A Case Study to Predict Endoleaks with Aortic Geometry*

Funding by the University of Chicago Jeff Metcalf Fellowship Grant and the National Institutes of Health (NIH 1R01HL159205-01)

The aorta is a pressurized shell whose geometry is subject to change depending on various conditions and stresses.  When this cylinder-like vessel becomes distressed, its walls weaken and can locally enlarge like a balloon, resulting in the formation of an aneurysm.  To treat this condition, physicians use an endovascular aortic repair (EVAR) technique to implant a stent in the affected region.  This restores normal blood-flow and reduces the aneurysmal sac’s diameter over time.  Physicians typically refer to the maximum aortic diameter as an indication of whether or not EVAR is appropriate.  The predictive power of this statistic is not absolute as a common complication of this procedure is an endoleak; this is where blood continuously leaks into the sac and the aneurysm regrows over time due to loss of seal or geometric incapability between the aorta and the stent.  To elucidate the geometric factors that may contribute to endoleak, we determined the curvedness, shape index, and maximum diameter profiles from computed tomography scans for a patient diagnosed with an endoleak post-EVAR over time.  We expect to find geometric signatures beyond the maximum diameter that can predict if an EVAR will be successful.