Surgeons will perform liver resections with greater accuracy and deliver improved patient outcomes thanks to new research by Nottingham Trent University. Senior research fellow Richard Arm has developed a way to 3D-print scan data of cancer-hit patient organs so that clinicians can rehearse difficult operations on lifelike models.
The aim is for them to become familiar with the hidden complexities of an operation – which are unique from patient to patient – prior to the real surgery.
A prototype 3D-printed model liver – based on an anonymised cancer patient – features the tactile qualities of a real diseased organ, including imitation blood and different tissue hardnesses, such as the blood vessels, liver tissue and the tumour itself.
The model – made from synthetic gels and fibres – even allows surgeons to use real surgical tools to practice endoscopies and laser ablation techniques, during which arteries are resealed by laser to prevent a patient bleeding out during surgery.
“Surgeons have an incredibly complicated job to remove some tumours to save people’s lives,” said Richard, who runs the Flexural Composite Research Laboratory for the Advanced Textiles Research Group (ATRG) in the School of Art and Design.
“But due to the limitations of existing technologies available to them, many surgeons only discover the true complexities of an operation when they are in the midst of the live procedure itself.
“Every patient is unique and has organs of different shapes, sizes and constructs, so there can be many hidden complications that they have to deal with.”
However, his research has shown that adapting scan data and new 3D-print processing methods could dramatically improve the quality of the preparation before the first incision is even made.
“It could give surgeons increased confidence and may provide patients with improved outcomes, such as the increased retention of healthy tissue, reduced risk of infections and swifter recovery times,” he said.
The research also considers the potential for teaching trainee cancer surgeons in traditional and robotic tumour removal and could improve robotic surgical interfaces and operator proficiency. It could also allow surgeons to become more familiar with using robots to perform surgery remotely.
The project was funded by Nottingham Trent University’s Medical Technologies and Advanced Materials fund and the School of Art & Design. Expertise in material testing and tissue characterisation was provided by Dr Arash Moghaddassian Shahidi, also of Nottingham Trent University’s ATRG, while scan data and medical expertise was provided by Dr Christopher Clarke, consultant radiologist at Nottingham University Hospitals NHS Trust.
Until now, surgeons for the most part have had to rely on 2D images of the tumour and affected anatomy to plan surgery, and on rare occasions, have used animal livers to train for biopsy and tumour extraction.
While there have been examples of people 3D printing livers based on patient data in the past, they have all been rigid in design, reliant on the capabilities of the printer in use to create a 3D representation of the organ, offering no opportunity for the practice the procedure being planned.
Richard said: “Rehearsing the surgery was never an option before this work, so we have taken things to the next level by transforming the rigid artefacts into biofidelic tissues representative of the living patients anatomy.”
“The physical properties and location of a tumour can now be understood in advance – how it feels, where it lies, how it responds to the force applied of surgical tools and intervention strategies.
The tumour implanted in the prototype 3D liver measures 12 to 15mm and is classed as a giant tumour, as anything over 10mm in diameter is. It sits nestled between two large veins which sit on the upper posterior of the organ, meaning a surgeon would have to go in from the front (in open surgery) and manoeuvre the liver into position to access and remove the tumour, without, crucially, rupturing a blood vessel.
But being able to practise in advance would allow the surgeon to perform keyhole surgery, going up through the vein to ablate the tumour using a laser.
The fact the model liver is reusable means it can also be taken into the lecture theatre to teach budding oncology surgeons the ropes.
“Unique to this work, we have created hollow blood vessels too,” said Richard. “Not only do they feel realistic, but they also have the right hardness and shape, because they are printed using the blood volume of each vessel.
“A surgeon would be able to use an endoscope to navigate round the vessels to trace the blood supply to the tumour.”
Pushing forward, the team aims to develop the 3D technology further to include other organs and connective vascular networks.
The real starting point for their work on transforming rigid prints into something surgeons could practise on began in 2016, when they produced a set of biofidelic heart and lungs. However, that was produced for trauma purposes and had no real internal anatomy.
The Nottingham Trent team has even more ambitious goals in sight now. “We’re working our way through the human anatomy,” said Richard. “It would be nice to do the rest of the organs, including the stomach, kidneys and intestines and the greater vessels that feed all these organs.
“Maybe one day we’ll be able to print the entire anatomy of a human being, so surgeons or even robots can learn on it without risk to patients and grow to a level of proficiency that has never been seen before.”
