scholarly journals 3D printed patient-specific aortic root models with internal sensors for minimally invasive applications

2020 ◽  
Vol 6 (35) ◽  
pp. eabb4641 ◽  
Author(s):  
Ghazaleh Haghiashtiani ◽  
Kaiyan Qiu ◽  
Jorge D. Zhingre Sanchez ◽  
Zachary J. Fuenning ◽  
Priya Nair ◽  
...  

Minimally invasive surgeries have numerous advantages, yet complications may arise from limited knowledge about the anatomical site targeted for the delivery of therapy. Transcatheter aortic valve replacement (TAVR) is a minimally invasive procedure for treating aortic stenosis. Here, we demonstrate multimaterial three-dimensional printing of patient-specific soft aortic root models with internally integrated electronic sensor arrays that can augment testing for TAVR preprocedural planning. We evaluated the efficacies of the models by comparing their geometric fidelities with postoperative data from patients, as well as their in vitro hemodynamic performances in cases with and without leaflet calcifications. Furthermore, we demonstrated that internal sensor arrays can facilitate the optimization of bioprosthetic valve selections and in vitro placements via mapping of the pressures applied on the critical regions of the aortic anatomies. These models may pave exciting avenues for mitigating the risks of postoperative complications and facilitating the development of next-generation medical devices.

Author(s):  
Brett G. Darrow ◽  
Kyle A. Snowdon ◽  
Adrien Hespel

Abstract Objective The aim of this study was to evaluate the accuracy of patient-specific three-dimensional printed drill guides (3D-PDG) for the placement of a coxofemoral toggle via a minimally invasive approach. Materials and Methods Pre-procedure computed tomography (CT) data of 19 canine cadaveric hips were used to design a cadaver-specific 3D-PDG that conformed to the proximal femur. Femoral and acetabular bone tunnels were drilled through the 3D-PDG, and a coxofemoral toggle pin was placed. The accuracy of tunnel placement was evaluated with post-procedure CT and gross dissection. Results Coxofemoral toggle pins were successfully placed in all dogs. Mean exit point translation at the fovea capitis was 2.5 mm (0.2–7.5) when comparing pre- and post-procedure CT scans. Gross dissection revealed the bone tunnel exited the fovea capitis inside (3/19), partially inside (12/19) and outside of (4/19) the ligament of the head of the femur. Placement of the bone tunnel through the acetabulum was inside (16/19), partially inside (1/19) and outside (2/19) of the acetabular fossa. Small 1 to 2 mm articular cartilage fragments were noted in 10 of 19 specimens. Clinical Significance Three-dimensional printed drill guide designed for coxofemoral toggle pin application is feasible. Errors are attributed to surgical execution and identification of the borders of the fovea capitis on CT data. Future studies should investigate modifications to 3D-PDG design and methods. Three-dimensional printed drill guide for coxofemoral toggle pin placement warrants consideration for use in select clinical cases of traumatic coxofemoral luxation.


2017 ◽  
Vol 10 (3) ◽  
pp. 285-289 ◽  
Author(s):  
Katrina L Ruedinger ◽  
David R Rutkowski ◽  
Sebastian Schafer ◽  
Alejandro Roldán-Alzate ◽  
Erick L Oberstar ◽  
...  

Background and purposeSafe and effective use of newly developed devices for aneurysm treatment requires the ability to make accurate measurements in the angiographic suite. Our purpose was to determine the parameters that optimize the geometric accuracy of three-dimensional (3D) vascular reconstructions.MethodsAn in vitro flow model consisting of a peristaltic pump, plastic tubing, and 3D printed patient-specific aneurysm models was used to simulate blood flow in an intracranial aneurysm. Flow rates were adjusted to match values reported in the literature for the internal carotid artery. 3D digital subtraction angiography acquisitions were obtained using a commercially available biplane angiographic system. Reconstructions were done using Edge Enhancement (EE) or Hounsfield Unit (HU) kernels and a Normal or Smooth image characteristic. Reconstructed images were analyzed using the vendor's aneurysm analysis tool. Ground truth measurements were derived from metrological scans of the models with a microCT. Aneurysm volume, surface area, dome height, minimum and maximum ostium diameter were determined for the five models.ResultsIn all cases, measurements made with the EE kernel most closely matched ground truth values. Differences in values derived from reconstructions displayed with Smooth or Normal image characteristics were small and had only little impact on the geometric parameters considered.ConclusionsReconstruction parameters impact the accuracy of measurements made using the aneurysm analysis tool of a commercially available angiographic system. Absolute differences between measurements made using reconstruction parameters determined as optimal in this study were, overall, very small. The significance of these differences, if any, will depend on the details of each individual case.


