Robotic Cardiac Surgery

Journal of Long-Term Eff ects of Medical Implants, 13(6)451–464 (2003)

Document ID# JLT1306-451–464(206)

1050-6934/03 $5.00 © 2003 by Begell House, Inc.

Robotic Cardiac Surgery

Alan P. Kypson, MD, L. Wiley Nifong, MD, & W. Randolph Chitwood Jr., MD

Department of Surgery, Division of Cardiothoracic Surgery, Brody School of Medicine, East Carolina University, Greenville, North Carolina, USA

Address all correspondence to Alan P. Kypson, Department of Surgery, Division of Cardiothoracic Surgery, Brody

School of Medicine, East Carolina University, 600 Moye Boulevard, Room 252, Greenville, North Carolina, 27858,

USA; [email protected]

ABSTRACT: Traditionally, cardiac surgery has been performed by median sternotomy. How-ever, a renaissance is occurring. Cardiac operations are being performed through smaller and alternative incisions with enhanced technological assistance. Both coronary artery bypass graft-ing and valve surgery can be accomplished with this novel methodology. Specifi cally, minimally invasive mitral valve surgery has become standard for many surgeons. At our institution, we have developed a robotic mitral surgery program with the da Vinci™ telemanipulation system. Th is system allows the surgeon to perform complex mitral valve operations through small port sites rather than a traditional median sternotomy. Our techniques and initial results are reported, as is a brief overview of the evolution of robotic cardiac surgery.

KEY WORDS: cardiac, surgery, robotic

Journal of Long-Term Effects of Medical Implants

A. P. KYPSON ET AL.

I. INTRODUCTION

Traditional cardiac surgery is performed through a

median sternotomy, which provides generous expo-

sure and access to all cardiac structures and the great

vessels. During the past decade, improvements in

endoscopic technology and techniques have resulted

in a substantial increase in the number of minimally

invasive noncardiac surgical procedures performed.

Unfortunately, because of the complexity of most

cardiovascular procedures, a median sternotomy and

cardiopulmonary bypass have been required.

However, in the early 1990s, alternative, less

traumatic methods for performing cardiothoracic

surgery were developed. Th e minimally invasive di-

rect coronary artery bypass (MIDCAB) provided a

single vessel bypass on the anterior surface of a beating

heart through a small anterior thoracotomy. Th e Port-

Access™ (Cardiovations Inc., Ethicon, Somerville,

New Jersey) method involved endoscopic cardiac

surgery on an arrested heart using novel closed-

chest cardiopulmonary bypass and cardioplegic ar-

rest methods.¹²

Nevertheless, there were many limitations that pre-

cluded the widespread adaptation of these methods.

For example, standard endoscopic instruments, with

only four degrees of freedom, reduce dexterity signifi -

cantly. Working through fi xed entry points (trocars),

operators have to reverse hand motions (fulcrum ef-

fect), and at the same time, instrument drag induces

the need for higher manipulation forces, leading to

hand muscle fatigue.³

Computer-enhanced instrumentation systems

have been developed to overcome these and other

limitations. Systems can be classifi ed according to the

tasks they help perform. Th e fi rst group functions as

an assisting tool that holds and positions instruments.

Th e Automated Endoscopic System for Optimal

Positioning (AESOP™ 3000, Computer Motion,

Inc., Santa Barbara, California) is typically used to

guide an endoscope, which is controlled using voice

activation. One can order the robot to hold a specifi c

position or reorient to a specifi c operative fi eld, pro-

viding a clear and steady view without tremor. Th e

second group consists of telemanipulators that were

invented to facilitate fi ne manipulations done under

remote conditions. Connected through a controller

panel, the operator’s motions direct the remote ma-

nipulator or end-eff ector. Currently, in cardiac surgery

there are two telemanipulation systems in use—the

da Vinci™ (Intuitive Surgical, Inc., Mountain View,

California) and the Zeus™ robotic system (Computer

Motion).

