Robotic cardiac surgery: current status and future directions
Robotic Surgery: Research and Reviews
Robotic cardiac surgery: current status and future directions
emmanuel Moss Douglas A Murphy Michael e Halkos 0
0 Division of Cardiothoracic Surgery, emory University School of Medicine , Atlanta, GA , USA
Since robotic cardiac surgery was first described nearly 2 decades ago, technological advance along with a growing demand for less invasive procedures have given way to increased development and adoption of robot-assisted cardiac surgery. Coronary revascularization is now being performed with varying degrees of robotic assistance. Robot-assisted single vessel and hybrid coronary artery revascularization is gaining popularity, and multivessel totally endoscopic coronary artery bypass surgery is being performed safely in select highly specialized centers. Intracardiac robot-assisted surgery has also become an attractive alternative to midline sternotomy and thoracoscopic approaches for mitral and tricuspid valve disease, atrial septal defect repair, and intracardiac tumors. This review will describe the current state of robotic cardiac surgery and offer some insight into future advancement.
The theoretical advantages of minimally invasive cardiac surgery have been well
described, and favorable reports continue to surface in the literature. In addition to
smaller incisions and improved cosmesis, patients may benefit from shorter intensive
care unit (ICU) and hospital stays, and an earlier return to their preoperative functional
level. Although robot-assisted cardiac surgery was first described nearly 2 decades
ago,1,2 recent technological advances occurring concurrently with the growing demand
for less invasive procedures have given way to the development and more widespread
implementation of robotic telemanipulation platforms to facilitate the performance
of minimally invasive cardiac surgery. These advancements include higher definition
three-dimensional scopes, thinner and longer instruments, and a third robotic arm
that allows for the addition of an endostabilizer to use for coronary bypass surgery or
a left atrial retractor for intracardiac surgery. The da Vinci Surgical System (Intuitive
Surgical, Sunnyvale, CA, USA) is currently the only robotic surgical system approved
by the United States Food and Drug Administration (FDA) for cardiac surgery. When
used concomitantly with techniques, perfusion systems, and myocardial protection
strategies that have been developed to facilitate minimal access surgery, robotic
technology demonstrates obvious advantages over traditional video-assisted thoracoscopic
surgery. Its three-dimensional high definition capabilities and articulating wrists allow
a greater freedom of movement in an enclosed space compared with traditional
longshafted instruments. The da Vinci system allows articulating instruments to move
with six degrees of freedom, rather than four degrees with long-shafted instruments,
and eliminates the surgeon’s tremor, if present. Robotic technology has now been
shown safe and feasible, being routinely used in specialized
centers to perform surgeries of varying levels of
complexity, including coronary surgery, mitral and tricuspid valve
surgery, atrial fibrillation ablations, cardiac tumor resections,
and congenital heart operations. In addition to the technical
advantages of robot-assisted surgery, the body of literature
supporting equivalent or improved perioperative outcomes
is steadily growing. Authors have found advantages over
traditional surgery with regard to decreased transfusion
requirements, decreased hospital length of stay, and faster
return to preoperative functional levels when compared with
sternotomy. Future iterations of the robotic telemanipulation
system may introduce haptic technology and facilitate even
further its use for complex cardiac surgery. This review will
describe the current state of robotic cardiac surgery and offer
some perspectives for future advancement.
.vodw l.y Coronary revascularization
ww no The surgical treatment of coronary artery disease (CAD)
:/s se has evolved significantly over the last several decades, with
h an regard to both conduits and the introduction of less invasive
from rsoe approaches. Since Loop et al3 reported a significant survival
deda ropF benefit grafting the left internal mammary artery (LIMA) to
lno the left anterior descending artery (LAD), it has become the
dow gold standard in surgical revascularization.3,4 This has caused
isew surgeons to focus on this conduit-vessel combination and
veR has led to the development of minimal access techniques
dna for LIMA harvest and anastomosis to the LAD. This began
rch with minimally invasive direct coronary artery bypass
(MIDsae CAB) procedures with LIMA harvesting and LIMA-LAD
:rryegeR iannathsteofmouorstihs oprerffioftrhmiendtetrhcroosutaglhspaalceeft.5–a9nSteurrigoerotnhsorsakciollteodmiyn
uS endoscopy applied these techniques to LIMA harvest and
itcbo successfully performed EndoACAB (endoscopic atraumatic
oR coronary artery bypass graft [CABG]) procedures.7,10 The
technique allows complete LIMA harvest to be performed
via small thoracoscopic incisions without the significant
upward chest wall retraction that is required with MIDCAB.
