability at the time of procedure [9,65] Inclusion of the pelvis in the study also aids in procedure planning by allowing evaluation of the iliofemoral access vessels. Femoral access is typically preferred for endovascular repair, although access vessels must typically be suitable in size, tortuosity, and calcification of the iliac vessels to permit device delivery to the aorta. In patients with inappropriate iliofemoral vessels, groin cutdown with conduit, direct aortoiliac access, or brachial access can be used. Before open or endovascular repair of a thoracoabdominal aneurysm or dissection, some authors have advocated for imaging for identification of the artery of Adamkiewicz because preoperative identification could potentially reduce the risk of spinal cord ischemia [68]. Given the variability of the origin of this artery, preoperative identification of the origin of this vessel allows for operative planning that minimizes risk of damage. Multiple studies evaluating the ability of CT and MRI to identify the artery of Adamkiewicz show that the artery can be identified and traced in >75% of patients, with identification rates typically higher in MRA compared with CTA [68,70-73]. MRA Chest, Abdomen, and Pelvis Without IV Contrast A 2012 study by Shaida et al [63] compared aortic measurements in 20 patients undergoing both CTA and noncontrast MRI before EVAR. The study measured vessel diameter at multiple points as well as several vessel lengths and found small discrepancies between MRI and CTA, typically <1 mm for diameters or 5 mm for lengths [63]. The authors concluded such measurements were unlikely to alter planning of the repair but favored CTA in most patients [63].