Th e da Vinci™ system comprises three compo-

nents; a surgeon console, an instrument cart, and a

visioning platform (Fıg. 1). Th e operative console is

physically removed from the patient and allows the

surgeon to sit comfortably and ergonomically with

his/her head positioned in a three-dimensional vi-

sion array. Th e surgeon’s fi nger and wrist movements

are registered digitally, through sensors, and these

FIGURE 1A. da Vinci™ robotic telemanipulation system:

operative console where the surgeon is seated.

ROBOTIC CARDIAC SURGERY

Volume 13, Number 6, 2003

actions are transferred to an instrument cart, which

operates the synchronous end-eff ector instruments

(Fıg. 2). “Wrist-like” instrument articulation emulates

the surgeon’s actions at the tissue level, and dexterity

becomes enhanced through combined tremor sup-

pression and motion scaling. A clutching mechanism

enables readjustment of hand position to maintain an

optimal ergonomic attitude with respect to the visual

fi eld. Th e three-dimensional digital visioning system

enables natural depth perception with high-power

magnifi cation (10×). Visualization of the internal

thoracic artery, coronary arteries, and mitral appa-

ratus is excellent.

Th e Zeus™ system comprises three interactive arms,

mounted directly on the operating table (Fıg. 3). Al-

though the Zeus™ system lacks a fully articulated wrist

and allows only four degrees of freedom, the instru-

ment diameter is only 3.9-mm compared with the 7-

mm da Vinci arm. Th e surgeon also works at a console

that controls the instrument arms. Th e basic Zeus™

visualization system is two-dimensional; however, it

can be used in combination with an independently

developed three-dimensional visualization system.

FIGURE 1B. da Vinci™ robotic telemanipulation system:

the instrument cart.

FIGURE 2. da Vinci™ robotic telemanipulation system:

end-effector arms demonstrating all axis of motion.

FIGURE 3A. Zeus™ surgical console. Note the two-di-

mensional monitor the surgeon uses.


A. P. KYPSON ET AL.

II. EVOLUTION OF ROBOTIC CARDIAC SURGERY

Given the availability of telemanipulative systems,

endoscopic robotic cardiac operations have become

possible and have evolved through graded levels of

diffi culty with increasingly less exposure to a progres-

sive reliance on video assistance. In this scheme, entry

levels of technical complexity are mastered premoni-

tory to advancing past small incision, direct-vision

approaches (Level I), toward more complex video-

assisted procedures (Levels II-III), and fi nally, to

robotic cardiac operations (Level IV).

II.A. Level I: Direct Vision and Mini-Incisions

Initially, minimally invasive cardiac valve surgery

was based on modifi cations of previously used

incisions and performed under direct vision. In

1996, mini-sternotomies, parasternal incisions, and

mini-thoracotomies were used in the fi rst minimally

invasive aortic valve operations.⁴⁶ In Cosgrove’s fi rst

50 aortic procedures, operative times approximated

conventional operations, and mortality was 2%, with

half of the patients being discharged by postoperative

day fi ve.⁵ Cohn⁴ presented his series of 41 minimally

invasive aortic operations and demonstrated economic

benefi ts. Others⁶⁹ also found that minimal access in-

cisions provided adequate exposure of the mitral valve.

Surgical mortality (1–3%) and morbidity were com-

parable to those of conventional mitral surgery. Falk

reported on 24 mitral valve repairs performed through

a mini-incision with Port-access™ techniques.¹⁰ By

1997, the New York University group had done 27

Port-access™ mitral repairs/replacements with one

death. Th ere were no aortic dissections and no repairs

had residual regurgitation requiring reoperation.¹¹

Port-access™ methods were also used for coro-

nary artery bypass operations.¹²¹³ Th rough incisions

other than a median sternotomy, cardiac standstill was

feasible, allowing surgeons to graft multiple vessels.

Port-access™ coronary operations proved effi cacious

although they were more complex and required longer

perfusion times. Results of a prospective multicenter

trial¹⁴ on 302 consecutive patients demonstrated an

operative mortality of 0.99%, with a 3.3% incidence

of reoperation for bleeding and a 1.7% incidence

of stroke. Th ese encouraging results confi rmed the

feasibility and safety of these techniques and further

advanced the next level of “minimal invasiveness.”

