Mack MJ. Minimally Invasive and Robotic Surgery. JAMA. 2001;285(5):568–572. doi:10.1001/jama.285.5.568
Author Affiliation: Cardiopulmonary Science Research and Technology Institute, Dallas, Tex.
Advances in surgery have focused on minimizing the invasiveness of surgical
procedures, such that a significant paradigm shift has occurred for some procedures
in which surgeons no longer directly touch or see the structures on which
they operate. Advancements in video imaging, endoscope technology, and instrumentation
have made it possible to convert many procedures in many surgical specialties
from open surgeries to endoscopic ones. The use of computers and robotics
promises to facilitate complex endoscopic procedures by virtue of voice control
over the networked operating room, enhancement of dexterity to facilitate
microscale operations, and development of virtual simulator trainers to enhance
the ability to learn new complex operations. Future research will focus on
delivery of diagnostic and therapeutic modalities through natural orifices
in which investigation is under remote control and navigation, so that truly
"noninvasive" surgery will be a reality.
Substantial improvements in the art and science of surgery were made
over the 150 years since the introduction of antiseptic techniques by Lister,
including improved anesthetic agents, antibiotics, surgical nutrition, and
organ transplantation, in which the basic tools and techniques remained basically
unchanged. The core task of "surgery," that is, "cutting and sewing," with
hand instruments and direct visualization of and contact with the organ or
tissue has remained the same. However, during the last quarter of the 20th
century, and especially during the last decade, there has been a paradigm
shift in the methods for performance of surgery. For many procedures, the
"invasiveness" involved has been dramatically reduced resulting in superior
outcomes manifested as improved survival, fewer complications, and quicker
return to functional health and productive life. This focus on less or "minimal"
invasiveness has gained momentum and has been the subject of intense investigation
in recent years.
The methodological innovations in surgery are only beginning. For the
first time, it is possible for surgeons neither to look directly at nor touch
the tissues or organs on which they operate. Building on the precedent of
pelviscopy in gynecology and arthroscopy in orthopedic surgery, the use of
minimally invasive approaches into other surgical specialties, including general
surgery, urology, thoracic surgery, plastic surgery, and cardiac surgery,
has changed not only the performance of specific operations but more important
the strategic approach to all surgeries.
The pain, discomfort, and disability, or other morbidity as a result
of surgery is more frequently due to trauma involved in gaining access to
the area to perform the intended procedure rather than from the procedure
itself. For example, following a cholecystectomy, the need for hospitalization
was not related to the removal of the gallbladder but rather was necessary
because of the pain from the trauma to the abdominal wall caused by the incision
to gain access the gallbladder.
Following the introduction of the laparoscopic cholecystectomy by Mouret
in France and shortly thereafter by Reddick in the United States, a cascade
of events was set in motion that impact on the performance of surgery in the
21st century.1 The concepts of "surgery through
a scope" dated to the end of the 19th century but the technology of the late
20th century made laparoscopic surgery and minimally invasive surgery not
an isolated event but a reality.2,3
These technologies facilitated this shift: (1) development of the charge coupling
device (CCD) chip that allowed high resolution video images to be transmitted
through an optical scope to the surgeon, (2) high intensity xenon and halogen
light sources that improved visualization of the surgical field, and (3) improved
hand instrumentation designed for endoscopic approaches. For the first time,
the surgeon did not look directly at the target structure but viewed digitally
enhanced images that provided a better visualization because of the magnification
Within a few years gallbladder surgery changed from an open technique
to an endoscopic procedure (Table 1).
Laparoscopic techniques were then applied to other procedures in the abdominal
cavity, including hernia repair,4 esophageal
reflex surgery,5 and colon surgery.6 Applications include pelviscopy in gynecology, blebectomy
and lung biopsy in thoracic surgery,7 and cardiac
surgery.8,9 However, the enthusiasm
and momentum initiated by laparoscopic cholecystectomy (lapcholy), led to
unrealistic expectations of early conversion of other surgical procedures
to less invasive approaches. The immediate and overwhelming success of this
one procedure was not repeated with other procedures.
