The on-demand advantage of 3D printing continues to allow health providers to reach new heights in patient-specific care. Surgical models, guides and pandemic-related personal protective equipment are being printed at an accelerating rate right where caregivers and patients need those items.
High-volume point of care production as practiced at the Mayo Clinic is being echoed in programs like the new 3D printing lab at Montefiore Medical Center. And a collaboration between 3D Systems and the Veterans Health Administration announced in November will bring the manufacturing-in-the-hospital model to dozens more facilities nationwide.
Continuing to raise the bar on its industry-leading model for bringing manufacturing into the health-care setting, Minnesota’s Mayo Clinic has recently expanded its centrally located production facility to 7,000 ft2.
“Since we founded our clinical service using additive manufacturing for patient care,” said Medical Director Dr. Jonathan Morris, “we’ve tried to make it the standard of care in several instances.” Since beginning its program 15 years ago, production has exploded from about 20 anatomical models a year to 3,000 models a year for an average of 850 patients for every surgical subspecialty at the main campus in Rochester. Those specialties include thoracic, colorectal, neurologic, pediatric, urologic, orthopedic and cardiovascular; the top specialties Morris’ lab serves are benign or cancerous facial reconstruction; all orthopedics; and congenital heart disorders.
Meanwhile, surgical guide output has increased 500 percent over the past two years.
The lab is a constant hub of activity thanks to its proximity to the clinic’s operating rooms. Surgeons routinely come to the lab for surgical planning and consultation on models “on the fly.”
Mayo has further made the ordering of 3D anatomical models the standard of care by making it easier for doctors to order them. “We continue to build IT workflows so physicians and surgeons can order models in the electronic medical records, or EMR system,” Morris said. “We’ve built into Epic [the Mayo Clinic’s EMR platform] the infrastructure needed for additive manufacturing of patient-specific models and guides.” This makes ordering a surgical model as easy as ordering a blood test, CT scan or other diagnostic. “Our surgeons are busy,” Morris said. “If [a 3D printed model or guide] is the standard of care, they have to be able to order it like anything else.”
For example, in the case of a jaw tumor, a surgeon can see a patient and order an anatomic model and surgical guides at the same time as a CT scan. That triggers the radiology department to use a specific protocol designed for 3D printed anatomic models. “All that automatically gets transferred to our clinical department, which is housed centrally in the department of radiology. We build a manufacturing workflow solution into our clinical care.”
Working with additive manufacturing software provider Link3D, “we build custom solutions for Mayo Clinic,” Morris said. “Once we have imaging and start the process of segmentation and virtual surgical planning and guide creation, that lives in a Link3D ecosystem with pertinent manufacturing data embedded into the electronic medical record. Every step of the manufacturing process when it comes to a patient-specific device is tied to that patient’s medical record.”
As with any other manufacturing process, quality control is built into every step, Morris added. “Someone’s signing off on their part of it, and we can look at dashboards and see how many models we have going, for how many people, and when surgical dates are. We can pull audit trails of how many jaw resections we’ve done per year using this type of printer.”
When a surgeon signs off on a medical model or guide, it goes to one of 36 printers; vat photopolymerization is the clinic’s predominant technology, with 27 Formlabs printers in house. The arsenal also includes a NewPro3D digital light processing (DLP) vat photopolymerization printer; Stratasys material jetting printers including the Objet500 and J55; 2 Ultimaker S5s and a five-filament input PRUSA for material extrusion; an EOS P110 Formiga SLS (selective laser sintering) printers for nylon 12; an HP multi-jet fusion printer for full photorealistic color nylon prints; and a ProJet 660Pro binder jetting printer from 3D Systems. “We have full color and photorealistic color capabilities and can produce multi-material models and sterilizable, biocompatible models, guides and swabs. With the DLP printer, we can print a skull in two hours, which has really helped for trauma cases.”
Because Mayo’s additive manufacturing center is staffed by subspecialty radiologists, they can give a model to, say, an orthopedic oncology surgeon and indicate where the margin of a tumor is—something an external 3D printing house cannot do.
In terms of materials, Mayo has entered into batch contracts with suppliers to ensure device consistency “because we can’t have differences in raw materials if we’re screwing something inside a person’s body.” Mayo’s model of manufacturing means its specialists can perform enterprise-wide consultation, design and printing—for instance, a device can be printed at its Jacksonville, Fla., campus, or printed parts can be sent state to state.
It’s a big paradigm shift.
“Instead of using traditional manufacturing at a medical device company—where the surgeon might upload imaging through a HIPAA-compliant cloud, schedule time with an engineer of a company and then review plans and re-review plans, then the device is manufactured somewhere and shipped to the hospital—this is a truly disruptive way to manufacture medical devices and anatomic models. Although other centers are increasing their use of 3D printing across the country, Mayo’s been at the forefront. We’ve built regulatory, IT and intrahospital infrastructure in terms of space, equipment and personnel to make this a reality.”
Ultimately, “we’re using industrial manufacturing equipment to change the way we fundamentally treat patients,” Morris said. “We’re doing it in a distributive way at the point of care; the traditional manufacturer has become the hospital.”