II.B. Level II: Video-Assisted and Micro-Incisions

Video assistance was fi rst used for closed chest in-

ternal mammary artery harvests and congenital heart

operations.¹⁵¹⁷ Although Kaneko¹⁸ fi rst described the

use of video assistance for mitral valve surgery done

through a sternotomy, it was Carpentier¹⁹ who in Feb-

ruary 1996 performed the fi rst video-assisted mitral

valve repair via a minithoracotomy using ventricular

fi brillation. Th ree months later, our group performed a

mitral valve replacement using a microincision, video-

scopic vision, percutaneous transthoracic aortic clamp,

and retrograde cardioplegia.²⁰²¹ In 1998, Mohr re-

ported 51 minimally invasive mitral operations using

FIGURE 3B. Zeus™ instrument arms. Note that they are

mounted directly to the surgical table.



Port-access™ technology, a 4-cm incision, and three-

dimensional videoscopy. Video technology was helpful

for replacement and simple repairs; however, complex

reconstructions were still approached under direct vi-

sion.²² Concurrently, our group reported 31 patients

using video-assistance with a two- dimensional 5-mm

camera. Complex repairs were possible and included

quadrangular resections, sliding valvuloplasties, and

chordal replacements with no major complications

and mortality less than 1%.²³

Unfortunately, early attempts at coronary revas-

cularization with long instruments through small

incisions proved futile. Surgeons began to also use

voice-activated robotic camera control to harvest in-

ternal mammary arteries with excellent facility and

less patient trauma than experienced by conventional

means.¹⁶ Th e addition of three-dimensional visual-

ization, robotic camera control, and instrument tip

articulation were the next essential steps toward a

totally endoscopic procedure where wrist-like instru-

ments and three-dimensional vision could transpose

surgical manipulations from outside the chest wall to

deep within the mediastinum.

II.C. Level III: Video-Directed and Port Incisions

In 1997, with the assistance of AESOP™ 3000,

cardiac surgery entered the robotic age and allowed

smaller incisions with better mitral valve and subval-

vular visualization.²⁴ Th e following year, we performed

the fi rst video-directed mitral operation in the United

States using the AESOP™ 3000 robotic arm and a

Vista™ (Vista Cardiothoracic Systems, Westborough,

Massachusetts) three-dimensional camera.²⁰²¹ Visual

accuracy was improved by voice manipulation of the

camera. We now use the robotic arm, endoscope, and

a conventional two-dimensional monitor routinely

and have done over 300 videoscopic mitral operations

successfully using this method. Recently, we reported

on the use of this approach²⁵ and compared the results

to a cohort who underwent conventional sternotomy.

Reduced bleeding, ventilator times, and hospital stays

were shown for the minimally invasive cohort.

II.D. Level IV: Video-Directed and Robotic Instruments

In 1998, Carpentier²⁶ performed the fi rst mitral valve

repair using an early prototype of the da Vinci™. Two

years later,²⁷ our group performed the fi rst complete

repair of a mitral valve in North America using the

da Vinci™ system. A trapezoidal resection of a large

P₂ was performed with the defect closed using mul-

tiple interrupted sutures, followed by implantation of

a #28 Cosgrove annuloplasty band. Subsequently, we

have performed over 70 other mitral repairs as part

of Food and Drug Administration (FDA)-approved

trials. To date, more than 250 mitral operations have

been done between Europe and North America using

the da Vinci™ system. Complex mitral repairs can

be done with reasonable cross clamp and perfusion

times as well as excellent midterm results. Repairs

have included annuloplasty band insertions, chordal

replacements, sliding valvuloplasties, chordal trans-

fers, and leafl et resections. Th e advancements in three-

dimensional video and robotic instrumentation have

progressed to a point where totally endoscopic mitral

procedures are feasible. In fact, Lange and associates²⁸

performed a totally endoscopic mitral valve repair

using only the 1cm ports with da Vinci™. Future

refi nements in these devices are needed to apply this

new technology more widely.

In May of 1998, Mohr and Falk harvested the

left internal mammary artery (LIMA) with the

da Vinci™ system and performed the fi rst human

coronary anastomosis through a small left anterior

thoracotomy incision.²⁹³⁰ More recently, work with

da Vinci™ has lead to FDA approval for internal

mammary harvesting in the United States.