The LIMA-LAD anastomosis can then be performed through
a small anterior minithoracotomy. Although this procedure
can be performed safely and with good results in experienced
hands, its broad adoption has been hindered by the long
learning curve of the thoracoscopic harvest.
Robot-assisted LIMA harvest
Robot-assisted LIMA harvest with a hand-sewn LIMA-LAD
anastomosis offers the same advantages as EndoACAB, but
the shorter learning curve using the da Vinci system has
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mitted more widespread implementation of the approach. It
can generally be performed with three 8–10 mm incisions
followed by a 3–4 cm anterior minithoracotomy without using a
rib spreader. Pericardiotomy and target vessel localization are
accomplished prior to the thoracotomy, facilitating a smaller
incision directly over the target vessel. While our institution
has previously published excellent results with EndoACAB,
we have evolved to perform the robot-assisted CABG
technique exclusively because we believe it provides the optimal
mix of practicality, patient benefit, “teachability,” and
operating room efficiency.5,10,11 We recently published our
institution’s series of 307 patients who underwent robot-assisted
CABG surgery, with a low 30-day mortality (1.3%), low rates
of conversion to sternotomy (5.2%), perioperative myocardial
infarction (1.6%), and postoperative stroke (0.3%), and a
97% graft patency when including patients that underwent
intraoperative graft revisions.12–14 Nesher et al15 published a
series of 146 consecutive robot-assisted CABGs without any
in-hospital deaths and 96.3% patency rate.15 A more recent
study by Currie et al1 reported 93.4% patency at a mean of
96 months follow-up in 82 patients who underwent
robotassisted CABG.1,2 The study also evaluated quality of life and
demonstrated an overall positive effect; however, the report
lacked a comparison with standard CABG.
Some surgeons have transitioned to robot-assisted totally
endoscopic coronary artery bypass (TECAB). The first
TECAB operation was performed in 1999 on an arrested
heart utilizing femoral arterial and venous cannulation and
intra-aortic balloon occlusion.3,4 Subsequent reports evolved
toward an off-pump beating-heart technique with an
anastomosis that can be performed using monofilament suture or
anastomotic devices.5–9 The first larger series was reported by
Mohr et al
7 in 2001
, describing 27 patients who underwent
LIMA harvest and LIMA to LAD anastomosis using the da
Vinci telemanipulation system.7,10 In 2006, a multicenter
FDA-sanctioned trial demonstrated the safety and efficacy of
TECAB using the da Vinci system in 85 patients.5,10,11 There
were no deaths or strokes during the follow-up period, and
91% freedom from reintervention or angiographic stenosis of
greater than 50%. Although many authors have shown
singlevessel TECAB to be technically feasible, with an overall
improvement in quality of life compared with conventional
CABG, there is a significant learning curve that results in
prolonged operative times and possibly increased
complication rates early in a surgeon’s experience.12–14 Despite overall
good short-term results, the aforementioned shortcomings
and minimal perceived advantages over single-vessel robotic
MIDCAB has limited its widespread adoption.
Multivessel TECAB is the least invasive but most
complex method of non-sternotomy revascularization.
Beatingheart surgery, either off-pump or pump-assisted, is facilitated
by using the endostabilizer that attaches to the fourth arm on
the da Vinci robot, available on newer generation machines.
