Note: Descriptions are shown in the official language in which they were submitted.
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POLYPECTOMY DEVICE AND METHOD
Field of the Inventions
The invention relates general to medical devices, and
more specifically to devices for performing a polypectomy.
Background of the Inventions
Polyps are defined as any growth or mass protruding from
a mucous membrane. Polyps can occur wherever there is mucous
membrane, namely, in the nose, ears, mouth, lungs, Heart,
stomach, intestines, urinary bladder, uterus, and cervix.
Most polyps are benign growths that eventually stop growing.
But some of these polyps keep growing. Genetic mutations can
transform them into cancerous tumors. As these cancerous
tumors grow larger, they continue growing and begin to burrow
deeper and deeper into the tissue supporting the polyp. In
the final stages the cancer invades the blood and lymph
systems and the malignant cells of the tumor spread to other
organs. The problem is particularly severe, yet readily
treated, in the colon. Colorectal cancer is the second
leading cause of death due to cancer in the United States. If
the cancer is detected and treated in its early stages, it can
be cured more than 90% of the time. Thus, early detection and
removal of colorectal polyps, whether benign, pre-cancerous,
or cancerous, is highly effective in avoiding or treating
colorectal cancer.
Polyps may be attached to a mucous membrane by a thin
stalk or the polyp may have a broad base. A polyp that is
attached by a thin stalk is called a pedunculated polyp and a
polyp that is attached by a broad base is called a sessile
polyp. Various devices have been proposed for removing
polyps, especially pedunculated polyps, from the body. For
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example, Avellanet, Polypectomy Snare Instrument, U.S. Patent
6,015,415 (Jan. 18, 2000) teaches a polypectomy device using a
snare loop connected to a power source to supply cautery
current. The snare loop is used to capture the polyp and
current is applied to the snare loop which cauterizes the
polyp as the snare is closed tightly around the polyp.
McKeating, Polypectomy Instrument, U.S. Patent 5,746,747 (May
5, 1998) teaches a polypectomy device using grasping forceps
to hold the polyp and a snare wire for cutting the polyp.
Electrical current is supplied to the snare wire to cut and
cauterize the polyp while the grasping forceps hold onto the
body of the polyp. Nakao et al., Surgical Cauterization Snare
with Ligating Suture, U.S. Patent 5,906,620 (May 25, 1999)
teaches using two snare loops. The first loop cauterizes the
polyp while the second loop acts as a suture for ligating the
polyp. The second loop is left behind in the colon.
Summary
The present polypectomy device and method effectively
removes polyps from the body. The device includes a first jaw
and a second jaw. One of the jaws includes a heating element
for cauterizing the tissue of the polyp. A snare cable is
routed through each of the jaws. The snare cable forms a hoop
for capturing the polyp. As the snare cable is pulled
proximally it positions the jaws at the base or stalk of the
polyp. As the snare cable is pulled further it closes the
jaws. The closing of the jaws works in conjunction with a
heating element to cut and seal the tissue between the jaws.
Brief Description of The Drawings
Figure 1 is an overview of the polypectomy device
inserted into the colon of a patient.
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Figure 2 is an overall side-view of the polypectomy
device with a handle, an electrical connector, and a jaw
assembly.
Figure 3 is a close-up cross sectional view of the jaw
assembly located on the distal end of the polypectomy device.
Figure 4 is an overview of the polypectomy device
inserted into a sinus of a patient with the snare wire
encircling the base of the polyp.
Figure 5 is a like view with the snare wire pulled
proximally to align the jaws of the polypectomy device.
Figure 6 is an overview of the polypectomy device
inserted into the uterus of a patient with the snare wire
encircling the base of the polyp.
Detailed Description of the Inventions
Figure 1 shows an overview of the polypectomy device
inserted into the colon of a patient 1. The polypectomy
device 2 includes an elongated flexible catheter 3 extending
out of the distal end of an endoscope 4. The distal end of
the catheter includes a fixed jaw 5, a moveable jaw 6, and a
snare cable 7. The snare cable may be operated to capture the
polyp 8 and as the length of the snare cable is shortened, the
polyp is drawn into the jaws and the moveable jaw is pulled
toward the fixed jaw. The heating element 17 on the fixed jaw
(See Figures 2 and 3) may be operated to necrose the tissue
trapped between the jaws. The combination of heat and
pressure causes the tissue to divide which severs the polyp
from the colon wall 9 of the colon 10.
