Applications in brachial plexus and peripheral nerve surgery

Despite great advances in microsurgery, peripheral nerve repair continues to result in suboptimal functional outcomes. Part of the problem lies in micro-imperfections of such a delicate surgical repair. An imprecise nerve coaption is recognised as a significant impediment to nerve functional recovery. In fact, it is very challenging to achieve perfect matching of the internal nerve fascicles (a necessity underlined by Millesi^61–63) using standard microsurgical techniques. Inadequate matching of motor and sensory fibres in mixed nerves can result in non-functioning cross-connections ,thus prohibiting the relay of adequate nerve signals to end organs. Achieving a more precise nerve coaptation may increase the chances of full functional recovery.

On the other hand, it is equally important to ensure gentle handling of the injured nerve stumps when performing meticulous suturing of the various layers of the peripheral nerve. In this regard, the benefits of robotic assisted microsurgery, including 100% filtration of human tremor, magnification and high-quality imaging, and amplification of surgeons’ dexterity, range of motion and precision, are especially useful in nerve repair procedures, and can confer a number of advantages over conventional microscopes and instruments⁶⁴. This type of robotic microsurgery was pioneered by Livernaux, who demonstrated that telesurgery allows very safe and precise peripheral nerve repairs by counteracting physiological tremor and by improving the overview of the surgical field, either with an anatomical or a neurotrophic technique⁶⁵.

Owing to these advantages in nerve repair, the robot has found applications in brachial plexus surgery. The brachial plexus has a complex anatomy and poses a number of challenges for the reconstructive surgeon. In such injuries, it is not only important to identify the origin and pathway of the damaged nerves, but it is also crucial to re-establish proper orientation of the damaged branches to ensure accurate matching of motor and sensory fascicles⁶⁶. Furthermore, in injuries affecting branch points, it is very challenging to accurately re‑establish the proper anatomic pathways. Robotic‑assisted surgery for brachial plexus trauma, also pioneered by Livernaux^67, 68, offers great benefits, as more precise and highly controlled surgical procedures can be performed under high magnification⁶⁹; this may result in improved surgical outcomes. In addition, the robot is ergonomic, enabling the surgeon to assume a comfortable position during such lengthy procedures. The use of the da Vinci system in their three reported cases provided excellent conditions for the surgical performance⁷⁰. The authors noted, however, that although the nerve coaptation is not, in itself, an indication for the use of the robot at this time because of the increase in surgery costs, it can be the first step toward minimally-invasive brachial plexus surgery.

Novel applications: lymphoedema surgery and lymphatico-venous bypass

The main highlights of robot-assisted surgery (ultra-precision and 100% tremor filtration) are currently being expanded to the field of supermicrosurgery, specifically to lymphoedema surgery. Lymphaticovenular bypasses are generally performed end-to-end using 11-0 or 12-0 nylon sutures on a 50 μm needle⁷¹. These are extremely technically challenging cases and can push — and in certain cases exceed — the limits of human precision. The supra-human precision afforded by the robot can be of great benefit in such a setting. In addition, the robotic platform allows rapid transitioning of the visual system between near-infrared laser vision (when using indocyanin green to identify lymphatics) to normal bright field vision, a great advantage for lymphatics surgery in identifying lymphatic vessels with physiologic flow.

Limitations of robotic surgery

Cost

With the increase in the indications for robotic-assisted procedures in the field of plastic surgery, comes the concern for an effective dissemination of this innovative technology to a higher number of surgeons and centres. Cost presents the most obvious obstacle. The current cost of the da Vinci system is $2.2 million and annual maintenance is $138000. However, it is worth noting that it is the hospital that purchases the system anticipating increased patient volumes and reputational benefit from urological and cardiothoracic procedures. When using the robot for plastic surgery, the ‘extra’ costs are those of the additional OR time and the semi-disposable instruments (which are designed for 10 uses, so cost must be amortised over those cases). In the authors’ institution (MD Anderson Cancer Center), a robotic LD harvest costs an additional $800–900 as compared with an open LD flap⁵⁸. Although at first glance cost seems to be a substantial drawback for the widespread application of the robot, when considering the advantages offered in terms of decreased morbidity and hospital length of stay, robotic-assisted procedures might compare favourably to traditional approaches. Prospective long-term studies are needed to objectively assess the cost-effectiveness of this new technology in terms of operative time, recovery period, hospital length of stay, and morbidity rates.

Learning curve

Another important question affecting broader application of robotic-assisted surgery is its learning curve. There are a number of challenges when teaching this technique to residents and already trained plastic surgeons. One of them is that plastic surgeons have never (or very rarely) used a telemanipulator instrument during their training and practice. Plastic surgeons have always relied on haptic feedback and on their sense of touch for optimal results; however, telemanipulation might be an easily adopted technology despite all its advantages. On the other hand, when operating the robot, a comprehensive understanding of its mechanics, kinetics, and operative dynamics is a major pre-requisite; basic functionality alone is not enough⁵⁹. Therefore, a significant amount of time and energy should be spent on learning the subtle nuances of the robotic mechanics to be able to troubleshoot the machine when it is not performing optimally. Appropriate teaching modules and evaluation and credentialing systems for specific plastic surgical skill sets do not yet exist. We must work as a specialty to define competency in robotic plastic surgery so insure that it is being done safely and according to best practices.

Another essential task to establish is the education of the operating room nursing staff, as significant differences between this modality and traditional surgery exist. Without adequate operating room support, most surgeons will switch back to conventional methods even after successful robotics cases are done. Such standardised modules are currently lacking, and their establishment requires a close collaboration with industrial companies who are currently more invested in advancing the fields of robotic urology and general surgery.