Robots are machines capable of endlessly repeating the same operation, without fatigue or making mistakes. With such qualities, they are now quietly moving into many areas of our socio-economic world, replacing human operators deemed less reliable and more expensive. Medicine, especially surgery, is a prime demand field for robots. The latter can carry out very precise operations, in a cluttered environment, reducing the risks for both the surgeon and the patient.
This article is the third of a series dedicated to robotics, which will be published within the next three months.
The surgical capacity of robots is impressive, to say the least, witness the instruments carried by the « Da Vinci », a flagship robot produced by the US company Intuitive Surgical, with its seven degrees of freedom, i.e., offering two more degrees – at the operating extremities – than with traditional endoscopes. The articulations imitate (and even improve on) the vertical and horizontal flexibility of a human wrist: they extend a surgeon’s capability in a new dimension, allowing as they do complex reconstructions operations through incisions no longer than one centimetre.
Growth observed in the surgical robot market is noteworthy. According to a survey conducted by the Wall Street Journal, under the title “The Pros and Cons of Robotic Surgery,” some 1000 surgical operations were performed worldwide in 2000 with assistance of robots. The figure for 2011 was 360,000 and 450,000 for 2102. For the consultants Wintergreen Research, these machines already generate a worldwide turnover of 3.2 billion $US, a figure that should rise to 19.96 billion $US by 2019. Certain markets are already mature, for instance in the USA, we observe that 80% prostate operations are now carried out using robotic assistance, while others are just beginning to expand. The prostate fraction is France is only 20%. On the market, there are only a few major stakeholders and schematically, robots fall into one of two categories: on one hand, machines that use imaging to assist surgeons who do the operations, as is the case for Rosa assembled by a French company based in Montpellier and, on the other, apparatus that augments the dexterity, such as the Da Vinci, specialized in abdominal surgery since 2003 and also used quite extensively in prostate cancer surgery.
Intuitive Surgical, who make the Da Vinci equipment, have benefited for a long time now from a monopoly position. However, numerous patents have moves, as of 2014, into public access and use and consequently many companies in Canada, South Korea or Italy will be able to take their share of the sunlights. Any enterprise with a solid experience of robotics is a priori capable of developing surgical robots.
The decade 2000 saw a sharp upturn in uses, consequent to the official authorization to implement several highly evolved machines such as the Cyberknife (Accurayn), which is a robot capable of destroying a tumour in a non-invasive manner using an accurately focused beam and Sensei, developed by Hansen Medical, used to assist the placing of catheters before heart surgery. In 2001, we can perhaps recall the “Lindbergh” operation that made the headlines of certain scientific journals: a remote surgical operation carried out by a robot controlled by a surgeon who was 8000 kilometres from the patient on the table, using an ultra-high speed data transatlantic link.
Robots also allow you to model an operation, for training purposes mainly and the most recent devices can be reconfigured to match a patient’s parameters. Professor Toshio Fukuda, at the University of Nagoya, a specialist in robotic microsystems, micro-sensors and micro-actuators) has developed an intravascular micro-surgical simulator that is quite unique today. His ‘Eve’ (endovascular evaluator) reconstitutes the vascular opening with a very high degree of accuracy, via a scanned recording made of the patient’s organs. An identical model can be built up in silicon rubber using a 3D printer. Next, a body fluid control is installed to simulate the patient‘s blood circulation. With this clone, the surgeon can simulate the operation and when satisfied that it can be done efficiently and safely, he can introduce the relevant parameters via the effector control panel, thus ensuring a semi-autonomous action by the robot on the patient. Why not imagine that, in the long term, the operation could be totally entrusted to the machine and carried out robotically? This is what is called “immediate pre-operating simulation.”
There is a fundamental difference between virtual reality (VR) simulators and real reality (RR) simulators. Henceforward, it is possible to make an error in reality – during a training session – and to correct the error without any consequence for the patient to be operated. Robotic surgery equipment allows the surgeon to have a 3D image of the patient’s body viewed from the inside and the robot operator will be able to do the job with extreme accuracy. In general terms, the benefits of robotic surgery are multiple: greater comfort for the surgeons, who can operate sitting down (at their consoles); better visibility of the operating field; hand trembling can be filtered out. Moreover, as an additional guarantee for overall safety, the robot’s system analyses the surgeon’s hand movements (his operating instructions) 1000 times/second. The effector – beyond this already high degree of precision – can magnify the movement required, e.g., when the surgeon’s hand moves one cm, the instrument-carrying effector will advance by only one mm.
Robotics also makes it possible to introduce new approaches to surgeons’ training, a highly sensitive subject in the profession as it impacts the already extremely long studies and tends to dampen candidates’ inclination to spend more time learning. Surgeons most often are specialized in a given body area, and consequently in certain types of operation. Learning to use robotic surgery could accelerate training. Dr François Pugin (HUG Geneva) and his colleagues testify that “the learning curve specific to each category of operation can be facilitated by coupling a second console to the surgeon at the main console, allowing for a dual control operation. The trainee surgeon is coached by his mentor during the operation and this reduces the learning curve while increasing the safety factor for the patient.” This is one of the reasons that encourage young surgeons to seek every opportunity to become trained in new robotic surgery techniques.
In heart surgery, miniature robots will play a major role. This traditional method – to install coronary bypasses – requires opening the thorax by sawing the sternum, a traumatic surgical experience. The patient needs between one to two weeks before being able to walk gain and the sternum takes three months to close. A 1 to 2mm robotic instrument inserted via a catheter can produce the same results and the patient, moreover, will be able to leave the hospital the same day (as an out-patient), with only three small incisions in the chest. Mini-invasive surgery on a national scale could play an important role in a national health economy, reducing substantially the in-hospital stays.