Although an off-pump approach is feasible for LAD and
diagonal vessel targets, exposing and grafting lateral and
inferior wall territories is technically demanding and requires
cardiopulmonary bypass (CPB) with or without cardioplegic
arrest. Bonatti et al have championed multivessel TECAB
and are responsible for a significant number of publications
on the subject. His group recently published their series of
500 totally endoscopic CABGs, including 166 multivessel
TECABs.16 The report assessed “success” and “safety” of
the procedure, stating rates of 80% and 95%, respectively.
In an earlier publication, the same group analyzed their
long-term results with multivessel TECAB specifically.17
The majority of these cases were two-vessel CABGs, with
11.7% being three-vessel TECABs, and one patient (0.5%)
underwent four-vessel TECAB. This group has previously
reported operative times averaging 225 minutes for
singlevessel TECAB, and in this publication they report an
average just over 6 hours for multivessel TECAB. Conversion
rate was 17%, with acceptable rates of typical perioperative
complications. Five-year survival and freedom from major
adverse cardiac and cerebrovascular events were 96% and
73%, respectively. The authors also reported an average return
to full physical activity of 42 days, which is significantly
lower than the 8–12 weeks of sternal precautions that are
typically recommended following sternotomy. Srivastava
et al18 reported their series of 164 consecutive beating-heart
TECABs, which included 73 multivessel CABGs. In-hospital
mortality and complication rates were low. Early graft
patency was 99.5% as assessed by either computed tomography
angiography or conventional angiography.
It is clear that robotic TECAB is a technically
challenging operation with a long learning curve and a high
risk of complications due to technical difficulties. While
most publications would suggest that the procedure can
be performed safely and effectively, one must remember
that learning curves are slow and operative times are long,
even in the most experienced hands. The controversy lies
in understanding whether patient safety and long-term
outcomes are being compromised to accommodate this
complex minimally invasive procedure. Wiedemann et al19
demonstrated that operative times longer than 478 minutes
are associated with intraoperative technical difficulties and
increased perioperative morbidity. Another study suggested
that TECAB may increase postoperative morbidity and
mortality compared with Society of Thoracic Surgeons National
Database expected outcomes. These concerns, along with
the previously stated long learning curve make widespread
adoption of this technique unlikely at this time.
Hybrid coronary revascularization
Fueled by the demand for less invasive procedures, good
outcomes with minimally invasive CABG, mediocre
outcomes with saphenous vein grafts, and improved results
with percutaneous coronary intervention (PCI) using drug
eluting stents, hybrid coronary revascularization (HCR)
has attracted significant interest in recent years from both
surgeons and cardiologists. Although many techniques
have been described, robotic assistance is ideally suited for
combining the sternal sparing surgical LAD
revascularization using the LIMA with PCI of non-LAD vessels. If both
LAD and non-LAD territories are suitable for each respective
procedure, patients can derive significant benefit from this
combined approach. Three strategies for timing of hybrid
revascularization exist, each with their own advantages
and disadvantages. These include CABG followed by PCI,
PCI followed by CABG, and simultaneous CABG and PCI
in a hybrid suite. With a CABG-first approach, PCI may
be performed during the index hospitalization or at a later
date, depending on the clinical scenario. The most obvious
advantage of this technique is the ability to perform CABG
without the need for perioperative potent antiplatelet agents.
Other advantages include the ability to verify LIMA
patency at the time of PCI, and the opportunity to perform
otherwise high-risk PCI knowing that left main or LAD
bifurcation lesions are protected by a patent graft to the LAD.
When considering a PCI-first approach, potential benefits
include the ability to subsequently perform CABG in the
event of suboptimal PCI results, and minimizing potential
ischemia during minimally invasive CABG by
revascularizing non-LAD targets. The tradeoff is the need for robust
platelet inhibition at the time of CABG, although this can
be minimized depending on the timing of surgery and the
type of stent implanted. Finally, with the growing number
of hospitals possessing hybrid suites, minimally invasive
CABG can more readily be performed simultaneously with
PCI in a combined procedure. This approach is attractive
from both an economic and patient convenience vantage
point. Clinical advantages include the ability to perform
intraoperative angiography of the LIMA-LAD anastomosis
and revision if necessary. Additionally, similar to the CABG
first technique, it permits safe performance of otherwise
high-risk PCI. The two primary disadvantages are increased
perioperative bleeding risk, and the difficulty of coordinating
cardiac catheterization and operative teams. Presently, there
is no evidence overwhelmingly favoring any one approach.20
081 The clinician must decide on a treatment plan by carefully
l-u2 considering the individual patient’s clinical and anatomic
-J12 criteria along with the merits of each HCR strategy and the
no institution’s resources.
