Surgery – Instruments – Cyrogenic application
Reexamination Certificate
2001-02-01
2003-03-04
Shay, David M. (Department: 3739)
Surgery
Instruments
Cyrogenic application
C606S107000, C606S169000, C606S171000, C604S022000, C604S035000, C128S898000
Reexamination Certificate
active
06527765
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates, generally, to a system and method for treating and removing tissue and, more particularly, to a system and method of use which includes a cryosurgical instrument for isolating and freezing unwanted living tissue and means for vibrating or otherwise treating the cryogenically-treated tissue and removing the tissue.
BACKGROUND OF THE INVENTION
In many types of medical procedures, tissue specimens of a patient are removed either for diagnostic purposes to study the tissue or for treatment purposes. For example and quite frequently, these tissue specimens include a cancerous tumor or other unwanted localized growth which is then preferably entirely excised from the patient during the medical procedure.
It is important that the cancerous tumor or other growth is localized and entirely removed from the patient to reduce or eliminate the risk that the tumor will return over time and/or will spread to other parts of the body. Therefore, in order to ensure that the tissue associated with the tumor is completely removed, the exterior of the removed section is carefully microscopically studied in order to determine whether there is only good healthy tissue or whether unwanted tissue is present. A physician can thus determine if a portion of the tumor has been left within the good healthy tissue. If this occurs, the physician removes another deeper layer of the good tissue and again performs the procedure.
However, one of the associated risks of removing cancerous tumors is that during one or more of the medical procedures, a portion of the cancerous tumor may separate and spread to another part of the patient's body. This may result in further medical complications including the risk that the cancer may spread to another part of the patient's body. It is therefore important that great care and precision be taken in removing the cancerous tissue (tumor).
Typically, the surgical approach for removing the cancerous tissue has involved open surgical procedures. However, such procedures may be accompanied by surgical trauma, such as formation of scar tissue, lengthy recuperation and pain and therefore there has been an increasing desire to expand the use of microsurgical techniques. These microsurgical techniques require the use of highly specialized instruments and therefore are generally much more intricate, time-consuming, and stressful than open surgical procedures. However, the use of microsurgical techniques does greatly reduce some of the common surgical traumas associated with open surgical procedures.
Over the past years, cryosurgical procedures have been advanced and more applications are being discussed for such surgical procedures. Cryosurgery is a surgical procedure that uses freezing temperatures to destroy tissue. Until recently, cryosurgery was utilized almost entirely for the treatment of tumors on the outer surface of the body, such as for treatment of skin cancer. Generally, in cryosurgical procedures, the tumor or the like is frozen to a temperature of preferably about −50° C. in order to attempt to completely destroy all of the cells of the tumor. After treating the cells of the tumor, the tumor is typically left in the body for the body to absorb. Thus, the tumor is not removed but rather remains in the body as the extent of the cryosurgical procedure is to simply freeze the cells to a point which hopefully causes the destruction of the cells.
One of the associated disadvantages is that it is difficult, if not impossible, to observe the extent of the frozen region using more conventional cryosurgical instruments. Thus, the difficulty with performing a cryosurgical procedure is that it is not easy to determine whether all of the cells, associated with the nondesirable tissue, have been destroyed. This is especially true when the surgeon simply tries to cryogenically treat only the nondesirable tissue itself. Cryosurgery is therefore a rather imprecise procedure and it is difficult to control the actual cryogenic freezing and destroying of all of the cells associated with the nondesirable tissue. For example, it is difficult to control the freezing gradient and rate of freezing when using cryosurgical instruments. It is also very difficult to predict or determine how many cells of the nondesirable tissue are destroyed during the cryosurgical procedure. As one of skill in the art will appreciate, it is of great importance that all of the cells associated with the nondesirable tissue are destroyed because the existence of even a few of these cells can cause regrowth of the nondesirable tissue and also provides an opportunity for the cells to travel to other locations of the body. Because the treated tissue is left in the body for absorption, any cells which are not destroyed remain in the body and can spread to other locations.
Advances in monitoring and imaging techniques have expanded the potential applications for cryosurgical procedures and have permitted this type of procedure to treat tissue deep within the body, e.g., organ or gland tissue. Monitoring by imaging techniques, such as magnetic resonance imaging or ultrasound, can be used to intraoperatively determine, in real time, the extent of the tumors as well as that of the frozen tissue during cryosurgery. Ultrasound techniques work by sensing a pressure wave from a pressure transducer. The wave is reflected from boundaries between regions that have differences in acoustic impedance such as between tumors and normal tissue, blood vessels and tissue and frozen and unfrozen tissue. The reflected wave is identified by the pressure transducer and the extent of the tumor, or of the frozen region, is shown on a monitor. Following computerized interpretation of the data, this procedure facilitates an accurate identification of the extent of the tumor and of the frozen region during the cryosurgery.
In addition, there is now a better understanding of the process by which a cell freezes and is destroyed. It is believed that freezing in tissue is greatly influenced by the structure of the tissue. The destruction of the frozen tissue is promoted by the fact that during freezing the vasculature network of the tissue is destroyed and, therefore, cancerous and other nondesirable cells in the region that has been frozen are deprived of their blood supply after thawing and die because of ischemic necrosis. The destruction of frozen tissue also results because ice spicules that are formed during the freezing process rupture the cell membranes and therefore cause the destruction of these cells.
It is therefore desirable to provide a surgical system and method for treating and removing cancerous or other nondesirable tissue from deep within a patient's body, e.g., within an organ or gland, wherein the system is simple yet effective and eliminates or substantially reduces the risk that cancerous cells might spread to other locations and also overcomes the disadvantages associated with the more conventional procedures.
SUMMARY OF THE INVENTION
The present invention provides a surgical system and method of use for treating and removing unwanted tissue, such as a cancerous tumor or other growth, which is formed within a patient's body, e.g., within an organ, gland, or other internal part of the body. The present system is simple yet effective to use and provides a relatively minimally-invasive surgical approach to treating and removing such unwanted tissue.
In one embodiment, a single probe type instrument is used to carry out the surgical procedure of the present invention. The instrument includes a delivery system for delivering a cryogenic fluid to a tip portion of the instrument so that the unwanted tissue is frozen by being placed in contact with the cryogenically-cooled tip portion. The instrument also includes means for vibrating the tip portion to cause the disintegration and break-up of the cryogenically-treated tissue. Preferably, the tip portion is vibrated at frequencies to cause the frozen tissue to disintegrate and break apart. The disintegrate
Kelman Charles D.
Perez-Soler Roman
Darby & Darby
Shay David M.
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