Cardiovascular Biology and Biomechanics Laboratory
Our laboratory is a venue of active collaboration among biomedical engineers, vascular biologists and medical doctors. We apply a unique translational approach that integrates mathematics, computational simulations, artificial intelligence, physiology and molecular biology to understand the role of local biomechanical factors in vascular biology of atherosclerosis, stent restenosis and thrombosis.
Our multi-scale investigations extend from in-vitro cell cultures to small and large animal studies, as well as clinical trials. The process:
- Basic science research
- Proof-of-concept studies
- Confirmatory studies
- Clinical studies.
Emphasis
- Biomechanics: Fluid shear stresses and solid stresses
- Multi-modality imaging: Invasive (OCT, IVUS) and non-invasive (CCTA, MRI, PET)
- Multidisciplinary: Biomedical and chemical engineering; molecular and vascular biology; and medicine
- Cardiovascular Disease: Pathophysiology and theranostics
Projects
We developed a novel 3D co-culture model of atherosclerosis, a systematic and cheap experimental approach on comprehending and reversing the atherosclerotic process. In this model, endothelial cells, smooth muscle cells and monocytes are cultured and interact together, simulating accurately the vascular milieu of atherosclerosis.
To reduce the side effects and increase the efficacy of anti-atherosclerotic medications, we are experimenting with a local approach against atherosclerotic plaques. Nanotechnology promotes the specific delivery of therapeutic compounds and offers significant advantages over more traditional therapies, both in terms of efficacy and safety. One drawback of conventional drug delivery nanotechniques is the lack of site targeting.
To answer that problem, we have developed lipid nanoparticles that can be loaded with anti-atherosclerotic drugs to specifically attach to the plaque, or inflamed endothelium, and interact with it. To manipulate those drug-loaded lipid nanoparticles, we have designed a novel atraumatic micro-catheter capable of local delivery. Both the design scheme and feasibility of the catheter, as well as the efficacy of the lipid nanoparticles are being tested in vitro and ex vivo in a custom-designed bioreactor, to be eventually studied in vivo (rabbits).
Percutaneous cardiovascular interventions are still associated with major technical challenges and require extensive planning and intra-procedural precise visualization methods. Advances in computational modeling and simulation science allow patient-specific rehearsal of endovascular stenting procedures.
Patient-specific rehearsal constitutes a unique tool that may help plan the endovascular material choice and navigation, optimize the preoperative preparation and predict the outcome.
This is how precision medicine along with pre-procedural planning can help optimize bifurcation stenting and improve clinical outcomes. Patient-specific computational stenting simulations may shift the management paradigm of coronary bifurcation interventions and provide a new dimension on how to improve the stenting and post-dilatation techniques.
For the first time in humans, we are conducting a randomized, multi-national, multi-centered clinical study – Effect of Local Biomechanical Factors on Bifurcation Stent Restenosis and Thrombosis, or the FLOW ISR study – to investigate the role of fluid stresses on stent restenosis.
We use a validated subject-specific finite element analysis of arterial bifurcations rooted in clinical and experimental data to faithfully predict stent restenosis. The overall objective of this study is to use an individualized approach to identify, for a specific bifurcation, the optimal bifurcation stenting technique that creates a favorable local biomechanical environment and reduces stent restenosis.
Our study brings together extensive expertise, infrastructure and preliminary work in fluid and solid mechanics, computational simulations and vascular biology. These findings will establish clinically-relevant hypotheses that will serve as basis for our long-term goal: a large, randomized controlled trial to show improved clinical outcomes with patient-specific bifurcation stenting strategies.
Whether arterial and venous innervation regulates renal blood flow is still disputed.
In collaboration with Dr. Zucker’s group, we block the renal nervous system in pigs, in anticipation of renal blood flow modification.
Using top-notch intravascular imaging modalities, we measure the arterial renal flow as well as the size of the renal artery, before and after the denervation.