.027 While randomized trials and other high-level evidence for
.964 HCR are lacking, several publications have shown HCR to be
.375 safe and effective. Reports dating as early as 1996 have
con/yb sistently reported low mortality rates, excellent graft patency,
com and acceptable rates of repeat revascularization in non-LAD
.sse territories.21–26 Some studies have shown advantages over
rvpe conventional CABG with regard to ICU and hospital length
.odw l.y of stay, perioperative blood loss, transfusion requirements,
ww no intubation time, and patient satisfaction.27,28 A recent
:/s se analysis by Harskamp et al,29 which included six studies and
h an 1,190 patients, found that patients who underwent HCR had
from rsoe shorter hospital stays, required less blood transfusions, and
deda ropF returned to work earlier. While short-term results with HCR
lno compare favorably to conventional CABG, long-term results
dow are limited. In 2011, our group published results
comparisveeRw ipnagtie1n4t7s pwahtioenhtasdwuhnodeurngdoenrewemnutlHtivCeRssewlitChA5B88G.m30 aTtchheerde
dna was no perioperative death, stroke, or myocardial infarction
rch among the HCR patients, and the overall incidence of major
sae adverse cardiac and cerebrovascular events (MACCE) was
:rryeegR sbiympialsasr(ObePtwCAeeBn) tghreouHpCs(R0%anvds o4.f9f-%pu).mTphectoraronnsfaursyioanrtreartye
uS was higher with OPCAB. At median follow-up of 3.2 years
itcob there was higher incidence of repeat revascularization with
oR HCR (12.2% vs 3.7%, P,0.0001); however, there was no
difference in 5-year survival (83.4% vs 88.6% for OPCAB
and HCR, respectively), and the vast majority of repeat
interventions were on PCI-treated targets. We recently
published our updated series of 300 patients who underwent
HCR with continued excellent outcomes.13 A 2013 report
suggested that higher risk patients with elevated SYNTAX
scores (euroSCORE .5, SYNTAX .33) may have better
outcomes with traditional CABG.31 In this high-risk group,
the incidence of MACCE at 30 days was 33% with HCR
compared with 0% following CABG. It is worth noting, however,
that this was a small subset that included only 27 patients
in the CABG group and nine in the HCR group, making it
difficult to draw any conclusions. Another subset of patients
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who may be at higher risk of perioperative complications are
those with isolated left main disease. When we compared our
series of 27 patients who underwent HCR with 81 matched
controls, we found no difference in MACCE between the two
groups at a mean follow-up of 3.2 years.32 Compared with
OPCAB, HCR was associated with a non-significant trend
toward increased repeat revascularization (7.4% vs 1.2%,
P=0.09) and a significant decrease in perioperative
transfusion requirements (33.3% vs 61.7%, P=0.01).
Some have raised concern about the cost of robotic
technology and HCR, and whether these approaches are
sustainable in the current economic climate. Several authors have
reported that despite initially higher costs, savings in
postoperative expenses create a favorable cost effective analysis
compared with OPCAB.23,28,33 Kon et al28 and Poston et al33
found that reduced perioperative complications (decreased
red blood cell transfusions and shorter ICU and hospital
length of stay) led to cost savings in the postoperative period
with HCR compared with OPCAB. This advantage was offset
by higher intraoperative costs, with no significant overall
cost difference. In the Poston et al33 study, when cost of the
robot itself was amortized per patient, the robotic cases had
significantly increased cost. In a recent publication by Halkos
et al,34 HCR yielded a greater contribution margin (best
hospital pay estimate – total variable costs) than OPCAB. This
analysis took into account the amortized cost of the da Vinci
robot system as well as maintenance and disposables. With
some studies also demonstrating earlier return to work, this
should result in societal cost savings.
