3D Printing of Preoperative Simulation Models of a Splenic Artery Aneurysm: Precision and Accuracy

Clinical situations for which 3D Printing is considered an appropriate representation or extension of data contained in a medical imaging examination: vascular conditions

BACKGROUND

Medical three-dimensional (3D) printing has demonstrated utility and value in anatomic models for vascular conditions. A writing group composed of the Radiological Society of North America (RSNA) Special Interest Group on 3D Printing (3DPSIG) provides appropriateness recommendations for vascular 3D printing indications.

METHODS

A structured literature search was conducted to identify all relevant articles using 3D printing technology associated with vascular indications. Each study was vetted by the authors and strength of evidence was assessed according to published appropriateness ratings.

RESULTS

Evidence-based recommendations for when 3D printing is appropriate are provided for the following areas: aneurysm, dissection, extremity vascular disease, other arterial diseases, acute venous thromboembolic disease, venous disorders, lymphedema, congenital vascular malformations, vascular trauma, vascular tumors, visceral vasculature for surgical planning, dialysis access, vascular research/development and modeling, and other vasculopathy. Recommendations are provided in accordance with strength of evidence of publications corresponding to each vascular condition combined with expert opinion from members of the 3DPSIG.

CONCLUSION

This consensus appropriateness ratings document, created by the members of the 3DPSIG, provides an updated reference for clinical standards of 3D printing for the care of patients with vascular conditions.

3D printing in the endovascular treatment of visceral artery aneurysms

Visceral artery aneurysms (VAAs) are vascular pathologies that are difficult to treat. The variable geometry of the vessels and the location of aneurysms render difficult their evaluation in radiological imaging studies. Less invasive endovascular procedures are increasingly used in common practice. Our aim was to test the feasibility of using 3D printing technology in the preparation of preoperative spatial models of visceral artery aneurysms and their impact on interventional treatment. In our observational study, we examined a group of patients with true aneurysms of the visceral arteries who were followed and who underwent endovascular procedures with the use of 3D prints for better imaging of vascular lesions. We analyzed the fused filament fabrication method of 3D printing and printable materials in the preparation of spatial vascular models. We confirmed that more accurate visualization and analysis of vascular anatomy could assist operators in attempting minimally invasive treatment with good results. Extending imaging studies using 3D printing models that allow for the assessment of the position, morphology and geometry of the aneurysm sac, particularly of vessel branches, could encourage surgeons to perform endovascular procedures.

Mechanical Properties of a 3 Dimensional-Printed Transparent Flexible Resin Used for Vascular Model Simulation Compared with Those of Porcine Arteries

PURPOSE

To develop a vascular intervention simulation model that replicates the characteristics of a human patient and to compare the mechanical properties of a 3-dimensional (3D)-printed transparent flexible resin with those of porcine arteries using the elastic modulus (E) and kinetic friction coefficient (μ_k).

MATERIALS AND METHODS

Resin plates were created from a transparent flexible resin using a 3D printer. Porcine artery plates were prepared by excising the aorta. E values and the adhesive strengths of the resin and arterial surfaces toward a polyethylene plate, were measured with a tensile-compressive mechanical tester. Resin transparency was measured using an ultraviolet-visible light spectrometer. The μ_k value of the resin plate surface after applying silicone spray for 1-5 seconds and that of the artery were measured using a translational friction tester.

RESULTS

E values differed significantly between the arteries and resin plates at each curing time (0.20 MPa ± 0.04 vs 8.53 MPa ± 2.37 for a curing time of 1 minute; P < .05). The resin was stiffer than the arteries, regardless of the curing times. The visible light transmittance and adhesive strength of the resin decreased as the curing time increased. The adhesive strength of the artery was the lowest. The μ_k value of the silicone-coated resin surface created by applying silicone for 2-3 seconds (thickness of the silicone layer, 1.6-2.0 μm) was comparable with that of the artery, indicating that the coating imparted a similar slippage to the resin as to the living artery.

CONCLUSIONS

A transparent flexible resin is useful for creating a transparent and slippery vascular model for vascular intervention simulation.

Endovascular embolization techniques in acute thoracic and abdominal bleedings can be technically reproduced and trained in a standardized simulation setting using SLA 3D printing: a 1-year single-center study

Background

Endovascular embolization techniques are nowadays well established in the management of acute arterial bleedings. However, the education and training of the next generation of interventionalists are still based on the traditional apprenticeship model, where the trainee learns and practices directly at the patient, which potentially affects the patient’s safety. The objective of this study was to design and develop a standardized endovascular simulation concept for the training of acute bleeding embolizations, based on real-life cases.

Results

An adaptable and cost-effective endovascular simulator was developed using an in-house 3D print laboratory. All thoracic and abdominal acute bleeding embolizations over more than a year with appropriate pre-interventional computed tomography scans were included to manufacture 3D printed vascular models. A peristaltic pump was used to generate pulsatile flow curves. Forty embolization cases were engaged in this study, and 27 cases were fully reproduced in the simulation setting (69.23%). The simulation success was significantly lower in pulmonary embolizations (p = 0.031) and significantly higher in soft tissue (p = 0.032) and coil embolizations (p = 0.045). The overall simulation success was 7.8 out of 10 available points.

