3-D Printing Reshapes Medicine

The creation of 3-D printing back in 1984 brought the promise of a new age in manufacturing. Although it has only begun its takeoff, there is already so much we are able to do with the technology. From building screwdrivers to chairs to cars, the possibilities are endless. More importantly, however, is the impact of 3-D printing in medicine. In the past few years, biomedical engineers and physicians alike have realized that 3-D printing can make surgery, bone replacement, organ transfers, and other procedures a whole lot easier and more effective.

There are three major steps involved in transplanting an organ: the organ distribution system, the surgery, and then the post-surgery recovery (6).

The organ distribution system is quite complicated, as finding an organ that will match the patient exactly among hundreds of thousands of organs is an arduous task. After anesthetizing the patient, the first step the transplant team takes is to inject an anticoagulant into the patient's bloodstream. Depending on the organ the physicians are attempting to transplant, they will then connect a temporary "organ machine," which performs the function of the organ during surgery, to the patient's body (5). Once blood is completely diverted away from the organ being replaced, they are finally able to surgically remove the organ/other body part. Once the new organ is in, the physicians are able to suture the necessary vessels/parts to the body, completing the transplant (6).

But what happens if our body rejects the organ? Our bodies manufacture specific antibodies, proteins with the purpose of destroying foreign objects in the body, which could easily prevent the long-term completion of a transplant. In the modern day, physicians use immunosuppressive drugs, which subdue the immune system's response to several different kinds of foreign objects, whether they are good or bad (6). The downside of using these drugs is that patients become more susceptible to many other kinds of diseases.

Although the surgery itself seems to be the most important step in the process, getting the organ there in a timely fashion is a pre-requisite to making it all happen. Here is where 3-D printing comes in. A CAT (or CT) Scan can reveal more to physicians today than it ever did in the past.

Current imagining technology combined with 3-D printers guides physicians in where to cut and position transplant materials, locates and identifies the areas to be removed with "pinpoint accuracy," and literally constructs specific implants for each patient out of the material physicians choose. The finished organ or other body part is perfectly built to fit in the patient's body, ready to replace the diseased tissue (1). With specialized 3-D printers at their disposal, physicians are able to conduct emergency surgeries and construct the necessary organs at the same time. Citing the example of an infant needing a lung transplant, Dr. Glenn Green of the University of Michigan explains that physicians are now able to make a complete body part using 3-D printing "within a day." Now, surgeons have everything they need to reconstruct a person at a moments notice. There is no longer a need to wait weeks or months for the organs to come in to the hospital, allowing physicians to quickly provide life saving surgery (4).

With its ability to construct tissues, 3-D printing has the potential to aid a spectrum of surgical procedures. Scientists at the University of Wollongong in Australia have developed a "bio pen" that allows physicians to physically draw healing cells onto damaged muscle tissue or bones. When the physician applies pressure onto the desired area, a thick gel made from human somatic cells and seaweed extracts is excreted and then cured with ultraviolet light. The cells in turn divide and grow into several kinds of tissue, including bones, muscles, nerves, and most other epithelial tissues (2). 3-D printing the cells right onto the wound provides precision and accuracy never seen before (check out this video). British surgeons were able to use 3-D printing to reconstruct a man's entire face. By taking an in depth image of the half of the man's face that wasn't destroyed, scientists were able to recreate an identical copy to replace the destroyed half. The amazing element of their achievement is that they were able to create a precise and perfect copy of the man's face, making it seem as if almost nothing happened once the surgery was complete. In order to rely less on immunosuppressant drugs, scientists are now using samples of the patient's own cells to construct the material necessary to build the organs/other parts themselves (1).

There are many implications for the future of medicine with the recent spike in 3-D printing advancements.

Not only does it aid current surgeons in effectively transplanting organs/other parts, but it also helps medical students practice their surgical skills. Now, biomedical corporations are able to create "ultra-realistic" 3-D printed organs and other parts that almost perfectly mimic the texture and structure of actual body parts. The plastic used in these parts can be made using several textures, shapes, colors, and degrees of sturdiness (3). The relative ease in creating these "parts" makes the practice faster, cheaper, and globally available. Whether it be performing heart surgery, removing tumors, or carrying out a knee replacement, the existence of such materials exponentially expands the frontiers of medical research.

References:

1. The Daily Mail. Sarah Griffiths. "British surgeons to use 3D printing to reconstruct a man's face after he was seriously injured in a road accident." (2013).

2. University of Wollongong. "Biopen to Rewrite Orthopaedic Implants Surgery." Latest News (2014).

3. New Scientist. "3D-printed skill simulates sensations of brain surgery." Health (2013).

4. Smith, Stephanie. "3-D Printer helps save dying baby." CNN Health (2013).

5. National Institutes of Health. "Organ Transplantation." U.S. National Library of Medicine (2013).

6. World Health Organization. "Human organ transplantation." Transplantation (2013)

Image Credit: Bart Dring (Wikipedia), Protonk (Wikipedia), HIA (Wikipedia)