George P Mylonas, PhD, Nisha Patel, PhD, Julian Teare, PhD, Ara Darzi, PhD. Imperial College London
Endoscopic submucosal dissection (ESD) is an established technique that allows en bloc resection of gastrointestinal lesions. Although its use has been increasingly reported, it is seldom carried out in the Western world due to its technical complexity, longer operating times and high perforation and bleeding rates. Typically, ESD involves an electrosurgical cutting tool introduced via the working channel of an endoscope. The aim is to endoscopically dissect the lesion in the submucosal plane. Limited control of the tool is possible by pushing and pulling it and by steering the endoscope using its dials. Moreover, care should be taken so the cutting device is operated in angles parallel to the wall and by using traction movements to minimise bleeding and perforation. The lack of bimanual dexterity and tissue-triangulation intrinsic to the endoscope and tools, are the main contributing factors to the technical complexity of ESD. Further technical advances and the availability of a standardised operational and training system are required for the wider adoption of colorectal ESD particularly.
A universal endoscopic attachment has been developed that allows augmentation and repurposing of any commercially available endoscope by turning it into an economic surgical robot. A novel component of the device is an inflatable peripheral scaffold that can be deployed at the distal-end of the endoscope. While deflated, the scaffold has minimal size and is placed around the endoscope by means of a flexible plastic sheath (Figure 1A,B), which is unobtrusive to the functionalities of the endoscope as it manoeuvres towards the lesion. When the endoscope is in operational position, the scaffold is inflated to form a quasi-rigid supporting structure (Figure 1C) for a tendon-driven parallel robotic manipulator packaged within (Figure 1D). The distal tendons are connected to hollow over-tubes which are used to accommodate and move introduced standard flexible instruments such as an ESD knife or forceps). The proximal end of the tendons is interfaced to external motors via flexible force-transmitting conduits. The fully deployed system provides dexterous bimanual control of the over-tubes (Figure 1E) and introduced instruments through a master manipulator connected to a computer. A purely mechanical master control approach is also possible. The size and shape of the scaffold can be patient or procedure specific. The scaffold is deflated for extraction and is envisaged as a single-use disposable product, while the motor unit as a one-off capital investment. Conceptually, the design is a soft, elastic endoscope skin that after inflation is transformed into a dexterous bimanual surgical instrument.
The device offers critical advantages that could make ESD common practice. These include bimanual dexterity, tissue manipulation and triangulation, high force delivery, large workspace, instrument stability and controllability . Preliminary ex vivo tissue trials have demonstrated striking improvement in task ergonomics and five-fold completion time reduction over the conventional approach (Figure 2). In vivo animal trials are scheduled for early in 2017.
1. Mylonas, G.P., et al. (2014). CYCLOPS: A versatile robotic tool for bimanual single-access and natural-orifice endoscopic surgery. Robotics and Automation (ICRA), 2014 IEEE International Conference on, pp.2436-2442
Presented at the SAGES 2017 Annual Meeting in Houston, TX.
Abstract ID: 84277
Program Number: ETP714
Presentation Session: Emerging Technology Poster
Presentation Type: Poster