Investigation of three-dimensional printing materials for printing aorta model replicating Type B aortic dissection

2021 ◽  
Vol 17 ◽  
Author(s):  
Chia-An Wu ◽  
Andrew Squelch ◽  
Zhonghua Sun
Keyword(s):  
3D Printing ◽  
Aortic Dissection ◽  
Three Dimensional ◽  
Ct Images ◽  
Patient Specific ◽  
Type B ◽  
Type B Aortic Dissection ◽  
Ct Attenuation ◽  
Significant Difference ◽  
3D Printed

Aim: To determine a printing material that has both elastic property and radiology equivalence close to real aorta for simulation of endovascular stent graft repair of aortic dissection. Background: With the rapid development of three-dimensional (3D) printing technology, a patient-specific 3D printed model is able to help surgeons to make better treatment plan for Type B aortic dissection patients. However, the radiological properties of most 3D printing materials have not been well characterized. This study aims to investigate the appropriate materials for printing human aorta with mechanical and radiological properties similar to the real aortic computed tomography (CT) attenuation. Objective: Quantitative assessment of CT attenuation of different materials used in 3D printed models of aortic dissection for developing patient-specific 3D printed aorta models to simulate type B aortic dissection. Method: A 25-mm length of aorta model was segmented from a patient’s image dataset with diagnosis of type B aortic dissection. Four different elastic commercial 3D printing materials, namely Agilus A40 and A50, Visijet CE-NT A30 and A70 were selected and printed with different hardness. Totally four models were printed out and conducted CT scanned twice on a 192-slice CT scanner using the standard aortic CT angiography protocol, with and without contrast inside the lumen.Five reference points with region of interest (ROI) of 1.77 mm2 were selected at the aortic wall and intimal flap and their Hounsfield units (HU) were measured and compared with the CT attenuation of original CT images. The comparison between the patient’s aorta and models was performed through a paired-sample t-test to determine if there is any significant difference. Result: The mean CT attenuation of aortic wall of the original CT images was 80.7 HU. Analysis of images without using contrast medium showed that the material of Agilus A50 produced the mean CT attenuation of 82.6 HU, which is similar to that of original CT images. The CT attenuation measured at images acquired with other three materials was significantly lower than that of original images (p<0.05). After adding contrast medium, Visijet CE-NT A30 had an average CT attenuation of 90.6 HU, which is close to that of the original images with statistically significant difference (p>0.05). In contrast, the CT attenuation measured at images acquired with other three materials (Agilus A40, A50 and Visiject CE-NT A70) was 129 HU, 135 HU and 129.6 HU, respectively, which is significantly higher than that of original CT images (p<0.05). Conclusion: Both Visijet CE-NT and Agilus have tensile strength and elongation close to real patient’s tissue properties producing similar CT attenuation. Visijet CE-NT A30 is considered the appropriate material for printing aorta to simulate contrast-enhanced CT imaging of type B aortic dissection. Due to lack of body phantom in the experiments, further research with simulation of realistic anatomical body environment should be conducted.

scholarly journals Optimization of Computed Tomography Angiography Protocols for Follow-Up Type B Aortic Dissection Patients by Using 3D Printed Model

2021 ◽  
Vol 11 (15) ◽  
pp. 6844
Author(s):  
Chia-An Wu ◽  
Andrew Squelch ◽  
Shirley Jansen ◽  
Zhonghua Sun
Keyword(s):  
Computed Tomography ◽  
Image Quality ◽  
Aortic Dissection ◽  
Signal To Noise Ratio ◽  
Three Dimensional ◽  
Ct Scans ◽  
Patient Specific ◽  
Type B ◽  
Type B Aortic Dissection ◽  
3D Printed