With a roadmap from the American Medical Association (AMA) and multiple modalities at her disposal, Dr. Nicole Wake of New York’s Montefiore Medical Center has been creating 3D printed models since she created the 3D Imaging Lab in the Department of Radiology in January 2019.
“In conjunction with the new AMA Category III CPT codes for 3D printing, which were released in July 2019, we have established a proper workflow and documentation method of our 3D printed anatomic models and guides,” said Wake, director of 3D imaging and assistant professor of radiology. “First, the clinician is asked to place an order in our patient medical record system.
Once a model has been ordered, it comes to the 3D lab work list, and we are able to consult with the physician and decide which printing approach to take. After the model has been printed, we document this through pictures and have a dictation template with information regarding printing technologies, material types, print times, and physician effort. All of these are exported back into the patient’s medical record before the model is delivered to the ordering physician.”
Montefiore uses multiple additive processes, including vat photopolymerization, material extrusion, material jetting and binder jetting. “We consider things like whether the model needs to be sterilized and brought into the OR, or if it needs to be flexible in order to perform a pre-operative simulation on the model,” Wake said. “Binder jetting allows us to achieve beautiful multi-colored prints, so we are able to properly depict all anatomical areas of interest within our models. We can even create lattice structures to allow for internal structures to be highlighted within organs, and these can be shown in full color.”
Specialists in orthopedic surgery, urology, plastic surgery and radiation oncology are Montefiore’s primary users of 3D printed models. They “are also especially useful for medical student and trainee education as well as for patient communication, allowing for patients to better understand their disease as well as to make more informed decisions about their treatment choices.”
Wake recently created a 3D printed kidney tumor model for a complex renal mass case, she explained. “This model was designed to be printed in multiple colors using our binder jetting printer, the Projet CJP 600, 3D Systems, and a lattice structure was created so we could see through the kidney to view an endophytic tumor and the internal components of a second partially endophytic tumor. The model was used pre- and intra-operatively and greatly assisted with the surgical procedure.”
Offering a unique take on 3D printing in the hospital, Cleveland Clinic combines augmented reality (AR), novel applications and an emphasis on patient education. In addition to 3D printed surgical models and tools, Cleveland Clinic printed the injection mold for a cured silicon airway stent for a cancer survivor experiencing abnormal stricture of the trachea and bronchus.
Karl West, director of Medical Device Solutions at Cleveland Clinic and a staff member of its Lerner Research Institute (LRI), brought his biomedical engineering background to the institution 18 years ago to begin working on stent grafts for aortic aneurysms. Having purchased the clinic’s first 3D printer in 2003, he now oversees LRI’s team of 3D printing professionals who run flexible, rigid and color materials including carbon fiber and ABS on an array of six printers, including a Stratasys J750 polyjet and an Ultimaker fused deposition printer. “We have a large material selection because we never know what we’re going to be asked to print.” In the case of a heart valve deformity, the valve and annulus can be printed in flexible material, while calcification is printed with hard material.
LRI interacts directly with the clinic’s clinicians and patients to devise optimum treatment plans, West said. Printing 3D surgical models requires careful interpretation of medical imaging to print exactly the right anatomy; that work can take hours or days, he added. But that critical work can cause a specialist to completely change a surgical approach—as in the case of a boy with a congenital heart deformity. In a more recent case, West and his team combined AR and 3D printing for a face transplant. “We were able to look at different scenarios as far as how much of [the patient’s] face to replace.”
Adding the HoloLens AR holographic computer headset provides that next level of anatomic certainty, West said. By looking through the headset a 3D printed model of a heart, for instance, a specialist can visualize the flow of electricity or blood, or how valves open and close.
Besides pushing the boundaries of 3D printing in the hospital, LRI is working to create a 3D printing center behind glass walls that will allow patients and visitors to see models being printed, as well as previous models on display. This will help the public understand more about anatomy, including what functions organs perform and how large they are.
For instance, “we have printed models of diseased and healthy livers,” West said. “We made them transparent so you can see the vasculature, because what you find in a diseased liver is the lack of vasculature.” One physician keeps all the liver models West’s team has printed to educate patients about diseases and procedures.
Looking ahead, West envisions patient-specific implants being printed at the hospital. For the military, a soldier’s dog tags might contain all the data required for caregivers to print replacements for damaged bones. In terms of preoperative training, surgeons could have desktop printers in their offices to print anatomical models for practice. This will continue fostering advances in minimally invasive care.“I really didn’t think we would be replacing an aortic valve without cracking the chest open,” West said. Now that that is a reality, mitral valve replacement is next, he added. “A lot of that has come about because of 3D printers allowing for benchtop simulations and models.”
In a collaboration that promises to provide federal regulators a wealth of data on the use of 3D printing for creating medical devices in situ, the Veterans Health Administration in November entered into a contract with 3D Systems to establish FDA-compliant manufacturing facilities within VA hospitals.
