ULTRASONIC PROBE FOR LIPOSUCTION

Abstract: A method of removing animal fatty tissue includes inserting an ultrasonic aspirating probe (10) into the body in the area of the fatty tissue between the flesh, including blood vessels and arteries, and the muscle. The probe (10) is ultrasonically vibrated at high frequencies and low amplitudes creating localized tissue separation and frictional heat. This heat causes the fatty tissue surrounding the probe (10) to melt. The probe (10) is specially adapted to provide a localized flow of irrigating fluid. This fluid serves to emulsify the melted and separated fat. The emulsified fat is then aspirated through specially designed orifices from the body using suction.

Description: This invention concerns an apparatus for liposuction. Liposuction is a type of cosmetic surgery whereby undesirable accumulations of body fat are removed by suction. Liposuction is becoming increasingly popular, and is seen by many as a way to quickly remove undesirable body fat which may or may not be removed by the more traditional ways of diet and exercise. Liposuction is rapidly gaining popularity because it provides an easy way to remove unwanted body fat. Generally, dieting serves only to reduce the size of fat cells, not their number. It is this fact which makes maintaining one's lowered body weight after dieting so difficult. Liposuction takes an alternative approach by physically removing the fat cells. Additionally, liposuction serves as a means for reducing the bulk in areas which could not be reduced by dieting and exercise. For example, it is not unusual to perform liposuction on an individual's eyelids or under the eyes, and at other localized areas on the face. The traditional liposuction techniques include the use of a cannula connected to an external source of suction. In use, an incision is made in the area of the fat desired to be removed, the cannula inserted in the area (between the flesh and muscle), and the suction begun. The fat is then sucked out of the body. This basic method has its disadvantages, however, because fat is relatively difficult to separate from the surrounding tissue by simply the sucking action. There is a tendency for the entry orifice on the cannula to clog with the fat. In other words, it is difficult to keep the operation going without stopping to clean out the cannula orifice. Normally, the surgeon attempts to compensate for this problem by manually moving the cannula within the cavity, and even periodically withdrawing it to force through the fat that is stuck in the orifice. Further, the surgeon must be careful not be allow to suction to pull and remove desirable tissues, such as the flesh, muscle, blood vessels and the like. Therefore, the speed, safety and effectiveness of the current liposuction method leaves much to be desired and a successful operation depends on the practitioner's exceptional skill. It is known to use ultrasonically vibrating/aspirating probes in the fields of cataract surgery and dental cleaning. There have also been suggestions of use of these probes in removing other types of relatively hard body tissues, such as brain tumors. In each case, the intention is to introduce the vibrating probe into the area of material desired to be removed, and use the ultrasonic vibrations to physically fracture or cut the material. Such a procedure lends itself well to cataract surgery, for example, because the cataract desired to be removed is relatively hard and capable to bring fractured. Representative patents in this field include U.S. Patent 4,169,984. Also U.S. Patent 4,515,583 and U.S. Patent 4,531,934 teach the same basic approach of an ultrasonic surgical probe with aspirator used to fragment and remove undesirable cataract or other hard tissue. Use of ultrasonics in cataract surgery is, in fact, widely regarded as safe and efective. U.S. Patent 4,516,398 discloses an ultrasonic probe for removing undesired fatty tissue from the body, comprising a housing, an operative tip, irrigating means for directing a flow of irrigating fluid to the operative tip, and aspirating means for aspirating the fatty tissue. Ultrasonic vibrations are produced by an ultrasonic motor and generate heat in the probe, which in accordance with a design consideration understood by those in the art is surrounded by the irrigation means to provide adequate cooling fluid if the ultrasonic vibration design requires more fluid for cooling than for irrigation. Similarly, U.S. Patent 4,223,676 discloses an ultrasonic probe which is surrounded by the irrigation means in order to prevent damage thereto. A need exists for an ultrasonic probe capable of performing liposuction which removes the unwanted relatively soft, fatty tissue more effectively and without interruption. An object of the present invention is to provide an apparatus for aspirating animal fatty tissue utilizing ultrasonic vibrations to create more efficient tissue separation, and even localised tissue melting through frictional heat, thereby allowing highly efficient removal. Another object of the present invention is to provide an apparatus for aspirating animal fatty tissue without damage to or removal of flesh tissue, blood vessels, and the like. According to the present invention, an ultrasonic probe for removing undesired fatty tissue from the body comprises a