Th e fi rst totally endoscopic coronary artery bypass

(TECAB) was performed on an arrested heart at the

Broussais Hospital in Paris³¹ using an early proto-

type of the da Vinci™ system. Th e Leipzig group

attempted a total closed chest approach for LIMA

to left anterior descending coronary artery (LAD)

grafting on the arrested heart in 27 patients and were

successful in twenty-two.³² Furthermore, surgeons

in Europe improved the initial da Vinci™ coronary


A. P. KYPSON ET AL.

method and eventually were able to complete bilat-

eral internal mammary artery grafts off -pump to the

anterior descending and right coronary arteries while

working from one side of the chest.³³³⁴

In September of 1998, Reichenspruner³⁵ performed

an endoscopic robotically assisted coronary anasto-

mosis using the Zeus™ system. He used a standard

myocardial stabilizer inserted through a mini-thora-

cotomy. Th e pericardiotomy, vascular occlusion, and

dissection of the LAD were all manually performed

using conventional instruments. Damiano³⁶ fi rst ex-

panded coronary surgery with Zeus™ to the United

States; and Boyd, at the London Health Services

Center in Canada, reported on six successful closed-

chest beating-heart single-vessel revascularizations

using the same system.³⁷ Despite early procedural

success, future refi nements in these devices are needed

to apply this new technology more widely.

III. CLINICAL APPLICATIONS/PATIENT SELECTION

Early in the development of any minimally invasive

cardiac surgery program, strict inclusion and exclusion

criteria should be followed. In our initial experience

with robotic mitral repairs, all patients had isolated

mitral insuffi ciency. Patients with a previous right

thoracotomy were excluded from the da Vinci™ pro-

cedures; however, we now approach these patients with

a video-assisted mitral valve operation. Patients with

severely calcifi ed mitral annulus are not candidates. De-

calcifi cation requires further instrument development

as well as a reliable means to evacuate any calcium that

may fall into the left ventricle. Patients with mitral valve

stenosis were excluded in the early FDA trials; however,

patients treatable by commissurotomy would be suitable

candidates for robotic repair. Th e improved visualiza-

tion of the valve and subvalvular apparatus along with

the maneuverability of bladed microinstruments would

facilitate performance of a commissurotomy.

As previously discussed, early eff orts at totally

endoscopic coronary surgery using conventional

instruments were discouraging and were hampered

with imprecision and two-dimensional visualization.

With the development of computer-assisted telema-

nipulation systems and three-dimensional visualiza-

tion, TECAB has not only become feasible but has

also been demonstrated to be safe. Nevertheless, with

current technology, these operations are usually per-

formed on single vessel (LAD) disease with either

an arrested heart using the Port-Access™ system, or

a beating heart using specially designed endoscopic

stabilizers. Clinical trials are currently underway in

Europe and North America.

IV. OPERATIVE TECHNIQUES

IV.A. Mitral Valve Surgery

Pre- and postoperative surface and transesophageal

echocardiographic (TEE) studies are performed. Pa-

tients are anesthetized and positioned with the right

chest elevated 30°–40° and the right arm suspended,

padded, and positioned over the forehead. Single left-

lung ventilation is used for complete intrathoracic

exposure.

Cardiopulmonary bypass is established at 26 °C

using femoral arterial infl ow and kinetic venous drain-

age through a femoral (21–23 Fr) and right internal

jugular vein (17 Fr) cannula. If the femoral artery is

too small or atherosclerotic, either a Bio-Medicus™

(Medtronic, Minneapolis, Minnesota, USA) or Di-

rectfl ow™ (Cardiovations, Somerville, New Jersey,

USA) cannula can be placed through a second inter-

space port for antegrade aortic perfusion. A 4–5 cm

infra-mammary incision is used, and a subpectoral

fourth-intercostal space (ICS) mini-thoracotomy is

developed to provide cardiac access. Th e pericardium

is opened under direct vision 2 cm anterior to the

phrenic nerve. Antegrade cardioplegia is given by an

aortic needle/vent placed either under direct vision

or videoscopically. To minimize intracardiac air en-

trainment, the thoracic cavity is fl ooded continuously

with carbon dioxide at 1–2 liters per minute. A trans-

thoracic aortic cross-clamp (Scanlan International,

Minneapolis, Minnesota, USA) is positioned in the



midaxillary line via a 4-mm incision in the third ICS,

and intermittent antegrade cold blood cardioplegia

maintains cardiac arrest and myocardial protection.

