DEVICES FOR REMOVAL OF VISCERAL FAT, AND RELATED SYSTEMS AND METHODS

Methods of treating a medical condition in a patient include performing a lipectomy of visceral fat to remove a quantity of the visceral fat from the subject. The removal of visceral fat treats the medical condition such that the subject experiences at least a reduction of symptoms of the medical condition.

TECHNICAL FIELD

The present invention relates to devices for removing visceral fat in vivo, as well as to systems and methods related to removing visceral fat in vivo.

BACKGROUND

It has come to light in recent years that visceral fat, unlike subcutaneous fat, poses significant risks to general health. Visceral fat is now viewed as not just an inert blob of fat, but as another endocrine organ and, further, a “high risk” endocrine organ. For example, visceral fat secretes chemical mediators which are believed to have deleterious effects, including causing insulin resistance and creating a systemic inflammatory state in the body. Visceral fat therefore is now viewed not only as a culprit in the pathogenesis of diabetes mellitus type II but also is suspected as a possible contributor to hypertension, cardiovascular disease, cancer, obesity, Alzheimer's disease, dementia, aging itself, non-alcoholic fatty liver disease (NAFLD), and non-alcoholic steatohepatitis (NASH), among other diseases and disorders.

Liposuction, also known as lipoplasty (fat modeling), liposculpture, or suction lipectomy (suction-assisted fat removal) is a cosmetic surgery operation that removes subcutaneous fat from many different sites on the human body (e.g., the chest, buttocks, hips, thighs, or arms). The typical liposuction procedure relies on the action of a sharp-edged instrument to shear away the fatty deposits. The sheared fatty deposits are then suctioned away into orifices on the cannula. This process is labor-intensive for the surgeon, traumatic to non-fat tissues and to the patient, and very time consuming.

Typical liposuction tools and methods cannot be used for visceral fat lipectomy in the same manner as they are used to remove subcutaneous fat because visceral fat contains, among other things, a plethora of delicate blood vessels, nerves and lymphatic vessels and is attached to sensitive internal organs. Those vital, non-fat tissues and organs will not tolerate the repeated thrusting and shearing required with traditional lipectomy.

SUMMARY

According to an embodiment of the present disclosure, methods of removing visceral fat from a subject include inserting at least a distal portion of a cannula into the anatomy of the subject, wherein the anatomy comprises peritoneal cavity, the retroperitoneal cavity, or visceral fat tissue that has been moved from its natural anatomical location in the body. The cannula is elongate along a longitudinal direction. The distal portion of the cannula defines at least one aperture that is open to an interior cavity of the cannula. The methods can include generating a negative pressure in the interior of the cannula so that the negative pressure draws a portion of visceral fat from the peritoneal cavity or the retroperitoneal cavity through the at least one aperture and into the interior cavity. The methods can further include delivering fluid through a conduit of the cannula along the longitudinal direction in a series of pulses that are individually at a pressure in a range of 600 psi to 1300 psi and at a temperature in a range of 80 degrees Fahrenheit and 140 degrees Fahrenheit. Representative methods include expelling the fluid in the series of pulses from the conduit, impacting the expelled fluid against the portion of visceral fat so as to liquefy the visceral fat, and suctioning at least a major portion of the liquefied visceral fat through the interior of the cannula and away from the subject responsive to the negative pressure.

According to another embodiment of the present disclosure, methods of treating a medical condition in a patient include performing a lipectomy of visceral fat to remove a quantity of the visceral fat from the subject. The removal of visceral fat treats the medical condition such that the subject experiences at least a reduction of symptoms of the medical condition.

According to an additional embodiment of the present disclosure, a cannula for removing visceral fat from a subject in vivo includes a cannula body defining a proximal end and a distal end spaced from each other along a longitudinal direction. The cannula body also defines an interior cavity and at least one aperture that is open to the interior cavity and is configured to draw visceral fat into the interior cavity responsive to vacuum pressure supplied to the interior cavity. The at least one aperture is located adjacent the distal end and remote from the proximal end. The cannula includes at least one fluid supply tube that extends along the longitudinal direction within the interior cavity and has a nozzle at a terminal end thereof. The fluid supply tube is configured to deliver fluid toward the aperture in a series of pulses that are individually at a pressure in a range of 600 psi to 1300 psi and at a temperature in a range of 80 to 140 degrees Fahrenheit. The nozzle is configured to eject the series of boluses from the at least one fluid supply tube and against visceral fat drawn into the interior cavity. The cannula can include at least one cauterizing electrode adjacent the distal end.

