Abstract:
An electronic surgical probe including an axially elongated member adapted to receive ultrasonic vibrations from an ultrasonic motor or transducer and having a circular cross-section, has a coaxially positioned cannula or sheath surrounding the elongated member, the cannula or sheath defining an aperture adjacent the distal end portion of the elongated member, wherein fluid adjacent the distal end portion of the elongated member is activated or cavitated by ultrasonic vibrations from the distal end of the elongated member and passing through the aperture of the cannula acts upon tissue and/or other matter.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to ultrasonic surgical probes or ultrasonic cutting devices for use in the removal of tissue and/or matter from a living body, and more particularly, to an improved ultrasonic probe which is capable of removing tissue through activation or cavitation of a fluid by ultrasonic vibration, and in which the ultrasonically activated member contains minimal features which may cause weakened portions. 
     2. Description of Related Art 
     Probes or scalpels for the fragmentation and removal of materials, tissue and fluids from living beings are known to the art. For example, U.S. Pat. No. 2,227,727, issued Jan. 7, 1941 to Vincent Leggiardro, discloses an apparatus for fragmenting naturally formed stones, such as kidney stones, and the like, utilizing a high speed reciprocating rod which may have a blunt end, a sharp or chisel point, a cutting blade, or combination thereof, such as a cutting blade having a blunt end. 
     While the apparatus disclosed in U.S. Pat. No. 2,227,727 involved a two part housing, with the sonic transducer in one part and the reciprocating rod in another part, in later apparatus the transducer and probe were connected together to form a unitary instrument. In U.S. Pat. No. 3,896,811, issued Jul. 29, 1975 to Karl Storz, the transducer and rod-like are coupled and both enveloped by a jacket providing an air gap and preventing the sides of the probe from contacting the body except at its end. An improvement in such instruments is disclosed in U.S. Pat. No. 3,990,452, issued Nov. 9, 1976 to Edward J. Murry and Joseph F. Brumbach, which also reviews a number of articles relating to the development of ultrasonics in medicine and notes the incorporation of irrigation and aspiration with ultrasonics. 
     A particular arrangement in an ultrasonically vibrated surgical tool using an irrigation fluid and an anti-coagulant is disclosed in U.S. Pat. No. 4,493,694, issued Jan. 15, 1985, to David G. Wuchinich, utilizes a hollow tool having a suction passage and at least one pre-aspirating orifice in the wall of the tool, and a plastic sleeve concentrically spaced about the tool for admitting fluid from a supply into the space between the tool and passing substantially all of the fluid through the pre-aspirating orifice. 
     In the application of ultrasonics to liposuction, instruments of varying configurations recently have been proposed. In U.S. Pat. No. 5,236,414, issued Aug. 17, 1993 to Katsuya Takasu, a tubular body defining a suction passage has an opening in its front lower end, and an outer tube having a corresponding opening, by means of which fat tissue is crushed and/or emulsified due to the vibration of the front end of the tubular body and is then aspirated. In U.S. Pat. No. 5,514,086, issued May 7, 1996, to Parisi et al., an ultrasonically vibrated hollow probe has a port in its surface for aspiration and a tip substantially formed of plastic. 
     In the previously known probes, particularly for the fragmentation or emulsification and aspiration of fat tissue, the ultrasonically activated member or tool had one or more ports or openings, which have been found to be points of stress which limited the amount of ultrasonic power which could be applied thereto, or limited the amount of travel or excursion of the distal end of the probe. If the power limit of the probe were exceeded, the probe was in danger of cracking at the points of stress, particularly at the ports or suction openings. Thus, there is a need for an improved ultrasonic surgical probe configuration which reduces the stress on the probe at higher ultrasonic power levels and at higher excursion of the distal end of the probe. 
     SUMMARY OF THE INVENTION 
     Therefore, it is one object of the present invention to provide an improved ultrasonic surgical probe for use in the removal of matter from a living body. 