Surgical procedures can be categorized based on complexity and can be
divided into either excisional, in which a structure is removed (eg, appendectomy,
cholecystectomy); ablative, in which tissue is destroyed (eg, cryosurgery
of hepatic tumors); or reconstructive, in which structures are joined or connected
(eg, bowel or Fallopian tube anastomosis, coronary artery bypass grafting).
Excisional or ablative procedures are easier to perform than reconstructive
procedures and are more easily adaptable to endoscopic techniques.
Surgical procedures also can be categorized as either high volume or
low volume. High-volume procedures are more successful in a shorter period
of time than low-volume procedures because of the opportunity to learn the
procedure more quickly and because of the "market opportunity" presented for
technology development. The success of the lapcholy was in large part due
to the simple excisional procedure, the opportunity (400 000 procedures
per year) for surgeons to perfect the approach, and for the medical device
industry to invest in development. Other excisional procedures have not been
as quick to convert because of lower case volumes. Neither have other high-volume
procedures, such as coronary artery bypass grafting, been as rapidly converted
to an endoscopic approach because of the complexity and reconstructive nature
of the surgical procedure.
Although cardiac surgery has been performed successfully more than 10
million times in the past 30 years with generally good results, splitting
the sternum and spreading the rib cage to gain access to the heart contributed
to significant morbidity. Cardiac surgery is different than other surgical
procedures because the heart-lung machine adds further morbidity. Although
coronary artery bypass graft surgery was performed in the late 1960s on a
beating heart,10 the heart-lung machine fostered
growth of cardiovascular surgery and allowed routine wide-spread application.
It is now clear that the morbidity associated with cardiopulmonary bypass
is higher than that of the sternotomy.11
Two approaches in the 1990s attempted to make cardiac surgery less invasive.
The MIDCAB (minimally invasive direct coronary artery bypass) procedure involved
a single vessel bypass on the anterior surface of the heart on a beating heart
through a small anterior thoracotomy.12 The
Port Access approach attempted totally endoscopic coronary artery bypass surgery
on an arrested heart still using cardiopulmonary bypass.13
Because of the complexities involved with cardiac surgery, the totally endoscopic
approach was prohibitive and both mitral valve and simple coronary bypass
procedures were performed through a small thoracotomy incision.
Although these initial developments catalyzed the minimally invasive
movement in cardiac surgery, they now constitute a minority of cardiac surgery
procedures. However, they did evolve to the current OPCAB (off pump coronary
artery bypass grafting) procedure in which multivessel bypass is performed
on a beating heart through a median sternotomy incision. Although wide exposure
is still presented and the surgeon performs the procedure under direct vision
with conventional instruments, elimination of the heart-lung machine and performance
of the procedure on a beating heart improves outcomes. This approach is less
invasive than conventional cardiac bypass surgery.14,15
The success of these procedures is facilitated by mechanical stabilizers,
that provide local immobilization and stabilization of the coronary artery
to be bypassed while the rest of the heart beats and supports the circulation.
The technique is still evolving but now is used in approximately 18% to 20%
of all coronary artery bypass procedures in the United States (Hospital Corporation
of America hospital system case-mix database, 1999).
The application of the minimally invasive procedure to more complex
surgeries will require the new technology and techniques. In general surgery,
techniques such as hand-assisted laparoscopy attempt to bridge the gap between
open and completely endoscopic procedures. Other possibilities include developing
new ways to perform conventional surgical tasks as a way to adapt these procedures
to an endoscopic or less invasive approach. Examples include using implantable
devices to treat gastroesophageal reflex disease and replacement of sutures
and staples by biological glues and sealants.
Much effort is being expended to improve endoscopic coronary bypass
surgery.16 To facilitate a totally endoscopic
approach on a beating heart, there is an intense interest in the use of facilitated
vascular anastomosis with connectors, coupling devices, glues, and sealants,
to perform a task now possible only with suturing. An alternative is the use
of precision enhancement, potentially with robotics.
The initial concept of robotics in surgery involved operating at a site
remote from the surgeon. The ability to transpose surgical and technical expertise
from one site to a distant site (eg, a battlefield, space station, or developing
country) was thought to expand surgical application. Although simple surgical
procedures have been performed remotely, there is no clear path to practical
application at present because of expense, transmission delay, and medical
and legal issues.17 Application of telepresence
surgery in the foreseeable future will probably be limited to telementoring
rather than to remote manipulation. Telementoring will allow the surgeon to
teach or proctor performance of an advanced or new technique at a remote site
using real-time teleobservation and monitoring.