According to yet another embodiment of the present disclosure, a cannula for removing visceral fat from a subject in vivo includes a cannula body defining a proximal end and a distal end spaced from each other along a longitudinal direction. The cannula body also defining an interior cavity and at least one aperture that is open to the interior cavity and is configured to draw visceral fat into the interior cavity responsive to vacuum pressure supplied to the interior cavity. The at least one aperture is located adjacent the distal end and remote from the proximal end. The cannula includes at least one fluid supply tube that extends along the longitudinal direction within the interior cavity and has a nozzle at a terminal end thereof. The fluid supply tube is configured to deliver fluid toward the aperture in a series of pulses that are individually at a pressure in a range of 600 psi to 1300 psi and at a temperature in a range of 80 to 140 degrees Fahrenheit. The nozzle is configured to eject the series of boluses from the at least one fluid supply tube and against visceral fat drawn into the interior cavity. The cannula includes an outer sleeve that is positioned over the outer surface of the cannula body. The outer sleeve defines at least one sleeve aperture aligned with the at least one aperture of the cannula.

According to a further embodiment of the present disclosure, a cannula for removing visceral fat from a subject in vivo includes a cannula body defining a proximal end and a distal end spaced from each other along a longitudinal direction. The cannula body defining an interior cavity and first and second apertures that are open to the interior cavity and are each configured to draw visceral fat into the interior cavity responsive to vacuum pressure supplied to the interior cavity. The first and second apertures are adjacent the distal end and remote from the proximal end. The first and second apertures are also spaced from each other along a circumference of the cannula body. The cannula includes at least one fluid supply tube that extends along the longitudinal direction within the interior cavity and is configured to deliver fluid toward one or both of the first and second apertures in a series of pulses that are individually at a pressure in a range of 600 psi to 1300 psi and at a temperature in a range of 80 to 140 degrees Fahrenheit. The cannula includes at least one nozzle at a terminal end of the at least one fluid supply tube. The at least one nozzle is configured to eject and the series of boluses from the at least one fluid supply tube and impact the series of boluses against visceral fat drawn into the interior cavity.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

As used herein with reference to fat (adipose) tissue, the terms “liquefy”, “liquefaction”, and their derivatives include actions of liquefying, softening, gellifying, and/or causing adipocyte cell disaggregation of the fat tissue.

The term “plurality”, as used herein, means more than one. When a range of values is expressed, another embodiment includes from the one particular value and/or to the other particular value. Similarly, when values are expressed as approximations, by use of the antecedent “about,” it will be understood that the particular value forms another embodiment. All ranges are inclusive and combinable.

The terms “approximately” and “substantially”, as used herein with respect to dimensions, angles, and other geometries, takes into account manufacturing tolerances. Further, the terms “approximately” and “substantially” can include 10% greater than or less than the stated dimension or angle. Further, the terms “approximately” and “substantially” can equally apply to the specific value stated.

The embodiments described below generally involve the delivery of pressurized heated biocompatible fluid to heat targeted tissue and soften, gellify, or liquefy the target tissue for removal from a living body. The heated biocompatible fluid is preferably delivered as a series of pulses, but in alternative embodiments can be delivered as a continuous stream. After the tissue has been softened, gellified, or liquefied, it is sucked away out of the subject's body.

Referring now toFIGS. 1-4, a tissue liquefaction system2includes a lipectomy cannula30having a distal end32that is smooth and rounded for introduction into the subject's body. A proximal end31of the cannula30is configured to mate with a handpiece20. The cannula30is elongate along a longitudinal direction L and defines a longitudinal axis33oriented along the longitudinal direction L. The distal end32is spaced from the proximal end31in a distal direction D. Moreover, the proximal end31is spaced from the distal end32in a proximal direction P. It should be appreciated that the distal and proximal directions D, P are each mono-directional components of the longitudinal direction L, which is bi-directional. The cannula30defines an interior cavity90and one or more apertures37that are open to the cavity90. These apertures37are in fluid communication with the interior cavity90and are preferably located near a distal portion of the cannula30. When a negative pressure (i.e., vacuum pressure) source is connected to the cavity90via a suitable fitting, suction can be generated which draws target visceral fatty tissue into the apertures37. Accordingly, the apertures37can also be referred to as “suction apertures”37or “induction apertures”37.

