Predicting Advanced Endovascular Aneurysm Repair Complications Using 3D Analytical Tools

Fenestrated and branched endovascular aneurysm repair [(F/B)EVAR] is a minimally-invasive method for the treatment of aortic aneurysms involving the visceral segment. These procedures involve the placement of a stent graft that incorporates fenestrations or branches with the goal of excluding the aneurysmal sac while preserving blood flow to the visceral arteries. These fenestrations or branches need to align precisely with the target arteries to maintain blood flow and prevent ischemia related adverse events. The objective of these studies is to provide a more comprehensive understanding of stent graft misalignment and to identify methods to predict and prevent stent graft misalignment with a long-term goal of making these procedures safer and more effective for patients. Stent graft misalignment is a multifactorial process that includes stent graft planning, intraoperative positioning, and stent graft rotation. Greater than 50% of patients undergoing (F/B)EVAR had at least one misaligned renal fenestration and misalignment was associated with higher rates of procedural target vessel complications and severe post-operative adverse events. Similarly, intraoperative stent graft rotation (occurring in 37% of fenestrated procedures) was also associated with a 36% absolute increase in post-operative adverse events. In a multivariate analysis, factors predictive of stent graft rotation included iliac artery torsion, iliac artery calcification, and device length. Insertion technique also plays an important role in the degree of stent graft rotation. In vivo correction for orientation which is commonly performed during the insertion of the device appears to increase the observed rotation and supports the concept of fully removing the device, adjusting the orientation, and subsequently reinserting. Finally, this thesis describes a finite element analysis-based method for predicting the final location of the delivery system and the resulting aortoiliac deformation.Ph.D