Over the past decade, roboticsurgery has ushered a new era of minimally-invasive procedures. It has found multiple applications in a number of specialties. The aim of this review is to
discuss the current application of the surgical robot in plastic surgery,
highlighting the clinical advances it has provided to the challenging field of
reconstructive surgery. The authors present the three most important robotic
systems designed to date and outline the major advantages of robotic surgery
that have stimulated its adoption by plastic surgeons. This is followed by
highlighting the range of applications in reconstructive surgery, specifically
head and neck, breast reconstruction, muscle flap harvest, lymphoedema surgery,
and brachial plexus/peripheral nerve surgery. The authors finish by presenting
some of the shortcomings of the da Vinci® (Intuitive Surgical, Inc., Sunnyvale,
CA) platform that preclude its broader application. 

Robotical systems 

The AESOP® system 

The AESOP® was designed byComputer Motion, Inc. (Santa Barbara, CA), a medical robotics company founded
in 1989. The purpose of this platform was to manipulate a laparoscopic surgical
camera. It received US Food and Drug Administration (FDA) approval in 1994¹.Later, this robotical system burgeoned forth to include additional
technologies, namely voice control, network facilities, and optical arms with
seven degrees of freedom². These contributed to improving the surgeon’s dexterity, asthey enhanced his/her ability to control a stable image and prevent
unnecessary/inadvertent movements (streaking the lens); also, fewer staff were
required in the operating room³. 

The ZEUS® system 

In 1995, Computer Motionadded a number of surgical arms to AESOP® for holding and manipulating surgical
instruments. This marked the birth of ZEUS® (FDA approved in 2001)¹. TheZEUS robotic system comprises a control console in which the surgeon is
comfortably seated outside the operating room, along with a minimum of three
robotic arms attached to the operating table. These can accommodate no less
than 28 different instruments². The ZEUS® platform was used during the famous ‘OperationLindbergh’, the first transcontinental robot-assisted laparoscopic
cholecystectomy⁴. Images were, however, still in 2D. 

The da Vinci® system 

Intuitive Surgical, Inc.(Sunnyvale, CA), along with other institutions, such as Massachusetts Institute
of Technology and International Business Machines Corporation, developed the da
Vinci® system (FDA approved in 2000)². This system is made of three components: the surgeon’sconsole, the patient trolley (holding articulated surgical arms), and an
advanced imaging system¹. The surgical arms allow very precise gestures in 7° movements,scaling down of movements up to 5 : 1, and give an instrument flexibility of
360°. These characteristics give the surgeon the illusion that the tips of the
instruments are an extension of the control grips³. 

Updated versions havefollowed: The da Vinci S® system had increased ease of handling and increased
amplitude of arm and instrument movements, and the da Vinci Si® system afforded
further improvements in manipulators and pedals with a high-definition vision^5, 6. 

The da Vinci® system is themost widely used and had successful applications in endocrine, gynaecologic,
urologic, and cardiothoracic surgeries. Its application to the ranging fields
of plastic and reconstructive surgery will be analysed in this article. 

Plastic surgeons are oftenconsidered head-to-toe surgeons by virtue of operating on the whole body, on
all groups of patients, and in emergency, as well as elective cases. One
commonality in plastic surgery procedures is delicacy, requiring the highest
levels of precision and meticulousness for optimal outcomes. Also, many
techniques are performed on high-risk patients in whom minimal surgical
morbidity is even more desirable owing to the consequences of complications.
With the improved da Vinci robot technology, and its increasing clinical
application in the fields of minimally-invasive general, urologic, and
cardiothoracic surgery⁷, it has become evident that robots might benefit thechallenging field of reconstructive plastic surgery. Computer-enhanced
technology and robotic precision are able to provide a level of surgical
precision never previously attained in the history of surgery⁸;this is also known as ‘supra-human’ precision. The robotic arms filter the fine
tremors of the human hand, in addition to providing motion scaling of up to
five times in amplitude reduction. This combination of attributes results in a
tremendous enhancement of the surgeon’s delicate control of the instruments and
tissue, allowing intricate procedures to be performed with more confidence.
These robotic advantages, in addition to better ergonomics and visual acuity,
has rendered many surgical approaches that were previously technically
difficult or unfeasible, now possible. 

Increased dexterity 

Improved dexterity isachieved in a number of ways. Robotic instruments are capable of increased
degrees of freedom, which greatly improve the surgeon’s ability to carefully
handle arteries, veins, nerves, and other tissues. These instruments are also
free of the fulcrum effect that makes manipulation more intuitive than
laparoscopy. In addition, the robot is designed in a way to annul the surgeons’
tremor on the end-effector arms through sophisticated hardware and software
filters. Furthermore, these systems can scale down movements (i.e. gross movements
of the control sticks are transformed into micro-movements on the patient side⁹). 