The one or more apertures37are open to the cavity90along a transverse direction T that is substantially perpendicular to the longitudinal direction L. Additionally, the one or more apertures37each define an aperture shape, which can be characterized with respect to a reference plane, such as a reference plane extending along the longitudinal direction L and a lateral direction A. For purposes of this disclosure, the longitudinal, lateral, and transverse directions L, A, T are substantially perpendicular to each other and effectively define a three-axis coordinate system in three-dimensional space.

The cannula30also includes one or more fluid supply tubes35that direct the heated fluid onto the target tissue that has been drawn into the cavity90. These fluid supply tubes35are preferably arranged within the interior cavity90, although in other embodiments, proximal portions of the fluid supply tubes35can extend externally from the cannula30, as more fully described in U.S. Pat. No. 8,366,700, issued Feb. 5, 2013, entitled “LIPOSUCTION OF VISCERAL FAT USING TISSUE LIQUEFACTION” (hereinafter referred to as “the '700 Reference”), the entire disclosure of which is incorporated by reference herein. The fluid supply tubes35are arranged to eject the fluid across interior aspects of the apertures37, respectively, so that the fluid impacts against the target fatty tissue that has been drawn into the cavity90.

The tissue liquefaction system2includes a fluid delivery sub-system3that includes a fluid supply reservoir4, a heat source8that heats the fluid in the reservoir4, and a temperature regulator9that controls the heat source8as required to maintain the desired temperature. The heated fluid from the fluid supply4is delivered under pressure by a suitable arrangement such as a pump system19with a pressure regulator11. Optionally, a heated fluid metering device12can also be provided to measure the fluid that has been delivered.

The fluid delivery sub-system3includes a pump19that pumps the heated fluid from the reservoir or fluid supply source4down the fluid supply tubes35that run from the proximal end31of the cannula30down to the distal end32of the cannula30. Near the distal tip32of the cannula30, these fluid supply tubes35can optionally make a U-turn so as to face back towards the proximal end of the cannula30. As a result, when the heated fluid exits such supply tubes35at their respective delivery orifices43(also referred to herein as “fluid ejection nozzles”43or simply “nozzles”43), the fluid is traveling substantially in the proximal direction P. Preferably, the pump19delivers a pressurized, pulsating output of heated fluid down the supply tube35so that a series of boluses of fluid are ejected from the nozzle43, as described in greater detail below.

The tissue liquefaction system2includes a suction subsystem5that includes a vacuum source14. The fluid delivery sub-system3and the suction sub-system can interface with the cannula30via a handpiece20. The heated solution supply is connected on the proximal side of hand piece20with a suitable fitting, and a vacuum supply is also connected to the proximal side of handpiece20with a suitable fitting. Cannula30is connected to the distal side of hand piece20with suitable fittings so that (a) the heated fluid from the fluid supply is routed to the supply tubes35in the cannula and (b) the vacuum is routed from the vacuum source14to the cavity90in the cannula30, to evacuate material from the cavity90.

More specifically, the pressurized heated solution that is discharged from pump19is connected to the proximal end of the handle20via flexible tubing (capable of delivering pressurized fluid), and routed through the handpiece20to the cannula30with an interface made using an appropriate fitting. The vacuum source14is connected to an aspiration collection canister15, which in turn is connected to the proximal end of the handle via flexible tubing16, and then routed through the handpiece20to the cannula30with an interface made using an appropriate fitting. The pressurized fluid supply line connection between the handle and the cannula30can be implemented using a quick disconnect fitting located at the distal end of the handle, and configured so that once the cannula is inserted into the distal end of the handle it aligns and connects with both the fluid supply and the vacuum supply. The cannula30can be held in place on the handle20by an attachment cap.