Figure 2 shows an overall side-view of the polypectomy
device 2. The proximal end of the device includes a two-wire
electrical connector 12, and a handle 13. The two-wire
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electrical connector connects the catheter 3 to an electrical
power source (not shown). The handle includes a cable trigger
14 and a fixed finger hold 15. The cable trigger may be
operated to pull the snare cable 7, which captures the polyp
and operates the moveable jaw 6. Closing the jaw assembly and
activating the power source to heat the heating element 17
cuts the polyp and seals the tissue.
Figure 3 is a close-up cross sectional view of the distal
end of the polypectomy device. The snare cable 7, the fixed
jaw 5 and the moveable jaw 6 extend out of the distal end of
the catheter body 3. The fixed jaw is attached to the
catheter body, and the moveable jaw is operatively connected
to the catheter body at a hinge 16. It should be noted that
while we have referred to a fixed jaw and a moveable jaw, both
jaws may be moveable. Both jaws may be hinged to the
catheter, or otherwise rotatable relative to each other and
secured to the catheter.
The fixed jaw 5 includes a heating element 17, an
insulation tube 18, and a lumen 19. The moveable jaw 6
includes a hole 20 (through which the snare cable passes) at
its distal tip, a hinge 16 at its proximal end, and a silicone
pad 21. A distal outlet 22 is formed by the lumen 19 of the
fixed jaw extending completely through the fixed jaw. The
fixed jaw and the moveable jaw close together in a scissor-
like movement. The surfaces of the fixed jaw and the moveable
jaw that fit together are the grasping faces. The silicone
pad 21 of the moveable jaw is located along the grasping face
of the moveable jaw and the portion of the insulation tube 18
facing the moveable jaw serves as the grasping face of the
fixed jaw.
The fixed jaw and the moveable jaw can be composed of
stainless steel or other suitable metal, plastic, or ceramic.
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The fixed jaw also includes an insulation tube that can be
composed of polyamide, fluropolymer, or a PTFE/polyamide blend
such as Xylan~ (other insulative materials can be used). The
insulation tube 18 isolates the heating element 17 from the
stainless steel portion of the fixed jaw thereby preventing
the heating element from heating the entire fixed jaw.
The heating element is composed of an electrically
conductive material, such as nichrome, which is sufficiently
resistive to heat up significantly when electricity is passed
through it. The heating element can be approximately 1/10,000
nicrome wire having a length of approximately 10 mm. The
power supply can generate approximately 3 to 30 watts of
power, and the heating element approximately 2 to 7 watts of
power. Alternative forms of heating elements may be used,
such as ceramic heating elements, RF heating elements, and
monopolar and bipolar heating elements. Additionally, heating
elements may be placed on either jaw, or on both jaws.
The distal end of the snare cable 7 is fixed to the
catheter body 3 and extends along the outside of the moveable
jaw 6 through the hole 20 in the distal tip of the moveable
jaw (though it may be fixed, at its terminus, to the distal
tip of the moveable jaw). The cable then goes into the distal
outlet 22 of the fixed jaw 5, through the lumen 19 to the
cable trigger 14 located at the proximal end of the device.
The lumen 19 of the fixed jaw includes a friction liner 23.
The friction liner can be composed of nylon or Teflon, which
reduces the friction created by the snare cable 7 moving
through the lumen of the fixed jaw, thereby permitting the
snare cable to be operated smoothly and easily.
The fixed jaw 5 is formed as a cylindrical tube and the
moveable jaw 6 is formed as a concave semicylindrical body
that mates with the fixed jaw. The fixed jaw and the moveable
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jaw are fashioned similar to a curling iron for hair, which
includes a cylindrical heated tube and a moveable
semicylindrical jaw that fit together to curl hair. In the
curling iron art the fixed jaw is called the barrel and the
moveable jaw is called the clip, and they function in a
similar manner as the fixed jaw and the moveable jaw in this
device. Thus, by analogy, the fixed jaw may be referred to as
a barrel, and the moveable jaw may be referred to as a clip.