Enhanced hand-eyecoordination 

The robotic vision systemprovides high definition, and 3D optics at 10-times magnification. The 3D view
with depth perception is far beyond what a conventional operating room camera
(e.g. laparoscopic camera) can offer. The high resolution images, coupled with
the increased degrees of freedom and enhanced dexterity, boost the surgeon’s
ability to identify and dissect fine anatomic structures and to perform
microanastomoses with more certainty and confidence. 

Ergonomic positioning 

Another significant highlightof the robot is ergonomic positioning. With the surgeon sitting at a remote,
comfortably-designed station, this system eliminates the need to twist and turn
in awkward positions — especially when performing subtle procedures in a narrow
visual field. In microsurgery, surgeons spend a lot of time working around
structures to fit their hands in space. Robotic microsurgery eliminates the
need to work around tracheostomy tubes, under the mandible or over large flaps. 

Smooth patientrecovery 

For patients, the results ofrobotic-assisted surgery, by virtue of its minimally-invasive nature, include
decreased postoperative pain, risk of infection and blood loss, in addition to
a potential shorter hospital stay, faster recovery, and quicker return to
normal daily activities. This is particularly seen in multi-service robotic
cases that include intra-abdominal or pelvic work in combination with
reconstructive procedures. These are typically associated with blood loss,
transfusions, the need for epidurals, and long hospitalisations and immobility.
Anecdotally, combined robotic procedures have reduced these drawbacks. 

Applications ofrobotic surgery in plastic surgery 

Head and neck surgery:oropharyngeal reconstruction 

Traditional upperaerodigestive tract oncologic reconstructive surgery relies on local and
free-flap coverage. The difficultly in accessing deep oropharyngeal tumours has
required adding a morbid procedure to increase visualisation for optimal tumour
extirpation and flap inset, such as lip splitting and/or mandibulotomy; these
result in speech and swallowing dysfunction, as well as poor aesthetic outcomes^10–13. 

From animal models intoclinical application, transoral robotic surgery (TORS) was introduced in 2003
by Mcleod et al¹⁴, and has since provided a number of key advantages in tumourresection surgeries. Improved optics and enhanced instrumentation allowed
multiple degrees of rotation with greater freedom of movement inside a narrow
cavity, with better exposure of anatomic landmarks in a 3D view. This has
obviated the need for additional incisions and jaw splitting manoeuvres (used
in the traditional approach). The TORS concept was further developed by
Hockstein et al¹⁵ and Weinstein et al^16, 17, who demonstrated wide access to the laryngopharynx incadaveric and animal models, respectively. In 2006, Hockstein introduced the
first clinical application of TORS for oropharyngeal cancer in 3 patients with
satisfying outcomes¹⁸. This was followed by a number of small series from differentinstitutions^19–22; ultimately, the superior ability of TORS for en bloc resectionof tumours while preserving vital functions, such as speech and swallow, became
evident. Consequently, in 2009, TORS obtained FDA approval for selected benign
and malignant tumours of the head and neck, and has since grown to enter
multiple centres around the world for tumour resection. 

