US 20090062794A1
(19) United States
(12) Patent Application Publication (10) Pub. No.: US 2009/0062794 A1
(43) Pub. Date:
Buysse et al.
(54)
ELECTROSURGICAL INSTRUMENT WHICH
on Sep. 1, 1999, noW abandoned, Which is a continu
ation of application No. 08/968,496, ?led on Nov. 12,
1997, noW Pat. No. 6,050,996.
REDUCES COLLATERAL DAMAGE TO
ADJACENT TISSUE
(76) Inventors:
Steven P. Buysse, Longmont, CO
(US); Michael C. Moses, Boulder,
CO (US); David A. Schechter,
Longmont, CO (US); Kristin D.
Johnson, Louisville, CO (US);
Philip M. Tetzlaff, Austin, TX
(US); Carolyn H. Mihaichuk,
Longmont, CO (US)
Mar. 5, 2009
Publication Classi?cation
(51)
(52)
Int. Cl.
A61B 18/14
(2006.01)
U.S. Cl. ........................................................ .. 606/51
(57)
ABSTRACT
An electrode assembly for use in combination With an elec
Correspondence Address:
Tyco Healthcare Group LP
60 MIDDLETOWN AVENUE
NORTH HAVEN, CT 06473 (US)
ing one portion Which is removably engageable With the
Oct. 3, 2003, noW Pat. No. 7,435,249, Which is a con
electrosurgical instrument and a pair of electrodes each hav
ing an electrically conductive sealing surface and an insulat
ing substrate. The electrodes are removably engageable With
the end effectors of the electrosurgical instrument such that
the electrodes reside in opposing relation relative to one
another. The dimensions of the insulating substrate are dif
ferent from the dimensions of the electrically conductive
sealing surface to reduce thermal spread to adjacent tissue
tinuation-in-part of application No. 09/387,883, ?led
structures.
(21) App1.No.:
12/211,261
(22) Filed:
Sep. 16, 2008
Related U.S. Application Data
(63)
trosurgical instrument having opposing end effectors and a
handle for effecting movement of the end effectors relative to
one another. The electrode assembly includes a housing hav
Continuation of application No. 10/474,168, ?led on
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ELECTROSURGICAL INSTRUMENT WHICH
REDUCES COLLATERAL DAMAGE TO
ADJACENT TISSUE
sents a design challenge to instrument manufacturers Who
must ?nd Ways to make surgical instruments that ?t through
the cannulas.
CROSS REFERENCE TO RELATED
APPLICATION
vessels or vascular tissue. HoWever, due to space limitations
[0008] Certain surgical procedures require sealing blood
[0001]
This application is a continuation of US. applica
tion Ser. No. 10/474,168 ?led on Oct. 3, 2003, Which is a
continuation-in-part of US. application Ser. No. 09/387,883
?led on Sep. 1, 1999, Which is a continuation ofU.S. appli
cation Ser. No. 08/968,496 and noW issued as US. Pat. No.
6,050,996 ?led on Nov. 12, 1997 the contents of Which are
hereby incorporated by reference in their entirety.
BACKGROUND
[0002] The present disclosure relates to electrosurgical
instruments used for open and endoscopic surgical proce
dures. More particularly, the present disclosure relates to a
bipolar forceps for sealing vessels and vascular tissue having
an electrode assembly Which is designed to limit and/or
reduce thermal spread to adjacent tissue structures.
Technical Field
surgeons can have dif?culty suturing vessels or performing
other traditional methods of controlling bleeding, e. g., clamp
ing and/or tying-off transected blood vessels. Blood vessels,
in the range beloW tWo millimeters in diameter, can often be
closed using standard electrosurgical techniques. If a larger
vessel is severed, it may be necessary for the surgeon to
convert the endoscopic procedure into an open-surgical pro
cedure and thereby abandon the bene?ts of laparoscopy.
[0009] It is knoWn that the process of coagulating small
vessels is fundamentally different than vessel sealing. For the
purposes herein the term “coagulation” is de?ned as a process
of desiccating tissue Wherein the tissue cells are ruptured and
dried. The term “vessel sealing” is de?ned as the process of
liquefying the collagen in the tissue so that the tissue cross
links and reforms into a fused mass. Thus, coagulation of
small vessels is su?icient to close them, hoWever, larger ves
sels need to be sealed to assure permanent closure.
