Published onChildren's View
As her 5-year-old daughter Arden prepared to face the second surgery of her young life, Tray Sullivan MacPhee grew more and more anxious. “I wasn’t yet Googling ‘kids on dialysis,’” Tray says. But she feared that would be Arden’s future.
That’s because back when Arden was 18 months old, she was diagnosed with a kidney cancer called Wilms tumor. Before she turned 2, Arden had undergone 12 rounds of chemotherapy at Children’s Hospital of Philadelphia. After chemotherapy, pediatric urologist Thomas Kolon, MD, performed surgery to remove the kidney that contained a large cancerous mass.
For three years, everything was fine — until cancer was detected in Arden’s other kidney. “It was more shocking than the first time,” says Tray.
If Arden’s remaining kidney had to be removed, she would require dialysis to clean her blood. Not only does each dialysis treatment take several hours, but it needs to happen every few days, indefinitely, until a possible kidney transplant — a challenge for anyone, especially a young child. Her family and the CHOP medical team hoped for a way to remove the cancer safely while saving the kidney.
As with all surgery patients, Arden underwent routine imaging that produced two-dimensional pictures of her kidney, which showed the tumor was sitting dangerously close to the organ’s main blood supply. This presented Kolon with a problem: What was the best way to access the tumor?
Luckily, there was a new development at CHOP: the Children’s Hospital Additive Manufacturing for Pediatrics (CHAMP) Lab in the Department of Radiology. Run by Elizabeth Silvestro, MSE, and Raymond Sze, MD, MAMS, the CHAMP Lab focuses on printing 3D models. Silvestro and Sze knew that using 3D models could open the door to innovative ways to treat patients. From the start, they actively solicited ideas and problems that needed solving from a range of specialists across the hospital.
After viewing a presentation about 3D printed models, Kolon saw an opportunity, and with Arden in mind, he approached Susan Back, MD, a pediatric radiologist, with a question: “Can we use this technology to take a better look at tumors and the surrounding tissue?”
Printing 3D replicas of organs
Silvestro and Back used Arden’s 2D imaging to create a 3D model of her kidney: “We took the images,” explains Back, “segmented the anatomy and used the lab’s advanced programming to print it.” The kidney model can be opened up to directly visualize the tumor and its relationship to the arteries, veins and other structures, allowing Kolon to study the anatomy from a new perspective.
“We wanted to save as much healthy kidney tissue as possible to avoid dialysis,” says Kolon. “This 3D model allowed me to see the critical blood supply to the kidney and to the tumor — views I would not have otherwise had. I carried this model around and looked at it from different viewpoints and looked at the blood supply. It made a tremendous difference.”
In April 2018, Kolon performed surgery that removed the tumor and spared the rest of Arden’s kidney.
Arden’s recovery from the six-hour surgery was difficult, but she’s now thriving. “She loves to dance and do gymnastics,” says Tray. Without the team’s innovative approach that resulted in successful surgery, “Arden would not have been able to do everything she’s doing now.”
Since Arden’s surgery, the 3D printing technology in the CHAMP Lab has been changing the equation for many other patients across the hospital. “The collaboration between the clinician, radiologist and engineer has been an important part of creating these models,” says Back. “Understanding how a surgeon uses the model allows us to plan and optimize the imaging study to create a presurgical print.”
Surgeons in the Division of Orthopaedics use 3D models to plan for tumor removal from the spinal canal and complex surgeries for abnormal vertebrae and fused ribs. Surgeons can bring the models into the operating room to orient themselves during procedures that often involve limited views of the anatomy they’re working on.
“Patient-specific 3D models remove risk and uncertainty from my most challenging surgeries,” explains Patrick Cahill, MD, a pediatric spine specialist in the Division of Orthopaedics. “It allows me to address problems that may have otherwise been untreatable.”
As an added benefit, when a surgeon has the opportunity to examine a 3D model closely and make a plan beforehand, the operation can be more seamless, and young patients spend less time under anesthesia.
3D models as teaching tools
Creating patient-specific 3D models to help surgeons prepare for complex procedures is a striking use of the technology, but CHOP’s CHAMP Lab members know that is just scratching the surface. In particular, the technology enhances CHOP’s mission to train the next generation of pediatric care providers.
Generalized 3D models help trainees learn all types of skills. Back, the pediatric radiologist who helped model Arden’s kidney, teaches a pediatric contrast-enhanced ultrasound course using 3D models of infant torsos (topped with baby doll heads to make them more realistic). At a recent course at CHOP, attendee Christina Hendricks, a sonographer from the University of Wisconsin, thought the models were “very useful. It’s nice to have a ‘standardized’ patient when getting the protocol down. This is an ideal situation, particularly in pediatrics — not worrying about the patient moving and just focusing on the technique.”
Elsewhere in the hospital, trainees use 3D models to practice placing stents. In the Emergency Department, models of child-size ears and noses let clinicians practice different methods of retrieving objects that little hands can push into those cavities.
Silvestro can craft a 3D model using materials that simulate a particular type of tissue or bone, so a trainee can get a sense of what a procedure actually feels like. The newest machine in the CHAMP Lab produces an even larger variety of flexible models and colors as well as transparent areas. “We’re able to make clear regions and show, for example, where a tumor sits inside an organ, which is particularly helpful for tumors that are fully encapsulated within the organ,” explains Silvestro.
CHAMP Lab team members are thrilled by what they’ve been able to accomplish to date, and they look forward to finding the next innovative use for 3D printing technology to enhance patient care. The team sees endless possibilities. As Sze notes with excitement, “We’re getting requests and new ideas from across the hospital!”