Parallel to the advances inrobotic resection of deep oropharyngeal tumours, trans-oral robotic
reconstructive surgery (TORRS) of oropharyngeal defects surfaced. After
resecting such tumours and creating substantial defects, there is a clinical
need for a reliable reconstructive technique of the oropharynx using
preferentially vascularised tissues, as this aids in optimal functional
recovery¹⁰. Introduced by Mukhija et al in 2009 in an animal thencadaveric model²³, trans-oral oropharyngeal reconstruction proved to be a viableoption after tumour resection, as it allowed flap inset in narrow areas inside
the oropharynx where direct visualisation is not possible. Furthermore,
microvascular anastomoses was enhanced owing to markedly decreased
tremulousness. This has allowed the robot to gain popularity in this
reconstructive field¹⁰. In 2010, Selber reported early favourable results of fiverobotic-assisted oropharyngeal reconstruction of heterogeneous defects using
different types of flaps²⁴. Deformities ranged from small tonsillar fossa defects to moreextensive ones extending from the tip of the tongue to the epiglottis.
Reconstruction was performed using local as well as free flaps. The main
advantage of using the robot in these cases was the ability to inset the flap
in locations that are not easily reachable using conventional reconstructive
techniques (i.e. without splitting the lip or performing a mandibulotomy).
Also, the first robotic microvascular anastomosis was performed in this series,
and showed distinct advantages of the robot for microsurgery: 100% tremor
elimination, motion scaling (up to 5:1), and the possibility to work with full
precision in confined spaces. However, some disadvantages were noted, and these
included inferior optics as compared with operative microscopes, relatively
unrefined instruments, and a lack of haptic feedback²⁵.Nevertheless, microanastomosis was performed entirely using the robot, without
the need for any additional hand-thrown sutures, and resulted in a 100% success
rate. Genden et al introduced the two earliest case reports of TORS
microvascular reconstruction consisting of two radial forearm free flaps for
different patients with complex orophayngeal defects²⁵. Inboth cases, flaps were inset robotically, but the microanastomosis was
performed in the standard hand-thrown fashion. Later in 2012, Genden et al
published a larger case series (31 cases) on primary TORS reconstruction²⁶. Themajority of cases were local advancement flaps and six were free flaps (radial
forearm) mainly performed for extensive wounds and/or radiation salvage. All
free flaps were inset robotically, but the anastomosis was also performed in
the standard fashion. Ghanem reported four cases of different complexity
treated with free flap in a relatively similar fashion to Genden’s
reconstruction²⁷. Given the relative infancy of these procedures, clear guidelineson the timing of reconstruction is still lacking. Recently, however, Selber et
al introduced, through a small series of 20 patients undergoing TORS, an
algorithm based on tumour location, tumour extent, prior treatment, and patient
specific criteria²⁴. The study included 13 free flaps and seven local flaps.Microvascular anastomosis was performed in four of these cases, with no
microvascular thrombosis, or free flap failures¹⁰. In2013, Song et al published a series of five patients who underwent free-flap
reconstructions (four radial forearm and one anterolateral thigh)²⁸.Flap inset and microanastomosis were performed robotically. No complications
such as flap necrosis, haematoma, or wound dehiscence were noted²⁸.TORS for oropharyngeal, hypopharyngeal and laryngeal tumours seems to be a
viable treatment option, with equivalent or potentially superior oncologic
outcomes as compared with chemoradiation therapy. In addition, TORS is safe,
feasible and effective even for large tumours^26, 29. 

Breast reconstructive surgery: applications in incisionlessharvest of the latissimus dorsi flap 

Since its earliestdescription in 1906³⁰, the latissimus dorsi (LD) muscle flap has been an essentialworkhorse for reconstructive surgery; it has since gained great popularity in
breast reconstruction, whether in second stage (after expansion) or in primary
reconstruction. This flap is typically harvested with a skin paddle providing
an intact non-irradiated skin to replace the irradiated area. Raising the
muscle alone (without skin) has also a number of applications in breast
reconstruction, including: 

·      Protectionof implants in stage 2 breast reconstruction, following expansion 

·      Firststage of an immediate or two-stage implant-based reconstruction following
Nipple-Areolar Complex (NAC) sparing mastectomy³¹ 

·      Partialbreast reconstruction following partial mastectomy of the outer quadrants 

·      As analternative to bioprosthetic mesh to support the lower pole of implants,
obviating the need for biologic materials and their additional cost and
infection risks^31, 32. 

Harvesting the latissimusdorsi flap requires a long incision on the back that ranges between 15 and
45 cm, in addition to an axillary incision for pedicle isolation and transfer^33, 34. 

When the skin component ofthe flap is not required for reconstruction (as in the aforementioned
scenarios), a minimally-invasive harvest technique with no scars on the back
would be very favourable with regard to donor site morbidity. This has been
attempted using lighted retractors and long instruments, known as the semi-open
approach, where the incision size was reduced to 5–8 cm (by 80–88%). However,
this approach is technically challenging, and surgeons commonly have to extend
their incision to complete their dissection at the paraspinal level. Endoscopic
harvest has also been attempted, but because of technical challenges related to
limitations of endoscopic instrumentation and difficulties in maintaining an
adequate optical window — especially when dissecting around the curvature of
the back — nearly all centres have abandoned this technique^35–38. Therobotic platform, on the other hand, confers unique benefits that overcome the
limitations of the traditional and endoscopic approaches, specifically: 

·      Highresolution with great picture clarity and magnification, allowing better
identification and control of perforators (a common problem in the endoscopic
approach) 

·      Sevendegrees of freedom of robotic instruments allowing incredible precision, maintaining
a consistent plane, and offering better negotiation around the curvature of the
back 

·      Surgeoncomfort and ease of dissection, limiting any mechanical disadvantage when
meticulous dissection is performed 

·      Needlessto say, aesthetics and donor site cosmesis, especially for breast
reconstruction patients, are significant determinants of final outcomes;
robotic incisions of the muscle-only LD flap are barely visible³⁹. 

