June 2nd, 2015
A few weeks ago, we had a call from a leading heart and Oncology treatment hospital in Bangalore, India to understand and to discuss the challenges they face during the complex treatments and surgical planning. They were trying to explore the possibility of integrating the benefits of 3D Printing to prepare better during the pre-surgical planning to minimise the surprises during the surgery.
The pre-surgical preparation largely depends on the input from the scans from the Imaging processes like CT or MRI. This data is usually a 2D visual displayed as a slice of the organ or the tissue at regular intervals. Though the doctors are intellectually capable to visualise the defective part , at times this depends on their previous experiences and can be tricky, even for the most experienced and talented surgeons, to visualise and estimate spatial relationships of some intra-cardiac structures.
As an example, with certain heart defects, the manner in which the heart can be repaired is determined by the distance between particular structures and in some instances the doctors are unable to visualise the depth of the malignancy of the tumor of a cancer affected patient. Relying on 2D data and even utilizing 3D models on the computer still doesn’t capture the space between these structures, and surgeons cannot formulate a surgical plan until they open up the patient’s heart or the affected organ.
However, 3D Printing allows surgeons to not only decide on the optimal repair, it additionally even allows them to practice the repair, ensuring the best possible outcome once the patient is in surgery and time is critical. The ability to plan and practice surgery is paramount for less bypass time, less circulatory arrest time, fewer days in the ICU and fewer reoperations.
The challenge that was directed at us was to 3D print the scans from a CT scan of a brain which was affected by a cancer tumor and capture all the details of the scan with differentiation in colour, texture and also replicate the hard and soft tissues as much as possible to plan the surgery. The data available from a CT/MRI scan is DICOM- Digital imaging and Communication in Medical which needs to be converted to a 3D CAD model for 3D printing. This is done by speciality Medical imaging conversion softwares like Mimics from Materialise.
After the files were converted from DICOM to a 3D CAD file in the form of .STL or VRML file which is the standard file format for color 3D printing is sent as the input to the 3D printing pre-processing software called Objet Studio.
The brain part was sectioned into 4 halves for better handling of the model and also to visualise the shape and the depth of the tumor for formulating surgical planning.
These sectioned parts were printed on flexible material called tango and the tumor was printed in a different color on the make Objet500 Connex3 3D Printer at India's first ever 3D Printing experience in Bangalore, India, which is capable of printing parts with various color hues and also different material properties like varying transparency, flexibility and color shades along with normal hard and opaque parts in a single build.
After some more interactions with the doctors , another model was printed in complete transparent material for the see through visual with which the doctors were impressed mightily as they were able to hold the exact replica in their hand and to plan and execute the surgeries efficiently.
A similar video of case study of the benefits of 3D Printing in a neonatal cardiology can be seen here:
Video & Blog title sourced from OpHeart