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History of bipolar coagulation

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Bipolar coagulation heralded an age of improved hemostasis for microneurosurgery. This, coupled with an improved understanding of microsurgical anatomy, has allowed access to areas of the brain once considered inaccessible. In this review, we trace the history of bipolar coagulation.
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Neurosurg Rev (2006) 29: 9396
DOI 10.1007/s10143-005-0012-6
REVIEW
Ketan R. Bulsara
.
Sunny Sukhla
.
Shahid M. Nimjee
History of bipolar coagulation
Received: 13 July 2005 / Revised: 25 August 2005 / Accepted: 28 August 2005 / Published online: 16 March 2006
# Springer-Verlag 2006
Abstract Bipolar coagulation heralded an age of improved
hemostasis for microneurosurgery. This, coupled with an
improved understanding of microsurgical anatomy, has al-
lowed access to areas of the brain once considered inac-
cessible. In this review, we trace the history of bipolar
coagulation
.
Keywords Bipolar cautery
.
Hemostasis
.
Microsurgery
Background
Maintaining hemostasis during neurosurgical procedures is
critical to favorable outcomes in the operating room. The
fundamental process of electrocauterization utilizes heat
generated from an electrical current that flows through a
metal probe to locally burn or destroy tissue, thereby pre-
venting bleeding. The use of heat-mediated hemostasis is
not a novel concept. In fact, the use of thermal cautery dates
as far back as 3000 B.C., when tools heated in fire were
used to reduce hemorrhage in accidental injuries [ 14].
Historically, boiled oil was initially used to achieve
hemostasis. The oil helped achieve hemostasis in the areas
in which it was employed during an operating procedure,
cauterizing the tissues to which it was applied. The result-
ing charred mass eventually sloughed away [11]. However,
this method fell out of favor because it charred adjacent
living tissue due to its large release of energy.
In 1926, Dr. Harvey Cushing worked with a physicist
named Dr. William T. Bovie, after whom the current elec-
trocautery instruments are named. Dr. Bovie was at The
Cancer Commission at Harvard University. They collabo-
rated to develop a more efficient electrocautery system and
synchronized circuits and electrodes, which became the
mainstay of electrical coagulators in neurosurgery [16]. The
principles and instruments of neurosurgery established in
the late 19th and early 20th century by Dr. Cushing have
largely remained consistent today. Dr. Cushings pursuance
of electrocautery stemmed from his guiding principle of
avoiding of injury to the brain by careful and gentle ma-
nipulation of the tissue and by maintaining hemostasis
throughout surgical procedures. This credo echoed that of
his mentor, William Halstead, largely recognized as the
father of surgery in the Western Hemisphere [9, 12, 16].
On October 1, 1926, Dr. Cushing completed his first re-
moval of a brain tumor using electrocautery [15]. At the
inception of the use of diathermy by Dr. Cushing, an amus-
ing event took place. Hugh Cairns, Dr. Cushings assistant
at the time, inhaled the smell of the tissue undergoing elec-
trocautery and subsequently fainted [5, 15]. In his post-
operative note, Dr. Cushing described the success of the
operation,
...Then with Dr. Bovies help I proceeded to take off
most satisfactorily the remaining portion of tumor
with practically none of the bleeding which was oc-
casioned in the preceding operation. The loop acted
perfectly and blood stilling was almost complete...[15]
Discussion
A common problem encountered by neurosurgeons in
utilizing electrocautery was the fact that, when heat was
applied, it was done so externally to the site where
coagulation was needed. In order to improve the existing
technology, Dr. William L. Clark, a gener al surgeon from
Philadelphia, designed an ele ctrosurgical to ol that provided
K. R. Bulsara (*)
.
S. Sukhla
Division of Neurosurgery, University of Missouri-Columbia,
Columbia, MO 65211, USA
e-mail: ketan.bulsara@hotmail.com
S. M. Nimjee
Duke University Medical Center,
Durham, NC, USA
an important spark. The devic e had a motor-driven rotating
disk that acted as a static generator with a spark gap. In
addition to the static generator , a Leyden jar served as a
capacitor , and a resonating coil was also used [16]. Dr. Clark
then realized that, when the device was attached to a current
and applied to a tumor, it destroyed the cells by desiccation.
