Surgical Models and 3D Printing in the Medical Profession

With the introduction of high-end, quality machines at reasonable prices, desktop 3D printing has transitioned from a maker and educational curiosity to an essential production tool in a diversified manufacturer’s quiver. One needs to look no further than the medical profession where desktop 3D printing has hit its stride. Join us on our journey to understand how 3D printing has transformed and continues to revolutionize the healthcare industry.

The use of 3D models within the medical profession has been around since the dissection of human cadavers in ancient Greece. Historically, medical professionals have utilized cadavers to understand anatomy, study disease, and practice surgical techniques in the advancement of modern medicine. With the growing demand for cadavers, and often their lack of availability, medical students and practitioners have been transitioning to synthetic models to bridge the availability gap. However, many of these synthetic models lack the true look, feel, uniqueness, and robustness of human cadavers.

With the advent of 3D printing, synthetic modeling of organs and human anatomy has made a significant leap forward. A case in point is the work being conducted by Dr. Jacques Zaneveld, President, and Founder of Lazarus 3D. Lazarus 3D is at the forefront of 3D printing technology in medicine, specifically in the domain of patient-specific surgery rehearsal models. With its patent-pending, silicone-based soft tissue models that exhibit properties similar to human tissue, doctors are able to rehearse difficult operations before they actually happen. This, combined with Magnetic Resonance Imaging (MRI) and/or Computerized Tomography (CT) scan data, allows doctors to rehearse medical procedures on a model that is an exact replica of the patient’s body part. This results in maximum precision, increased confidence/reliability, and minimizes risks during the actual medical procedure.

The sky is now the limit with respect to 3D printing in medicine. The ultimate goal is the replication of human tissue organs and body parts complete with vascular and neurological system components, which may become a part of clinical care in the next several decades. In order to make this a reality (and it is actively being progressed), there is much work to do. Lazarus 3D plans to follow the path for Food and Drug Administration (FDA) approval of their silicone training models as a component of patient care. If the phased approval process demonstrates even a 1-2% reduction in complications, this would translate into millions of dollars of medical savings and eventual cost reimbursement by medical insurance companies. With current medical practitioner and patient demand for its products and services, Lazarus 3D is well on the path to making realistic human tissue modeling a reality.

The medical profession has been at the vanguard in the use of 3D printing and additive manufacturing processes.  Human cadavers from ancient days have given way to synthetic models with the look and feel of human tissue. Eventual reproduction and regeneration of tissue are now on the horizon. Currently, there are four areas in which 3D printing has made substantial inroads: bioprinting tissues and organs, customized implants and prostheses, dosage forms and drug delivery devices and models for surgery preparation. These areas will see explosive growth as 3D printing concepts and capabilities move beyond the first adopters and become integrated into traditional patient care models.

So why have 3D printing and additive fabrication processes seen such widespread growth and adoption in the medical profession? The answer lies in the "sweet spot" where 3D printing shines. This includes customization and personalization in patient care, increased cost efficiency and the democratization of design and collaboration. This has enhanced productivity and the impact has been felt across the entire domain from suppliers to caregivers and patients.

Customization and personalization are extremely important in patient care. Every patient is unique and the care provided to patients has evolved from the proliferation of single care solutions for all patients to specialized treatments and care for each individual. Gone are the days of having only three standard choices for a joint replacement, e.g. small, medium and large, to now having a customized 3D printed joint utilizing information from patient MRIs and CT scans. Now instead of having to order a joint replacement from the manufacturer or supplier, a joint may be fabricated on the fly; ordered, fabricated and delivered on an as-needed basis. This translates directly into lower inventory costs through just-in-time delivery, decreased probability of patient rejection and decreased patient recovery time. All these factor into lower patient care costs.

Another example of customization and personalization is in the area of prosthetics. Customized prosthetics offer not only advanced capabilities for patients but possess a personalized look and feel which adds to patient comfort and usability. An even greater impact has been the use of 3D printed prosthetics in the developing world. Desktop 3D printers are now a tool in the arsenal of providing low cost and easily replaceable prosthetics for patients where no options were previously available. An example of this is encompassed in the e-NABLE Community and their distributed network of 3D printers that match individual 3D printed prosthetics with those that have a need. Additional information on this organization’s work and vision may be found at the e-NABLE Hub.

