Surgery – Instruments – Electrical application
Reexamination Certificate
1997-11-24
2004-05-04
Brown, Michael A. (Department: 3764)
Surgery
Instruments
Electrical application
C604S008000
Reexamination Certificate
active
06730081
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a surgical instrument and more particularly to an instrument with the capability for continuous irrigation and evacuation of fluid into and out from a body cavity of a patient during Laparoscopic or Endoscopic surgical procedures, and for the simultaneous measurement of tissue impedance and the ablation of tissue with fixed or retractable electrodes using R.F. energy.
2. Brief Description of the Prior Art
Laparoscopic/endoscopic surgical procedure allows a surgeon to see inside the body cavity of a patient without the necessity of large incisions. This reduces the chances of infection and other complications related to large incisions. The endoscope further allows the surgeon to manipulate microsurgical instruments without impeding the surgeon's view of the area under consideration.
During these surgical procedures it is desirable for as few lines as possible to enter the body of the patient. This reduces the size of the incision the surgeon needs to make. It follows from this that the greater the number of functions provided by a single instrument or the greater the number of instruments able to be passed through a single line entering the patient's body, the better.
Furthermore, in certain procedures it may be desirable to irrigate the area under consideration. This in turn necessitates the evacuation of the irrigation fluid or, when bleeding has occurred, the blood or smoke or tissue residue generated by the surgical procedure.
From what has been said above it should be apparent that it is preferable for both irrigation and evacuation to be conducted along a single conduit which, also, acts as an access line for surgical instruments.
A typical device which is used in endoscopic procedures is an electrosurgical probe. Typically such a probe will comprise a radio frequency (i.e. R.F.) energy conductive tube covered with a dielectric material such as polyolefin or Teflon. At one end, for convenience called the operational end, each probe could have any one of a number of functionally shaped monopolar or bipolar electrodes. In addition a probe could have its end formed specifically for irrigation and/or evacuation.
Monopolar and bipolar electrode probes are known in the prior art. Monopolar electrode probes include a single active electrode which is surgically introduced into a body cavity and engagable with and insertable into a tissue portion of the cavity. A passive electrode is attached to the outer body surface of the patient, e.g. typically a conducting plate is adhesively attached to the patient's leg. The body of the patient serves to complete the electrical circuit. Tissue ablation and coagulation is achieved by introducing sufficient power into the active electrode. Bipolar electrode probes include both active and passive electrodes which are similarly introduced together into the body cavity and are spaced apart from each other by a predetermined distance. Each electrode is engageable with and insertable into the tissue portion. Thus, the electrical circuit is completed by the body tissue disposed between the active and the passive electrodes and only the body tissue disposed between the two electrodes get coagulated.
In surgical operations it is often desirable to remove layers of body tissue. Such an operation can be readily performed if the affected area is totally exposed and large surgical devices can be used. However, large surgical openings are not desirable, due to the resulting bodily trauma, and exposure to the environment which increases the risk of infection. Endoscopic surgery minimizes body trauma and the risk of infection, but the devices of the prior art have significant limitations.
FIGS. 29-32
show prior art devices.
FIGS. 29-31
illustrate a roller ball, a flat roller bar, and a grooved roller bar respectively. These devices apply RF energy over a significant area and have proven useful for coagulating tissue to reduce bleeding, but they are not useful for tissue vaporization due to low power density.
FIG. 32
shows a thin wire loop that concentrates the RF energy and is effective in cutting tissue, but does not function to coagulate, and therefore its use results in significant bleeding which makes it difficult to use in an endoscope due to the time required to remove a cutting electrode and insert a coagulation electrode, and due to the build-up of blood which then needs to be evacuated in order to view the work through the endoscope. There is clearly a need for a surgical device that can remove tissue and simultaneously coagulate the resulting exposed tissue. Use of such a device would leave the surgeon's view unobstructed by blood, and reduce the chance of infection. As a result, more extensive and safer surgery could be performed.
Furthermore, any valves controlling the evacuation and irrigation procedures should be constructed so as to minimize the possibility of the valve malfunctions if, for example, any tissue or blood coagulates around their moving parts. Similarly if any of the instrumentation is to be reusable, such instrumentation, including the valves, should be capable of being efficiently cleaned by, for example, flushing.
U.S. Pat. No. 4,668,215 (Allgood) discloses a valve for switching between an evacuation-and an irrigation conduit and allowing both such evacuation and irrigation to be done via a single line entering the patient. The mechanism for switching between the irrigation, evacuation and closed configurations is by means of a L-valve or T-valve. This patent, in another embodiment thereof, further provides for a piston valve for making an on-off connection between an evacuation port and the line leading into the patient.
The L- and T-valves have the disadvantage that they must be manipulated by rotation by the surgeon, usually using his/her free hand. The piston valve disclosed in this patent has the disadvantage that it has many areas where blood and tissue accumulation and coagulation can occur which may result in the malfunctioning of the valve. In addition, the piston valve has numerous “dead” areas where fluid flow would not occur. This precludes the device from being effectively cleaned by commonly used flushing techniques. Finally, the Allgood patent does not disclose a single body for housing an evacuation/irrigation control valve together with a housing for laparoscopic and microsurgical instrumentation.
A surgical valve that the applicant is aware of is the piston valve illustrated in
FIG. 1
of the accompanying drawings.
In this valve a piston
10
is located within a cylinder
11
. The piston
10
can be moved along the bore of the cylinder
11
by means of a plunger
12
, from a closed position (as shown) to an open position in which a conduit
13
is aligned with an access port
14
. This allows fluid flow along a path to or from access port
14
, via conduit
13
and space
16
from or to a further port
15
. Upon release of the plunger
12
the piston
10
returns to its closed position under action of a spring
17
.
This valve, although easy to use, has the disadvantage that blood and tissue accumulation occurs in space
16
and clogs both the space and the spring
17
. This may result in undesirable over-evacuation or irrigation of the patient during surgical procedures.
OBJECTS OF THE INVENTION
It is therefore an object of this invention to provide a surgical instrument which includes control means to allow for the continuous irrigation and evacuation of a body cavity of a patient during microsurgical procedures, with both irrigation and evacuation being performed along a single line into the patient. The instrument should also act as a mounting for electrosurgical probes and microsurgical instruments.
A further object of the invention is to provide a configuration for an instrument which, depending on the material it is constructed of, can be both disposable and non-disposable. In the event that the instrument is “reusable” or “reposable” it is an object of the invention to provide the instrument wi
Brown Michael A.
Jaffer David
Pillsbury & Winthrop LLP
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