syed_tasnim_raza's picture
Medical Director, Cardiac Surgery Step-Down Unit at Columbia University Medical Center and New York Presbyterian Hospital
Use of 3D printing in the medical field

It may not be an exaggeration to say that within the field of medicine the most progress made in the last few decades is in the field of clinical imaging: starting with simple X-rays to computerized axial tomography (CT scan or CAT scan), magnetic resonance imaging (MRI), functional MRI (fMRI), positron emission tomography (PET scan), single photon emission computed tomography (SPECT scan), nuclear tagged scanning such as Ventilation/Perfusion scan to rule out blood clots in the lung (V/Q scan). And then there is Ultrasonography, which has been extensively used in diagnostic and also therapeutic interventions in many body cavities such as amniocentesis during pregnancy, or drainage of an inflamed gal bladder or evaluating kidneys for stones, or for evaluation of arteries and veins, etcetera.

Ultrasonography is also used extensively in imaging of the heart (Echocardiography), and is used for M-mode, 2D or 3D imaging. Cardiologists have used various imaging modalities for diagnosis of heart conditions. These include echocardiography as mentioned above, diagnostic heart catheterization in which a catheter is passed from the groin into the heart via the Femoral artery or vein, while watching the progress under x-ray. They perform contrast studies by injecting radio-opaque material in the heart chambers or blood vessels while recording moving images (angiograms). And then there is Computed Tomographic Angiography of the heart (CTA) with its 3-D reconstruction, which provides detailed information of the cardiac structure (Structural Heart Imaging).

Now comes 3D printing, adding another dimension to imaging of human body. In its current form, using computer aided design (CAD programs), engineers develop a three-dimensional computer model of any object to be “printed,” (or built), which is then translated into a series of two-dimensional “slices” of the object. The 3D Printer can then “print” or lay thousands of layers (similar to ink or toner onto paper in a 2D printer) until the vertical dimension is achieved and the object is built.

Within the last few years this technology has been utilized in the medical field, particularly in surgery. It is another stage in advancement of “imaging” of the human body. In the specialty of cardiac surgery, 3D printing is being applied mostly in congenital heart disease. In congenital heart malformations, many variations from the normal can occur. With current imaging techniques, surgeons have a fair idea as to what to expect before going to operate, but many times they have to “explore” the heart at surgery to really find out the exact malformation and then plan the operation at the spur of the moment. With the advent of 3D printing, one can do a CTA scan of the heart with its three-dimensional reconstruction, which can then be fed into the 3D printer and a model of the malformed heart can be created. The surgeons can then study this model and even cut slices into it to plan the exact operation they will perform and save valuable time during the procedure itself.

Three-dimensional printing is being applied in many areas of medicine, particularly in orthopedics. One of the more exciting areas is in use of 3D printing for making live organs for replacements using living cells and stem cells layered onto scaffolding of the organ to be “grown,” so the cells can grow into skin, ear lobe or other organs. One day in the future, organs may be grown for each individual, from his/her own stem cells, obviating the risk of rejection and avoiding the poisonous anti-rejection medicines. Exciting development.