“If I can make that decision beforehand by practicing on a model using the same tools and clips I plan to use in the final operation it really makes a difference during surgery.”
Challenge
Dr. Abdulrauf’s mission is to improve patient outcome during the most complicated neurosurgical operations using all the innovative tools available to him.
“I personally perform a lot of brain aneurysm surgeries. It is a complex operation given the number of anatomical issues that we’re dealing with under the microscope. I knew if there was a way of simulating those complications before the operation using the same tools and under the same microscope we’d have a higher positive impact on the procedure outcome for the patient,” explains Dr. Abdulrauf.
Brain aneurysms are minutely different from patient to patient. During the operation, a surgeon is tasked with determining how to reach the aneurysm with minimal effect on surrounding tissue. The surgeon must calculate, in real time, the optimum angle to get into the area while factoring in the depth at which the aneurysm occurs and the size of the clip to close the aneurysm area.
“Every aneurysm is different in size, contour, and location. We have hundreds of clips sizes and types we can use and we’re typically making the decision on clip size during surgery. If I can make that decision beforehand by practicing on a model using the same tools and clips I plan to use in the final operation it really makes a difference during surgery,” explains Dr. Abdulrauf.
Developing a method to simulate an individual patient’s specific brain aneurysm presented a few challenges. Because the simulation would be most effective as a physical model that the surgeon could interact with and practice the procedure on, the models therefore needed to be a 1:1 scale of the patient’s brain. If the models could additionally mimic the feel and look of brain matter, so that surgeons could use the same equipment on the model as they would on the patient, it would be even more beneficial to surgeons.
Achieving simulation models with those parameters first requires an accurate high resolution map of the patient’s brain translated into a 3D CAD model. Next, a manufacturing method that is extremely fast is needed because patients will be suffering from the aneurysm in real time. Lastly, for the models to truly demonstrate potential as a future business model viable for doctors, a fast and a cost-effective production solution is required. Ideally, each model would be created as a one-off part unique to each patient’s particular brain abnormality. Therefore conventional production, with high costs for single tools that are dedicated to large volumes of identical parts, would not be sustainable for the low volume needs pertinent to a patient case-by-case creation.
Solution
As one of the fastest and most cost effective production methods for one of a kind parts, 3D printing was on the top of the list to vet out as a viable solution for creating the brain models. From the selection of additive manufacturing technologies, PolyJet stood out as the most ideal 3D printing process because it is capable of meeting the time, cost, and material challenges Dr. Abdulrauf’s team faced. Additionally, PolyJet is one of the only 3D printing processes capable of printing a range of durometers into a single part, a significant boon to achieving the best feel for the skull of the model.
To create the models for the preliminary patients, scans of the patients’ brains were sent to the St. Louis University School of Engineering. The engineering students translated the scans into high resolution models which were exported as STL files compatible with 3D printing. Although the University had their own PolyJet machine, to achieve the quality and materials diversification necessitated by the project they chose to outsource the models. The team sent multiple CAD files of the brain, skull, and aneurysm to Stratasys Direct Manufacturing for printing. Together with Stratasys Direct Manufacturing, the engineering and medical students noted the critical area of the aneurysm. The Stratasys Direct Manufacturing team focused on maintaining flawless accuracy and detail on the aneurysm area throughout the entire production process.
