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Öğe 3D Modeling of Self-Expandable Valves for PPVI in Distinct RVOT Morphologies(Springer, 2026) Odemis, Ender; Aka, Ibrahim Basar; Kizilkaya, Mete HanTetralogy of Fallot often requires transannular patch repair, leading to pulmonary insufficiency. Percutaneous pulmonary valve implantation (PPVI) with self-expandable valves offers a promising alternative, especially for enlarged right ventricular Queryoutflow tracts (RVOT). Five RVOT types identified in patients with Tetralogy of Fallot reflect anatomical variations due to disease and prior surgeries. This study assesses the Pulsta THV (R) valve's in vitro hemodynamic performance across these RVOT morphologies using 3D-printed models. Five RVOT morphologies were recreated as 3D models from patient-specific imaging data. The Pulsta THV (R) valves, available in 28, 30, and 32 mm sizes, were evaluated using the ViVitro Pulse Duplicator System at three cardiac outputs (2, 3.5, and 5 L/min). Hemodynamic performance was assessed by measuring regurgitation rates and pressure gradients in the left and right pulmonary arteries. The Pulsta THV (R) performed optimally in RVOT Types 1 and 2, demonstrating lower regurgitation rates and pressure gradients, particularly with larger valve sizes. Conversely, RVOT Types 3 and 5 showed increased pressure gradients and hemodynamic variability, indicating less favorable outcomes. The results highlighted the critical role of precise anatomical compatibility, with larger valve sizes proving more effective in enlarged RVOT geometry. Valve sizes tailored to specific RVOT morphologies can enhance PPVI outcomes. Types 1 and 2 are ideal for PPVI, while Types 3 and 5 present challenges due to hemodynamic variability. This study supports 3D modeling and in vitro testing for pre-procedural planning to reduce complications, with future research exploring dynamic imaging and materials mimicking tissue properties.Öğe Computer-generated Clinical Decision-making in the Treatment of Pulmonary Atresia with Intact Ventricular Septum(Springer, 2025) Yildirim, Canberk; Ural, Berk; Odemis, Ender; Donmazov, Samir; Pekkan, KeremPurpose Pulmonary atresia with intact ventricular septum is a multifactorial disease requiring complex surgeries. The treatment route is determined based on the right ventricle (RV) size, tricuspid annulus size and coronary circulation dependency of RV. Since multiple parameters influence the post-operative success, a personalized decision-making based on computed hemodynamics is hypothesized to improve the treatment efficacy. Methods A lumped parameter cardiovascular model is developed to calculate the hemodynamics of virtual patients which are generated by statistical distribution of circulation parameters. Four cohorts each with 30 digital patients are grouped based on RV size. For each patient, biventricular and one-and-half ventricle (1.5 V) repair were applied in silico and assessed via pressure, flow and saturations computed for every organ bed. Results Biventricular and 1.5 V repair yield significant increase in the pulmonary flow and oxygen saturation for all patients compared to the pre-operative state (p-values < 0.001). Approximately 30% of generated patients failed to meet the sufficient saturation and flow following biventricular repair and were directed to 1.5 V repair. However, 14% of these 1.5 V repair patients failed post-operatively, requiring Fontan completion. Based on the pre-determined hemodynamics criteria, this study implies that patients having RV sizes larger than 22 ml/m(2) are likely to undergo successful biventricular repair. Conclusion Pending further clinical trials, computational pre-interventional planning has the potential to screen patients that would not optimally fit to the traditional pathway prior to in vivo execution by providing personalized hemodynamic outcome. Statistical approach allows in silico clinical trials, useful for diseases with low patient numbers.Öğe Development of an Ex Vivo Mitral Valve Evaluation Model Using a Pulsatile Flow Simulator(Journal of Visualized Experiments, 2025) Albrahimi, Ergida; Aka, Ibrahim Basar; Ali, Mhd Homam Alhaj; Korun, Oktay; Odemis, Ender; Ipek, GokhanSurgical mitral valve repair remains a challenging procedure. Although several repair techniques have been defined, data comparing their hemodynamic effects are lacking. The commercially available pulse duplicators are commonly used to simulate blood circulation through mechanical or 3D printed cardiac valves. However, due to the specific structure and working mechanism of the mitral valve, the experiments on surgical techniques require the use of biological tissues. Ex vivo lamb mitral valves are suitable for such experiments, but the methods for mounting these valves to the pulse duplicator system (PDS) are not well defined. To address this, we modified the system by 3D printing and silicone molding as a mitral valve holder. We excised the mitral valve from a lamb heart for each experiment, including its annulus and subvalvar apparatus. We implanted this into the atrioventricular (mitral) valve area of the test machine using the silicone holder. Papillary muscle tension was simulated by tying sutures around the chordae-papillary junctions and passing these sutures through the release hole at the bottom of the ventricular chamber. Initial testing of the valve competence was conducted at a heart rate of 120 beats per minute and a cardiac output of 2 L/min. Valve regurgitation and the pressure gradient between the atrial and ventricular chambers were measured using pulse duplicator electromagnetic flowmeters and validated with echocardiography. Baseline hemodynamic testing demonstrated consistent valve function across five experiments, with a mean regurgitation fraction of 21.1% and echo-derived transmitral gradients ranging from 5.15 to 8.13 mmHg. Stroke volumes and peak flow rates varied among specimens, reflecting physiological variability within the pediatric model.Öğe Evaluation of the total hydrodynamic energy loss using 4D flow MRI in a case with Fontan failure(Cell Press, 2024) Odemis, Ender; Gumus, Terman; Aka, Ibrahim Basar; Ozkok, Sercin; Pekkan, KeremFontan Failure (FF) is a common problem for single-ventricle patients as they reach adulthood. Although several mechanisms may cause FF, an optimized blood flow stream through the surgical conduits is essential to avoid excessive energy loss (EL). Recent clinical studies showed EL is related to the quality of life, exercise capacity, and hepatic function since the single-ventricle feeds pulmonary and systemic circulation serially. 4D flow MRI effectively estimates EL in Fontan circulation and allows clinicians to compare the effectiveness of the treatment strategy concerning pre-intervention. Here, we present 26-year-old women with FF who had normal cardiac catheterization findings and were treated according to high EL definitions that are measured through 4D flow MRI.