These results illustrated that cancer cells were more
vulnerable to heat than normal body cells. The heat produced
by the coagulation and desicc ation killed th e malignant cells,
thereby exposing blemishes in the actual tumor .
The mechanism by which bipolar coagulation works is
diathermy. Very high frequency of applied alternating cur-
rent causes motion of water molecules that then generates
the heat. Cutting currents are comprised of sine waves, while
coagulating currents contain jagged waves.
In monopolar cutting, an electric current at a high volt-
age is channeled to a fine tipped electrode, with the patient
serving as a ground via a ground plate. The current is di-
rected as a single point, and later branches out into the
surrounding tissues that are present. This branching limits
the utility of monopolar cautery as it cannot come into
contact with bone or metal and will not work in wet fields.
There is a significant amount of current and heat generated
from 12 cm away from the contact site which can cause
additional damage to the surrounding anatomy of the sur-
gical site. Bipolar cautery was developed in order to mini-
mize the non-specific activity of monopolar cautery and led
to more specific and controlled cauterization of tissue.
In 1940 bipolar cautery was pioneered by Dr. James
Greenwood, chief of the neurosurgical service at The
Methodist Hospital in Houston. At the time that bipolar
coagulation was invented, Baylor College of Medicine
was in Houston, not Dallas. Dr Greenwood introduced the
concept of two-point coagulation into the field of
neurosurgery. James Greenwood was aided in the devel-
opment of bipolar cautery by being gifted in the
electronics of his time. He was an amateur short-wave
radio operator. In his initial observations about electro-
cautery in neurosurgery, Greenwood stated that a strong
current maintained hemostasis of vessels in the scalp,
dura, or brain, but produced damage to the surrounding
tissue, with slight carbonization, necrosis, and later tissue
reaction [6]. He also mentioned how it was undesirable for
current to pass through vessels, since they would coagulate
and subsequently shrink beyond the field of vision, even
before the complete hemostasis occurred. This led
Greenwood to replace the conventional ball-type electrode
with fine-tipped forceps, which were attached to a current-
generating power source. In order to use the instrument,
vessels must be picked up so that the vessel actually lies
between the tips, Greenwood concluded [6]. He also
noted that the instrument was of exceptional value when
the neurosurgeon was involved in cortical dissection as
well as in the dura. The replacement of the ball-type
electrode with the forceps also facilitated fine manipula-
tion of the tissues and vessels in order to apply the current
in a specific and efficient manner [6]. In one instance,
Greenwood connected the bipolar forceps to the mono-
polar coagulating machine, and this led to only one side of
the bipolar forceps being active, which still provided
sufficient current to induce hemostasis during a neuro-
surgical procedure [17].
Dr. Greenwood modified his bipolar device, making one
of the two forceps blades hollow and attaching suction to
it. This bipolar suction allowed him to achieve the first
series of complete removals of intramedullary ependymo-
mas, with excellent results. The Greenwood bipolar-suction
device is still available and useful for lesions such as
acoustic neuromas and intramedullary gliomas.
A critical modification of the two-point coagulation sys-
tem, by Dr. Leonard Malis, led to the development of
bipolar cautery as it is used today. Dr. Malis trained in
neurosurgery at Mount Sinai in New York and completed
physiological research in Dr. John Fultons laboratory at
Yale University. He subsequently became the Chairman of
Neurosurgery at Mount Sinai. Dr. Malis designed and built
the first commercial bipolar coagulator in 1955 [11]. Malis
later carried out the first microneurosurgical operation in
1965 and designed the first practical course on microneu-
rosurgery in the United States of America in 1969. Jerry
Malis, Dr. Maliss brother and a physiologist, designed the
Malis CMC-II solid-state unit. Figure 1 shows a Malis
bipolar device that is currently available.
The bipolar system, first developed by Malis, uses a
1 MHz waveform for cutting and coagulation. A benefit of
bipolar cautery is that it does not require a grounding pad
as is required in monopolar cautery. The energy at the tips
is separate, so the current passes only between the two tips
of the instrument, eliminating the heat and current
spreading to the surrounding area. If the actual tips of
the bipolar forceps come into contact with each other
without a vessel passing between the tips, coagulation does
not occur. A majority of monopolar systems use 2,500 V,
while a bipolar system uses only 140 V [ 7]. Thus, bipolar
cautery requires only a fraction of the actual power that a
monopolar system uses. In fact, if a monopolar cautery
system is set to the same level as that of a bipolar system,
the power level is insufficient for operational use.