Thoracic endovascular aortic repair (TEVAR) is a life-saving therapy for type B aortic dissection (TBAD). However, surveillance computed tomography (CT) scans in post-TEVAR patients are associated with high radiation dose, thus resulting in potential risk of radiation-induced malignancy. In this study, we developed a patient-specific three-dimensional (3D) printed phantom with stent grafts in situ, then scanned the phantom with different CT protocols to determine the optimal scanning parameters for post-treatment patients. The CT scans were conducted with different kVp and pitch values (80, 100, 120 kVp and pitch of 1.2, 1.5, 2.0, 2.5), resulting in a total of 12 datasets. Signal-to-noise ratio (SNR) was measured to determine and compare the image quality between different datasets. Results showed no significant differences in SNR between different kVp when the pitch value was 1.2. At low pitch values, a decrease in kVp from 120 to 80 led to a significant effective dose reduction by more than 20%. SNR decreased by 30% when pitch was increased from 1.2 to 2.5 at 80 kVp, and 20% at 120 kVp. In contrast, there was only a 3.9% decrease in SNR when kVp was reduced from 120 to 80 at pitch 1.2, and 15.9% at pitch 2.5. High pitch with 100 kVp can effectively reduce the dose while maintaining image quality.

Endovascular Therapy for Nonischemic vs Ischemic Complicated Acute Type B Aortic Dissection

2019 ◽  
Vol 27 (1) ◽  
pp. 145-152 ◽  
Author(s):  
Ahmed Eleshra ◽  
Tilo Kölbel ◽  
Giuseppe Panuccio ◽  
Fiona Rohlffs ◽  
E. Sebastian Debus ◽  
...  
Keyword(s):  
Aortic Dissection ◽  
Uncontrolled Hypertension ◽  
Aortic Dilatation ◽  
Acute Type ◽  
Type B ◽  
Type B Aortic Dissection ◽  
Ischemic Group ◽  
Atherosclerotic Stenosis ◽  
Significant Difference ◽  
Branch Vessel

Purpose: To report a single-center experience with thoracic endovascular aortic repair (TEVAR) for complicated acute type B aortic dissection (cATBAD) comparing patients with vs without end-organ ischemia. Materials and Methods: Between November 2010 and December 2017, 64 patients (mean age 64.8±12.5 years; 49 men) underwent TEVAR for cATBAD. Patients were grouped into 2 cohorts: nonischemic (39, 61%) patients with unrelenting pain, early progressive aortic dilatation, uncontrolled hypertension, or rupture, and ischemic (25, 39%) patients with visceral, renal, lower extremity, or spinal cord hypoperfusion. Results: Mean time from diagnosis to treatment was 7.5 days (range 1–32) in the nonischemic group vs 2.3 days (range 1–14) days in the ischemic group (p=0.007). Fourteen (56%) of 25 ischemic cATBAD patients had stents implanted in the renovascular branch vessels, while 4 (16%) patients had stents implanted in the iliac arteries. When branch vessel cannulation failed, fenestrations were made in the intimal flap to improve perfusion of the involved branch (n=5). In the nonischemic group, 3 arteries were stented owing to atherosclerotic stenosis. Technical success was achieved in 62 (97%) of 64 patients; despite stenting, 2 patients had low renal artery perfusion on final angiography. There were no statistically significant differences in early or late outcomes between the nonischemic vs ischemic cATBAD patients. Six (9%) patients died within 30 days: 2 (5%) in the nonischemic group vs 4 (16%) in the ischemic group. Major complications (1 stroke, 2 cases of paraplegia, 1 retrograde type A dissection, and 1 case of bowel ischemia) occurred only in the nonischemic group. The mean follow-up was 28 months. Late endoleaks were observed in 3 (8%) nonischemic patients and 1 (4%) ischemic patient. Reinterventions were required in 7 (18%) nonischemic patients and 4 (16%) ischemic patients. Conclusion: TEVAR is an effective and safe method of treating cATBAD. Early intervention in ischemic cATBAD may have played a significant role in the lack of significant difference between ischemic and nonischemic cATBAD outcomes. Direct visceral reperfusion through branch vessel stenting during TEVAR may be crucial in achieving good outcomes in ischemic cATBAD.

scholarly journals Three-dimensional Printing Versus Conventional Machining in the Creation of a Meatal Urethral Dilator: a Cost and Mechanical Strength Analysis