2018 ◽  
Vol 140 (10) ◽  
Author(s):  
Wenbin Mao ◽  
Qian Wang ◽  
Susheel Kodali ◽  
Wei Sun

Paravalvular leak (PVL) is a relatively frequent complication after transcatheter aortic valve replacement (TAVR) with increased mortality. Currently, there is no effective method to pre-operatively predict and prevent PVL. In this study, we developed a computational model to predict the severity of PVL after TAVR. Nonlinear finite element (FE) method was used to simulate a self-expandable CoreValve deployment into a patient-specific aortic root, specified with human material properties of aortic tissues. Subsequently, computational fluid dynamics (CFD) simulations were performed using the post-TAVR geometries from the FE simulation, and a parametric investigation of the impact of the transcatheter aortic valve (TAV) skirt shape, TAV orientation, and deployment height on PVL was conducted. The predicted PVL was in good agreement with the echocardiography data. Due to the scallop shape of CoreValve skirt, the difference of PVL due to TAV orientation can be as large as 40%. Although the stent thickness is small compared to the aortic annulus size, we found that inappropriate modeling of it can lead to an underestimation of PVL up to 10 ml/beat. Moreover, the deployment height could significantly alter the extent and the distribution of regurgitant jets, which results in a change of leaking volume up to 70%. Further investigation in a large cohort of patients is warranted to verify the accuracy of our model. This study demonstrated that a rigorously developed patient-specific computational model can provide useful insights into underlying mechanisms causing PVL and potentially assist in pre-operative planning for TAVR to minimize PVL.


2013 ◽  
Vol 79 (1) ◽  
pp. 84-89 ◽  
Author(s):  
Paxton V. Dickson ◽  
Gillian C. Alex ◽  
Elizabeth G. Grubbs ◽  
Camilo Jimenez ◽  
Jeffrey E. Lee ◽  
...  

Posterior retroperitoneoscopic adrenalectomy (PRA) is a minimally invasive procedure offering several advantages over a transabdominal laparoscopic operation. The three-dimensional optics and articulating instrumentation offered by current robotic surgical technology potentially improve this procedure. Robotic-assisted PRA (RA-PRA) was performed in patients meeting standard criteria for minimally invasive adrenalectomy. We prospectively collected demographic, clinical, perioperative, and pathologic data on patients undergoing RA-PRA. Thirty consecutive RA-PRAs were performed in 28 patients (26 unilateral and 2 bilateral). Indications for adrenalectomy included pheochromocytoma (8), hyperaldosteronism (3), hypercortisolism (8), oligometastases (5), and nonfunctional tumors (6). Mean tumor size was 3.8 ± 1.6 cm. Mean body mass index was 30.7 ± 6.5 kg/m2. Mean operative time was 154 ± 43 minutes for unilateral total adrenalectomy. Four patients with multiple endocrine neoplasia Type 2A-associated pheochromocytomas underwent cortical-preserving procedures. Three patients experienced perioperative complications (one pneumothorax, one urinary retention, one required postoperative blood transfusion). No patient required conversion to an open procedure. Robotic surgical technology is an excellent complement to retroperitoneoscopic adrenalectomy. The three-dimensional view and ergonomic advantages of a robotic procedure promote better visualization and a more flexible approach to dissection. We believe these features may optimize the ability to maintain a vascularized remnant during minimally invasive cortical-sparing adrenalectomy.


Author(s):  
Michele Conti ◽  
Stefania Marconi ◽  
Ferdinando Auricchio

Endovascular aortic repair is a minimally invasive procedure to treat aortic diseases such as aneurysms and dissections. Thanks to technological advancements, such procedure has steadily shifted from the abdominal aorta towards the ascending part, i.e., near the heart, calling for an extensive and comprehensive benchmarking of (novel) endografts. Given such considerations, we have exploited porcine aorta with a pulse duplicator to analyse the mechanical interaction between the endovascular device and the native tissue. Our results have implications for using the porcine aorta as a model for human aorta in research. Particularly, the combination of in vitro tests performed using ex-vivo tissue, integrated validated patient-specific numerical simulations, mock arteries manufactured by 3D printing, can offer important insight on biomechanical impact of endograft design on post-operative aortic mechanical response.


2016 ◽  
Vol 138 (3) ◽  
Author(s):  
Simon Heide-Jørgensen ◽  
Sellaswasmy Kumaran Krishna ◽  
Jonas Taborsky ◽  
Tommy Bechsgaard ◽  
Rachid Zegdi ◽  
...  