Fig. 1 A commercially available Malis bipolar system
94
Bipolar cautery has been noted to be far superior to
monopolar coagulation. A laboratory comparison between
bipolar and unipolar coagulation demonstrates the differ-
ence in efficiency between to the two systems. In a study
done on one side of a rat brain, several surface vessels can
be sealed with the monopolar system at the lowest possible
power setting; on the other side of the brain, stroking with
bipolar forceps set at the lowest bipolar coagulating power
can coagulate all the surface vessels. After Evans blue dye
is injected, it is clear that, in comparison to the bipolar
system, the monopolar system causes excessive damage
that extends deep into the brain, the result of deliberate
destruction of the entire cortical vascular supply [11]. Sup-
portive findings in experiments conducted on rats showed
that damage from the unipolar system was far greater than
that from the bipolar system [11].
In addition to maintaining hemostasis, bipolar cutting
current may also be used for the removal of tumors. Sharp
forceps may be used to make almost parallel orange-slice
type cuts and then take out the segments. Another method
utilizes a loop attachment on the tips of the forceps. As the
paired loop tips are brought together in the tissue, the cut-
ting current removes neat cylindrical cores of the tumor,
thus permitting virtually bloodless decompression. For a
soft acoustic neuroma, a setting of 45 Malis units is suf-
ficient for tumor excoriation, and this level may be in-
creased to 50 Malis units in regions of the neuroma that
are more fibrotic. Most meningiomas require a setting of
60 Malis units, and, for densely fibrous meningiomas, a
setting of 70 is used. Calcified craniopharyngiomas can
be cut well, and fragment at 40 to 45 Malis units [11].
Neurovascular surgery with bipolar cauterization on middle
meningeal, superficial temporal, or occipital arteries are
easily closed with the use of a bipolar cautery [17].
While bipolar forceps have provided significant pro-
cedural advances in neurosurgery and reduced morbidity
during procedures, there are minor drawbacks to the tech-
nology. Sticking and charring are procedural problems
that affect traditional bipolar forceps. In most cases,
neurosurgeons are used to pausing while they are
performing a procedure, in some cases just to avoid
overheating or to pass the instrument to a surgical
technologist to be cleaned. In certai n situations the
forceps generate a significant amount of heat while
coagulation is being performed. This causes them to
adhere to and even tear blood vessels and tissue with
which it comes into contact during the procedure. Another
dilemma faced by neurosurgeons is that, when they pass
off their instruments, they must reposition themselves as
well as reorient their instruments to the site they are
actually working on. In 1966 the bipolar coagulator cost
$120; these days it may cost as much as a few thousand
dollars. Local heat is generated and causes tissue burns and
clot formation which adhere to the tips of forceps. Thus, it is
important to help irrigate the site where a neurosurgeon
intends to coagulate, since this prevents the adherence of
the tips of the forceps. A very important adaptation, by Dr.
Manuel Dujovny and his team in 1975, was the use of
automatic simultaneous irrigation [5]. The major advan-
tages included adjustable fluid pressure and the presence
of constant irrigation, and it also eliminated the need for
an associate to help irrigate the site [4]. Other minor
improvements included scratch pads and scalpels that were
used to clean forceps that had accumulated charred blood
and tissue, which hindered the coagulation process.
Another novel advancement was insulating forceps,
which limited the actual charring of tissues and limited
adjacent damage. A thermistor-regulated bipolar forceps
was later introduced by Sugita and Tsugane, but, although it
minimized local overheating or sparking, irrigation was still
necessary [5]. Greenwood and, later, T.B. Scarf developed
suction irrigation forceps; however, their use was compli-
cated by the fact that irrigation was not easily controlled [4].