Robotic mitral valve surgery
Surgery for the mitral valve has evolved considerably over the
last several decades. The largest shift has been with regard to
the notion that in most cases valve repair is more beneficial
than replacement. This philosophy was pioneered by Dr Alain
Carpentier as “The French Correction” and has subsequently
been championed by many surgeons.35 Since the advent of
the Heartport (Cardiovastions; Edwards Lifesciences, Irvine,
CA, USA) system in the 1990s, which allowed for reliable
peripheral CPB cannulation and perfusion, there has been
a growing trend toward minimally invasive sternal sparing
techniques to treat isolated mitral valve disease. When
compared with the sternotomy approach, these sternal sparing
techniques may be advantageous with regard to hospital
length of stay, cosmesis, and time until return to
preoperative functional level. While the earliest non-sternotomy
surgeries were performed via right anterior
minithoracotomy with central cannulation, they subsequently evolved
to a smaller incision mini-thoracotomy with peripheral
cannulation and videoscopic assistance.36–38 These
minimally invasive techniques have been shown to be safe,
effective, and durable, even in the setting of redo
operations and left ventricular dysfunction.39–41 Despite excellent
results, there are unique challenges that arise with these
techniques, including limited visualization of the
subvalvular apparatus, the mandatory use of long-shafted
instruments limiting dexterity, and anatomic variations such as
small chest cavities or obesity that limit applicability to all
patients, and may impact the type of valve repair that can
be accomplished. These limitations prompted the industry
and some surgeons to develop robot-assisted approaches,
which improved visualization, dexterity, and applicability
to a broader range of patients. The first reported case of
robot-assisted intracardiac surgery with the da Vinci
telemanipulator system was by Alain Carpentier’s group in 1998.2
They successfully repaired a large atrial septal defect and
aneurysm. The following year Falk and colleagues reported
results in their first ten patients undergoing robot-assisted
mitral valve surgery.42 Although they had initial success
in 90% of patients, they cautioned that surgery times are
lengthier and the learning curve is long. Since that time,
the robotic technology as well as surgical technique has
evolved considerably, and more complex repairs can be
accomplished reproducibly and in a timely manner. The
surgery can now be accomplished with five 1–2 cm
incisions in the right thorax, in addition to a femoral cutdown
for venous and arterial cannulation.
In 2005, the results of a multicenter trial, which included
112 patients from ten centers led to FDA approval of the
da Vinci telemanipulator system for mitral valve surgery.43
The following year, Murphy et al44 published their results
in 127 patients using a totally endoscopic robot-assisted
approach. Mitral valve repair was successfully accomplished
in 94.2% of patients, and echocardiographic follow-up of
98 patients at a mean of 8.1 months revealed 96.9%
freedom from greater than 1+ mitral regurgitation (MR), and
a 3.1% incidence of 2+ MR. Since that time, a number of
other high volume centers have reported their results with
minimal rates of conversion to sternotomy, high repair
rates, and excellent short-term outcomes.45–47 The largest
of these series was by the Chitwood group and included
540 patients.45 Mihaljevic et al48 from the Cleveland Clinic
published a large series comparing robotic mitral valve
surgery to other approaches. They compared 261 posterior
leaflet robotic mitral valve repairs to 114 repairs done by
sternotomy, 114 by anterolateral mini-thoracotomy, and
270 by partial sternotomy. They found longer CPB and
aortic cross-clamp times with the robotic approach, but
similar quality of mitral repair, and similar rates of
pulmonary, renal, and neurologic complications. The robotic
group had less postoperative atrial fibrillation and an overall
hospital length of stay that was approximately 1 day shorter
than all other approaches. In 2010, Gammie et al49 reported
results from the Society of Thoracic Surgeons database of
over 28,000 mitral valve surgeries, including 4,322
“lessinvasive mitral valve surgeries.” The report showed a high
repair rate and lower transfusion requirements with the
less-invasive approach, but raised concerns regarding an
increased stroke risk compared with sternotomy (1.87% vs
1.16%, adjusted odds ratio 1.96, 95% confidence interval
1.46–2.63). However, when comparing specifically the
robotic approach to sternotomy, there was no difference in
the incidence of perioperative stroke.