First introduced by Selber ina cadaver model, then in a clinical series of eight patients, robotic harvest
of the LD muscle-only flap is a feasible technique that allows effective
coverage and provides a reliable reconstruction with well-concealed incisions.
In addition, it is safe, with decreased donor site morbidity and no major complications^31, 40. Theuse of this technique has been steadily increasing in recent years; Selber
performs an average of 15 robotic LD harvests for breast reconstruction per
year. The main indications for the robotic technique include reconstructions of
lateral defects post-partial mastectomy, implant-based reconstruction post-NAC
sparing mastectomies, and in patients with expanders who receive radiation.
Owing to the safety and tremendous advantages of this technique, its
indications are increasing³⁹. 

The average set up time(including initial axillary incisions, port placement, and docking of the
robot) is approximately 30 minutes. The actual harvest itself takes a little
over 1 hour. No conversion to open technique has occurred so far, and all flaps
were harvested and transferred in their entireness. Most importantly, no
surgically-related complications such as haematoma, seroma, or overlying skin
injury have occurred³⁹. It is worth noting that this technique has a certain learningcurve for it to be performed in a safe and efficient manner. Studies are needed
to assess the steepness of such a learning curve, but it is recognised that
roboticassisted procedures are in general much easier to learn than
laparoscopic procedures. 

Abdomino-pelvicreconstructive surgery: applications in morbidity-free rectus muscle and
omental flap harvest 

Pelvic defects afteroncological resections (being colorectal, gynaecological or urological) are
common and challenging reconstructive problems for plastic surgeons^41–44. Thesetypes of resections are extensive and leave a substantial dead space that, if
not replaced with vascularised tissue, would lead to high rates of infection
and abscess formation⁴⁵. The pedicled rectus abdominis muscle flap is a first-choicereconstruction for such defects. In cases where the defect is larger than usual
and a muscle flap alone would not be enough for adequate coverage, a pedicled
omentum or a de-epithelialised myocutaneous vertical rectus abdominis
myocutaneous (VRAM) can be added⁴⁶. In cases where skin or vaginal wall are missing and areplacement is needed, a VRAM flap is then an essential requirement. 

Traditionally, the rectusmuscle is accessed through the same abdominal laparotomy incision that was
created by the oncological surgeon; this is followed by vertical division of
the anterior rectus sheath along the length of the entire muscle. This approach
carries substantial postoperative complications (such as wound infection,
seroma, abdominal hernia and pain), and has undesirable cosmetic results.
Reported rates of bulge and hernia range from 1.7–4% and 0.85–2.9%,
respectively^47–51. Overall, surgical site morbidity incidence ranges from 8.5 to14.3%^{47, 48, 52}. The concept of a minimally-invasive approach that does notentail violating the anterior rectus sheath to access the rectus muscle is very
appealing for reconstructive surgeons. This was introduced by endoscopic
extraperitoneal and laparoscopic transperitoneal approaches to harvest the rectus
muscle^53–55. These techniques did not gain popularity owing to theirlimited success; the endoscopic technique still violated the anterior rectus
sheath to varying degrees, and the laparoscopic technique required advanced
skills to be performed⁵⁶. 

Robotic surgery, on the otherhand, has gained wide applications in pelvic oncologic procedures. Manipulation
of the robot is more intuitive than laparoscopy and is much easier to operate
as proven by a lower learning curve^57, 58. This offers significant advantages for plastic surgeons (andtheir patients alike) for performing minimally-invasive procedures, such as
robotic harvest of the rectus abdominis muscle. Whenever needed, the omentum
can be harvested in a similar fashion. 

Intraperitonealrobotic-assisted harvest of the rectus muscle was first developed on a cadaver
model by Selber and Pederson in 2009⁵⁹. It was translated clinically by Pederson in 2010, and sincethen many cases have been performed at different institutions⁶⁰. Thesalient lessons learned from this procedure so far, are: 

·      Onlythree trocars are needed in the contralateral quadrants of the hemi-abdomen. If
needed, a fourth trocar can be inserted, free-style, to help the first
assistant in difficult situations 

·      Thepresence of the plastic surgeon during trocars insertion is essential 

·      Thehighlight of this approach is avoidance of any violation of the rectus muscle
and its anterior sheath. 

Experience with the roboticapproach has so far proven to be superior to the laparoscopic method, as well
as to the endoscopic-assisted technique for harvesting the rectus muscle. This
is mainly owing to the ease and simplicity of dissection (as compared with
laparoscopy, in which it is almost impossible for the human arms to direct the
instruments towards the midline when performing the initial dissection), and,
as outlined above, the preservation of the anterior rectus sheath with a
potential decrease in the incidence of hernia (as compared to the endoscopic
approach).