The transcatheter aortic valve implantation (TAVI) valve is a bioprosthetic valve within a metal stent frame. Like traditional surgical bioprosthetic valves, the TAVI valve leaflet tissue is expected to calcify and degrade over time. However, clinical studies of TAVI valve longevity are still limited. In order to indirectly assess the longevity of TAVI valves, an estimate of the mechanical wear and tear in terms of valvular deformation and strain of the leaflets under various conditions is warranted. The aim of this study was, therefore, to develop a platform for noncontact TAVI valve deformation analysis with both high temporal and spatial resolutions based on stereophotogrammetry and digital image correlation (DIC). A left-heart pulsatile in vitro flow loop system for mounting of TAVI valves was designed. The system enabled high-resolution imaging of all three TAVI valve leaflets simultaneously for up to 2000 frames per second through two high-speed cameras allowing three-dimensional analyses. A coating technique for applying a stochastic pattern on the leaflets of the TAVI valve was developed. The technique allowed a pattern recognition software to apply frame-by-frame cross correlation based deformation measurements from which the leaflet motions and the strain fields were derived. The spatiotemporal development of a very detailed strain field was obtained with a 0.5 ms time resolution and a spatial resolution of 72 μm/pixel. Hence, a platform offering a new and enhanced supplementary experimental evaluation of tissue valves during various conditions in vitro is presented.


Author(s):  
Antonio Gallarello ◽  
Andrea Palombi ◽  
Giacomo Annio ◽  
Shervanthi Homer-Vanniasinkam ◽  
Elena De Momi ◽  
...  

Abstract Validation of computational models using in vitro phantoms is a nontrivial task, especially in the replication of the mechanical properties of the vessel walls, which varies with age and pathophysiological state. In this paper, we present a novel aortic phantom reconstructed from patient-specific data with variable wall compliance that can be tuned without recreating the phantom. The three-dimensional (3D) geometry of an aortic arch was retrieved from a computed tomography angiography scan. A rubber-like silicone phantom was manufactured and connected to a compliance chamber in order to tune its compliance. A lumped resistance was also coupled with the system. The compliance of the aortic arch model was validated using the Young's modulus and characterized further with respect to clinically relevant indicators. The silicone model demonstrates that compliance can be finely tuned with this system under pulsatile flow conditions. The phantom replicated values of compliance in the physiological range. Both, the pressure curves and the asymmetrical behavior of the expansion, are in agreement with the literature. This novel design approach allows obtaining for the first time a phantom with tunable compliance. Vascular phantoms designed and developed with the methodology proposed in this paper have high potential to be used in diverse conditions. Applications include training of physicians, pre-operative trials for complex interventions, testing of medical devices for cardiovascular diseases (CVDs), and comparative Magnetic-resonance-imaging (MRI)-based computational studies.


Author(s):  
Kamaljit Singh Boparai ◽  
Gurpartap Singh ◽  
Rupinder Singh ◽  
Sarabjit Singh

Abstract In this work, 3D printed master patterns of acrylonitrile butadiene styrene (ABS) thermoplastic material have been used for the preparation of Ni-Cr based functional prototypes as partial dentures (PD). The study started with patient specific three dimensional (3D), CAD data (fetched through scanning). This data was used for preparation of .STL file for printing of master patterns on fused deposition modeling (FDM) setup. The 3D printed master patterns were further wax coated to reduce the surface irregularities (as cost effective post processing technique). The hybrid patterns were subjected to investment casting for the preparation of Ni-Cr based PD. The finally prepared functional prototypes as PD were optimized for dimensional accuracy, surface finish and surface hardness as responses. The results are visualized and supported by photomicrographs and in-vitro analysis.


2019 ◽  
Vol 29 (06) ◽  
pp. 733-743 ◽  
Author(s):  
Mari Nieves Velasco Forte ◽  
Tarique Hussain ◽  
Arno Roest ◽  
Gorka Gomez ◽  
Monique Jongbloed ◽  
...  

AbstractAdvances in biomedical engineering have led to three-dimensional (3D)-printed models being used for a broad range of different applications. Teaching medical personnel, communicating with patients and relatives, planning complex heart surgery, or designing new techniques for repair of CHD via cardiac catheterisation are now options available using patient-specific 3D-printed models. The management of CHD can be challenging owing to the wide spectrum of morphological conditions and the differences between patients. Direct visualisation and manipulation of the patients’ individual anatomy has opened new horizons in personalised treatment, providing the possibility of performing the whole procedure in vitro beforehand, thus anticipating complications and possible outcomes. In this review, we discuss the workflow to implement 3D printing in clinical practice, the imaging modalities used for anatomical segmentation, the applications of this emerging technique in patients with structural heart disease, and its limitations and future directions.


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