Conclusions

Using stereolithography 3D printing in a standardized simulation concept, endovascular embolization techniques for treating acute internal hemorrhages in the chest and abdomen can be simulated and trained based on the patient-specific anatomy in a majority of the cases and at a broad spectrum of different causes.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13244-022-01206-7.

3D Printing Applications for Radiology: An Overview

Three-dimensional (3D) printing technologies are part of additive manufacturing processes and are used to manufacture a 3D physical model from a digital computer-aided design model as per the required shape and size. These technologies are now used for advanced radiology applications by providing all information through 3D physical model. It provides innovation in radiology for clinical applications, treatment planning, procedural simulation, medical and patient education. Radiological advancements have been made in diagnosis and communication through medical digital imaging techniques like computed tomography, magnetic resonance imaging. These images are converted into Digital Imaging and Communications in Medicine in Standard Triangulate Language file format, easily printable in 3D printing technologies. This 3D model provides in-depth information about pathologic and anatomic states. It is useful to create new opportunities related to patient care. This article discusses the potential of 3D printing technology in radiology. The steps involved in 3D printing for radiology are discussed diagrammatically, and finally identified 12 significant applications of 3D printing technology for radiology with a brief description. A radiologist can incorporate this technology to fulfil different challenges such as training, planning, guidelines, and better communications.

Accessing 3D Printed Vascular Phantoms for Procedural Simulation

Introduction: 3D printed patient-specific vascular phantoms provide superior anatomical insights for simulating complex endovascular procedures. Currently, lack of exposure to the technology poses a barrier for adoption. We offer an accessible, low-cost guide to producing vascular anatomical models using routine CT angiography, open source software packages and a variety of 3D printing technologies.

Methods: Although applicable to all vascular territories, we illustrate our methodology using Abdominal Aortic Aneurysms (AAAs) due to the strong interest in this area. CT aortograms acquired as part of routine care were converted to representative patient-specific 3D models, and then printed using a variety of 3D printing technologies to assess their material suitability as aortic phantoms. Depending on the technology, phantoms cost $20–$1,000 and were produced in 12–48 h. This technique was used to generate hollow 3D printed thoracoabdominal aortas visible under fluoroscopy.

Results: 3D printed AAA phantoms were a valuable addition to standard CT angiogram reconstructions in the simulation of complex cases, such as short or very angulated necks, or for positioning fenestrations in juxtarenal aneurysms. Hollow flexible models were particularly useful for device selection and in planning of fenestrated EVAR. In addition, these models have demonstrated utility other settings, such as patient education and engagement, and trainee and anatomical education. Further study is required to establish a material with optimal cost, haptic and fluoroscopic fidelity.

Conclusion: We share our experiences and methodology for developing inexpensive 3D printed vascular phantoms which despite material limitations, successfully mimic the procedural challenges encountered during live endovascular surgery. As the technology continues to improve, 3D printed vascular phantoms have the potential to disrupt how endovascular procedures are planned and taught.

Embolization of visceral arterial aneurysms: Simulation with 3D-printed models

Objectives

The present technical article aimed to describe the efficacy of three-dimensional (3D)-printed hollow vascular models as a tool in the preoperative simulation of endovascular embolization of visceral artery aneurysms.

Methods

From November 2015 to November 2016, four consecutive endovascular treatments of true visceral artery aneurysms were preoperatively simulated with 3D-printed hollow models. The mean age of the patients (one male and three females) was 54 (range: 40–71) years. Three patients presented with splenic artery aneurysm and one with anterior pancreaticoduodenal artery aneurysm. The average diameter of the aneurysms was 16.5 (range: 10–25) mm. The 3D-printed hollow models of the visceral artery aneurysms and involved arteries were created using computed tomography angiography data of the patients. After establishing treatment plans by simulations with the 3D-printed models, all patients received endovascular treatment.

Results

All four hollow aneurysm models were successfully fabricated and used in the preoperative simulation of endovascular treatment. In the preoperative simulations with 3D-printed hollow models, splenic aneurysms were embolized with coils and/or n-butyl-2-cyanoacrylate to establish the actual treatment plans, and a small arterial branch originating from an anterior pancreaticoduodenal artery aneurysm was selected to obtain feedback regarding the behavior of catheters and guidewires. After establishing treatment plans by simulations, the visceral artery aneurysms of all patients were successfully embolized without major complications and recanalization.

Conclusions

Simulation with 3D-printed hollow models can help establish an optimal treatment plan and may improve the safety and efficacy of endovascular treatment for visceral artery aneurysms.

An overview on 3D printing for abdominal surgery

BACKGROUND

Three-dimensional (3D) printing is a disruptive technology that is quickly spreading to many fields, including healthcare. In this context, it allows the creation of graspable, patient-specific, anatomical models generated from medical images. The ability to hold and show a physical object speeds up and facilitates the understanding of anatomical details, eases patient counseling and contributes to the education and training of students and residents. Several medical specialties are currently exploring the potential of this technology, including general surgery.

