Key result
Increasing stent-graft length in a virtual deployment model reduced maximum von Mises stress at the distal landing zone by approximately 17% with a medium-length graft and 60% with a long graft.
Why the study?
Short stent-graft length has been linked to increased distal SINE risk after TEVAR for type B aortic dissection, but its impact on local biomechanical conditions is unknown.
Does increasing stent-graft length reduce local wall stress at the distal landing zone in patients undergoing TEVAR for type B aortic dissection?
Does increasing stent-graft length reduce local wall stress at the distal landing zone in patients undergoing TEVAR for type B aortic dissection?
Effect estimate: 60% reduction
Absolute Event Rate: 96.69% vs 238.89%
Virtual stent-graft deployment simulations demonstrate that longer stent-grafts may reduce local wall stress at the distal landing zone, potentially lowering the risk of stent-graft-induced new entry in type B aortic dissection.
Longer stent-grafts may reduce distal landing zone stress in TEVAR simulations; leaves open clinical impact on SINE risk.
Thoracic endovascular aortic repair (TEVAR) has been accepted as a standard treatment option for complicated type B aortic dissection. Distal stent-graft-induced new entry (SINE) is recognised as one of the main post-TEVAR complications, which can lead to fatal prognosis. Previous retrospective cohort studies suggested that short stent-graft (SG) length (<165 mm) might correlate with increased risk of distal SINE. However, the influence of SG length on changes in local biomechanical conditions before and after TEVAR is unknown. In this paper, we aim to address this issue using a virtual SG deployment simulation model developed for application in type B aortic dissection. Our model incorporates detailed SG design and hyperelastic behaviour of the aortic wall. By making use of patient-specific geometry reconstructed from pre-TEVAR computed tomography angiography (CTA) scan, our model can predict post-TEVAR SG configuration and wall stress. Virtual SG deployment simulations were performed on a patient who underwent TEVAR with a short SG (158 mm in length), mimicking the actual clinical procedure. Further simulations were carried out on the same patient geometry but with different SG lengths (183 mm and 208 mm) in order to evaluate the effect of SG length on changes in local stress in the treated aorta. Comparisons of simulation results for different SG lengths showed the location of maximum stress varied with the SG length. With the short SG (deployed in the patient), the maximum von Mises stress of 238.9 kPa was found on the intimal flap at the distal landing zone where SINE was identified at 3-month follow-up. Increasing the SG length caused the maximum von Mises stress to move away from the distal landing zone where stress values were reduced by approximately 17% with the medium-length SG and by 60% with the long SG. This pilot study demonstrates the potential of using the virtual SG deployment model as a pre-surgical planning tool to help select the most appropriate SG length for individual patients.
No takes yet. Share an insight, caveat, or question.
Kan et al. (2021) studied Type B aortic dissection (n=1). Virtual stent-graft deployment with varying lengths (183 mm and 208 mm) vs. Short stent-graft (158 mm) was evaluated on Maximum von Mises stress on the intimal flap at the distal landing zone (60% reduction). Increasing stent-graft length in a virtual deployment model reduced maximum von Mises stress at the distal landing zone by approximately 17% with a medium-length graft and 60% with a long graft.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: