PRAGUE, Czech Republic – The shift to single-port access (SPA) for endoscopic procedures is shaking the entire surgical supply chain for what is ultimately a device-dependent medical practice.
Training tools, essential for surgeons to either learn or to sharpen their skills manipulating instruments, provides an insight into the coming impact the change to SPA will exercise on industry.
And surgeons lining up for a chance to get their hands on training demonstrators in the exhibition area of the recent congress of the European Association for Endoscopic Surgery (EAES) provided a convincing proof of the high interest in this new surgical technique.
Start-up D-Box Medical (Lier, Norway) set up two box trainers in the Covidien (Mansfield, Massachusetts) exposition at EAES that featured the new single-incision laparoscopic surgery (SILS) multiple instrument access port, enabling doctors to test their skills threading a simple plastic peg through a series of eye-hole screws.
Box trainers seem sadly low-tech alongside the array of sophisticated virtual reality (VR) trainers for surgery, yet changes to equipment to adapt to new SPA techniques is easier and faster than the investments required to rewrite code and training scenarios for the computer-based trainers.
The results are not less daunting for surgeons, as a moment practicing on a box trainer demonstrates with the complexity, and frustration, of a seemingly simple task, such as picking up the peg with graspers.
For example, the Covidien SILS port solves the problem of triangulating tools inside the patient's abdominal cavity by crossing the instrument shafts so that the left hand is now operating on the right side of the screen, and vice-versa for the right hand.
Infuriating at first, the exercise become intriguing with a bit of practice. "Surgeons love this," said Arild Hermanssen, managing director of D-Box. "The exercise has what we call a Tetris-effect," he said, referring to a popular, and addictive, computer game.
"At these conferences there are surgeons who come back at every break in the scientific sessions to continue working on the exercises," he said.
In its first year of business, D-Box has expanded rapidly to cover 20 countries with its desktop exercise station.
"The key to success with training in hospitals is availability of the trainer," Hermanssen explained.
"This unit can be placed anywhere and has the advantage of not making you wait while the software boots up," he said.
"For example, if a surgeon wants to warm up for five minutes before a procedure, is he going to wait for 10 minutes for some VR software to be ready? He does not want to lose that time," Hermanssen said.
Despite the dazzling advances in VR trainers, the old-fashioned box trainer is not going to disappear from surgical training curriculum anytime soon.
Clinical studies presented at EAES comparing the two training methods invariably concluded that both techniques were essential for developing the surgical skills of new surgeons.
Another enduring benefit for box trainers is that surgeons can use the same instruments in practice sessions that will be used during a surgical procedure, simply sliding the shaft into the port.
And haptic feedback, the sense in the hand of the action being exercised on the display screen, are identical to real-time surgery for pinching, grasping and cutting.
Excessive force for any of these actions can result in trauma or bleeding for a patient leading to post-surgical complications that can cost up to 1300,000 ($423,000) per patient for a healthcare system.
Box trainers also allow a surgeon to take a remedial training step that is simply not possible with VR.
The surgeon can remove the cover and directly observe the actions caused by hand motions without the display screen.
Ultimately a surgeon must be able to direct his actions by watching the screen in live surgery, but this intermediate step can help train hand-eye coordination before operating by instrumentation only.
iSurgicals (Chorley, UK) is another start-up that began offering a box trainer for laparoscopic surgery in March 2008.
The iSIM trainer does not yet feature an SPA exercise, although Mudit Matanhelia, who is responsible for product development, said modifications to accommodate the new procedure are now under way.
"It is not difficult to add this feature," he said, as it requires a slightly larger port to be placed in the center of the panel next to the camera.
A unique feature of iSIM among box trainers is the ability to connect the unit's built-in camera to a laptop computer to record performance during a training session for review by a mentor, or for students to monitor progress across a series of exercises.
iSIM is not a closed box model, using an angled panel to block the student's view and force monitoring of movements on a display screen, so that the unit can be operated using ambient light and set up for practice anywhere there is a table and an electric plug for the camera unit.
iSIM ports also accept any instrument a surgeon uses in regular practice and offers a more sophisticated series of accessories for exercises, including an insert panel for cutting and then suturing real tissue.
"We use animal skin, for example. Chicken skin is quite popular and available," said sales manager Mike Greenhalgh, adding that real tissue provides true haptic feedback for tissue responses to cutting force and the effects of elasticity for suturing using needleholders and graspers.
Challenging exercises include cutting a single layer of a double layer synthetic tissue strip, or simple knot-tying on an eye-hole screw.
Ease-of-use and portability in a suitcase are key features that, according to Greenhalgh, pushed first-year sales "to in excess of 40% of our expectations," almost all of which were in the UK.
iSurgicals is negotiating with distributors for the European market and Greenhalgh said that distribution to the U.S. is still one year out.
"Of course, there is nothing to prevent someone from ordering units directly from our website," he said, adding that the unit is shipped in a transport-hardened suitcase.
For Americans, the unit is priced at $8,000, he said, for Europeans at €5,800, and in the UK the iSIM trainer sells for £4,994.50.