Later, a continuous saline drip irrigation system was in-
vented by T.T. King and R. Worpole, but it was undesirable
because (a) it was difficult to regulate the amount of ir-
rigation required during coagulation and (b) it provided
continuous flow even if the bipolar cautery was not being
used [5]. Other solutions that have been used to irrigate the
Table 1 The advantages of bipolar tissue management (adapted
from http://www.dentalexplorations.com/articles/23.html)
Advantages of bipolar tissue management
Less tissue dehydration, carbonization and further tissue reaction
Permits the control of hemorrhage
May be used on patients with pacemakers, and with defibrillators
Permits planning of soft tissue, a procedure unique to bipolar
electrosurgery
Provides a clear and improved view of the operative site
Increases the efficiency of the operation
Reduces chair time for each operation
There is no shrinking of the blood vessels being coagulated
Reduces fatigue of the surgeon
No shrinkage of the dura when a vessel is coagulated
Cuts and coagulates in irrigated, minimal blood, or dry fields
No grounding pads are needed
Coagulation is possible under saline and other fluids
May be able to control actual current being used
No tissue charring seen
Risk of thrombosis is minimized
Minimal damage being produced in coagulation since current flows
only between the forceps tips
Distinct circuitry and waveforms
Current is not carried along a blood vessel into deeper tissues
Voltage used may be kept constant throughout the procedure
Can handle vessels in certain areas where monopolar cautery may
not be possible
Cuts and coagulates at energy levels that are a fraction of those
required for monopolar electrosurgery
Eliminates heat and current spread to surrounding tissues
Cost efficient, very good results, and relatively safe
95
site of coagulation are physiological saline and artificial
cerebrospinal fluid. The use of mannitol is beneficial in
limiting the adherence of coagulated tissue and clots, and it
keeps the tissues cool at the same time.
The most important benefit seen in the use of bipolar
cautery is that the length of surgery is markedly decreased
and there is a significant reduction in intraoperative blood
loss. There is also a smaller portion of the tissue in the elec-
trical field and decreased heat production, which decreases
tissue damage. Finally, an important but overlooked fact
is that the forceps used in bipolar cautery facilitate gentle
and precise manipulation of the tissue. Bipolar cautery for-
ceps are available in many different lengths, which helps
surgeons to adjust to coagulating vessels, such as longer
forceps for use deeper in the cranium. Typically, six grad-
uations are found that are indicative of the current intensity.
A graduation of 1 may be best used on vessels 0.050.5 mm
in size; graduation 2 for vessels 0.51.0 mm, and grad-
uation 3 for vessels1.52.5 mm [17]. In addition, a great
improvement encountered in bipolar cautery was the use of
titanium forceps, because of their ability to remain cool on
the exterior and since tissues did not attach to the forceps.
The advantages of bipolar tissue management are shown
in Table 1.
In recent years many other surgical specialties have also
incorporated the use of bipolar cautery. In obstetrics and
gynecology, cauterization may help arrest excessive bleed-
ing that occurs during surgical procedures or that is related
to bleeding in the female genital tract [2]. Also, in general
surgery, bipolar cautery plays an important role in the
treatment of hemorrhoids, when there is a great deal of
bleeding [10]. Through the pioneering work of bipolar
cautery by Dr. James Greenwood and Dr. Leonard Malis,
neurosurgeons have seen improved outcomes in their sur-
gical procedures. These intraoperative improvements have
also extended to post-surgical benefits, as patients do not
require blood transfusions as was needed in earlier cases,
and there is also a reduced incidence of infection from
focused hemostasis of bipolar cautery compared to pre-
vious techniques [8]. Further modifications by pioneers
such as Drs. Yasargil, Fukushima and Spetzler have facil-
itated its use in microneurosurgery and deep-seated brain
tumors [1, 3, 13].
Summary
Bipolar cautery is a significant invention in the field of
neurosurgery. It was designed to deal with the complica-
tions that resulted from the available devices of the time,
and, moreover, it responds to the key principle of gentle
tissue management espoused by Halsted and Cushing [12].
The development of bipolar cautery represents a classic
paradigm of scientists from a variety of disciplines working
together towards improving therapy that has had a direct
impact on procedural outcomes, not only in neurological
surgery but also in other surgical subspecialties.
