arXiv subjects

Seda Aslan

Publications and source records attributed to Seda Aslan.

3 recordsLinked to original sources

arXiv2026

Assessing Hemodynamic Impact of Tissue-Engineered Vascular Graft Displacement: Combining Postoperative in vivo Results and Computational Modeling to Improve Surgical Planning

Tissue-engineered vascular grafts (TEVG) have shown promise in advancing vascular reconstructions. However, precise in vivo implantation is challenging, and it is unclear how deviations in location and size affect hemodynamics. This study aims to compare preoperative designs and postoperative anatomies of TEVG in an in vivo study to evaluate discrepancies and investigate the impact of graft displacement and size on hemodynamics by virtually simulating implantation scenarios that are informed by in vivo postoperative results. Designed and postoperative geometries of four porcine aortas were compared to measure the mismatch in implantation location and graft shape. These results informed a virtual TEVG implantation study. TEVG location, orientation, and size were varied to investigate the effects on the final aorta shape and hemodynamics. Anastomosis of TEVG was simulated using finite element modeling. Key hemodynamic metrics were obtained from virtual implantations and actual postoperative anatomies using computational fluid dynamics. Our in vivo study showed that TEVGs can experience up to 6.9 mm displacement and a 38 degree rotational shift post-implantation, leading to discrepancies in pressure drop (2.5 mmHg, 50%) and time-averaged wall shear stress (7.2 Pa, 72%) compared to predictions. Virtual anastomosis simulations improved aortic shape predictions by 27.5%. Our results highlight the sensitivity of key hemodynamic metrics to graft implantation location and size mismatch. By quantifying displacement ranges and their impacts during surgery, surgeons can make informed decisions.

physics.med-ph↗

arXiv2025

Simulation of Transcatheter Therapies for Atrioventricular Valve Regurgitation in an Open-Source Finite Element Simulation Framework

Purpose: Transcatheter edge-to-edge repair (TEER) and annuloplasty devices are increasingly used to treat mitral valve regurgitation, yet their mechanical effects and interactions remain poorly understood. This study aimed to establish an open-source finite element modeling (FEM) framework for simulating patient-specific mitral valve repairs and to evaluate how TEER, annuloplasty, and combined strategies influence leaflet coaptation and valve mechanics. Methods: Four G4 MitraClip geometries were modeled and deployed in FEBio to capture leaflet grasp and subsequent clip-leaflet motion under physiologic pressurization. CardioBand annuloplasty was simulated by reducing annular circumference via displacement-controlled boundary conditions, and Mitralign suture annuloplasty was modeled using discrete nodal constraints. Simulations were performed for prolapse and dilated annulus cases. Valve competence (regurgitant orifice area, ROA), coaptation/contact area (CA), and leaflet stress and strain distributions were quantified. Results: In prolapse, TEER restored coaptation but increased leaflet stresses, whereas band and suture annuloplasty produced distinct valve morphologies with lower stress distributions. In dilation, TEER alone left residual regurgitation, while annuloplasty improved closure. Combined TEER & band annuloplasty minimized ROA, maximized CA, and reduced stresses relative to TEER alone, though stresses remained higher than annuloplasty alone. Conclusion: This study establishes a reproducible, open-source FEM framework for simulating transcatheter TEER and annuloplasty repairs, with the potential to be extended beyond the mitral valve. By quantifying the mechanical trade-offs of TEER, suture annuloplasty, band annuloplasty, and their combinations, this methodology highlights the potential of virtual repair to guide patient selection and optimize surgical planning.

physics.med-ph↗

arXiv2025

Integrated Open-Source Framework for Simulation of Transcatheter Pulmonary Valves in Native Right Ventricular Outflow Tracts

Background - Pulmonary insufficiency is a consequence of transannular patch repair in Tetralogy of Fallot (ToF), leading to late morbidity and mortality. Transcatheter native outflow tract pulmonary valve replacement (TPVR) has become common, but assessment of patient candidacy and selection of the optimal device remains challenging. We demonstrate an integrated open-source workflow for simulation of TPVR in image-derived models to inform device selection. Methods - Machine learning-based segmentation of CT scans was implemented to define the right ventricular outflow tract (RVOT). A custom workflow for device positioning and pre-compression was implemented in SlicerHeart. Resulting geometries were exported to FEBio for simulation. Visualization of results and quantification were performed using custom metrics implemented in SlicerHeart and FEBio. Results - RVOT model creation and device placement could be completed in under 1 minute. Virtual device placement using FE simulations visually mimicked actual device placement and allowed quantification of vessel strain, stress, and contact area. Regions of higher strain and stress were observed at the proximal and distal end locations of the TPVs where the devices impinge the RVOT wall. No other consistent trends were observed across simulations. The observed variability in mechanical metrics across RVOTS, stents, and locations in the RVOT highlights that no single device performs optimally in all anatomies, thereby reinforcing the need for simulation-based patient-specific assessment. Conclusions - This study demonstrates the feasibility of a novel open-source workflow for the rapid simulation of TPVR which with further refinement may inform assessment of patient candidacy and optimal device selection.

q-bio.TO↗