     It is another object of the present invention to provide an improved ultrasonic surgical probe capable of removing tissue and/or matter of hard or soft nature through activation or cavitation of a fluid by ultrasonic vibration and aspiration of fluid and tissue. 
     It is still another object of the present invention to provide an improved ultrasonic surgical probe capable of emulsifying and removing tissue and other matter through activation or cavitation of a fluid by ultrasonic vibration and aspiration of fluid and tissue. 
     Still another object of the present invention is to provide a surgical probe which can be used to remove soft tissue from a living body by causing a fluid to emulsify the soft tissue through activation or cavitation of the fluid and aspiration of fluids and emulsified tissue. 
     Another object of this invention is to provide an ultrasonic surgical probe which can control the amount of tissue removed from a living body through emulsification of tissue by activation or cavitation of a fluid by ultrasonic vibration by controlling the size of an aperture in a cannula or sheath of the probe. 
     These and other objects and advantages of the present invention will be apparent from the following description considered in conjunction with the accompanying drawings. 
     In accordance with the present invention an improved ultrasonic surgical probe for removing material from a living body is provided having an axially elongated member having a circular cross-section, a proximal end portion adapted to receive ultrasonic vibrations and a distal end portion; and a coaxially positioned cannula or sheath surrounding the elongated member, isolated from the transmission of ultrasonic vibrations to the member and having an opening adjacent the distal end portion of the member. 
     The elongated member of the probe is desirably mounted to a handpiece manipulable by a surgeon in which or through which ultrasonic vibrations are imparted or transmitted to the proximal end portion of the member, and causing the distal end portion of the member to have successive axial excursions capable of activating or cavitating a fluid adjacent its distal end portion. The elongated member can be solid or can be hollow, and preferably is of a metal or alloy or other material capable of transmitting ultrasonic vibrations therethrough while maintaining its structural integrity upon receiving and transmitting such vibrations. Preferably the member is formed of titanium or an alloy of titanium. 
     The cannula or sheath which surrounds the elongated member can also be mounted to the handpiece, but in a manner which isolates the cannula from the transmission of ultrasonic vibrations to the elongated member. The mounting of the cannula to the handpiece in an isolated manner can be the same type of mounting shown for the sleeve in U.S. Pat. No. 5,562,609, issued Oct. 8, 1996 to Joseph F. Brumbach. The cannula or sheath in the present invention is termed a cannula as it is that part of the probe which is intended to be inserted into the opening or cavity of the body of a patient from or through which matter such as stones, tumors and tissue is to be removed. More particularly, and as one embodiment, the opening can be an incision made in a selected portion of the skin of a patient through which tissue, such as soft or fatty tissue, underlying the skin is to be removed, as in liposuction. 
     The cannula is desirably formed of a metal or an alloy of two or more metals, such as stainless steel, or other material, preferably extends beyond the distal end of the elongated member, and has at least one aperture at or adjacent its distal end portion. In the operation of the probe of the present invention, fluid surrounding the distal end portion of the elongated member, which is initially confined by the cannula, is believed to be activated by the ultrasonic vibrations and/or the successive excusions of the distal end portion of the member, and through the opening in the cannula adjacent the distal end of the member, causes the fragmentation and/or emulsification of tissue of the body of the patient in the area of the distal end portion of the cannula. The fragmented or emulsified tissue and fluid can then be aspirated from the site of the probe. 
     In one embodiment of the present invention, the distal end of the cannula, extending beyond the distal end of the elongated member, may be blunt, and, in a further embodiment, the cannula can be open-ended, the open end of the cannula constituting the opening in the distal end portion of the cannula. In either embodiment, the fluid can be supplied to the distal end portion of the elongated member through the annular space between the elongated member and the cannula, for example, in the same manner that irrigation fluid is supplied in the annular space between the needle and the sleeve in U.S. Pat. No. 5,562,609. The fluid in the area of the distal end portion of the elongated member is activated by the ultrasonic vibrations from or excusions of the distal end portion of the member, and acts on tissue as the fluid exits the opening at the distal end portion of the cannula. In a still further embodiment, the elongated member can be hollow and constitute a suction or aspiration passage in the same manner as in the needle in U.S. Pat. No. 5,562,609, and provide the aspiration passage for the removal of tissue and fluid through the opening in the distal end of the cannula. 