Under video-assisted guidance, the posterior tine of

the clamp is passed through the transverse sinus with

care taken not to injure the right pulmonary artery,

left atrial appendage, left main coronary, or aorta.

After cardioplegic arrest, a transthoracic retractor

is used to expose the mitral valve through a 3–4 cm

left atriotomy made medially to the right superior

pulmonary vein entrance (Fıg. 4).

After valve inspection, positions for da Vinci™ left

and right arm port incisions are determined. Th e right

trocar is placed in the fourth ICS posterior lateral to

the incision and parallel to the right superior pulmo-

nary vein. Occasionally, the fi fth ICS provides a better

angle for the right robotic arm. Th e left trocar generally

is placed 6 cm cephalad and medial to the right trocar,

insuring internal clearance between arms to avoid both

external and internal confl icts. Optimal robotic arm

convergence avoids left atrial wall tearing during in-

strument manipulations. A high-magnifi cation camera

is used with a 30° (looking up), 3D endoscope placed

through the medial portion of the mini-thoracotomy.

Th e remainder of the incision is used as a working port

for the assistant. Needles are retrieved using a long

magnetic device, and suture remnants are removed

from the surgical fi eld using vacuum assistance.

Operative procedures are performed from the

surgeon’s console placed approximately ten feet from

the operating table but in the same operating room.

Th e patient-side assistant changes instruments and

supplies and retrieves operative materials. Most often

an annuloplasty band (Edwards Lifesciences, Irvine,

California, USA) has been used to support repairs or

provide annular reduction. In video-assisted robotic

cases, early placement of annuloplasty sutures facili-

tates exposure during complex repairs. Exposure of

each new suture often becomes predicated on retrac-

tion of the previous one. Leafl et resections, papillary

muscle reconstruction, and chord insertions or trans-

positions should be performed after annular sutures

are completed and suspended. Each suture is placed

and tied intracorporeal. Upon completion of the re-

pair, robotic devices are removed, and the left atrium

is closed under direct vision to decrease operative

times. Standard de-airing and weaning procedures

are performed under TEE control. A typical robotic

mitral valve repair is depicted in Fıgure 5. One month

FIGURE 4. Operative view through the working port.

Note the excellent view of the mitral valve apparatus

with the left atrial retractor in place seen exiting through

the chest wall.

FIGURE 5. Typical da Vinci™ mitral valve repair: the P2 seg-

ment of the posterior leafl et is being resected by robotic

microscissors. The annulus is reduced and both P1 and P3

are approximated.


A. P. KYPSON ET AL.

after discharge, all patients return for a follow-up visit

and a transthoracic echocardiogram.

IV.B. Coronary Artery Bypass Surgery

Patients are intubated with a dual-lumen endotra-

cheal tube, allowing single right-lung ventilation. Th e

patient is placed on the operating room table in a

supine position with the left side of the chest elevated

about 30°, with the left arm placed along the body

below the midaxillary line. Th oracic landmarks such

as the sternal notch, xiphoid, and ribs are marked

for external orientation and port placement. Proper

port placement is essential for initiating endoscopic

mammary artery harvesting. After defl ation of the

left lung, the camera port is placed bluntly in the fi fth

intercostal space on the anterior axillary line. Th e chest

is insuffl ated with continuous CO₂ at pressures of

5–10 mm Hg to increase the available space between

the heart and sternum. An endoscope is placed into

this port and under visual control; two more port sites

are placed, usually in the third and seventh intercostal

spaces above the anterior axillary line, for both robotic

arms, forming a triangle. Th e LIMAis mobilized from

the subclavian artery all the way down to the distal

bifurcation with a 30° endoscope. Th e distal end is

skeletonized with the concomitant veins and fascia

left intact to provide countertraction.