2020 ◽  
Author(s):  
Michael Yue-Cheng Chen ◽  
Jacob Skewes ◽  
Ryan Daley ◽  
Maria Ann Woodruff ◽  
Nicholas John Rukin
Keyword(s):  
3D Printing ◽  
Three Dimensional ◽  
Patient Specific ◽  
Strength Analysis ◽  
Fused Deposition Modelling ◽  
3D Printer ◽  
Current Time ◽  
Fused Deposition ◽  
3D Printed ◽  
Conventional Machining

Abstract BackgroundThree-dimensional (3D) printing is a promising technology but the limitations are often poorly understood. We compare different 3D printingmethods with conventional machining techniques in manufacturing meatal urethral dilators which were recently removed from the Australian market. MethodsA prototype dilator was 3D printed vertically orientated on a low cost fused deposition modelling (FDM) 3D printer in polylactic acid (PLA) and acrylonitrile butadiene styrene (ABS). It was also 3D printed horizontally orientated in ABS on a high-end FDM 3D printer with soluble support material, as well as on a SLS 3D printer in medical nylon. The dilator was also machined in stainless steel using a lathe. All dilators were tested mechanically in a custom rig by hanging calibrated weights from the handle until the dilator snapped. ResultsThe horizontally printed ABS dilator experienced failure at a greater load than the vertically printed PLA and ABS dilators respectively (503g vs 283g vs 163g, p < 0.001). The SLS nylon dilator and machined steel dilator did not fail. The steel dilator is most expensive with a quantity of five at 98 USD each, but this decreases to 30 USD each for a quantity of 1000. In contrast, the cost for the SLS dilator is 33 USD each for five and 27 USD each for 1000. ConclusionsAt the current time 3D printing is not a replacement for conventional manufacturing. 3D printing is best used for patient-specific parts, prototyping or manufacturing complex parts that have additional functionality that cannot otherwise beachieved.

Living the heart in three dimensions: applications of 3D printing in CHD

2019 ◽  
Vol 29 (06) ◽  
pp. 733-743 ◽  
Author(s):  
Mari Nieves Velasco Forte ◽  
Tarique Hussain ◽  
Arno Roest ◽  
Gorka Gomez ◽  
Monique Jongbloed ◽  
...  
Keyword(s):  
3D Printing ◽  
Heart Surgery ◽  
Wide Spectrum ◽  
Three Dimensional ◽  
Structural Heart Disease ◽  
Medical Personnel ◽  
Three Dimensions ◽  
Patient Specific ◽  
3D Printed

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.

scholarly journals The Role of 3D Printing in Medical Applications: A State of the Art

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Anna Aimar ◽  
Augusto Palermo ◽  
Bernardo Innocenti
Keyword(s):  
3D Printing ◽  
Three Dimensional ◽  
Patient Specific ◽  
Digital Information ◽  
Medical Implants ◽  
Medical Field ◽  
3D Printed ◽  
Pipe Dream ◽  
Manufacturing Technologies

Three-dimensional (3D) printing refers to a number of manufacturing technologies that generate a physical model from digital information. Medical 3D printing was once an ambitious pipe dream. However, time and investment made it real. Nowadays, the 3D printing technology represents a big opportunity to help pharmaceutical and medical companies to create more specific drugs, enabling a rapid production of medical implants, and changing the way that doctors and surgeons plan procedures. Patient-specific 3D-printed anatomical models are becoming increasingly useful tools in today’s practice of precision medicine and for personalized treatments. In the future, 3D-printed implantable organs will probably be available, reducing the waiting lists and increasing the number of lives saved. Additive manufacturing for healthcare is still very much a work in progress, but it is already applied in many different ways in medical field that, already reeling under immense pressure with regards to optimal performance and reduced costs, will stand to gain unprecedented benefits from this good-as-gold technology. The goal of this analysis is to demonstrate by a deep research of the 3D-printing applications in medical field the usefulness and drawbacks and how powerful technology it is.