As with any surgical procedure, variations in technique
exist between robotic mitral centers. One important variation
is with regard to the aortic clamping and cardioplegia
strategies, with centers using either a transthoracic clamp and a
cardioplegia needle in the root, or the endoballoon system
(Intraclude aortic occlusion device; Edwards Lifesciences).
The endoballoon is typically advanced from the femoral
artery to the aortic root, with aortic occlusion being
accomplished by inflating the balloon and cardioplegia delivery
through the lumen at the distal end of the endoballoon
catheter. The previously mentioned study by Gammie et al49
found that, although the endoballoon was associated with
an increase in perioperative stroke in non-robotic minimally
invasive mitral valve surgery, this was not the case in patients
undergoing robot-assisted surgery. A more recent study, from
a center performing thoracoscopic mitral valve surgery,
suggested that good results can be achieved using either aortic
occlusion technique.50 Being facile with both may increase
the applicability of the robotic technique to a larger
proportion of patients.
A common theme among papers studying robotic mitral
valve surgery is that the same repair techniques used in open
surgery are being applied during robotic surgery.46,47,51 This is
important when considering implementing this relatively new
technology to address a pathology that has been successfully
treated with good long-term results via median sternotomy.
If the only difference is the approach to the mitral valve and
not the repair itself, then the long-term repair results achieved
with the sternotomy approach should be generalizable to the
robotic mitral patient population. Although limited, there is
some data on mid- and long-term results with robotic mitral
valve surgery. Chitwood et al52 reported echocardiographic
follow-up in 279 patients at a mean of 2.2 years with 92%
freedom from greater than mild MR. Other studies have
reported between 89% and 97% freedom from moderate or
severe MR at 1 year.44,53 Although there is clearly a learning
curve that must be overcome with this technique, these results
are comparable to published results for open surgery.
Quality of life and cost of robotic mitral valve surgery
As with robotic coronary surgery, significant concern exists
regarding the cost of robotic mitral valve surgery and its
sustainability in the current economic health care climate.
The cost disparity, if indeed one does exist, must be
evaluated against the potential benefit, which in the case of robotic
mitral valve repair likely relates to improved quality of life
(QOL). Suri et al56 compared QOL following robotic mitral
valve surgery to sternotomy. They found a slight improvement
with the robotic approach in the first postoperative year, and
comparable QOL after 2 years. Unfortunately, at this time
there is limited quantifiable QOL data comparing robotic to
open mitral valve surgery, and the benefit must be inferred
from shorter hospital stays and earlier return to work. It is
clear that more studies on the subject are needed.
In comparison to QOL, there is more available data
analyzing cost. In 2005, the group from Columbia University
reviewed a group of 40 patients who underwent atrial septal
defect or mitral valve repair using a robotic (n=20) or
sternotomy (n=20) approach.57 When capital costs for the robot
were excluded, total hospital cost was similar. However,
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when the analysis included amortized capital costs of the da
Vinci system, robotic mitral valve surgery was associated
with an increased cost of US$3,444 per patient. Similarly, an
Australian study showed no increase in cost when excluding
the initial cost of the robot.58 The group from the Mayo clinic
compared costs of robotic and open surgery before and after
implementing systemic changes to their cardiac surgery care
pathway. Interestingly, while robotic surgery at their
institution was associated with increased cost prior to
implementation of the changes, (US$34,920 vs US$32,650, P,0.001),
the cost difference disappeared after implementing protocols
that improved efficiency in operating room management and
standardized postoperative care (US$30,606 vs US$31,310,
P=0.876).59 Unlike the previously mentioned reports, this
study included amortized costs of the robot in the analysis.