After LIMA harvesting, the patient is placed on

cardiopulmonary bypass through femoral vessel can-

nulation if the procedure is being performed on an

arrested heart. Otherwise, attention is turned to the

pericardium, which is opened. Th e target vessel (LAD)

is identifi ed and sharply dissected free. For beating

heart operations, a 1-cm skin incision is created at

the subxiphoid area, and an endoscopic stabilizer is

introduced. Th is stabilizer resembles conventional off -

pump stabilizers and consists of two arms that contain

special slots for attachment of silastic vessel loops used

for coronary artery occlusion during the creation of

the anastomosis (Fıg. 6). An irrigation tube is attached

to this endo-stabilizer, allowing saline fl ushing for

clear visualization of the desired area. After placing

the stabilizer onto the LAD, blood fl ow through this

vessel is temporarily interrupted using silastic loops.

After incision of the LAD with the robotic system,

the anastomosis is completed on a beating heart using

7-0 polypropylene running suture. After completion

of the procedure, chest tubes are placed through the

camera port and the instrument port.

V. CLINICAL OUTCOMES

Currently, the world experience with robotic mitral valve

surgery is mostly anecdotal, retrospective, and noncon-

trolled. Nevertheless, surgical results thus far have been

encouraging and are hastening the way toward a com-

pletely endoscopic, robotic mitral valve operation.

FIGURE 6. Coronary stabilizer placed endoscopically as

used for TECAB. Note the irrigator that provides a clear

view for creation of the anastomosis.



Recently, we published our results of the fi rst 38

mitral repairs with the da Vinci™ system.³⁸ Total

robot time represents the exact time of robot deploy-

ment after valve exposure and continues until the end

of annuloplasty band placement. Th is time decreased

signifi cantly from 1.9 hours in the fi rst group of 19

patients to 1.5 hours in the second group. At the same

time, leafl et repair times fell signifi cantly from 1.0

hour to 0.6 hours, respectively. Also, total operating

times decreased signifi cantly from 5.1 hours to 4.4

hours in the second group of patients. Furthermore,

both cross-clamp and bypass times decreased signifi -

cantly with experience as well. For all patients, the

total length of stay was 3.8 days, with no diff erence

between the two groups. Of all patients in the study,

84% demonstrated a grade 3 or greater reduction in

mitral regurgitation at follow-up. In the entire series

there were no device-related complications or opera-

tive deaths. One valve was replaced at 19 days because

of hemolysis secondary to a leak that was directed

against a prosthetic chord.

In reviewing the Leipzig robotic mitral experi-

ence, Mohr described 17 patients that underwent

robotic mitral valve repair.³ Fourteen of the 17

patients underwent a successful mitral valve re-

pair with the da Vinci™ system. In three patients,

conversion to conventional endoscopic instruments

became necessary. Th e average cross clamp time was

89 ± 18 minutes. Following the repair, intraoperative

TEE demonstrated no regurgitation in 13 patients

and trace regurgitation in three. One patient had a

grade 2 leak requiring immediate endoscopic valve

replacement. Postoperative results were notable for

one failure of a repair requiring emergent valve

replacement on postoperative day 3 secondary to a

disrupted annuloplasty ring.

To date, we have completed over 60 robotic mitral

valve repairs with the da Vinci™ system and have

noted certain trends. For example, bypass and cross-

clamp times between the fi rst 25 patients and the

second group of 25 patients continue to signifi cantly

decrease and are currently averaging 2.69 and 2.12

hours, respectively. Suture placement time for annu-

loplasty rings has decreased signifi cantly from 2.15

minutes per suture to 1.46 minutes in the second

group. When P₂ robotic repair times were compared

from the fi rst group of 25 to the second, there was

a signifi cant decrease from 54.19 minutes to 30.79

minutes. A multicenter da Vinci™ trial enlisting

112 patients has recently been completed and dem-

onstrates effi cacy and safety in performing these

operations by multiple surgeons at various centers,

thereby becoming the fi rst robotic telemanipulation

system to become FDA approved for mitral valve

repair surgery.