     In a second embodiment, the cannula can have a closed distal end which can be blunt or rounded, and has at least one opening through the side of the cannula in its distal end portion. In this embodiment, the amount of tissue to be removed from the body per unit of time can be controlled by the dimensions of the opening or openings. Fluid can be supplied to the distal end portion of the elongated member, and acted upon by the ultrasonic vibrations and/or the excusions of the member, in the same manner as in the previously described embodiments. The fluid and tissue can be aspirated in the same manner in a further embodiment wherein the elongated member is hollow, is provided with suction and constitutes a suction passage of the probe. 
     In another embodiment of the present invention, the distal end portion of the cannula is rounded, and is partially cut away to expose part of the distal end and part of the side of the cannula, thereby also exposing the distal end portion of the elongated member. 
     As a consequence of the present invention as described above, the elongated member which receives and transmits ultrasonic vibrations is mainly free of any apertures, caps or other potential points of stress in its side surface, thus minimizing points where structural failure can occur upon being subject to repeated or higher ultrasonic frequency or amplitude than the elongated member can withstand if higher stress points were present. Additionally, the outer element, i.e., the cannula, which is intended to be inserted into the incision or body cavity, is also relatively free of stress as it is isolated from the transmission of ultrasonic vibrations to the elongated member. The improved probe of the present invention permits the elongated member to have excursions up to several times the excursion distance of elongated members with apertures in its side surface or caps on its end, and the probe provides effective cavitation and emulsification of such soft tissue as fat tissue. Additionally, since the elongated member is not connected to the cannula at the distal end it is free to move without the added stress of pulling the cannula along with it. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a side view of one embodiment of the probe of the present invention mounted to a handpiece; 
     FIG. 2 is an enlarged sectional side view of the embodiment of the probe shown in FIG. 1 and a portion of a handpiece to which it is mounted; 
     FIG. 3 is an exploded sectional side view of another embodiment of the present invention with alternate fittings for the supply of fluid through the annular space between the elongated member and the cannula; 
     FIG. 4 is a sectional view of the probe illustrated in FIG. 3, assembled and without the fluid supply fittings; 
     FIG. 5 is a sectional view similar to FIG. 4, of another embodiment of the probe of the present invention; and 
     FIG. 6 is a sectional side view similar to FIG. 4, of still another embodiment of the probe of the present invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     In one preferred embodiment of the present invention, which is schematically illustrated in FIGS. 1 and 2, the probe is generally referenced by numeral  10 . Probe  10  comprises an elongated member  12 , which can be hollow as shown or can be solid (not shown), and a coaxially positioned cannula  14  which surrounds member  12 . Member  12  has a proximal end portion  16  and a distal end portion  18  which terminates in a transverse distal end  20 , i.e., end  20  is perpendicular to the elongation along the axis of member  12 . 
     Elongated member  12  is mounted to a handpiece  22 , which preferably has a housing  24  of non-conducting material, such as a polymer. Handpiece  22  encloses an ultrasonic motor or transducer (not shown) which may be of a type known to the art which is coupled to a member, such as horn  26 , capable of transmitting ultrasonic vibrations generated by the ultrasonic motor or transducer. In the embodiment shown in the drawings, proximal end portion  16  of member  12  is mounted to horn  26 , for example, by portion  16  having external threads  28  and horn  26  having internal threads  30 , and threadingly engaging the former with the latter. 