Evaluation and verification of patient-specific modelling of type B aortic dissection

2021 ◽  
pp. 105053
Author(s):  
Chlöe H. Armour ◽  
Baolei Guo ◽  
Simone Saitta ◽  
Selene Pirola ◽  
Yifan Liu ◽  
...  
Keyword(s):  
Aortic Dissection ◽  
Patient Specific ◽  
Type B ◽  
Type B Aortic Dissection

scholarly journals A Retrospective Observational Study to Assess Prescription Pattern in Patients with Type B Aortic Dissection and Treatment Outcome

2016 ◽  
Vol 2016 ◽  
pp. 1-10
Author(s):  
Kuang-Ming Liao ◽  
Chung-Yu Chen ◽  
Shih-Han Wang ◽  
Jiann-Woei Huang ◽  
Chen-Chun Kuo ◽  
...  
Keyword(s):  
Aortic Dissection ◽  
Primary Outcome ◽  
Proportional Hazards Model ◽  
Medical Center ◽  
Treatment Strategies ◽  
Cox Proportional Hazards Model ◽  
Type B ◽  
Type B Aortic Dissection ◽  
Increased Risk ◽  
Significant Difference

Aortic dissection is a life-threatening condition. However, the use of medication to treat it remains unclear in our population, particularly in patients with a type B aortic dissection (TBAD) who do not receive surgery. This retrospective cohort study evaluated antihypertensive prescription patterns and outcomes in patients with nonsurgical TBAD. We reviewed the hospital records of patients with TBAD at a medical center in Taiwan from January 2008 to June 2013 to assess the baseline information, prescribing pattern, event rate, and clinical effectiveness of different antihypertensive treatment strategies. A Cox proportional hazards model was used to estimate outcomes in different antihypertensive strategies. The primary endpoints were all-cause mortality and hospital admission for an aortic dissection. We included 106 patients with a mean follow-up period of 2.75 years. The most common comorbidity was hypertension followed by dyslipidemia and diabetes mellitus. Study endpoints mostly occurred within 6 months after the index date. Over 80% of patients received dual or triple antihypertensive strategies. Patients treated with different treatment strategies did not have a significantly increased risk of a primary outcome compared with those treated with a monotherapy. We found no significant difference in the primary outcome following the use of different antihypertensive medication regimes.

scholarly journals 3D Printing Custom Bioactive and Absorbable Surgical Screws, Pins, and Bone Plates for Localized Drug Delivery

2019 ◽  
Vol 10 (2) ◽  
pp. 17 ◽  
Author(s):  
Karthik Tappa ◽  
Udayabhanu Jammalamadaka ◽  
Jeffery Weisman ◽  
David Ballard ◽  
Dallas Wolford ◽  
...  
Keyword(s):  
Drug Delivery ◽  
3D Printing ◽  
Flexural Strength ◽  
Bone Plates ◽  
Patient Specific ◽  
Fixation Devices ◽  
Significant Difference ◽  
3D Printed ◽  
Localized Drug Delivery ◽  
Orthopedic Applications

Additive manufacturing has great potential for personalized medicine in osseous fixation surgery, including maxillofacial and orthopedic applications. The purpose of this study was to demonstrate 3D printing methods for the fabrication of patient-specific fixation implants that allow for localized drug delivery. 3D printing was used to fabricate gentamicin (GS) and methotrexate (MTX)-loaded fixation devices, including screws, pins, and bone plates. Scaffolds with different infill ratios of polylactic acid (PLA), both without drugs and impregnated with GS and MTX, were printed into cylindrical and rectangular-shaped constructs for compressive and flexural strength mechanical testing, respectively. Bland PLA constructs showed significantly higher flexural strength when printed in a Y axis at 100% infill compared to other axes and infill ratios; however, there was no significant difference in flexural strength between other axes and infill ratios. GS and MTX-impregnated constructs had significantly lower flexural and compressive strength as compared to the bland PLA constructs. GS-impregnated implants demonstrated bacterial inhibition in plate cultures. Similarly, MTX-impregnated implants demonstrated a cytotoxic effect in osteosarcoma assays. This proof of concept work shows the potential of developing 3D printed screws and plating materials with the requisite mechanical properties and orientations. Drug-impregnated implants were technically successful and had an anti-bacterial and chemotherapeutic effect, but drug addition significantly decreased the flexural and compressive strengths of the custom implants.

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