Similarly, experience with endoscopic coronary

artery bypass surgery has been limited to only a

few centers, and results are highly controlled. Be-

cause the success of coronary surgery depends on

multiple, complex steps culminating in the creation

of a vascular anastomosis, most clinical series have

introduced robotically assisted coronary surgery in

a stepwise fashion. Specifi cally, initial experience is

limited to endoscopic LIMA harvesting, followed by

a robotically assisted anastomosis through a median

sternotomy, and fi nally a total endoscopic procedure

performed on an arrested heart followed by a beating

heart operation.

Currently, the largest published series of TECAB

come from Europe. Wimmer-Grenecker’s group in

Frankfurt reported on 45 patients that underwent

TECAB on an arrested heart.³⁹ Most of these (82%)

were single-vessel bypass (either LIMA–LAD or

right internal mammary artery to right coronary

artery). Th e fi rst 22 patients had angiograms prior

to discharge, revealing a 100% patency rate. Mean

operative time for single-vessel TECAB was 4.2 ±

0.9 hours and 6.3 ± 1.0 hours for double-vessel bypass

procedures. Th e average cross clamp time for single

bypass was 61 ± 16 minutes and 99 ± 55 minutes

for double bypass. Th e initial conversion rate of 22%

decreased to 5% in the last 20 patients, refl ecting an

obvious learning curve.

Kappert⁴⁰ described TECAB in 37 patients, of

which 29 were performed on a beating heart. Of

these 29 patients, three received double vessel bypass

using bilateral mammary arteries, and the rest were

revascularized with a LIMA–LAD. As experience was


A. P. KYPSON ET AL.

gained, the duration of surgery decreased noticeably

from 280 ± 80.2 to 186 ± 58.6 minutes. An average

of 30 ± 6.5 minutes for robotically performed anas-

tomosis versus 12 ± 3 minutes for directly hand-sewn

anastomoses was observed. Nevertheless, none of the

37 patients revealed any sign of delayed wound heal-

ing, but three patients did undergo a reexploration for

bleeding. Currently, midterm follow-up angiography

is being performed to assess graft patency.

In the United States, Damiano and colleagues⁴¹

initiated multicenter clinical trials on robotically

assisted coronary surgery using the Zeus™ system.

In his FDA safety and effi cacy trial, 19 patients

underwent a median sternotomy with cardioplegic

arrest of the heart. All grafts were sewn by hand in a

traditional manner except the LIMA–LAD, which

was sewn robotically. Seventeen had adequate intra-

operative fl ow (mean 38.5 ± 5 mL/min) in the LIMA

graft. Anastomotic time was 22.5 ± 1.2 minutes. One

patient underwent reexploration for mediastinal hem-

orrhage. At eight weeks’ follow-up, graft patency was

assessed by angiography and all grafts were open. Th e

average hospital stay was 4.1 ± 0.4 days.

Boyd and associates³⁷ from London Health Sci-

ences Center in Ontario, Canada, have also been

extensively involved in initial endoscopic coronary

surgery trials with the Zeus™ system. In 2000, he

published a report on a series of six patients that

were the fi rst to undergo TECAB in North America

on a beating heart using a specialized endoscopic

stabilizer. Each of these patients had single-vessel

LAD disease and underwent LIMA–LAD grafting.

Special 8-0 polytetrafl uoroethylene suture 7 cm in

length was used to minimize suture time placement.

Intracoronary shunts were used to provide needle

depth landmark when performing endoscopic anas-

tomosis with two-dimensional cameras. LIMA

harvest time averaged 65.3 ± 17.6 minutes (range

50–91 min). Th e anastomotic time was 55.8 ± 13.5

minutes (range 40–74 min) and median operative

time was 6 hours (range 4.5–7.5 h). All patients had

angiographically confi rmed patent grafts before leav-

ing the hospital. Th e average hospital length of stay

was 4.0 ± 0.9 days.

