Patient-specific tissue engineered vascular graft for aortic arch reconstruction.

Objectives: The complexity of aortic arch reconstruction due to diverse 3-dimensional geometrical abnormalities is a major challenge. This study introduces 3-dimensional printed tissue-engineered vascular grafts, which can fit patient-specific dimensions, optimize hemodynamics, exhibit antithrombotic and anti-infective properties, and accommodate growth.

Methods: We procured cardiac magnetic resonance imaging with 4-dimensional flow for native porcine anatomy (n = 10), from which we designed tissue-engineered vascular grafts for the distal aortic arch, 4 weeks before surgery.

In vitro investigation of axial mechanical support devices implanted in the novel convergent cavopulmonary connection Fontan.

Objectives: The 2 opposing inflows and 2 outflows in a total cavopulmonary connection make mechanical circulatory support (MCS) extremely challenging. We have previously reported a novel convergent cavopulmonary connection (CCPC) Fontan design that improves baseline characteristics and provides a single inflow and outflow, thus simplifying MCS. This study aims to assess the feasibility of MCS of this novel configuration using axial flow pumps in an in vitro benchtop model.

Virtual Planning and Patient-Specific Graft Design for Aortic Repairs.

Purpose: Patients presenting with coarctation of the aorta (CoA) may also suffer from co-existing transverse arch hypoplasia (TAH). Depending on the risks associated with the surgery and the severity of TAH, clinicians may decide to repair only CoA, and monitor the TAH to see if it improves as the patient grows. While acutely successful, eventually hemodynamics may become suboptimal if TAH is left untreated.

Validity of Customized Branched Tissue Engineered Vascular Graft in a Porcine Model.

Background: Patient-specific, 3-dimensional printed, tissue engineered vascular grafts (3DTEVGs) are manufactured to optimize hemodynamic performance and to accommodate growth. We evaluate growth outcomes of 3DTEVGs compared with standard grafts for pulmonary artery reconstruction in porcine models.

Methods: Magnetic resonance imaging (MRI) with 4-dimensional flow data was acquired in porcine models (n = 8).

Location matters: Offset in tissue-engineered vascular graft implantation location affects wall shear stress in porcine models.

Objective: Although surgical simulation using computational fluid dynamics has advanced, little is known about the accuracy of cardiac surgical procedures after patient-specific design. We evaluated the effects of discrepancies in location for patient-specific simulation and actual implantation on hemodynamic performance of patient-specific tissue-engineered vascular grafts (TEVGs) in porcine models.

Methods: Magnetic resonance angiography and 4-dimensional (4D) flow data were acquired in porcine models (n = 11) to create individualized TEVGs.

Computational Fontan Analysis: Preserving Accuracy While Expediting Workflow.

Postoperative outcomes of the Fontan operation have been linked to geometry of the cavopulmonary pathway, including graft shape after implantation. Computational fluid dynamics (CFD) simulations are used to explore different surgical options. The objective of this study is to perform a systematic validation for investigating the accuracy and efficiency of CFD simulation to predict Fontan hemodynamics.

Altered hemodynamics by 4D flow cardiovascular magnetic resonance predict exercise intolerance in repaired coarctation of the aorta: an in vitro study.

Background: Coarctation of the aorta (CoA) is associated with decreased exercise capacity despite successful repair. Altered flow patterns have been identified due to abnormal aortic arch geometry. Our previous work demonstrated aorta size mismatch to be associated with exercise intolerance in this population.

Teachers' views related the middle school curriculum for distance education during the COVID-19 pandemic.

This qualitative study aims to examine teachers' opinions concerning the middle school curricula that have been in use for years, in order to determine its suitability for distance education during the COVID-19 pandemic. The participants consisted of eighteen middle school teachers from different subject areas in Turkey. A maximum variation sampling method was employed for participant selection.

Aorta size mismatch predicts decreased exercise capacity in patients with successfully repaired coarctation of the aorta.