     Cannula  14  is also mounted to handpiece  22 , but in a manner which isolates cannula  14  from the ultrasonic vibrations being transmitted from horn  26  to member  12  and cannula  14 . In particular, cannula  14  has a distal end portion  32  and a proximal end portion  34 , which is affixed, for example, by brazing to and partially through a cup-shaped member  36 , which is preferably formed of a metal or an alloy, such as stainless steel. For the sake of clarity, member  36  will be referred to herein as “cup  36 ”. Cup  36  also has two diametrically opposed apertures  38  and  40  in its cylindrical surface spaced from its distal end. Cup  36  further has three apertures  41  equidistantly spaced about the surface of cup  36  to enable the passage of fluid therethrough as will be hereinafter described. Aperture  38  is dimensioned to hold a pin (not shown) or a screw  42 , or a similar fastener, such as a rivet (not shown) for a purpose to be hereafter described. Where screw  42  is used as the fastener-like member, aperture  38  is tapped to enable screw  42  to be advanced through and extend outwardly of the wall of cup  36 . 
     Cannula  14  and attached cup  36  are secured to handpiece  22  by means of a cup-shaped front piece  44 , which has an aperture  46  in its otherwise closed distal end which is axially aligned and adapted to receive member  12 . Front piece  44 , desirably is formed of a non-conductive material, preferably of a non-flexible polymer. Front piece  44  also has a slot, i.e., a keyway  48 , extending from its open, proximal end toward its distal end. Keyway  48  is adapted to receive screw  42  to prevent relative rotation of cup  36  and cannula  14  with respect to front piece  44  about their common axis. Front piece  42  has internal threads  50  adjacent its open, proximal end adapted to engage external threads  52  on the distal end of housing  24  of handpiece  22 . 
     As best shown in FIG. 3, probe  10  can be assembled by first threadingly securing member  12  to horn  26  by means of threads  28  of the former engaging threads  30  of the latter. A wrench (not shown), such as a torque wrench, can be used to tightly secure member  12  to horn  26 . Screw  42  is placed in aperture  38  and advanced through the wall of cup  36  by inserting a screw driver (not shown) through aperture  40  and rotating screw  42 . A relatively compressible sealing member, such as O-ring  54 , of neoprene or similar substance, is placed about the threaded end of housing  24 . Cup  36  and attached cannula  14  is then placed over elongated member  12  with member  12  passing through the hollow bore of cannula  14  until proximal end  34  of cannula  14  abuts the distal end of housing  24 . An annular spacer, such as washer  56 , is placed within front piece  44  so that it abuts against its inside circular corner at its distal end. Washer  56  preferably is formed, such as by stamping, from a relatively compressible sealant material such as RTV. Front piece  44  is next placed over cannula  14  and cup  36  with screw  42  of the latter entering keyway  48 , and rotated with cannula  14  as it advances to cause threads  50  to engage threads  52  of housing  24  and compressing O-ring  54  between the proximal end of front piece  44  and housing  24 . At the same time, tightening of front piece  44  to housing  24  compresses washer  56  between the internal surface of the distal end of front piece  44  and the outside circular corner of the distal end of cup  36 . 
     The thus assembled probe  10  can be fitted with a suitable fitting, for example, one of fittings  58  and  60 , for the supply of irrigation fluid, such as by having an aperture  62  in the side surface of front piece  44 , positioned opposite keyway  48  so that upon assembly with cap  36 , aperture  62  is in alignment with aperture  40 . Preferably aperture  62  is tapped so that either of fitting  58  and  60 , fitting  58  preferably being a barbed nipple with a threaded end, and fitting  60  preferably being a Luer fitting, can be threaded into and secured to front piece  44 . 
     In the first preferred embodiment of the invention, as best illustrated in FIGS. 1 and 2, elongated member  12  is hollow and distal end portion  32  of cannula  14  is rounded and partially cut away so that both a portion of its end or tip and its adjacent side surface has been removed forming an aperture  64  in the cannula. In this manner, a portion of the distal end portion  18  of member  12  is exposed. 