Again in the area of mini-invasive diagnosis, a large range of robotized devices with magnetic controls are being readied and these will be used for specific body organs (eyes, ears, abdomen, heart, brain and the vascular systems). The range and potential here are wide and high, running from targeted in situ delivery of active ingredients, to diagnostic imaging, to graft insertion, biopsies and tissue removal. The underlying concepts are varied. Certain robots would ‘swim’ in body fluids via the vessels, others would be propelled by bacteria.
In the case of a delicate operation such as a prostatectomy, to cure a local cancer, care must be taken to avoid the patient becoming incontinent and to continue to be able to have an erection – for this essential, preservation act, the nerves that run across the prostate must not be damaged. Mini-invasive surgery is a plus. But, beyond the sheer technical marvels they demonstrate, what have robots to offer? First and foremost, a decrease in the time spent in hospitals and, subsequently, better cost management.
Indeed it is this factor that drives the demand for surgical assistance robotics. Patients gain through absence of scar tissue, a phenomenal drop in post-op pain, a shorter hospital stay and therefore a faster return to daily social and professional activities, as before. All of these points constitute a global savings that has its consequences on Society at large. If the cost of using mini-invasive surgical instruments momentarily costs a lot (for the hospital), the fact of spending three days under post-op surveillance in the hospital compared with three weeks at 1500 euros/day largely compensates for the machine procurement costs. One of the main complications that follow suit to traditional surgery - with a large incision to open and expose the body cavity – is a post-op hernia. Some 15% of the patients operated suffer from this to the point that they must be re-operated, have a retainer net put in place and with serious sequels: if the patient previously held a physical occupation, this will no longer be possible.
Even if the presence in a hospital of a robot will helps the establishments to recruit talented young surgeons, the investment outlay is a major cause for hospital boards to hesitate: between 1.5 and 2 M$US for a Da Vinci model and between 350,000 and 450,000 euros for a Rosa Brain from Medtech. On top of this initial outlay, cost of maintenance must be added (approx. 120 000 euros/yr.) and system upgrades, as is the case for any rapidly evolving technology. The economic profitability for such a level of investment has not yet been clearly established: implementing a robot increases the basic cost of running an operation theatre, requires extra technical staff to run the equipment, requires specific training of personnel and can extend the operation time quite considerably. We are facing a change in cultural paradigm and the change will take quite a time to settle. We need to train an entire medical team to use this new generation of equipment and tools. The cost of special instruments has also to be added to that of the basic robot, with an amount that can be as high as 4000 euros per operation, even if some hospital establishments are considering making the instruments themselves using 3D printer techniques coming on line. Moreover, they are wary about how they see profits from their chosen level of investment and tend to over-use robotic surgical assistance.
The potential for robotic surgery seem unlimited, however using machines like these does carry a degree of risk. Critical assessment is often raised: admittedly, robots multiply the surgeon’s hand movements but there is no haptic force indicator and it is possible to inflict damage on areas and organs close to the field without becoming aware of this. When miniature haptic force and touch sensors become practical and when integration, sterilization and resilience factors have been proven, the surgeon will be able to receive information as to, for example, the physical deformation force he is applying to a tissue and will experience tactile sensations similar to when he is feeling organs in an open thorax/abdomen traditional operation. Even today’s most sophisticated robots do not offer these features and associate safety assurance.
Research has been devoted to this sensitive question for several years now. As of 2006, a doctoral thesis defended by Nabil Zemiti at the University Paris 6 Pierre & Marie Curie (in French) signalled two difficulties: the first relates to metrology since it is technically very difficult to make a direct measurement of distal interaction, whilst complying with constraints in regard to keeping the operation field sterile and the local cramming of instruments in the patient’s body. The second relates to control of the interactions where the dynamics and the geometry vary considerably and are not well known (contact with the patient’s organs, with the surgeon or with other instruments) in a special context where the kinetics of passing instruments through the same fixed passage does not enable all the components of the operation screw to be controlled [Ed. Screw_theory relates to the algebra and calculus of pairs of vectors]. Dr Zemiti proposed a robotic system assembled round a compact spherical area movement arm, with a return on force sensor placed outside the patient with a control module for the force applied. Considerable R&D have gone into this concept but when we think about it, robotic surgery is only 20 years old today and lots of improvements can still be envisioned.
According to a survey published in The Journal for Healthcare Quality, thousands of incidents were reported between 2000 and 2012 in respect to the Da Vinci robot unit and researchers discovered a number of other botched and undeclared operations. Sometimes the consequences can be dramatic. In 2009, we read in the New York Times, the history of a 30 year old American woman who had undergone robotic assisted surgery to treat an endometriosis, a pathology affecting the uterus, who was taken 10 days later to the emergency unit where the doctors discovered that her colon and rectum had been torn in the operation. She had to undergo a series of new operations to repair the damage, including a temporary colostomy. Over a ten years period, Da Vinci units have completed over a million operations, but between January 2000 and August 2012, one thousand mishaps had been reported to the Federal Drug Administration (FDA). The Administration had registered 174 post-op complications and 71 deaths. However, the FDA had too few in-house robotic analysts to really assess the situations and the data.
No independent study to date has assessed the pros of using robotic technologies compared with traditional surgery. The advent of robots, moreover, requires that the surgeons attend a hard, time-consuming training course and one cannot as yet measure the loss of the robot-assisted surgeons’ capability to pursue traditional surgery. Even this special training dos not come in standardized modules. Courses vary according to the establishments, to their budget possibilities, to available space and time and other constraints and this makes the choice of the patients difficult. Lastly, the predominant position and sheer power of the American company Intuitive Surgical do not make the situation exactly transparent, so to speak.