The outer most layer of the catheter body is an insulated
catheter jacket 24. Inside the catheter body are the
electrical wire 25, the braided conductor 26, the lumen, and
the snare cable 7. The electrical wire is connected to the
distal end of the heating element 17, which is located on the
grasping face of the fixed jaw, and supplies the electrical
current from the electric source to the heating element. The
current flows from the electric power source into the two-wire
electrical connector 12 through the electrical wire 25 into
the heating element 17. The current then flows from the
heating element through the conductive crimp 27, located at
the proximal end of the heating element, into the braided
conductor 26 and back to the two-wire connector to complete
the circuit. The braided conductor may be replaced with a
wire if space permits.
In use, an endoscope is inserted into the patient's body
to the area where the polyp is located. The endoscope is used
to view inside the patient's body and look for polyps. If a
polyp is found the surgeon inserts the polypectomy catheter
into the working lumen of the endoscope. The surgeon then
moves the distal end of the catheter toward the polyp and
extends the snare cable to form a hoop which enables the
surgeon to capture the polyp. The surgeon manually rotates
the catheter such that the snare cable hoop can be properly
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oriented and placed over the polyp. The manual rotation of
the catheter is accomplished by rotation of the handle.
Once the polyp is encompassed lay the snare cable, the
surgeon activates the cable trigger thereby drawing the snare
cable proximally relative to the catheter and closing the loop
about the polyp. As the surgeon pulls the snare cable, the
fixed jaw and the moveable jaw are pulled into place on either
side of the polyp. As the surgeon further shortens the snare
cable, it operates the moveable jaw to draw it toward the
fixed jaw, thereby pulling the jaws together. The electrical
power source is activated, which heats the heating element
located on the fixed jaw. Therefore, as the jaws are held
closed, the heating element and the jaws work together to both
cut and seal the tissue. The power source may be activated by
a footswitch (not shown), or it may be operated by a switch or
button located on the catheter or the power source. It may
also be activated by a limit switch which is activated by the
proximal movement of the cable trigger.
As discussed above, polyps form in mucous membrane, and
mucous membranes exist in many areas of the body. Polyps can
form in a patient's colon 10. One way of looking for polyps
in a patient's colon is a colonoscopy. During a colonoscopy
the surgeon inserts an endoscope 4 into the patient's colon
through the patient's anus 28 (See Figure 1). If a polyp 8 is
found, the surgeon inserts the polypectomy device 2 into the
working lumen of the endoscope and follows the procedure
discussed above.
Similarly, as shown in Figure 4, polyps formed in the
nasal sinuses can be removed with the device. A like procedure
is followed. An endoscope 4 is inserted into the patient's
nasal sinuses 29, through the patient's nostril 30. Once a
polyp 8 is located, the polypectomy device 2 is inserted into
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the endoscope. The snare cable 7 extends to form a hoop which
enables the surgeon to capture the polyp. Once the polyp is
encompassed by the snare cable, the surgeon activates the
cable trigger 14 thereby drawing the snare cable proximally.
As shown in Figure 5, as the surgeon pulls the snare cable
proximally, the fixed jaw 5 and the moveable jaw 6 are pulled
into place on either side of the polyp 8. As the surgeon
further pulls the snare cable, it operates the moveable jaw to
draw it toward the fixed jaw, thereby mating the jaws
together, or at least bring the jaws into apposition with the
polyp stalk caught between them. With the activation of the
moveable jaw, the electrical power source is activated, which
heats the heating element located on the fixed jaw. The power
source is activated by a footswitch (not shown). Thus, as the
jaws are held closed, the heating element and the jaws work
together to both cut and seal the tissue.
As illustrated in Figure 6, polyps in a patient's uterus
can be removed with the device. Again, a like procedure is
followed. An endoscope 4 is inserted into the patient's
uterus 31 through the vagina 32. If a polyp 8 is found, the
surgeon inserts the polypectomy device 2 into the working
lumen of the endoscope and follows the procedure discussed
above.
Similar procedures can be performed in other parts of the
body where polyps or other abnormal tissue growth occur, and
the examples of colon polyps, sinus polyps, and uterine polyps
illustrate the procedure which can readily be adapted to other
conditions. Thus, while the preferred embodiments of the
devices and methods have been described in reference to the
environment in which they were developed, they are merely
illustrative of the principles of the inventions. Other
embodiments and configurations may be devised without
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departing from the spirit of the inventions and the scope of
the appended claims.