The cost efficiency of 3D printing directly correlates to the quality of patient care through lower risks and customized solutions. Previously, cost efficiency was concentrated on the upstream end of the patient care model where standardized solutions could be mass produced and distributed worldwide. Now these cost efficiencies have progressed downstream and are realized in the diagnostic, surgical, treatment, and patient recovery domains. Even if a specialized solution or treatment costs more on the upstream end, the cost savings are magnified downstream.

An example is the work being conducted by Lazarus 3D; a Houston based start-up that specializes in patient-specific surgery rehearsal models. Utilizing a patent-pending silicone extrusion process, Lazarus 3D can fabricate individual patient soft tissue models that exhibit properties similar to human tissue. With these models, doctors may rehearse difficult procedures before actual surgery. Using MRI and CT scan data, exact replica models of the patient’s body are fabricated within 24-48 hours and delivered directly to the practicing physician for a rehearsal of the entire procedure. This may result in maximum precision, less tissue damage, and minimizes unknowns during the actual medical procedure.

Problem Definition

The Holy Grail of 3D printing and additive manufacturing in the medical profession is the bioprinting and regeneration of human tissue and organs. While companies such as Organovo, EnvisionTEC, and Aspect Biosystems are able to print living tissue from hydrogels, the uses are limited to drug testing and small regenerative processes. Still ahead lies emerging research and multifarious clinical trials to prove efficacy before adoption. As a result, there are many hurdles to overcome in the production of fully functional tissue with the proper vascular and neurological properties.

High-Level Solution

The pathway to bioprinting and regeneration of human tissue and organs begins with the work and outputs of organizations and companies across a distributed spectrum. At the base level, companies such Organovo and Aspect Biosystems are conducting research in cellular level gels and inks that are extruded to form three-dimensional living human tissues that are proven to function like native tissues. However, the current capabilities are limited to thin cell structures since large cell aggregates develop necrotic cores.

There is also the question of form versus function. As stated by Jordan S. Miller in The Billion Cell Construct: Will Three-Dimensional Printing Get Us There? “...we struggle to approximate the architecture of living tissues experimentally, hoping that the structure we create will lead to the function we desire.” Miller goes on to state that 3D printing provides a “...new means to explore the relationship between form and function in living tissue...” which is where Lazarus 3D enters the picture. Lazarus 3D is in the position to explore the form versus function relationship in the bioprinting realm.

Other challenges are present in the vascular capabilities and structures that are essential to provide the necessary supply of oxygen and nutrients to bioprinted tissues. The surface has barely been touched with bringing scaffold-free vascular tissue into the bioprinting domain. Even more study is needed to ensure that the gels of pooled organic cells can scale into robust, fully functional living tissue.

Currently, Lazarus 3D is able to replicate patient-specific anatomical models of human tissue and organs. Some organs even include vascular structures as seen in their liver models where the model bleeds once an incision is made. These are ideal for pre-surgical rehearsal and for resident training and are the initial step in exploring the form and function relationship.  According to Dr. Zaneveld, “The production of realistic models of tissue and organs for surgery preparation, especially in oncology, allows us to meet existing customer demand and fund further research into bioprinting and 3D printing technology.”

Lazarus 3D is presently pursuing a patent on its silicone 3D printing system. Following soon will be the entire process of FDA approval for its human tissue and organ models that will encourage insurance companies to fund pre-surgery rehearsals using patient-specific models. This will provide resources from which Lazarus 3D will fund additional research in bioprinting.

Solution Details

Additive manufacturing and 3D printing have moved beyond the realms of arthroplasty and cranium replacement. Now, oncology patients have a real opportunity to take advantage of the advances in desktop 3D printing. Whether tumors grow in soft tissue, organs or near skeletal structures, 3D printing provides a complete dimensional picture of each individual patient’s condition. Utilizing MRIs and CT scans, medical professionals can easily replicate the exact location of the tumor, thereby allowing the surgeon the opportunity to better understand and rehearse the surgical techniques that will be necessary to complete a successful procedure.

But why 3D printing and not some other technology? “What other technology is there?”, was Dr. Zaneveld’s adamant response. The key lies in the rapid prototyping to rapid production timeline. With 3D printing, soft tissue models are produced in 24-48 hours while traditional model making may take months and tens or hundreds of thousands of dollars. As a result, traditional models cannot feasibly be made in time for upcoming surgeries.

