Brachial Plexus: Use of the Da Vinci Robot

10.1055/b-0034-78110

Brachial Plexus: Use of the Da Vinci Robot

Philippe A. Liverneaux and Gustavo Ruggiero Mantovani

Regarding treatment of traumatic brachial plexus palsy, recent development of “targeted” nerve transfers should not lead us to forget that direct exploration of radicular lesions still has some indications, especially in total brachial plexus palsies. A supraclavicular approach to the plexus, most often performed over 3 months after the injury, is rendered challenging because of soft-tissue sclerosis. Development of robotically assisted minimally invasive techniques should enable earlier surgical exploration, within 8 days of the injury. The main goal would be to perform both an initial assessment of the lesions and semiurgent repair of potentially graftable nerve roots, without secondary complementary nerve transfer being required.

Description of the Robot

Utilization of the Da Vinci robot (Intuitive Surgical, Sunnyvale, CA, USA) is still in its infancy in microsurgery. This technique is called “telemicrosurgery” or robotic-assisted microsurgery.1

The Da Vinci robot consists of three subunits: one mobile cart with articulated arms, one cart for the video-imaging, and a console for the surgeon to control the articulated arms of the mobile cart ( Fig. 23.1 ).

The mobile cart carries four articulated arms: three for the surgical instruments and one for the optical device screening the surgical field. Each arm has several articulations, allowing three-dimensional (3D) movements of both the instruments and the optical device. The three arms dedicated to the surgical instruments have an intracorporeal articulation designed for 360-degree circumduction movements (Endowrist, Intuitive Surgical, Sunnyvale, CA, USA). These instruments can include dissecting forceps, Potts scissors, scalpels, needle holders, and others ( Fig. 23.2 ). The fourth arm holds the optical device.

The imaging cart holds a video column similar to those in use in conventional arthroscopy, except that two different light sources and cameras allow 3D vision with a progressive 40× magnification.

The telesurgical console comprises an optical device, two handles for telemanipulation, and pedals. The optical device, called a stereoviewer, enables 3D vision of the surgical field and displays text messages and icons for real-time information on the system′s status. Two handles are for remote manipulation of the four arms holding the camera and the surgical instruments. Handles allow control of only two arms at a time. A clutch pedal is used by the surgeon to switch easily from one arm to another during the procedure. Another pedal controls the optical focus of the surgical field on the one hand, while a third pedal allows optimal positioning of the surgical instruments within the optical range of the camera. A surgical assistant may even control one of the instrumental arms using a tactile screen on the latest generation of robots ( Fig. 23.1 ).

Potential Benefits of Robots in Brachial Plexus Surgery

During the last decade, therapeutic management of traumatic brachial plexus palsy has dramatically evolved since the arrival of “targeted” nerve transfers. These nerve transfers give far better results than conventional nerve grafts,2 mainly for three different reasons:

A donor nerve is always anatomically intact when a transfer is performed, whereas a graftable root is invariably of lesser quality.
The recipient nerve in a transfer is sutured immediately before its intramuscular ramification, thus preventing any fiber from the donor nerve from getting lost amid sensitive fibers or other fibers gaining other nerves.
A single suture is performed in a transfer, whereas two sutures are necessary in a nerve graft, and saving sutures helps to prevent axonal loss.

Even though the advantages of nerve transfers are evident, results of the treatment of traumatic brachial plexus palsies may be further improved by modifying therapeutic management by three different means, thanks to telemicrosurgery or robotic-assisted microsurgery.

The first modification concerns the delay between surgery and initial trauma. Previous chapters have clearly demonstrated that results were far better when the delay was under 6 months because of the persistence of both number and quality of motor plates. No paraclinical investigation to date can provide an accurate lesional assessment within a few hours of the initial trauma. Only a close clinical follow-up looking for spontaneous nervous recovery can provide a rather precise lesional diagnosis. The latter situation explains that optimal delay between onset of the palsy and surgical exploration is believed to vary between 3 and 6 months. It should be of utmost interest to shorten this delay to improve the quality of the neural regrowth. Surgical techniques using early robotic-assisted limb endoscopy are options actually considered and under evaluation by some surgical teams.3

The second modification concerns the microsurgical technique. Quality of the neural regrowth depends on the quality of the nerve suture. Conventional microsurgery has not made any major progress since its advent in the 1960s. The characteristics of the surgical robot (suppression of physiological tremor, magnification of the surgical procedure, enhancement of surgical ergonomics) allow dramatic improvement of the precision of microsurgical nerve suture techniques.4

The third modification concerns the development of minimally invasive microsurgery. Plexus brachial surgery involves open microsurgical techniques with extensive scarring well over several decimeters going from the mastoid process to the upper third of the arm. The resulting fibrous scars are externally unsightly and internally prone to perineural sclerosis, hindering regeneration quality after the nerve repair. Robotic-assisted minimally invasive surgery of the brachial plexus might provide the double advantage of limiting both aesthetic and functional impairment due to scar formation.5

Da Vinci SI robot. At the foreground, the mobile cart with its four articulated arms, at the background the console used by the surgeon, and at the back of the room the assistant′s console.

Da Vinci SI robot microinstruments. At the top, three complete instruments each measuring almost 50 cm. At the bottom, a schematic view of the mobile tips of the microinstruments. From left to right: Potts scissors, Black Diamond forceps, bipolar Maryland forceps. (With permission from Intuitive Surgical, Inc., ©2012 Intuitive Surgical, Inc.)

Telemicrosurgery Technique

Installation

Regardless of the surgical field localization, the arms of the robot are positioned in the same direction as a conventional microsurgeon′s forearms. The body of the robot needs to be positioned facing the telemicrosurgeon, as if the robot were about to perform a conventional microsurgical procedure. The telemicrosurgeon is comfortably seated at the master remote control console of the robot, distant from the patient.

Adequate positioning of the robot is dictated by the anatomic area and required surgical exposure ( Fig. 23.3 ). In supraclavicular brachial plexus telemicrosurgery,3 the patient is placed in dorsal decubitus, the body of the robot is positioned at the back of the patient, between the head and the shoulder undergoing surgery. In axillary nerve surgery, the patient is installed in lateral decubitus opposite to the nerve undergoing surgery, the body of the robot is positioned in front of the patient, next to the operated shoulder. In telemicrosurgery nerve transfer of the arm, the patient is placed in dorsal decubitus, with 90 degrees of abduction and 90 degrees of external rotation of the shoulder and 90 degrees of flexion in the elbow. The robot can be positioned on either side of the trunk, with the body of the robot adjacent to the contralateral upper limb and the surgical instruments on the side of the upper limb undergoing surgery.