Scalpel. Retractor. Sutures. The equipment that surgeons use hasn't changed significantly for many decades. However, if one trial is anything to go by, clinicians could soon be taking augmented-reality glasses into the operating theatre.
Interventional cardiologist Dr Maksymilian Opolski, of the Warsaw Institute of Cardiology, first tested out virtual reality glasses for a heart procedure known as a PCI back in 2015, where he navigated the inside of the patient's heart using pictures projected onto the heads-up display.
A PCI, short for 'percutaneous coronary intervention', is a common procedure performed on people that whose coronary arteries -- the large blood vessels that provide blood to the heart -- have started to close up. If a significant artery becomes too narrowed, blood flow to some parts of the heart can become cut off and the heart muscle in that area can die -- causing a myocardial infarction, or heart attack.
In order to restore blood flow to the entire heart, a surgeon inserts a catheter into a vein in a patient's arm or leg, finds where the coronary artery is blocked, and uses a balloon or stent to help open the vessel back up.
In traditional PCIs, a dye that shows up on X-ray, known as contrast, is injected into the patient's blood vessel. As the dye travels through the blood vessel, it paints a 2D picture of the patient's arteries for the clinician to follow with the catheter. However, it only allows the surgeon to see ahead of the blockage, not behind it -- depriving them of useful information.
Another type of medical imaging, called CT angiography, can be used to provide a 3D view of the vessels both in front of and behind the blockage; surgeons are now looking at whether CT angiography pictures can be combined with augmented reality technology to offer a new way to see inside the vessels that keep the heart beating. One day, it could be common for surgeons to put on a pair of Google Glass along with their scrubs.
Seeing inside the heart
PCIs are often done on blood vessels that are partially narrowed, rather than totally blocked off. Operating on patients with totally closed off arteries is a particular challenge, and comes with an increased risk of complications during surgery.
It was on one of these patients that Opolski first used Google Glass to assist with a PCI, where CT images of the patient's blood vessels seen on the augmented reality glasses were used to guide the catheter as it travelled through the veins to the heart.
Nearly three years on from his first Glass-assisted procedure, and Opolski has led a 15-patient pilot of the technology that could pave the way for the use of such wearables more widely in future. Traditionally, images of the patient's heart were shown on monitors in the catheterisation lab; in the pilot, they were projected onto head-mounted augmented reality glasses worn by the surgeon.
Opolski said the wider trial of the technology was "a natural consequence" of the procedure in 2015 which "received a substantial wave of publicity worldwide".
"I guess it was not until August 2014 when I had started planning to launch a pilot feasibility study on the use of AR technology for CT-guided percutaneous revascularisation of coronary chronic total occlusions, and we eventually started enrolling first patients in January 2015. The whole concept was quite smart and catchy so we had to act fast," Opolski added.
The surgeon credits the progress of the project to the "tremendous support" he received from the from the Institute of Cardiology in Warsaw, as well as the team of physicists from the Interdisciplinary Centre for Mathematical and Computational Modelling of the University of Warsaw, who were responsible for developing the mobile app that allowed the CT datasets to be displayed on the Google Glass headsets.
The difference in preparing for augmented reality and traditional surgery is only a matter of a few minutes of training, thanks to the "simple and intuitive" nature of the app, says Opolski. Cardiologists could navigate through the images of the patient's heart using voice commands -- not just making the software easy to use, but also ideal for maintaining the sterile conditions of the operating theatre.
After 15 PCIs with the Google Glass and accompanying app, Opolski and his team's research have shown the technology is "not only feasible and safe, but also does not interfere with the routine activities performed in the catheterization laboratory by operators". The chances of having an 'adverse event' -- such as a heart attack -- was found to be the same for with-Glass PCIs and without Glass.
While the study was too small to provide a definitive answer to whether the Glass-assisted procedures were better for patients than those conducted without the tech, there are hints that AR can bring some benefits. PCIs where surgeons wore Glass tended to use less contrast to visualise the course of the vessels, which can be beneficial to patients that react to the dye. It also helped surgeons better choose which types of guidewire to use during the procedure.
The surgeons who used the Glass during the PCIs reported high levels of satisfaction with the technology, and indicated they would be amenable to using the kit in their regular surgical work.
Keeping surgeons happy with their AR kit as its use increases will represent a challenge for the technology industry. As well as putting a heavy emphasis on making the software as user-friendly as possible, technology vendors and the healthcare industry will need to work together on open standards if augmented reality is to take off in the operating theatre.
"The biggest challenge relates to wider cooperation between individual users of AR devices and vendors of angiography systems to easily implement AR technology in the catheterization laboratories. This would require the readiness on the side of angiography providers to customize their products with open-source operating systems so that one could easily connect and share imaging data with AR devices," Opolski said.
The reaction from the medical community to his work with Glass, says the surgeon, has been one of both curiosity and positivity, with requests to present his work at conferences and offers to collaborate on research. However, there is a mountain to climb before the technology reaches widespread adoption among healthcare professionals.
"I am aware that we are at the very beginning of the fascinating journey called 'AR in medicine', and there is still a behemoth effort ahead of us to encourage a wider adoption of this leading-edge technology in the catheterization laboratory. I am planning further studies to propagate AR in cardiology."
As well as the CT images of the coronary blood vessels that Opolski's team were able to see on their Google Glass, in future, several types of imaging could be combined to help the surgeon see into the heart in ways that haven't been possible before.
"Wearable computers are easily accessible and offer a unique opportunity for limitless display of multiple imaging data (both of which might overcome the economic and capacity limitations of the most advanced angiography systems), I have no doubt that AR will shake up clinical practice in the near future," Opolski said.