housing, an operative tip, irrigating means for directing a flow of irrigating fluid to the operative tip, and aspirating means for aspirating the fatty tissue, characterized by a transducer assembly mounted in the housing for ultrasonically vibrating the operative tip at sufficient frequency and amplitude for generating localized frictional heat to melt at least some of the fatty tissue for more efficient removal from the body. A thermal insulator is preferably provided for a portion of the operative tip so as to protect delicate tissue near the fatty tissue from damage due to heating; and the thermal insulator conveniently comprises a portion of the irrigating means for directing a flow of irrigating fluid to the operative tip. The transducer assembly preferably vibrates the operative tip at substantially 40 kHz at an amplitude of substantially 50 µm (2 mil). The choice of the tip depends upon the precise nature of the liposuction procedure being performed. Three alternative tips are illustrated and a selection is made based on the particular type of body area being treated. A rounded, bullet-shaped tip with a closed end and a single elongated entry orifice is the standard configuration and may be used for a majority of body areas, A tip with a portion of the end open is utilized for localised entry and fat removal, such as in areas around the smaller body appendages; whereas, a tip having multiple entry orifices is provided for unobstructed and flatter areas, such as the thighs and buttocks, where the probe tip may be extended into the fatty area for a substantial distance. Embodiments of the invention will now be described by way of example only, with reference to the accompanying drawings in which: Figure 1 is a cut-away view of an ultrasonic aspirating probe shown inserted into the fatty tissue cavity of a body between the skin/flesh layers and the muscle layer; Figure 2 is a cross-sectional view of the area of the body as shown in Figure 1 with the fat having been removed; Figure 3 is a cut-away view of a complete ultrasonic probe in accordance with the invention; Figure 4 is a cross-sectional view taken along the section line 4-4 of Figure 3; Figure 5 is a perspective view of a preferred, general purpose insert for use with the probe and with an extra detailed plan view of the tip illustrating the entry orifice; and Figure 6 is a composite showing of two additional tips, including for each a plan and side view illustrating alternative orifice configurations. The probe 10 shown in Figures 1 and 3 includes a hollow insert 12 having a probe tip 14, and an internal ultrasonic transducer assembly 20, which includes piezoelectric crystals 22, 24 which are securely retained within body members 26, 28. As is known in the art, an alternating voltage of ultrasonic frequency is applied to the transducer assembly 20. This causes the crystals 22, 24 to vibrate ultrasonically. This vibration is transferred to the hollow insert 12 and the probe tip 14. For a more detailed review of the transducer assembly and how it operates to produce ultrasonic vibration, reference is made to U.S. Patent 4,169,984, mentioned above. The probe tip 14 is modified from the probe tips commonly known and used by practitioners of the liposuction art. As shown in Figures 5 and 6, various probe tips 14, 16 and 18 are provided, the choice of which depends upon the precise nature of the liposuction procedure being performed. More specifically, the choice of which tip 14, 16 or 18 to use depends upon the particular type of body area being treated. Figure 5 shows an insert 12 having a rounded bullet-shaped tip 14, with a closed end and a single elongated entry orifice. From experimentation this probe tip 14 has been established as the standard configuration, and it is used for the majority of body areas. Figure 6 shows two alternative probe tip configurations. Probe tip 16 is a bullet-shaped tip having a portion of the end open. Probe tip 16 is used to remove fat in tight areas, such as around the small apendages of the body. Probe tip 18 having multiple entry orifices is used in body areas providing clear access over a wider area, and is particularly useful in areas, such as the thighs and buttocks, where the probe tip 18 may be extended into the fatty area for a substantial distance. This allows faster fatty tissue removal, resulting in quicker, more efficient liposucion operations. An irrigation sleeve 30 is provided to direct a flow of irrigating solution directly to the probe tip 14 (see Figures 1, 3 and 4). The sleeve 30 partially surrounds the insert 12 including the probe tip 14. Advantageously, the sleeve 30 snaps on to the probe 10 and is readily removable. Because the sleeve 30 is non-vibrating and closely surrounds the insert 12 (see Figure 4), sleeve 30 serves as a thermal insulator. In other words, the tissues found in the areas above the sleeve 30 are protected from the ultrasonically created heat. In this way, ultrasonic liposuction may be performed in areas very close to the skin, without damaging this delicate tissue. During operation, the surgeon determines the location and extent of fatty tissue to be removed. Based on this initial determination, the surgeon next chooses, and installs within probe 10, the hollow insert 12 having the appropriate probe tip 14, 16 or 18. An incision is made, and the