METHODS

In this review, we provide an overview on the available 3D printing technologies, together with a systematic analysis of the medical literature dedicated to its application for abdominal surgery. Our experience with the first clinical laboratory for 3D printing in Italy is also reported.

RESULTS

There was a tenfold increase in the number of publications per year over the last decade. About 70% of these papers focused on kidney and liver models, produced primarily for pre-interventional planning, as well as for educational and training purposes. The most used printing technologies are material jetting and material extrusion. Seventy-three percent of publications reported on fewer than ten clinical cases.

CONCLUSION

The increasing application of 3D printing in abdominal surgery reflects the dawn of a new technology, although it is still in its infancy. The potential benefit of this technology is clear, however, and it may soon lead to the development of new hospital facilities to improve surgical training, research, and patient care.

Triple-balloon-assisted n-butyl-2-cyanoacrylate embolization of a cirsoid renal arteriovenous malformation

We report a patient with a cirsoid renal arteriovenous malformation (AVM) causing massive hematuria that was successfully embolized by n-butyl-2-cyanoacrylate under triple-balloon occlusion. Proximal balloons were placed in the renal artery and vein for flow control, and a coaxial microballoon was placed in a feeding artery of the AVM to control the delivery of n-butyl-2-cyanoacrylate. Under triple-balloon occlusion, n-butyl-2-cyanoacrylate embolization achieved complete occlusion of the AVM with no procedure-related complications, such as renal infarction. This triple-balloon-assisted technique enabled us to control blood flow and the delivery of n-butyl-2-cyanoacrylate, allowing complete occlusion of the AVM. This approach may prevent proximal embolization and distal migration of n-butyl-2-cyanoacrylate.

Radiological Society of North America (RSNA) 3D printing Special Interest Group (SIG): guidelines for medical 3D printing and appropriateness for clinical scenarios

Medical three-dimensional (3D) printing has expanded dramatically over the past three decades with growth in both facility adoption and the variety of medical applications. Consideration for each step required to create accurate 3D printed models from medical imaging data impacts patient care and management. In this paper, a writing group representing the Radiological Society of North America Special Interest Group on 3D Printing (SIG) provides recommendations that have been vetted and voted on by the SIG active membership. This body of work includes appropriate clinical use of anatomic models 3D printed for diagnostic use in the care of patients with specific medical conditions. The recommendations provide guidance for approaches and tools in medical 3D printing, from image acquisition, segmentation of the desired anatomy intended for 3D printing, creation of a 3D-printable model, and post-processing of 3D printed anatomic models for patient care.

Artificial vascular models for endovascular training (3D printing)

The endovascular technique has led to a revolution in the care of patients with vascular disease; however, acquiring and maintaining proficiency over a broad spectrum of procedures is challenging. Three-dimensional (3D) printing technology allows the production of models that can be used for endovascular training. This article aims to explain the process and technologies available to produce vascular models for endovascular training, using 3D printing technology. The data are based on the group experience and a review of the literature. Different 3D printing methods are compared, describing their advantages, disadvantages and potential roles in surgical training. The process of 3D printing a vascular model based on an imaging examination consists of the following steps: image acquisition, image post-processing, 3D printing and printed model post-processing. The entire process can take a week. Prospective studies have shown that 3D printing can improve surgical planning, especially in complex endovascular procedures, and allows the production of efficient simulators for endovascular training, improving residents’ surgical performance and self-confidence.

The Role of Three-Dimensional Printing in Contemporary Vascular and Endovascular Surgery: A Systematic Review

BACKGROUND

Three-dimensional (3D) printing, also known as rapid prototyping or additive manufacturing, is a novel adjunct in the medical field. The aim of this systematic review is to evaluate the role of 3D printing technology in the field of contemporary vascular surgery in terms of its technical aspect, practicability, and clinical outcome.

METHODS

A systematic search of literatures published from January 1, 1980 to July 15, 2017 was identified from the EMBASE, MEDLINE, and Cochrane library database with reference to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guideline. The predefined selection inclusion criterion was clinical application of 3D printing technology in vascular surgery of large and small vessel pathology.

RESULTS

Forty-two articles were included in this systematic review, including 2 retrospective cohorts and 1 prospective case control study. 3D printing was mostly applied to abdominal aortic aneurysm (n = 20) and thoracic aorta pathology (n = 8), other vessels included celiac, splenic, carotid, subclavian, femoral artery, and portal vein (n = 10). The most commonly quoted materials were acrylonitrile-butadiene-styrene (n = 2), polylactic acid (n = 4), polyurethane resin (n = 3) and nylon (n = 3). The cost per replica ranged from USD $4-2,360. Cost for a commercial printer was around USD $2,210-50,000.

CONCLUSION

3D printing was recognized and gradually incorporated as a useful adjunct in the field of vascular and endovascular surgery. The production of an accurate anatomic patient-specific replica was shown to bring significant impact in patient management in terms of anatomic understanding, procedural planning, and intraoperative navigation, education, and academic research as well as patient communication. Further analysis on cost-effectiveness was indicated to guide decisions on applicability of such promising technology on a routine basis.