Overall, it would appear that robotic mitral valve
procedures have a tendency to cost more than open surgery,
particularly if capital costs are considered. However, if care teams
focus on streamlining care, the difference can be minimized.
Additionally, the morbid complication of deep sternal wound
infection is eliminated with robotic mitral valve surgery. This
has been reported to cost greater than US$33,000 per patient,
with an incidence of 0.27%–1.30% in mitral valve surgery
done via sternotomy.60,61 Considering these comparisons,
along with the potential QOL benefits, robotic mitral surgery
appears to be a responsible and viable option. Furthermore, as
with coronary surgery, additional savings are likely to be seen
on a societal basis, with an earlier return to work compared
Atrial fibrillation ablation
Both transcatheter and surgical treatments of atrial fibrillation
are becoming increasingly popular. While the Cox–Maze
procedure is most commonly performed concomitantly with
mitral valve surgery, there are published reports describing
isolated full Cox–Maze procedures performed with robotic
assistance, with the energy source of choice generally being
cryotherapy. In 2009, Rodriguez et al62 described their
technique for stand-alone robotic atrial fibrillation surgery, and
reported 88% freedom from atrial fibrillation at 6 months in
71 patients. As with most atrial fibrillation ablation
procedures, the technique suffers from lack of rigorous long-term
follow-up, but early results are promising.
Epicardial lead placement
Cardiac resynchronization therapy requires a pacing lead to
be in contact with left ventricular muscle. This is most often
accomplished by navigating a transvenous lead through the
coronary sinus and into a coronary vein. This procedure
is limited by the anatomy of the coronary venous system,
making it technically challenging and in some cases not
feasible. An alternative has been to place an epicardial lead
via a left anterior minithoracotomy; however, some view
this as a morbid procedure in patients with left ventricular
dysfunction and other comorbidities. Robotic epicardial lead
placement has been suggested as an alternative, and several
authors report excellent immediate and long-term results with
no complications.63–65 The largest published series included
78 patients with a mean follow-up of 44 months. This group
reported 100% procedural success and stable pacing
thresholds throughout follow-up.65
Intracardiac mass resection
While there have been a limited number of case reports and small
case series describing robotic resection of left and right atrial
tumors, this procedure is certainly being frequently performed
in actual practice.66,67 One of the first reports was in 2005 by
Murphy et al68 who described a series of three patients who
underwent left atrial myxoma resection without any
perioperative complications. Gao et al69 reported a series 19 consecutive
patients, without any complications. Hassan and Smith70
published a case report describing robot-assisted excision of a left
ventricle myxoma. We recently reviewed our center’s experience
in 69 patients, comparing robotic left atrial tumor resection
(n=30) with a conventional transsternal approach (n=39).71 We
found a trend toward shorter ICU and hospital length of stay,
and fewer perioperative transfusions in the robotic group. There
were no strokes in the robotic group, compared with two in
the sternotomy group. The robotic technique is well suited for
intracardiac tumor resection because it allows high definition
visualization, favoring complete tumor resection and
minimizing the chance of leaving behind residual tumor particles with
embolization potential. Robotic excision of aortic valve papillary
fibroelastoma has also been reported.44,72,73
Other robotic procedures
Case reports have been published describing technique for
approaching various other cardiac pathologies robotically,
including aortic valve replacement,74 apico-aortic conduit
surgery,75 myotomy for myocardial bridging of the LAD,76
and right internal mammary to right coronary artery bypass
for aberrant origin of the right coronary artery.77
Congenital cardiac surgery
Robotic assisted procedures have been performed in children;
however, the technology is not as readily applicable as it is
in adults. This is due to the smaller thoracic cavities and
intercostal spaces, and limitations in peripheral cannulation.
Suematsu et al78 reported nine successful robotic patent
ductus arterious closures and six vascular ring repairs in
2005. The same year, Bacha et al79 described a robotic assisted
repair of a sinus venosus defect in a 40-year-old male.