[0010] Several journal articles have disclosed methods for
sealing small blood vessels using electrosurgery. An article
entitled Studies on Coagulation and the Development ofan
A hemostat or forceps is a simple plier-like tool
Automatic Computerized Bipolar Coagulator, J. Neurosurg.,
Which uses mechanical action betWeen its jaWs to constrict
Volume 75, July 1991, describes a bipolar coagulator Which is
tissue and is commonly used in open surgical procedures to
used to seal small blood vessels. The article states that it is not
[0003]
grasp, dissect and/or clamp tissue. Electrosurgical forceps
possible to safely coagulate arteries With a diameter larger
utiliZe both mechanical clamping action and electrical energy
to effect hemostasis by heating the tissue and blood vessels to
coagulate, cauteriZe and/or seal tissue.
than 2 to 2.5 mm. A second article is entitled Automatically
[0004] By utiliZing an electrosurgical forceps, a surgeon
can either cauteriZe, coagulate/desiccate tissue and/or simply
reduce or sloW bleeding by controlling the intensity, fre
quency and duration of the electrosurgical energy applied to
the tissue. Generally, the electrical con?guration of electro
surgical forceps can be categorized in tWo classi?cations: 1)
monopolar electrosurgical forceps; and 2) bipolar electrosur
gical forceps.
[0005] Monopolar forceps utiliZe one active electrode asso
ciated With the clamping end effector and a remote patient
return electrode or pad Which is attached externally to the
patient. When the electrosurgical energy is applied, the
energy travels from the active electrode, to the surgical site,
through the patient and to the return electrode.
[0006] Bipolar electrosurgical forceps utiliZe tWo generally
opposing electrodes Which are generally disposed on the
inner facing or opposing surfaces of the end effectors Which
are, in turn, electrically coupled to an electrosurgical genera
tor. Each electrode is charged to a different electric potential.
Since tissue is a conductor of electrical energy, When the end
effectors are utiliZed to clamp or grasp tissue therebetWeen,
the electrical energy can be selectively transferred through
the tissue.
[0007]
Over the last several decades, more and more sur
geons are complimenting traditional open methods of gaining
access to vital organs and body cavities With endoscopes and
endoscopic instruments Which access organs through small
puncture-like incisions. Endoscopic instruments are inserted
into the patient through a cannula, or port, that has been made
With a trocar. Typical siZes for cannulas range from three
Controlled Bipolar Electrocoagulationi“COA-COMP”,
Neurosurg. Rev. (1984), pp. 187-190, describes a method for
terminating electrosurgical poWer to the vessel so that char
ring of the vessel Walls can be avoided.
[0011] In order to effect a proper seal With larger vessels,
tWo predominant mechanical parameters must be accurately
controlledithe pressure applied to the vessel and the gap
betWeen the electrodes both of Which affect thickness of the
sealed vessel. More particularly, accurate application of the
pressure is important for several reasons: 1) to oppose the
Walls of the vessel; 2) to reduce the tissue impedance to a loW
enough value that alloWs enough electrosurgical energy
through the tissue; 3) to overcome the forces of expansion
during tissue heating; and 4) to contribute to the end tissue
thickness Which is an indication of a good seal. In some
instances a fused vessel Wall is optimum betWeen 0.001 and
0.006 inches. BeloW this range, the seal may shred or tear and
above this range the lumens may not be properly or effec
tively sealed.
[0012] Numerous bipolar electrosurgical instruments have
been proposed in the past for various open and endoscopic
surgical procedures. HoWever, some of these designs may not
provide uniformly reproducible pressure to the blood vessel
and may result in an ineffective or non-uniform seal. For
example, US. Pat. No. 2,176,479 to Willis, US. Pat. Nos.
4,005,714 and 4,031,898 to Hiltebrandt, US. Pat. Nos. 5,827,
274, 5,290,287 and 5,312,433 to Boebel et al., US. Pat. Nos.
4,370,980, 4,552,143, 5,026,370 and 5,116,332 to Lottick,
US. Pat. No. 5,443,463 to Stern et al., US. Pat. No. 5,484,
436 to Eggers et al. andU.S. Pat. No. 5,951,549 to Richardson
millimeters to tWelve millimeters. Smaller cannulas are usu
et al., all relate to electrosurgical instruments for coagulating,
sealing and cutting vessels or tissue.
[0013] Many of these instruments include blade members
ally preferred, Which, as can be appreciated, ultimately pre
or shearing members Which simply cut tissue in a mechanical