Surgery – Means or method for facilitating removal of non therapeutic... – Liposuction
Reexamination Certificate
2001-08-16
2004-07-06
Milano, Michael J. (Department: 3731)
Surgery
Means or method for facilitating removal of non therapeutic...
Liposuction
C604S022000, C606S171000
Reexamination Certificate
active
06758842
ABSTRACT:
BACKGROUND OF THE INVENTION
The invention relates to a medical instrument for treating, in particular for removing tissue, bone cement or the like in the human or animal body, comprising a hand piece and an application part arranged on the distal end of same, wherein the application part is axially movable to-and-fro relative to the hand piece, wherein the hand piece contains a drive mechanism for the application part, which transfers a pressure being continuously present in the hand piece in the to-and-fro movement of the application part.
Such an instrument is known from DE 34 39 434 A1.
The known instrument mentioned before serves for the creation of mechanical oscillations for medical curing purposes even in deeper body layers.
An instrument mentioned at the outset is to be suitable, according to the present invention to remove biological tissue, in particular soft or fatty tissue, from the human or animal body. A special application of such an instrument is the removal by suction of fat within the scope of cosmetic surgery. Another application of such an instrument is the removal of bone cement, by which an endoprosthesis, e.g. a hip joint endoprosthesis, is anchored in a bone of the human skeleton, in order to be able to take the endoprosthesis out of the bone for the purpose of revision.
From U.S. Pat. No. 5,685,840, an instrument is known that has an application part having an opening at its distal end and a cutting element moving to-and-fro within the stationary application part, which cuts off tissue sucked into the opening of the application part in co-action with the edge of the opening. As a drive for the cutting element moving to-and-fro in the application part, an electric motor is provided, which is arranged in the hand piece.
A disadvantage of this instrument is that the removed tissue, first of all, is sucked into the opening and, subsequently, is cut off, so that it cannot be prevented that also vessels are sucked into the opening and cut, which may result in considerable bleedings.
A further disadvantage of such an instrument is that the instrument itself has a high weight due to the motor integrated in the hand piece, which results in a quick fatigue of the user's hand. Furthermore, a movement transforming element is necessary in order to transform the rotation movement of the motor into an axial movement of the cutting element. This movement transforming element is also relatively large and heavy, and losses occur in the transformation from the rotation movement into the axial movement of the cutting element.
For the disintegration of soft tissue, purely mechanical instruments are also known, which are configured in the shape of cannulas, these being connected to a common syringe. By moving to-and-fro the cannula by hand, fatty tissue can be separated and sucked off by means of the syringe.
The disadvantage of these instruments is that by the mechanical movement transmitted by hand and the large lengths of stroke resulting therefrom of the to-and-fro movement, not only fatty tissue, but also blood vessels and other tissue may be removed, which may result in inner injuries and inflammations.
Further, from U.S. Pat. No. 4,886,491, a method for tissue removal with an ultrasound instrument is known, in which an ultrasound suction cannula is entered into the body in the area of the soft tissue or the fatty tissue. The cannula is excited to high frequency oscillations with low amplitude by means of ultrasound, whereby a local mechanical tissue disintegration, but also additional frictional heat is generated. The disintegrated fatty tissue is then sucked off via the cannula.
The disadvantage of ultrasound supported tissue removal is that operations of longer duration, as it is the case particularly in the abdominal area, which may last up to four hours, cause a significant heating of the ultrasound hand piece, which cannot be prevented even by additional irrigation. Moreover, the ultrasound hand pieces with the piezo-oscillators are relatively large and heavy. This is a problem in particular for fat removal in the face area. Apart from that, the piezo-elements are to be run with relatively high voltages, which causes additional insulation problems and safety problems. Also, the tissue removal speed or the disintegration speed is not satisfying.
On the other hand, it could be envisaged to use the instrument of WO 99/09897 used in pneumatic lithotripsy, which is used for fragmentation of hard concrements, like e.g. body stones, in modified form also for removal of tissue, in particular soft tissue and fatty tissue. In this known instrument for pneumatic lithotripsy, a bolt movable in a probe is axially moved to-and-fro by means of compressed-air impulses, wherein the probe impulse transmitted by the bolt fragmentizes the concrement to be dissolved.
Another lithotripter of that kind is known from DE 44 05 656 A1, in which the probe transmitting the shock waves runs in a stationary guide tube, which has a take-in and/or suction conduit for the stones that were smashed by the probe.
The disadvantage of such pneumatic lithotripsy instruments is the low repeat frequency of the movement of the probe, which is less than 20 Hz, and the relatively large hand piece. The low repeat frequency of the probe movement is due to the fact that pressure impulses have to be generated, and that the bolt has to be moved back into its initial position after each shot. Apart from that, besides the hand piece and a compressed-air supply, an additional device for the generation of pressure impulses is necessary. Such a pneumatic lithotripsy instrument, which is optimized for the fragmentation of concrements due to the very high probe speed and the very strong probe impulse, is extremely expensive for the removal of tissue or bone cement.
The instrument known from DE 34 39 434 A1 mentioned at the outset has as application part a probe, a cannula or a needle, in the distal part of which there is a linear motor having a piston, which is moved to-and-fro by a pressure of a fluid, in order to generate oscillations up to approximately 20 kHz, to reach different biological effects in different parts of the body, even deep in the inner part of the body. This known instrument is not adapted for the removal of soft tissue and fatty tissue due to the configuration of the application part, which is formed by the piston itself.
The invention has, thus, the object to provide an instrument of the type mentioned at the outset, by which tissue, in particular soft tissue and fatty tissue, can be removed without the danger of bleedings and inner injuries, as well as bone cement and the like.
SUMMARY OF THE INVENTION
This object is achieved by a medical instrument for treating, in particular a medical instrument for treating, in particular for removing tissue, bone cement or the like in the human or animal body, comprising:
a hand piece having a distal end;
an application part arranged at said distal end of said hand piece, said application part being axially movable to-and-fro relative to said hand piece, said application part having at least in a region of a distal end of said application part a conduit, which has, in a distal region of said conduit, at least a suction and/or irrigation aperture; and
a drive mechanism for said application part, said drive mechanism being provided in said hand piece, said drive mechanism transferring a pressure being continuously present in said hand piece into said to-and-fro movement of said application part.
In the instrument according to the invention, the application part itself is, thus, axially movable to-and-fro relative to the hand piece, whereby the tissue to be removed is gently loosened by the application part. In particular fat particles may be released from the tissue compound and sucked off through the configuration according to the invention as hollow probe, and/or an irrigation liquid may be fed into the area to be treated in order to facilitate sucking off tissue or bone cement.
In comparison to the known instruments in which the tissue to be cut off
Irion Klaus M.
Isse Nicanor G.
Karl Storz GmbH & Co. KG
Milano Michael J.
Pantuck Bradford C
St. Onge Steward Johnston & Reens LLC
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