Referring now toFIG. 2, after the cannula30is inserted into the fat tissue; vacuum source14creates a vacuum pressure region within the cavity90of the cannula30such that the target fatty tissue is drawn into the cannula30through the aperture37. The geometry of the end of the supply tube35is configured so the trajectory of the boluses leaving the nozzle43will strike the fatty tissue that has been drawn into the cannula30through the aperture37. For that purpose, the nozzle43at the end of the supply tube35preferably points in a direction that is substantially parallel to that of the inside wall of the cannula30where the supply tube35is affixed. Preferably, the supply tube35and nozzle43are oriented so that the stream flows across the aperture37in the proximal direction P. This placement of the nozzle43of the supply tube35advantageously maximizes the energy transfer (kinetic and thermal) to the fatty tissues, minimizes fluid loss, and helps prevent clogs by pushing the heated fluid and the liquefied material in the same direction that it is being pulled by the vacuum source.

Once the targeted fatty tissue enters the aperture37, it is repeatedly impacted by the boluses of heated fluid that are exiting the supply tubes35via the nozzle43. Adipocytes, which comprise the majority of the targeted fatty tissue mass, undergo a virtually instantaneous process of partial cell disaggregation caused by the impacting boluses of fluid and the fatty tissue is resultantly liquefied. The partial cell disaggregation produces a lipoaspirate that is a multi-cell suspension composed of tiny clusters of fat cells. Such a multi-cell suspension is not a single cell suspension composed of individual fat cells, although it should be appreciated that the multi-cell suspension can include a minor amount of individual fat cells in the suspension. After the partial cell disaggregation occurs, the loose material in the cavity90(i.e., the heated fluid and the liquefied fat tissue) is drawn away from the surrounding tissue by the vacuum source14, and deposited into the canister15(shown inFIG. 1).

In the present embodiment, the proximal direction P of the boluses is the same as the direction that the liquefied tissue travels when it is being suctioned out of the patient via the cannula30. By having the fluid stream flow in the proximal direction P, additional energy (vacuum, fluid thermal and kinetic) is transferred in the same direction, which aids in moving the aspirated tissues through the cannula30. This further contributes to reducing clogs, which can reduce the time it takes to perform a procedure.

Notably, in the embodiments described herein, the majority of the fluid stays within the interior of the cannula during operation (although a small amount of fluid can escape into the subject's body through the aperture37). This is advantageous because minimizing fluid leakage from the cannula30maximizes the energy transfer (thermal and kinetic) from the fluid stream to the tissue drawn into the cannula30for liquefaction.

Each of the supply tubes35is provided for delivering the heated fluid. Supply tube35extends from the proximal portion of cannula30toward the distal tip32of cannula30. Supply tube35extends along the interior of cannula35and can be a separate structure secured to the interior of cannula35or lumen integrated into the wall of cannula30. Supply tube35is configured to deliver heated biocompatible solution for liquefying tissue. The heated solution is delivered through hand piece20and into supply tube35.

The supply tube35extends longitudinally (i.e., along the longitudinal direction L) from the proximal end31to the distal tip32. Supply tube35can optionally include a bend, such as a U-bend41that effectively redirects the direction of fluid flow to the proximal direction P. Adjacent the terminal end of the U-bend41is a supply tube terminal portion42, which includes the nozzle43. The nozzle43is configured to direct heated solution exiting supply tube35across the aperture37. In this manner, supply tube35is configured to direct the fluid onto a target tissue that has entered the cannula30through the aperture37. As an alternative to the U-bend41configuration, the supply tube35can include a manifold that is located at the distal portion of the cannula30and includes a nozzle43for each aperture37.

Heated solution supply tube35can be constructed of surgical grade tubing. Alternatively, in embodiments wherein the heated solution supply tube is integral to the construction of cannula30, the supply tube35can be made of the same material as cannula30. The diameter of supply tube35can be dependent on the target tissue volume requirements for the heated solution and on the number of supply tubes35required to deliver the heated solution across the one or more apertures37. The cannulas30described herein define inner diameters D1or “tube” diameters that can vary with respective outer diameters D2of the cannulas30. The fluid supply tube35defines an inner diameter, which can be in a range from about 0.008 inch. to 0.032 inch. In one preferred embodiment, the portion of the supply tube35within the cannula30has an inner diameter of about 0.02 inch and an exit nozzle43formed by reducing the inner diameter to about 0.013 inch along the final 0.1 inch of length of the supply tube35. The shape and size of the nozzle43can vary, including reduced diameter and flattened configurations.

