The OR of tomorrow

Albertinen Hospital in Hamburg has ten operating rooms. Since 2014, one of those has been a hybrid theatre, used exclusively in situations where at least part of the surgery is an endovascular procedure – a minimally invasive method of treating problems affecting blood vessels, such as implanting a stent to treat complex aortic aneurysms. Sometimes, the Albertinen surgeons will perform an endovascular procedure alongside a traditional open procedure, reducing the risk to the patient, who only has one dose of anaesthetic and one hospital stay rather than two. The simplest definition of a hybrid operating room is one that incorporates radiological imaging technology to guide a surgeon performing a minimally invasive (keyhole) procedure. The key component is a C-arm image intensifier, built either into the ceiling or the floor. Because it can be moved to any position above the patient’s body, the C-arm is able to produce a sharp X-ray image of the internal organ on which the surgeon is operating. This enables the surgeon to see even tiny body parts, such as thin heart vessels.

While some hybrid ORs use multiple screens, the one in Albertinen uses Siemens’ Artis zeego, with its single large screen. Lars Kock, head of the department for vascular and endovascular surgery, explains: “The screen has different areas showing the live image, the recorded image and the vital parameters for heart frequency or blood pressure, so we have everything that we need to know while we are operating on this large display.” Increasingly, hybrid ORs are also equipped with MRI or CT scanners to guide complex procedures such as brain surgery.

Cardiac surgeons are now carrying out far fewer open operations, especially on the aorta, says Kock, because they are “big operations with high risks”. As the population ages, demand for endovascular interventions will increase. “For many of our patients, who are mostly elderly, it’s a great benefit that we can treat them with endovascular techniques, because they have far less risk than the open operations,” says Kock.

Although it’s possible to perform endovascular procedures in a standard OR with an ordinary C-arm, the image is of lower quality and the radiation dose higher, he adds. The hybrid OR is “the gold standard” for endovascular procedures: “If you are used to it, as we have been for seven years, it’s hard to think how you can provide good treatment to patients without these techniques.”

Obstacles to uptake

Although hybrid ORs are not a new phenomenon – in the UK, the first one was opened in Liverpool Heart and Chest Hospital in 2007 – adoption is increasing rapidly, with one study predicting a compound annual growth rate (CAGR) of 12% between now and 2030. The main driver has been near-universal acceptance of the value of minimally invasive surgery. While its merits were hotly debated 20 or 30 years ago, says Mark Slack, chief medical officer and co-founder of CMR Surgical, the debate has now been won conclusively. “You reduce complications by 50% by doing keyhole,” he says, explaining that it also results in fewer infections, fewer hernias and a lower risk of opiate dependency. Hospital stays are typically shorter. Currently, wound infections from open surgery cost the US healthcare system an estimated $3.5bn to $10bn per year. The widespread adoption of minimally invasive techniques would slash that cost significantly. As Slack says: “If you have a keyhole surgery scar, nobody goes back to hospital and nobody goes back to theatre, because you can treat it as an outpatient.”

So, if a hybrid OR enables surgeons to carry out minimally invasive surgery, and minimally invasive surgery provides unequivocal benefits to patients, then why not convert every OR to a hybrid?

In practice, hospitals have good reasons for not taking such a bold step. Currently about half of the 12 million surgical procedures carried out in the UK annually are still performed under traditional open conditions – even though, in principle, most could be performed using minimally invasive techniques.

The reason, as Slack points out, is that minimally invasive surgery is a highly specialised and difficult skill, performed by a minority of surgeons. It is also extremely demanding. Anthony Fernando, president and CEO of Asensus Surgical, notes that traditional laparoscopic surgical practices “take a toll on surgeons, both mentally and physically, with 87% experiencing performance-related symptoms, including musculoskeletal disorders”.

While open surgery is still so prevalent, it makes no sense to convert all ORs to hybrid status. Hybrid ORs require far more space than traditional ORs because the C-arm and other equipment take up a lot of room. Albertinen’s hybrid OR, for example, is at least 100m2 in size. As Kock points out: “You need a lot of space for all the products that you implant in patients – all the stents, balloon stent grafts, catheters.”

Space is often at a premium in hospitals – in many cases, there simply isn’t enough room to convert every OR into a hybrid. The size also increases the risk of infection. A larger OR will usually have more people in it, says Slack, adding: “There is a relationship between volume of the theatre, the number of people and infections. And if you have too many people you do get a rise in infections.” He notes, however, that this risk “is largely overcome by increasing the rate of filtration, and you change your air more commonly”. Most hybrid ORs use laminar air flow diffusers to ensure that air flow is of a uniform direction and speed.