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Comment
David Rojas-Zalazar, Jorge Mura, Evandro de Oliveira, São Paulo,
Brazil
Bulsara et al. present an interesting review about the History of
bipolar coagulation. Starting with the electrocautery used by
Professor Cushing to remove a brain tumor in 1926, today, a modern
operating room for any neurosurgical procedure is not conceived
without available bipolar coagulation. This article shows how
modern microvascular and tumoral neurosurgery is possible because
of the advantages of using diathermy coagulation. This 50-year-old
tool is as important as the operative microscope, modern neuro-
anesthesia and the evolution of neuroimaging for current state-of-the-
art microneurosurgery. Professor Yasargil and others mastered the
use of modern bipolar coagulation not only to maintaining hemo-
stasis; the bipolar forceps can be used as well for gentle dissection of
the neural structures or for the remodeling of the aneurysm neck for
proper clipping, among many other useful microsurgical technical
applications. This is an interesting historical review of this milestone
device of the neurological surgery operating room and it must be read
by residents and young neurosurgeons.
96
... In order to provide hemostasis and keep the surgical field free of blood, a new electrocautery device needed to be developed that could minimize trauma in the miniaturized surgical field. The original monopolar cautery was developed by Harvey Cushing and a physicist named William T. Bovie in 1926 [46]. However, its use could result in damage to the local anatomy due to uncontrolled discharge of the current. ...
... However, its use could result in damage to the local anatomy due to uncontrolled discharge of the current. In the 1940s, James Greenwood from the Methodist Hospital in Houston, Texas engineered the bipolar coagulator to address this problem [46]. The first commercial bipolar coagulator was made in 1955 through the design of Dr. Leonard Malis [46]. ...
... In the 1940s, James Greenwood from the Methodist Hospital in Houston, Texas engineered the bipolar coagulator to address this problem [46]. The first commercial bipolar coagulator was made in 1955 through the design of Dr. Leonard Malis [46]. By adding a damped-wave spark unit, he was able to achieve nearly zero current leakage from the forceps tips into the surrounding anatomy [47]. ...
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MODERN NEUROSURGERY HAS long had a strong laboratory foundation, and much of this tradition can be traced to the Hunterian Neurosurgical Laboratory of the Johns Hopkins Hospital. Founded with the basic goals of investigating the causes and symptoms of disease and establishing the crucial role that surgeons may play in the treatment of disease, the Hunterian laboratory has adhered to these tenets, despite the dramatic changes in neurosurgery that have occurred in the last 100 years. Named for the famous English surgeon John Hunter (1728–1793), the Hunterian laboratory was conceived by William Welch and William Halsted as a special laboratory for experimental work in surgery and pathology. In 1904, Harvey Cushing was appointed by Halsted to direct the laboratory. With the three primary goals of student education, veterinary surgery that stressed surgical techniques, and meticulous surgical and laboratory record-keeping, the laboratory was quite productive, introducing the use of physiological saline solutions, describing the anatomic features and function of the pituitary gland, and establishing the field of endocrinology. In addition, the original development of hanging drop tissue culture, fundamental investigations into cerebrospinal fluid, and countless contributions to otolaryngology by Samuel Crowe all occurred during this “crucible” period. In 1912, Cushing was succeeded by Walter Dandy, whose work on experimental hydrocephalus and cerebrospinal fluid circulation led to the development of pneumoencephalography. The early days of neurosurgery evolved with close ties to general surgery, and so did the Hunterian laboratory. After Dandy began devoting his time to clinical work, general surgeons (first Jay McLean and then, in 1922, Ferdinand Lee) became the directors of the laboratory. Between 1928 and 1942, more than 150 original articles were issued from the Hunterian laboratory; these articles described significant advances in surgery, including pioneering research on calcium metabolism by William MacCallum and Carl Voegtlin and seminal preclinical work by Alfred Blalock and Vivian Thomas that led to the famous “blue baby” operation in 1944. With the introduction of the operating microscope in the 1950s, much of the focus in neurosurgical science shifted from the laboratory to the operating room. The old Hunterian building was demolished in 1956. The Hunterian laboratory for surgical and pathological research was rebuilt on its original site in 1987, and the Hunterian Neurosurgical Laboratory was reestablished in 1991, with a focus on novel treatments for brain tumors. The strong tradition of performing basic research with clinical relevance has continued.
