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Page 2 of 10 Sebastián-Tomás et al. Mini-invasive Surg 2019;3:30 I http://dx.doi.org/10.20517/2574-1225.2019.29
[2]
of total mesorectal excision (TME) . Preoperative radiotherapy and chemotherapy have a major role in
[3]
the treatment of locally advanced rectal tumors . To perform an accurate mesorectal dissection achieving
clean margins is mandatory for rectal resections. Obtaining both negative circumferential resection
margin (CRM-) and a complete mesorectal excision is associated with lower recurrence rates an improved
long-term survival [4-10] .

Laparoscopic rectal surgery was introduced shortly after 1990. The earliest large randomized controlled
trials (RCT) comparing conventional laparoscopic and open approaches for rectal cancer showed that
the use of laparoscopy was associated with a lower blood loss, an earlier return of bowel movement, and
a shorter length of hospital stay [11-14] . Further studies questioned the oncological safety of the approach,
by means of obtaining a complete mesorectal quality or a composite pathologic outcome associating also
free circumferential and distal margins [15-17] . Remarkably, the observed impairment should be reflected in
the long-term oncologic prognosis in order to reach any clinical interest. The question remains still open
after the publication of the mid-term (2-year) results of the latest trials [18-20] . Conventional laparoscopic
instruments may not be appropriate for assuring the achievement of the best plane of dissection in all
[21]
patients, especially in those with the narrow or irradiated pelvis . Due to this, TME seems to be one of
the procedures in which the robotic assistance will have a critical role [22-25] .

At the time of the present review, the ROLARR study was the largest RCT comparing robotic-assisted
[26]
vs. conventional laparoscopic surgery for patients with rectal cancer . Two recent systematic reviews
with meta-analyses summarized the outcomes from 7 and 5 RCTs with a similar design [27,28] . Other meta-
analyses have been published including also non-randomized clinical trials [29,30] . No guidelines are now
available suggesting the true role of robotics in colorectal surgery, high-quality clinical data is similarly
lacking. In the present review, we dissected the current status of robotic TME, with special emphasis on
surgical outcomes and near future perspectives.

BACKGROUND
A robot is a device that can be programmed to carry out a task, being controlled by mechanical and
[31]
computing systems . The concept of robotic surgery appeared in the 1970s as a military project of the
Defense Advanced Research Project Administration endorsed by the National Aeronautics and Space
[32]
Administration aiming to keep the surgeon from the battlefield . In 1985, a robot was introduced into
an operating theatre, an industrial robotic arm (PUMA 200) was modified to perform a preprogrammed
intracranial biopsy. Shortly thereafter, the PROBOT® and ROBODOC® systems were developed,
designed for transurethral prostatic resections and total hip arthroplasties, respectively [33,34] . The earliest
systems required prior task programming, implying longer procedure duration and poor response to
unexpected events. At the end of the 20th century, the way of conceiving abdominal surgery changed
by the introduction of laparoscopy. The first laparoscopic colorectal surgery was performed in 1990 by
[35]
Fowler . In 1994, the automated endoscopic system for optimal positioning was the first real-time surgical
manipulation system being commercialized. It consisted of an endoscope attached to a voice-controlled
mechanical arm that modified its position following surgeon’s orders. It allowed greater image stability
and sometimes dispensed the need for an assistant but provided longer operative time compared with
conventional laparoscopy [36,37] .

In 2000, ZEUS® (Computer Motion, Goleta, California, USA), a three-armed robot mounted on the
operating table; and the da Vinci® robot (Intuitive Surgical, Sunnyvale, California, USA) were developed.
In 2003 Computer Motion was incorporated into Intuitive Surgical. The da Vinci® system provided a fourth
arm and an independent console where the surgeon has a three-dimensional view of the field. Specifically
[38]
designed devices with Endowrist® technology allow for 7º of freedom, 180º articulation and 540º rotation .