Lazarus 3D's strategy of replicating soft tissue models is the first step in a grand strategy of bioprinting new or replacement tissue that is specific for each patient. The pursuit of this goal has companies attacking the issue from different vantage points corresponding to their requisite skills and technology. Lazarus 3D is following the path of form versus function by 3D printing with silicone. The models produced by Lazarus 3D possess the form and feel of actual live tissue. This not only provides surgeons with patient-specific models for surgical rehearsal, it opens up the pathway to understand the functional characteristics of the soft tissue and organs in question.

For example, the function of the heart is to pump blood while the veins and arteries are the pipes through which the blood travels. This function can be replicated mechanically utilizing off the shelf materials traditional to standard water pumping equipment. The key was to distill this function down for patient use, e.g. what was accomplished through the Jarvik 7 total artificial heart. Subsequent iterations improved upon the heart’s function as well as on the power source and materials.

Lazarus 3D will be exploring the form versus function dynamic in more detail. One area of research is to determine whether microvascular cells can be added to tissue through bioprinting. This would allow each individual cell to receive the nutrients essential for cell survival. Much like printing the electrical connections on circuit boards, introducing microvascular cells would augment the function of the bioprinted tissue.

Another area of research will be how to introduce or mimic neurological capabilities in living tissue. It is unknown whether these capabilities need to be biological in nature or the electrical impulses and messaging capabilities of human tissue be produced synthetically. It is within the realm of possibility that 3D printed synthetic cells may one day be fully encased in surrounding living tissue and replaced at a later date by fully functioning bioprinted tissue. Whatever the possibilities, the use of 3D printed synthetic cells should be fully explored.

Other areas of research include cell diversity within living tissue, integration of the tissue within the patient and bioprinted tissue contamination. It is not enough just to produce the living tissue. That tissue has to be placed in a patient with minimal complications and with a high rate of acceptance. The bottom line is that many challenges regarding 3D bioprinting need to be addressed before making its debut in prime time.

Business Benefits

The benefits of 3D printing and additive manufacturing in the medical profession are tremendous. It is highly likely that a majority of people will within the course of their life need some type of medical treatment where 3D printing or bioprinting could be utilized. This utilization would lower the overall cost of treatment, aid in patient recovery and produce better end results.  As a result, these benefits cannot be understated.

According to Dr. Zaneveld, the total potential market size for 3D printed models in the rehearsal of surgical procedures may be as high as $50 billion annually in the US. A small reduction in complications during surgery caused by using surgical models and the resulting decreases in recovery time could translate into billions of dollars worth of cost savings to our taxed medical system. Since unique patient tissue models can be fabricated within 24-48 hours upon receipt of patient data, the speed advantage over traditional patient models is incomparable. Patients and surgeons have near real-time access to information that was previously unattainable. With this in mind, unique 3D printed tissue models may be easily and cheaply integrated into the majority of surgical oncological treatments. This leads to wider adoption across the entire medical profession.

In the end, the quality of patient care and patient satisfaction will increase once these 3D printed surgical models are in wide use. The benefit will be experienced by new medical professionals as well as the most experienced surgeons since training will be more realistic and pervasive. This minimizes surgical error as well as individual patient risks which only improves the quality of patient care.

Summary

Since the beginning of recorded history, the medical profession has employed the use of models in studying anatomy and acquiring the knowledge essential to patient health and welfare. Human cadavers have been replaced by synthetic models which closely mimic the look, feel and function of human tissue. Now with the advent of 3D printing and additive manufacturing, unique tissue models are now the norm and no longer the exception.

Modern techniques of 3D printing are now commonplace in thin layer bioprinting of tissue, prosthetics, patient unique drug delivery devices and dosage forms as well as in unique tissue surgical models. With the advantages of customization, personalization increased cost efficiency and the reduction of time from prototyping to production, 3D printing is now at the vanguard of patient care. This will eventually lead to the full production and acceptable of large, unique 3D printed tissues and organs for needy patients across the world.

As a fabricator of realistic 3D printed tissues and organs, Lazarus 3D is working towards bringing 3D bioprinting to reality.  “From our standpoint, the production of realistic soft tissue organs and models for surgery preparation is a path forward for us to meet surgical demand as well as to fund further research into the application of 3D printing technology,” states Dr. Zaneveld. “Of course one of these applications is the bioprinting of functional human tissues and organs.”

The story of 3D printing and additive manufacturing in the medical profession is a work in progress with many challenges to come. However, if recent progress is any indication, the future holds explosive potential in advancing the medical profession and improving the human condition.