Robotic assisted repair of congenital defects, such as
isolated atrial septal defects, are now routinely repaired in
adults. Bonaros et al80 reported a series of 17 patients, ranging
from 16 to 35 years of age, showing it to be safe and effective.
At this time, the future of robotic assisted pediatric congenital
cardiac surgery is uncertain due to the higher cost, lack of
pediatric sized instruments, and smaller thoracic cavities in
young children. On the other hand, robotic technology is
well suited to approach a variety of adult congenital
pathologies such as atrial septal defect, sinus venosus, and partial
anomalous pulmonary venous return.
Although slowly adopted initially, robotic cardiac surgical
procedures are increasing in popularity. This trend has been
fueled by advances in robotic technology, pioneering work
by innovative surgeons, and increased demand by patients
and cardiologists. Additionally, over the last 10 years,
numerous publications have demonstrated the safety and potential
advantages of robot-assisted surgery.
Robotics in CABG surgery has certainly evolved more
slowly than in other surgical specialties. Some blame the
absence of tactile feedback, but it also related to the meticulous
nature of the surgery, which involves anastomosing 1–2 mm
vessels on a potentially beating heart in a relatively fixed
position within the thorax. Despite this limitation, pioneers
in the field have made impressive strides, and the potential
for progress is evident. With regard to robot-assisted mitral
valve surgery, critics cite longer CPB times as a significant
drawback of the procedure; however, these have not translated
into increased perioperative morbidity, and in fact, patients
tend to have shorter overall ICU and hospital stays.
While significant progress has been made, the da Vinci
robot still has potential for improvement. A common belief is
that the lack of haptic feedback severely limits its use in cardiac
surgery; however, many surgeons that use it have found that
the learning curve to adapt to visual cues is relatively short.
Regardless, it is likely only a matter of time before haptic
feedback is introduced. Other aspects of robotic technology
will certainly evolve relatively quickly as well. Cameras will
continue to get better, and instrument sizes will get smaller.
Additionally, as with fluoroscopy, improvements in robotic
software will allow three-dimensional echocardiography and
computed tomography scan images to be overlaid onto the
field, serving as a surgical blueprint.
Other robotics systems, some of which are not yet
available for clinical use, are evolving alongside the da Vinci
robot and are helping to shape the future of the field. Efforts
are ongoing to produce new telemanipulation systems,
including the DLR MiroSurge robotics system (German
Aerospace Center, Oberpfaffenhofen-Wessling, Germany)
and the SPORT Surgical System (Titan Medical, Toronto,
ON, Canada). The Sensei X Robotic system (Hansen
Medical Inc., Mountain View, CA, USA) is used for
intracardiac navigation during cardiac ablation procedures.
Snake-robotic technology, which allows telemanipulation
of flexible arms that can more easily be maneuvered in a
confined space, is also being developed and will aid
intracorporeal surgery. Another area of research includes robotic
cardiac stabilizers, which can compensate for residual
of the art.
One elusive question is whether robotic cardiac surgical
procedures will gain widespread acceptance and become
routine for cardiac surgeons at large. Several limitations
may prevent this from coming to fruition – most
importantly, the necessity for a highly specialized team of
surgeons, anesthesiologists, echocardiographers, and surgical
assistants. Thankfully, centers interested in starting cardiac
surgical robotic programs can benefit from the knowledge
gained by experienced centers in order to mitigate the
learning curve. These experienced centers have succeeded in
decreasing the operative times and are now able to perform
two or three robotic procedures in a day, resulting in a safer
and more efficient operation that is more fiscally responsible.
Given the exponential advances in robotic and general
computer technology that we have witnessed over the last 20
years, it is impossible to predict what these machines will
be capable of another 20 years from now. However, we are
confident that robotics will be applicable to a wider variety
of procedures and available to a larger number of surgeons,
which will ultimately make its potential benefits accessible
to a greater number of patients.
Drs Halkos and Murphy serve as consultants for Intuitive
Surgical. The other authors report no conflicts of interest
in this work.
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