MDNews - Cleveland-Akron-Canton

A D VA N C E S I N 3 - D p r i nt i n g demonstrate that the technol- ogy could be uniquely suited to t he a noma lous, rapidly changing nature of pediatric cases. As costs associated with 3-D printing decrease, developing custom products for growing patients may also become more cost-effective. Around the country, physicians are taking note. Many children have already benefi ted from models used for surgical preparation, precisely fi tted implantables and low-cost prosthetics made possible with this technology. Two Tiny Futures Three-dimensional rendering played a key role in the successful separation of Tyler and Tyson Proctor, twins who were conjoined at the chest and shared a liver. Using data from a CT angiogram, Carolyn Cochenour, a research engi- neer with the Sheikh Zayed Institute for Pediatric Surgical Innovation at Children's National Medical Center in Washington, created and printed a 3-D replica of the twins to help physicians understand the challenges they would face during separa- tion surgery. Cochenour took the process one step further, doing something she calls "LEGO-izing" the model. "That's the term we've come up with to describe making pieces so you can fi t them together, take them apart and take the organs out, separating them in multiple ways," Cochenour explains. "This is a case where LEGO-izing really does help because you can see what you're going to have once you separate the twins." With the Proctor twins, traditional imaging failed to fully answer some ques- tions, such as where their gallbladders were in relation to the midline. The 3-D rendering created an accurate model of the boys' biliary systems, allowing surgeons to ma ke incisions without compromising either twin's system. Heart Matters In Februar y, Erle Austin III, MD, a ca rd iot horacic su rgeon w it h t he University of Louisville Physicians, used 3-D modeling to help plan a lifesaving surgery on 14-month-old Roland Lian Cung Bawi, who was born with several heart defects, including a hole in his heart and a double outlet right ventricle. It was a complex case, one for which Dr. Austin says he received conf licting advice about how to address. Children of a similar age with the same type and grade of heart defect are still entirely individual, with intricacies that even experienced pediatric physi- cians may never have seen before. That makes the opportunity to hold and touch a 3-D rendering of the anomaly all the more important. The R apid Protot y ping Center at the University of Louisville J.B. Speed School of Engineering used a MakerBot 3-D printer to create a replica of Roland's heart that was 50 percent larger than the original and separated into three pieces. Dr. Austin used it to plan his approach before surgery, reducing the amount of time the child would need to be under anesthesia. The model cost about $600 to produce. "Once I had a model, I knew almost exactly what I needed to do and how I could do it," Dr. Austin said in a February inter v iew w ith T he Cour ier-Jour nal. "Being able to determine exactly what that abnormality is, in a three-dimen- sional way, is going to be very helpful for children with complicated hearts." Looking Ahead Pediatric specialists are looking into improvements in efficiency, reduction of radiation exposure for imaging and new uses of implantable, biodegradable, 3-D-printed structures. At Children's National, Cochenour uses a program ca lled 3-matic from Materialise to create the renderings that become 3-D models. This computer- aided design anatomy program evolves as Cochenour and other engineers apply it to new cases. Each new application sup- ports Materialise's efforts by providing user insights as the company seeks to build a stronger software suite. This collaborative development model is particularly helpful for improving the time-consuming process of segmen- tation — a detailed phase of the 3-D process that requires physicians and engineers to carefully identify the tissue in images they want the program to recognize and recreate. New algorithms could speed this process, lessen the time burden on physicians and further reduce the cost of creating 3-D medical devices. "Biodegradables are really where the future is," Cochenour says. "The goal is to eventually be able to 3-D-print cus- tomizable implants. We've already done some mouse studies with biodegradable grafts. Hopefully those can make it to the market in the next five to 10 years." A few cases have been successf ul already. For example, Glen Green, MD, with the University of Michigan, has used biodeg radable dev ices to help two children with collapsed air ways due to tracheobronchomalacia. These complex splints were designed to provide a clear airway and then slowly dissolve as patients' growing bodies developed enough to naturally support breathing. No additional procedures are expected to be necessary. B e y o n d a n a t o m i c m o d e l s a n d biodeg radable impla nts, 3-D print- i n g 's p o t e n t i a l a p p l i c a t i o n s f o r pediatrics remain somewhat speculative. Specialists and engineers will continue to imag ine t he possibilities, a nd if innovation continues on its current trajector y, the technolog y will prove to be a manufacturer of hea ling for more children. ■ FROM EXACT REPLICAS OF THE INFANT HEART TO ARTIFICIAL TRACHEAS THAT A GROWING BODY CAN ABSORB, PEDIATRIC APPLICATIONS OF 3-D PRINTING ARE SHAPING THE FUTURE OF CUSTOMIZABLE MEDICINE FOR CHILDREN. 2 0 1 4 S E P T E M B E R /O C T O B E R ■ M D N E W S . CO M ■ MD NEWS Cleveland/Akron/Canton | 4 1

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