Nevertheless, robotics can be expected to impact the field of minimally
invasive surgery. Potential tasks facilitated by computers and robotics include
information gathering and networking, navigation and guidance,18
dexterity enhancement,19 and simulation of
virtual environments. The goal is to create a completely integrated system
that converts information to action. The ideal would be to transcend human
limitations by information gathering and sensing (computed tomography, magnetic
resonance imaging, and ultrasonography) or by improved delivery either on
a microscale basis or areas of the body difficult to access.
Current applications of robotics include surgical assistance, dexterity
enhancement, systems networking and image-guided therapy. Dexterity is enhanced
by placing a microprocessor between the surgeon's hand and the tip of the
surgical instrument. Doing so allows performance of microscale (superhuman)
tasks not possible without computer enhancement. "Motion scaling" in which
gross hand movements can be reduced and in which precision and eventually
force feedback can be enhanced allow surgeons to perform tasks not possible
today. One such example is retinal vein cannulation with a needle for administration
of a local therapy for retinal vein thrombosis; this technique (involving
cannulation of a 100-micron structure) would not be possible without the dexterity
enhancement of robotic assistance.20
Another focus on dexterity enhancement is in laparoscopic surgery and
endoscopic coronary artery bypass surgery using surgical robotic systems
Endoscopic coronary bypass procedures performed on a beating heart have been
performed although enhancements and further technique development are necessary
before routine application. Virtual immobilization or motion stillness should
eventually allow beating heart surgery under the illusion of stillness by
"gating" or timing the instrumentation and scope with the heart beat.
Endoscopic approaches involve special challenges. First, loss of degrees
of freedom are lost by the limitation of performance of a task in a confined
space and the range of motion of instruments is restricted automatically.
Robotics and the other techniques should address this issue. Second, 3-dimensional
imaging is lost on a 2-dimensional television screen, and potential solutions
to current 2-dimensional imaging systems include digital enhancement, shadowing
to create the illusion of 3 dimensions, and high resolution image display.
Three-dimensional imaging has been limited by the loss of resolution associated
with filtering systems and by the size of the visualization system necessary
to produce depth perception. These challenges are being addressed by some
current and soon to be available systems.
Potential use of nonvisual imaging techniques, including 3-dimensional
modeling and reconstruction of imaging data from computerized tomography,
magnetic resonance imaging, and ultrasound, provide real-time data acquisition
of pathological characteristics and to assess delivery of percutaneous therapy
remotely. Other possible roles for computer and robotic assistance in surgery
include voice control over surgical manipulators and information manipulators.
At present, technology exists to give the surgeon voice control over virtually
all operating room equipment including electrocautery, operating table position,
endoscopic manipulation, lighting, and telephone. Future developments promise
the overlay of additional data to the operative field, including 3-dimensional
magnetic resonance imaging reconstructions and physiologic data acquisition.
Advancements in the last 10 years made it possible to perform a surgical
procedure without directly visualizing or touching the organ being operated
on. Efforts are now focused on those techniques that facilitate the more complex
tasks by minimally invasive approaches. Technologies that will impact surgery
include those that allow procedures to be performed through natural orifices,
such as treatments for esophageal reflex disease performed through a transoral
rather than a laparoscopic approach and with flexible miniaturized instruments
capable of delivering sutures, clips, or energy sources for excising or shrinking
tissue. Developments in the remote delivery of focused energy (eg, ultrasound
and radiation) under image guidance (eg, magnetic resonance imaging and ultrasound)
will permit the ablation of tumors of the prostate, breast, liver, and lung
without the need for an incision. Noninvasive approaches may potentially be
used for ablating plaques in arteries, revascularizing the myocardium, treating
tennis elbow, and nonunion fractures.
Advancements in microchip and wireless technology may allow the development
of swallowable cameras, implantable sensors and medical records, microrobots
for completing surgical procedures, and magnetically controlled implants that
can be navigated remotely. The technology is here, the potential is enormous,
and the path is minimal.