Virtual reality simulation of cardiovascular procedures can contribute to interventional training and improve the educational experience without putting patients at risk, raising ethical conflicts nor requiring expensive animal or cadaver facilities. The ability to demonstrate complex anatomic relationships and the capacity to collect great amounts of data lets us meet the needs of training and assessing interventional skills. Using 3-D printing of soft materials, such as coronaries, with embedded electronics and sensors is one other way we use to study our data and reflect patient-specific rehearsal before stenting.
Guidance with augmented and virtual reality can help achieve this goal, by visualizing the plaque and facilitating alignment of the stent graft with the artery of interest. Our division has an active collaboration with the iEXCEL – UNMC's state-of-the-art program and infrastructure on medical simulations.
Through iEXCEL, we provide a unique training and education on cardiovascular imaging and interventions to our faculty, fellows and staff. We are building simulation models that will form an essential component of the fellows’ experience in a step towards migrating the education out of the conventional lecture rooms to a whole new world that allows the learners to dive within and relate to the educational materials.
Patents
#17056P1
To facilitate a systematic and cheap experimental approach on comprehending and reversing the atherosclerotic process, we developed a novel 3D co-culture model of atherosclerosis. In this model, endothelial cells, smooth muscle cells and monocytes are cultured and interact together simulating in an accurate way the vascular milieu of atherosclerosis.
#18040P
The invention is a catheter head that consists of multiple suturing units that are placed next to each other in a circumferential manner. Each suturing unit consists of two needles with a U-shaped wire hanging in between. A vascular graft will be mounted on the suturing head before-hand. The catheter with the suturing head will be introduced into the vessel using standard endovascular techniques, and a hole into the vascular walls will be made to create the communication between the two lumens.
PCT/US19/19110
Technology that can be used for continuous measurements of blood pressure and arterial blood flow to automatically derive time-varying estimates of multiple factors pertaining to a patient's vascular system. Such factors can include, but are not limited to, resistive flow, capacitive flow, vascular resistance, and arterial capacitance. Determination of such factors can allow for the meaningful assessment of the control of vascular resistance and capacitance in real time.
WO2109/032473
In embodiments, the catheter includes a catheter shaft with a guidewire lumen disposed within the catheter shaft and an infusion lumen at least partially defined by the catheter shaft.
The infusion lumen may at least partially surround the guidewire lumen. The catheter shaft includes a plurality of pores extending through an outer surface of the catheter shaft to the infusion lumen. The plurality of pores are disposed near a distal end of the catheter shaft and are configured to radially dispense a fluid from the infusion lumen.
A catheter system as well as a method for atraumatic fluid delivery of fluid to a target within a biological lumen are also disclosed.
17/076,213 and PCT/US20/57304
In accordance with embodiments of this disclosure, a computational simulation platform comprises a computer-implemented method that includes:
- Generating a 3D reconstruction of a vessel lumen and a surface of the vessel lumen based on invasive or non-invasive imaging
- Generating a mesh of the 3D reconstructed vessel lumen and surface of the vessel lumen
- Assigning material properties to the 3D reconstructed surface of the vessel lumen
- Importing design and material properties of stents and balloons
- Generating a mesh of a stent and balloon
- Positioning the meshed stent and balloon within the mesh of the 3D reconstructed vessel lumen and surface of the vessel lumen
- Performing balloon pre-dilation, stenting and balloon post-dilation computational simulations with the mesh of the 3D reconstructed vessel lumen and surface of the vessel lumen
- Assessing stent and vessel morphometric and biomechanical measures based on the computational simulations.

Yiannis S. Chatzizisis, MD, PhD, FAHA, FACC, FESC, FSCAI
Professor, Division of Cardiovascular Medicine
Section Chief, Interventional Cardiology
Medical Director, Cardiovascular Catheterization Lab
Dr. Chatzizisis is the Director of the Cardiovascular Biology and Biomechanics Laboratory at UNMC.
Contact Us
Lied Tower
Room 12727
4315 Emile St.
Omaha, NE 68105
402.559.5156