The collaboration grew out of the VA’s need for face masks early in the COVID-19 pandemic. When 3D Systems helped get a stop-gap mask into production, the VA then requested printable testing swabs. Now, the company will begin installing ProX SLS 6100 printers and materials and enabling its VSP surgical planning solutions at multiple facilities in the VA’s expansive network of hospitals, said Ben Johnson, director of product development, healthcare for 3D Systems.
With the VA, “we’re very interested in setting up medical device manufacturing capability that’s compliant with FDA standards,” he noted. “Many hospital networks are using 3D printing equipment to manufacture low-risk devices and developing controlled workflows to fabricate the devices, but this effort raises the bar for U.S. point of care manufacturing with a compliant quality management system and associated FDA registrations.”
It will take about a year to set up the quality management system and manufacturing capabilities at several VA sites.
“In the near term, we’re looking at setting up operations at a handful of hospitals across the U.S.,” Johnson said. “Once set up, the rolling out of additional tools and capabilities can be much quicker, depending on the risk level of the product.” Low-risk (Class 1) devices can be developed in months; higher-risk devices like surgical guides would still take about a year to develop, validate and transfer to production. A GMP-compliant system ensures control over device materials, designs and testing — especially when transitioning from low-volume production to tens of thousands of units, as with PPE.
With facility space an issue, hospitals might look to create 3D printing facilities in spaces nearby. Creating a localized hub for device manufacturing run as a managed service would be “very interesting for a company like ours with expertise spanning the technology and how it is deployed in a controlled manufacturing environment.”
For the past 15 years, 3D Systems has run a medical device facility with about 80 plastics and metals printers in Littleton, Colo., producing models, surgical instruments and implants. “That’s something we can translate and educate hospitals like the VA to do themselves.”
While the VA hospital network “is quite sophisticated in its capabilities and know-how with 3D printing, and this collaboration is an evolution in their journey to increase their capability to do surgical planning, patient-matched instrumentation and eventually implants within their network.”
In addition, the VA’s partnership with FDA promises a healthy pipeline of additive manufacturing data and metrics from this collaboration to regulators who are drafting guidance of medical device manufacturing at the point of care.
While 3D printing of dental fixtures like dentures and implants is commonplace, general dentist Perry Jones of Richmond, Va., has seen an opportunity to simplify the direct manufacture of orthodontia with digital scanning and modeling. This would prove especially useful in eliminating the multiple physical models used to produce multiple clear Invisalign-like corrective devices for different stages of a patient’s progress.
His ultimate goal is threefold:
--Eliminate impressions taken with messy, inaccurate elastomeric materials used directly in the patients mouth.
--Eliminate models and directly manufacture end-use appliances like retainers, occlusal guards and mouth guards.
--Eliminate cumbersome, time-consuming software required to repair the digital file surface and trim the digital model.
“My primary focus is to help simplify the process of everyday dentistry,” Jones said. “3D printing … is not well integrated as yet into everyday dental practice. Digital scan technology is not new but has been very slow in adoption. I placed the first iTero scanner in service in the U.S. in 2005, and yet the world market penetration of intraoral digital scanning is only in the 10 percent range or so. Over six years age I removed gypsum, and fully integrated 3D printing in my GP practice.”
Most dental offices make their own appliances, like occlusal guards and retainers, he said. “The most common technique used to make a thermoplastic appliance requires an impression, usually taken using an elastomeric material such as PVS or alginate,” he said. “The traditional process required a model to be poured using a gypsum material.” Digital scanning lets dentists eliminate “the mess and inaccuracies” of elastomeric” impressions and gypsum to pour stone models.”
That virtual model can be used to create a physical model using additive manufacturing to create a physical polymer/resin model, he added. “That 3D printed model may then be used to create the actual appliance using thermoplastic material that is either vacuum formed or pressed.”
In the case of clear, Invisalign-style aligners, another layer of software—segmentation software—is needed. “A virtual model is created from the digital scan of the patient. The software can then create virtual ‘dies’ that can then be virtually moved to create virtual movements using established orthodontic and physics principles. The software allows the operator to view and create a virtual model of each movement stage. The virtual model can be sent to a machine such as a 3D printer to create a physical resin/polymer model.”
Jones’ patent for a software, a process and a prototype to directly manufacture the end use product is under review. The process is called galvanometer-guided material ablation.
“The .stl design file from the segmentation software would be sent to my software,” Jones explained. “The user would the use the simple steps to design and create a virtual aligner; a physical model is not necessary. The design file is sent to a 3D printer or CNC mill to be directly manufactured. No physical model is required as the material used to make the aligner is not a thermoplastic material.”
He has been working with material suppliers “to develop a polymer with a wall thickness thin enough to replicate a thermoformed aligner. We have not as yet found a liquid resin/polymer to use in a 3D printer that will produce an end-use aligner with sufficient properties to direct print end-use aligners.
Thermoformed materials used on models to create an aligner appliance are typically in the .040 material blank thickness. After thermoforming, the thickness is roughly reduced by 1/4 to 1/2 depending on the heating system and application techniques.”
Compared with his process, “I do not know of a company that has a direct manufacture process using 3D printing that produces a viable aligner product with a wall thickness in the 0.5mm range.”
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