Determination, Calculation and Representation of the Upper and Lower Sealing Zones During Virtual Stenting of Aneurysms

The minimal-invasive or endovascular treatment of aneurysms requires the selection of an appropriate prosthesis (stent) before an intervention. A stent with wrong dimensions in length or diameter can lead to fatal outcomes for the patient: artery branches can be covered and thus can be excluded from the blood flow. The indicators for a correctly dimensioned stent are the sealing zones where the stent fits to the healthy artery wall. The sealing zones must also have a certain size [1, 2] because an insufficient sealing zone can cause shifting of the stent inside the artery or stress the relevant artery wall. Avoiding stent shifting, stressing of the artery wall and covering branches requires an accurate preoperative stent planning. The importance of this accurate stent planning is indicated by the randomized EndoVascular Aneurysm Repair (EVAR) trials [3]. Within the first four years, 41% of the cases after an endovascular treatment showed complications that required an additional intervention. In this contribution, a novel method for stent simulation in preoperative computed tomography angiography (CTA) acquisitions of patients is presented where the sealing zones are automatically calculated and visualized. The method is eligible for nonbifurcated and bifurcated stents (Y-stents). Results of the proposed stent simulation with an automatic calculation of the sealing zones for specific diseases (abdominal aortic aneurysms (AAA), thoracic aortic aneurysms (TAA), iliac aneurysms) are presented. The contribution is organized as follows. Section 2 presents the proposed approach. In Section 3, experimental results are discussed. Section 4 concludes the contribution and outlines areas for future work.