V.A. Limitations

Th e early clinical experience with computer-enhanced

telemanipulation systems has defi ned many of the

limitations of this approach despite rapid procedural

success. Th e lack of force feedback is currently being

addressed, and a strain sensor is being incorporated

into advanced robotic surgical tools that may allow

for greater control of force applied at the robotic end-

eff ector.⁴² Furthermore, conventional suture and knot

tying add signifi cant time. Advancements, such as

nitinol U-clips™ (Coalescent Surgical, Sunnyvale,

California, USA) should decrease operative times sig-

nifi cantly. In a series of experiments at East Carolina

University, average suture/clip placement times and

knot tying/deployment times signifi cantly decreased

from 4.9 minutes to 2.6 minutes by using clips. When

implanting mitral annuloplasty bands, a clip deploy-

ment time of 0.75 minutes versus 2.78 minutes for

suture tying was noted.⁴³ Because of these promis-

ing results, we have begun using the U-clip™. To

date, four patients have had mitral annuloplasty ring

implantation performed (Fıg. 7) and intraoperative

times have been analyzed. Fırst, there is no diff er-

ence between the placement times of the U-clip™

and conventional suture (1.1 ± 0.5 vs. 1.5 ± 0.9 min).

Most likely, this is because the motion of placing a

U-clip™ and a suture is the same. However, U-clip™

deployment time is signifi cantly less than suture tying

time. Th e average deployment time of a suture is 1.1 ±

0.7 minutes versus 0.5 ± 0.2 minutes for the U-clip™.

Th is novel technology may ultimately help reduce

cardiopulmonary bypass time and arrested heart times

in minimally invasive cardiac surgery.

For endoscopic coronary surgery, where port

placements are critical to the procedure’s success,

the potential use of image-guided surgical tech-

nologies will provide real-time data acquisition of

physiological characteristics, allowing one to better

assess the delivery of percutaneous therapy. Preop-

erative three-dimensional images of the thorax are

acquired by both computed tomography and electro-

cardiogram-gated magnetic resonance imaging and

are imported into a planning platform. A surgeon



may visualize and manipulate simulated objects in-

teractively, and once optimal access port placements

are determined, the positions of the simulated tools

can be recorded and marked directly on the patient to

specify positions for port incisions. Current research

being conducted in collaboration with Carpentier is

focusing on simulating and planning robotic proce-

dures. Surgeons will have a virtual platform to analyze

and plan optimal topographic surface targets that

would optimize port site placement.⁴⁴⁴⁵ Such three-

dimensional planning systems based on preoperative

imaging data have already been introduced into other

surgical specialties, including craniomaxillofacial and

orthopedic surgery.⁴⁶

VI. CONCLUSION

Clearly, advances in cardiopulmonary perfusion,

intracardiac visualization, instrumentation, and ro-

botic telemanipulation have hastened a shift toward

effi cient and safe minimally invasive cardiac surgery.

Today, cardiac surgery, particularly valve surgery done

through small incisions, has become standard practice

for many surgeons. Moreover, closed-chest coronary

bypass surgery is in its early developmental phases.

A renaissance in cardiac surgery has begun, and

robotic technology has provided benefi ts to cardiac

surgery. With improved optics and instrumentation, in-

cisions are smaller. Th e placement of wrist-like articula-

tions at the end of the instruments moves the pivoting

action to the plane of the operative fi eld. Th is improves

dexterity in tight spaces and allows for ambidextrous

suture placement. Sutures can be placed more accu-

rately because of tremor fi ltration and high-resolution

video magnifi cation. Furthermore, robotic systems may

serve as educational tools. In the near future, surgical

vision and training systems may be able to model most

surgical procedures through immersive technology.⁴⁷⁴⁸

Th us, a “fl ight simulator” concept emerges where one

may be able to simulate, practice, and perform the op-

eration without a patient. Already, eff ective curricula

for training teams in robotic surgery exist.⁴⁹

Robotic cardiac surgery is an evolutionary pro-

cess, and even the greatest skeptics must concede that

progress has been made. Surgical scientists must con-

tinue to evaluate this technology critically in this new

era of cardiac surgery. Despite enthusiasm, caution

cannot be overemphasized. Surgeons must be careful,

because indices of operative safety, speed of recovery,

level of discomfort, procedural cost, and long-term

operative quality have yet to be defi ned. Traditional

cardiac operations still enjoy long-term success with

ever-decreasing morbidity and mortality, and thus

remain our measure for comparison.

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