Introduction
Advanced visualization and simulation technologies can help a surgeon practice and plan for complex procedures. It also helps a patient to be better prepared and educated about the procedure by visualizing the impact of the procedure without having to go through large numbers of pamphlets. Digital reality (DR), an umbrella term for virtual reality, augmented reality, mixed reality, and 360-degree visualization can deliver close to real-life immersive experiences that can help in this process.
We are now taking a step further where digital reality can help not only plan for the complex procedure but assist in the same with significant benefits to both the patient and the doctor.
1. Reduced Surgery Time: Faster recovery and ability to increase utilization of operation theatres.
2. Reduced Risk: Surgeons are able to practice the procedure and, once satisfied, record the best approach that can be used to 3D print stencils and other tools required for the procedure.
3. Better Planning: 3D visualization and interactive simulation helps in preparing the various tools and techniques required for the surgery well ahead of time.
Each human body is unique and while there are common features in general, each human possesses unique characteristics. Some common examples are fingerprints, retina, lip prints, ears, voice – humans in general possess these features but each has unique feature allows us to separate one from another. This phenomenon is more prevalent within the human body and is therefore relevant to this discussion. The shape and size of each internal organ and its ailment for which a procedure is required, is unique. Modern medicine, combined with technology, utilizes different scanning methods to understand these unique characteristics. However, most of these scanning methodologies deliver their results in two dimensional (2D) images that are difficult even for trained professionals to interpret. The scan results are currently used more for diagnosis and have limited application in planning a procedure.
It is now possible with DR to interpret these 2D images into a 3D model. These models can be programmed to simulate the various functions and properties of the organ and the ailment, including visualizing blood vessels, tumors, major arteries, veins, bones, etc. The 3D model allows a surgeon to plan the procedure required to help with the treatment of the patient. Based on the plan, the surgeon is able to practice the procedure and make necessary corrections to the plan. The final procedure can be recorded digitally and combined with the 3D model, used for preparing stencils using 3D printing techniques. The 3D stencils assist the surgeon in making the necessary incisions without fear of puncturing neighboring organs or blood-carrying channels that could complicate the procedure.
In most surgeries, the time taken to make incisions and in cutting through a tumor is extremely slow and painstaking. A systematic review in the Journal of Surgical Infections concluded that prolonged operative time can increase the risk of surgical site infections. A 60-minute surgery had a 37% likelihood of surgical site infection according to the review[i].
The use of DR combined with the 3D printed stencils helps reduce the overall time taken to make these incisions, and ensures prevention of damage to the neighboring organs or blood carrying channels, improving the likelihood of success of the procedures.
Liver transplant from a live donor – A case in point
Liver transplants have been done successfully for a few years and the duration of a liver surgery could be about 12 hours depending on the specific conditions of the recipient. In a living donor transplant a portion of the donor’s liver is cut and transplanted to the recipient and it is expected that within 2 months both the donor’s and the recipient’s livers would grow back to the right size and regain normal functionality.
There are several complications that can occur during the surgery, including the fact that after the incisions are made on the donor and the recipient, the surgeon may discover certain complications, including incompatibilities that can make the procedure impractical.
With advanced visualization combined with 3D printing we can help plan the surgery. Scans of the organs of the donor and recipient converted into 3D models allow the surgeon to plan and practice the surgery digitally. Once an initial plan is devised, a 3D printed liver made out of silicone with the haptic feel of a real liver will allow the surgeon to practice the various aspects of the surgery.
The strategy of the surgery can then be updated in the digital model. Stencils can be prepared based on this data to assist in the surgery. The strategy could include the angle at which incisions are made, workarounds for any incompatibilities such as differences in the sizes of arteries between the donor and the recipient.
The overall result is a better prepared surgeon and team who can significantly reduce the time of the surgery, improve the likelihood of success, and reduce the overall recovery time period.
In addition, the surgeon can use the digital models to educate the recipient and the donor on the procedure and the plan thus aiding patient education.
Surgery archives with more cases and models would serve the medical community at large, and save many more lives.
[i] Cheng et al, Prolonged Operative Duration Increases Risk of Surgical Site Infections: A Systematic Review, Surgical Infections, 2017 Aug 1; 18(6): 722–735, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5685201/