The other barrier to universal adoption of hybrid ORs is the cost. Both the initial investment and the ongoing maintenance and upgrade costs are roughly double that of conventional ORs. Kock points out that the more sophisticated the technology, the greater likelihood there is of technical difficulties. “The technology is so complex that you as a user, a vascular surgeon, don’t have the knowledge or expertise to solve these technical problems,” he says. There is also a maintenance burden: every few months surgeons will lose the OR for a day or two because of the need for regular inspections and checks of the equipment. So, what might change? Can the barriers to adopting minimally invasive surgery be overcome so that it makes sense to convert all, or most, ORs to hybrid status?

From keyhole to robotic

The most promising developments come in robot technology, which could enable far more surgeons to perform minimally invasive techniques. Until recently, says Slack, deficiencies in robot design – including the huge footprint – have made uptake relatively low; the vast majority of keyhole surgeries are still carried out manually. Innovators are, however, making robots smaller, more ergonomic and easier to use. Versius, the robot designed by Slack and his colleague Luke Hares, is guided by the surgeon from a 3D magnified monitor. The four robotic arms controlling the instruments move independently of each other, and, like human arms, have wrists on the end. “Because it’s modular, and all the bases are a separate unit, we can mimic the port placement and the procedural steps of keyhole surgery,” says Slack. Complex procedures that would normally take up to 60 hours to learn, such as tying a surgical knot, can be learnt in 30 minutes. The robot is also easily portable from one OR to another.

Versius does not achieve better outcomes than a very skilled laparoscopic surgeon, says Slack. Its advantage is that it creates a far bigger pool of surgeons able to use laparoscopic techniques, thereby allowing more patients to benefit from it. Ultimately, the cost to hospitals, from shorter patient stay and fewer infections, is also significantly reduced.

Similarly, Asensus Surgical’s Senhance Surgical System is designed to reduce surgical errors by combining augmented intelligence, machine vision and deep learning. The 3D HD visualisation “provides the surgeon with additional intelligence regarding depth and spatial relation of organs,” says Fernando. The more ergonomic design enables the surgeon to sit comfortably and move their hands rather than keeping them static. It also addresses some of the cost issues that have proved a deterrent to robot adoption. Because the technology uses “standard reusable instruments and an open-platform architecture strategy” the cost-per-procedure, says Fernando, is “comparable to manual laparoscopy.”

Minimally invasive techniques have already proved their worth, particularly in cardiac surgery, and Slack believes there is increasing desire among surgeons to take advantage of these techniques. Chest surgeons, for example, “are trying to get away from splitting the chest, so increasingly the valves are put up through the arteries and so that needs hybrid theatres”. Similarly, a hybrid OR makes it possible to perform image-guided biopsies – in a lung resection, without a clear image of the tumour, surgeons may resect too much material, Slack explains.

If robot technology is able to remove some of the current barriers to adoption, then it seems highly likely that minimally invasive surgery – and hybrid ORs – will become more and more widespread, perhaps eventually replacing the traditional OR altogether. Surgery is undergoing a “sea change moment”, Slack argues, with even small hospitals starting to invest in robot technology: “In the 1990s we went from open to keyhole surgery. Now we are going from keyhole to robotic.”

Orthopaedic surgical robots

A lot of the focus in surgical robotics is on devices like Versius and Senhance, which are geared towards making general surgery easier – but orthopaedic surgeons have their own mechanical assistants.

Mako – Stryker’s Mako device combines 3D CT-based planning, haptic feedback and data analytics to make minimally invasive joint replacement procedures, such as total knee and hip arthroplasty, simpler to carry out. The medical device giant bought Mako Surgical Corp to take ownership of the robot back in 2013. Mako‘s co-founder Rony Abovitz was part of the company‘s predecessor Z-KAT, which developed its initial haptic robotic arm technology, known as the Whole Arm Manipulator (or WAM Arm) in coordination with Massachusetts Institute of Technology and robotics specialist Barrett Technology. Mako improved the haptic system and demonstrated its ability to perform accurate bone shaping through minimally invasive incisions and performed 23,000 total or partial joint replacement procedures by 2012, which was enough to capture Stryker’s interest.

Rosa – Mako isn’t the only option for orthopaedic surgeons carrying out arthroplasty procedures, there’s competitor Zimmer Biomet with its own device named Rosa (robotic surgical assistant). Interestingly, Zimmer opted not to include a haptic feedback system akin to Mako’s, as it felt the feature could limit surgeons’ ability to perform full bone cuts comfortably.

Rosa comes in several varieties: The Rosa One Knee System, the product designed to rival Mako, as well as the Rosa One Spine System and Rosa One Brain System – a product made for stereotactic brain surgery.