tip 14, 16 or 18 is guided through the skin and flesh layers, which include the blood vessels, and into the layer of fatty tissue below. The probe 10 is preferably vibrated at approximately 40 kHz, at an amplitude of about 50 µm. This high frequecy, low amplitude vibration serves to efficiently and safely separate the fatty tissue and create localised heat through frictional contact. Advantageously, this localised frictional heat serves to assist in the removal by physically melting a thin layer of surrounding fatty tissue. During use, the probe 10 is moved in a back and forth and twisting manner as is indicated in Figure 1, by arrows L and R respectively. This motion helps to further separate the fatty tissue, and generally speeds up the operation. The separated and melted fatty tissue is emulsified by application of a saline irrigating solution from the tip of the irrigating sleeve 30. The emulsified solution is then aspirated by use of an external suction source. The intensity of the vibration and localised heat applied can be varied by adjusting the frequencies and amplitudes of ultrasonic vibration. This allows the surgeon to fine tune the liposuction procedure to each individual situation. As shown in Figure 2, the fatty tissue and its associated bulk is removed, leaving the desired thinner profile appearance. The choice of how much fatty tissue to remove depends on the final appearance desired by the patient. The surgeon can remove as little, or as much fatty tissue as necessary, to achieve the desired final appearance. Use of the ultrasonic probe in accordance with the present invention permits liposuction procedures significantly more reliable than were possible using the traditional non-vibrating cannula method. This is because the ultrasonic probe 10 aspirates only the undesirable fatty tissue while leaving the desirable tissue such as blood vessels, muscle and the like intact. Advantageously, this provides for a safer surgical procedure characterised by reduced healing times. The vibration constantly and effectively shakes the separated fatty tissues at the entry orifice(s) to allow easier entry into the tip 14, 16 or 18 and prevent clogging. In this manner the process is substantially accelerated providing greater efficiency and further lessening the trauma to the patient. Also the heat generated to assist in melting some of the fat tends to be focused in the area of the entry orifice(s). The additional heat is generated along the remaining length of the exposed insert 12 thereby providing the relatively thin layer of melted fat. A roughened texture on the insert may provide additional heat generation thereby allowing the surgeon to further fine tune the procedure.

Claims: 1. An ultrasonic probe (10) for removing undesired fatty tissue from the body, comprising: a housing; an operative tip (14); irrigating means for directing a flow of irrigating fluid to the operative tip (14); aspirating means for aspirating the fatty tissue; characterised by a transducer assembly (20) mounted in the housing for ultrasonically vibrating the operative tip at sufficient frequency and amplitude for generating localised frictional heat to melt at least some of the fatty tissue for more efficient removal from the body. 2. An ultrasonic probe as in Claim 1, further characterized by a thermal insulator for a portion of the operative tip so as to protect delicate tissue near the fatty tissue from damage due to heating. 3. An ultrasonic probe set forth in Claim 2, characterised in that the thermal insulator comprises a portion of the irrigating means (30) for directing a flow of irrigating fluid to the operative tip (14). 4. An ultrasonic probe (10) for removing undesired fatty tissue from the body, comprising: a housing; an operative tip (14); irrigating means for directing a flow of irrigating fluid to the operative tip (14); and aspirating means for aspirating the fatty tissue; characterised by a transducer assembly (20) mounted in the housing for ultrasonically vibrating the operative tip at sufficient frequency and amplitude for generating localized frictional heat to melt at least some of the fatty tissue for more efficient removal from the body, and in that the irrigating means includes an irrigating sleeve (30) partially surrounding the operative tip (14) for thermally insulating a portion of the operative tip so as to protect delicate tissue near the fatty tissue from damage due to heating. 5. An ultrasonic probe as in any one of Claims 1 to 4, characterised in that the transducer assembly (20) serves to vibrate the operative tip (14) at substantially 40 kHz cycles per second at an amplitude of substantially 50 µm (2 mil). 6. An ultrasonic probe as in any one of Claims 1 to 4, characterised in that the operative tip (14) includes a rounded, closed end and at least one entry orifice. 7. An ultrasonic probe as in any one of Claims 1 to 5, characterised in that the operative tip (14) includes a rounded, partially closed and partially open end. 8. An ultrasonic probe as in any one of Claims 1 to 5, characterised in that the operative tip (14) includes a rounded, closed end and multiple in-line orifices.

Inventors: MASSENGILL, RICHARD KEMP, PARISI, TULIO
Applicants: MASSENGILL, RICHARD KEMP, PARISI, TULIO
Application year: 1989
Main classification: A61M1
IPC codes: A61B17, A61N7, A61M1