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THIS ARTICLE IS written at the request of the editor. It contains my autobiographical sketch, professional memories, lessons, axioms, and reflections on the present problems in neurodiagnosis and neurotherapy.The combination of microsurgical techniques, the bipolar coagulation technique, the concept of arachnoidal exploration, and the concept of segmental and compartmental occurrence of vascular and neoplastic lesions of the central nervous system, with their predilection sites, allowed microneurosurgery to gradually unfold and proceed within the last 30 years as a continuation of conventional neurosurgical principles established by the founder generation. Today, the lesions in each region of the central nervous system can be accessed without using computer-assisted targeting and navigation technology and can be selectively eliminated (“pure lesionectomy”) with acceptable outcomes; the mortality and morbidity rates have been reduced remarkably. Further scientific and technological advances will promote the ongoing evolution in neurodiagnosis and neurotherapy. Competitive neurospecialties are welcomed in the interest of patients, medical sciences, and surgical advances. The younger generation of neurosurgeons will have spent more time in laboratory training, deepening their knowledge of neuroanatomy and gaining experience in surgical techniques.The achievements, limits, and problems of neurosurgery in relation to technology, medical and surgical standards, and controversial treatment options have been presented thoroughly in numerous professional publications. However, the relationship of neurosurgery to the evolution of integral neurophysiology and biochemistry has hitherto been inadequately evaluated. The advances in microbiology, anesthesiology, and topographic neurology have been viewed as essential components of neurosurgery’s foundations. A critical analysis proves that this is only partially true.The turning point in the development from craniospinal surgery to physiological neurosurgery began with the research of Th. Kocher, V. Horsley, H. Cushing, and W. Dandy concerning the importance of the cerebrospinal fluid system. This was the first step in a trend toward integral neurophysiology, which initiated neurosurgical procedures on a routine basis. The intensive research on the hypothalamus by R.W. Hess and associates led to intensified studies on the autoregulated integral functional units of the central nervous system (“dynamic homeostasis,” in the words of W.B. Cannon). This slowly developing but exciting history of neurophysiology requires patient study to seek out solutions for the present difficulties in neurodiagnosis and neurotherapy, which constitute a similar situation to that encountered by the pioneer surgeons at the end of the last century.In pertinent sections, my personal opinions relating to observations and experiences with a large number of operated patients with vascular and neoplastic lesions are presented. The predilection sites of brain tumors in the neopallial and paleopallial (limbic-paralimbic) areas and brainstem, and their expansive but usually not infiltrative growth, are discussed and documented. The current hypothesis of infiltrative growth of gliomas is opposed. The microsurgical technique for the treatment of various types of lesions is summarized. The principal microsurgical instruments and apparatus are presented with some remarks relating to their conception and manufacture.
Article
DISSATISFIED WITH THE available macrosurgical techniques and encouraged by colleagues such as Donaghy and Krayenbuhl, M. Gazi Yasargil possessed the ingenuity to take advantage of and further improve emerging technologies such as angiography to develop microsurgery. To enable the advancement of microsurgical techniques, Yasargil created innovative instrumentation, such as the floating microscope, the self-retaining adjustable retractor, microsurgical instruments, and ergonomic aneurysm clips and appliers. His genius in developing microsurgical techniques for use in cerebrovascular neurosurgery has transformed the outcomes of patients with conditions that were previously inoperable.
Article
Coagulation is an essential part of a surgical procedure, especially in neurosurgery. Beginning in the early years of this century, various techniques have been used to control bleeding at the surgical site. Over the years, these techniques have led to the invention of the bipolar coagulator and its modifications. Prevention of charring and tissue adhesion have been the goals of bipolar coagulator manufacturers all over the world; new techniques and different metallurgical compositions for the forceps have been tried to achieve these results. The NS2000, with its microprocessor-based controlled coagulative sequence, can be a good system for reducing tissue adhesion and charring under desired limits of low output power ranges provided by the system. Comparable results can also be obtained with the Malis CMC III and Synergy Malis systems with irrigation channels. These systems have the additional advantages of providing higher power outputs at lower panel settings and a maximum power output greater than that of NS2000. For neurosurgeons who need the additional option of cutting, the Malis CMC III is the recommended system.
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The authors describe a newly developed automatically irrigated bipolar forceps with controlled irrigation pressure. The forceps can be of help in brain surgery.
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In this paper the author reviews the development of electrosurgery in neurosurgical procedures. Particular stress is placed on bipolar coagulation and the more recent addition of bipolar cutting. Basic electric principles are discussed as well as the electrophysiological basis of coagulating and cutting currents. Neurosurgical techniques and instrumentation criteria are presented. The material is planned to provide the neurosurgeon with greater understanding of the function of the equipment and, perhaps, to improve usage.