Objective: Coarctation of the aorta (CoA) is associated with decreased exercise capacity despite successful repair with no residual stenosis; however, the hemodynamic mechanism remains unknown. This study aims to correlate aortic arch geometry with exercise capacity in patients with successfully repaired CoA and explain hemodynamic changes using 3-dimensional-printed aorta models in a mock circulatory flow loop.

Methods: A retrospective chart review identified patients with CoA repair who had cardiac magnetic resonance imaging and an exercise stress test.

Automatic Shape Optimization of Patient-Specific Tissue Engineered Vascular Grafts for Aortic Coarctation.

This paper proposes a computational framework for automatically optimizing the shapes of patient-specific tissue engineered vascular grafts. We demonstrate a proof-of-concept design optimization for aortic coarctation repair. The computational framework consists of three main components including 1) a free-form deformation technique exploring graft geometries, 2) high-fidelity computational fluid dynamics simulations for collecting data on the effects of design parameters on objective function values like energy loss, and 3) employing machine learning methods (Gaussian Processes) to develop a surrogate model for predicting results of high-fidelity simulations.

Non-invasive Prediction of Peak Systolic Pressure Drop across Coarctation of Aorta using Computational Fluid Dynamics.

This paper proposes a novel method to noninvasively measure the peak systolic pressure difference (PSPD) across coarctation of the aorta for diagnosing the severity of coarctation. Traditional non-invasive estimates of pressure drop from the ultrasound can underestimate the severity and invasive measurements by cardiac catheterization can carry risks for patients. To address the issues, we employ computational fluid dynamics (CFD) computation to accurately predict the PSPD across a coarctation based on cardiac magnetic resonance (CMR) imaging data and cuff pressure measurements from one arm.

In vivo implantation of 3-dimensional printed customized branched tissue engineered vascular graft in a porcine model.

Background: The customized vascular graft offers the potential to simplify the surgical procedure, optimize physiological function, and reduce morbidity and mortality. This experiment evaluated the feasibility of a flow dynamic-optimized branched tissue engineered vascular graft (TEVG) customized based on medical imaging and manufactured by 3-dimensional (3D) printing for a porcine model.

Methods: We acquired magnetic resonance angiography and 4-dimensional flow data for the native anatomy of the pigs (n = 2) to design a custom-made branched vascular graft of the pulmonary bifurcation.

Effects of simulated lateral canals on the accuracy of measurements by an electronic apex locator.

Background: Accurate determination of the apical terminus plays a significant role in the success of root canal therapy, but accuracy may be affected by the presence of accessory canals.

Objective: To evaluate the accuracy of a ratio-based electronic apex locator for roots with simulated lateral canals.

Methods: Forty-two single-rooted human teeth were randomly divided into 2 groups.

Levels of PCDD/Fs in local and non-local food samples collected from a highly polluted area in Turkey.

A sampling and analysis program were conducted to determine the PCDD/F levels in various food samples collected in Kocaeli, one of the highly polluted areas in Turkey. Several food samples including animal (egg, chicken, meat and cow's milk) and plant (fruits, leafy vegetables, fruiting vegetables, rooty vegetables and flour) products were collected from both local and non-local (commercial) sources. The local food samples were taken from 20 sampling points selected by taking into account the location of the possible PCDD/F sources, dominant wind directions and representing the major part of the Turkish daily diet The PCDD/F concentrations in local eggs and milk samples were ranged from <1.

The prevalence of molar incisor hypomineralization (MIH) in a group of children in a highly polluted urban region and a windfarm-green energy island.

Background: Children's developing teeth may be sensitive to environmental pollutants such as polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans. The term molar incisor hypomineralization (MIH) was introduced to describe the clinical appearance of enamel hypomineralization of systemic origin affecting one or more permanent first molars (PFMs) that are associated frequently with affected incisors.

Aim: The aim of this study was to determine the prevalance of MIH in children from the most industrialized and polluted region and the most green-energy island of Turkey.