     In the use of the probe of this embodiment, one of the fittings  58  or  60  is mounted in aperture of front piece  44 . Irrigation fluid is supplied (not shown) through the fitting into the interior of front piece  44  and through aperture  40  and through apertures  41  to the interior of cup  36 . Irrigation fluid then flows from the interior of cup  36  through the annular space between member  12  and cannula  14  to the interior of distal end portion  32  of the cannula and to the exterior and about the end of distal end portion  18  of elongated member  12 . Ultrasonic vibrations transmitted from an ultrasonic motor or transducer (not shown) through horn  26  to member  12 , causes the distal end portion  18  of member  12  to vibrate longitudinally, causing the fluid adjacent to end portion  18  and partially confined by cannula  14  to be activated or cavitate. The activated fluid exiting aperture  64  is believed to act upon tissue or other material adjacent the aperture in distal end portion of cannula  14 , causing the tissue or material to be fragmented or emulsified. Suction (not shown) is provided to the handpiece  22  and through horn  26  and the interior of elongated member  12 . Fluid and fragmented or emulsified tissue and/or material can be removed from the area adjacent aperture  64  by aspiration through aperture  64  regulated by the amount of suction applied to the handpiece  22  and member  12 . 
     In the embodiment thus described, and in the other preferred embodiments of this invention, the amount or depth of tissue and/or other material to be removed can be controlled by the shape and size of the aperture in the distal end portion  32  of cannula  14 , such as aperture  64  in the embodiment described above, and the ultrasonic energy power and amplitude and excursion of the elongated member. The surgeon or operator can manipulate the handpiece, and thus direct the distal end portion of the cannula to the precise location of the tissue and/or other material to be removed. The surgeon or operator can also readily remove and replace the cannula with a cannula of another embodiment of this invention during a surgical procedure to select the cannula design most suited for a particular phase of the procedure. 
     In another embodiment of the invention, as best shown in FIG. 4, wherein like reference numerals refer to substantially similar elements common to the first embodiment, probe  70  has a cannula  72  which is open-ended to form an aperture  74  which includes the entire distal end of the cannula. As in the previous embodiment, cannula  66  extends distally beyond the distal end of member  12 , minimizing direct contact of member  12  with tissue of the patient. The assembly and use of probe  70  can be accomplished in the same manner as in the first embodiment, and further explanation is not required. 
     Another embodiment of the invention is best illustrated in FIG. 5, again with like reference numerals to the first embodiment, wherein probe  80  features a cannula  82  having a relatively elongated aperture  84  having its direction of elongation parallel to the axis on the surface of the cannula spaced from its rounded distal end. The dimensions of the aperture  84  can be selected to control the amount and rate of tissue or other material to be removed from the patient&#39;s body. The same manner of assembly and usage as in the previous embodiment can be used for the assembly and use of probe  80 . 
     Still another embodiment is illustrated in FIG. 6, with like reference numbers for elements which are substantially similar to elements of the first embodiment. In this embodiment, probe  90  has a cannula  92  with three apertures  94  spaced equidistantly about the surface of the distal end portion of the cannula and closely spaced to the rounded distal end of the cannula. The manner of use, operation and assembly of probe  90  is substantially similar to the use, operation and assembly of probe  10  in the first embodiment, and further explanation to one skilled in the art is not required. 
     Optionally, if desired, at least one aperture  95  can be provided in the distal end portion  18  of elongated member  12  to permit pre-aspiration of a portion of the irrigation fluid from the annular space between member  12  and cannula  14  before all of the fluid reaches the distal end of member  12 . Pre-aspiration is discussed in earlier patents, such as U.S. Pat. No. 4,493,694. 
     While particular embodiments of the ultrasonic probe of the invention have been shown and described, it will be appreciated by those skilled in the art that changes and modifications may be made thereto without departing from the invention in its broader aspects and as set forth in the following claims.