In other embodiments, the cannula30can have a different number of heated solution supply tubes35, each corresponding to a respective aperture37. For example, a cannula30with three apertures37would preferably include three heated solution supply tubes35. Additionally, heated solution supply tubes can be added to accommodate one or more induction ports, e.g., when four apertures37are provided, four heated solution supply tubes can be provided. In another embodiment, a supply tube35can branch into multiple tubes, each branch servicing a induction port. In another embodiment, one or more supply tubes can deliver the heated fluid to a single induction port. In yet another embodiment, supply tube35can be configured to receive one or more fluids in the proximal portion of cannula30and deliver the one or more fluids though a single nozzle43. In another embodiment, the cannula30can be attached to an endoscope or other imaging device.

The heated fluid should be biocompatible, and can comprise a sterile physiological serum, normal saline solution, glucose solution, Ringer-lactate, hydroxyl-ethyl-starch, or a mixture of these solutions. The heated biocompatible fluid can also comprise saline or sterile water or can be comprised solely of saline or sterile water.

Referring now toFIG. 5, another embodiment of a fluid delivery sub-system3for heating and delivering the fluid to the cannula30will be described. The components inFIG. 5can operate using the following steps: Room temperature saline drains from the IV bag51into mixing storage reservoir54. Once the fluid in the reservoir54reaches a fixed limit, the fixed speed peristaltic pump55of the heater system8moves fluid from the reservoir54to the heater bladder56. The fluid is circulated through the bladder and is heated by the electric panels57of the heater system8. The heated fluid is returned back to the reservoir54and mixes with the other fluid in the storage container. The fixed speed peristaltic pump55continues to circulate fluid to the heater unit and back into the reservoir54. The continuous circulation of fluid provides a very stable and uniform heated fluid volume supply. Temperature control can be implemented using any conventional technique, which will be readily apparent to persons skilled in the relevant arts, such as a thermostat or a temperature-sensing integrated circuit. The temperature can be set to a desired level by any suitable user interface, such as a dial or a digital control, the design of which will also be apparent to persons skilled in the relevant arts.

The pump58can be a piston-type, positive displacement pump that draws heated fluid from the fluid reservoir54into the pump chamber when the pump plunger travels in a backstroke. The fluid inlet to the pump has an in-line one-way check valve that allows fluid to be suctioned into the pump chamber, but will not allow fluid to flow out. Once the pump plunger backstroke is completed, the forward travel of the plunger starts to pressurize the fluid in the pump chamber. The pressure increase causes the one-way check valve at the inlet of the pump58to shut preventing flow from going out the pump inlet. As the pump plunger continues its forward travel the fluid in the pump chamber increases in pressure. Once the pressure reaches the preset pressure on the pump discharge pressure regulator the discharge valve opens. This creates a bolus of pressurized heated fluid that travels from the pump58through cannula handle20and from there into the supply tube35in the cannula30. After the pump plunger has completed its forward travel the fluid pressure decreases and the discharge valve shuts. These steps are then repeated to generate a series of boluses. Suitable repetition rates (i.e., pulse rates) are discussed below.

One example of a suitable approach for implementing the positive displacement pump is to use an off-set cam on the pump motor that causes the pump shaft to travel in a linear motion. The pump shaft is loaded with an internal spring that maintains constant tension against the off-set cam. When the pump shaft travels backwards towards the off-set cam it creates a vacuum in the pump chamber and suctions heated saline from the heated fluid reservoir. A one-way check valve is located at the inlet port to the pump chamber, which allows fluid to flow into the chamber on the backstroke and shuts once the fluid is pressurized on the forward stroke. Multiple inlet ports can allow for either heated or cooled solutions to be used. Once the heated fluid has filled the pump chamber at the end of the pump shaft backwards travel, the off-set portion of the cam will start to push the pump shaft forward. The heated fluid is pressurized to a preset pressure (e.g., 1100 psi) in the pump chamber, which causes the valve on the discharge port to open, discharging the pressurized contents of the pump chamber to fluid supply tubes35. Once the pump plunger completes its full stroke based on the off-set of the cam, the pressure in the pump chamber decreases and the discharge valve closes. As the cam continues to turn the process is repeated.

The heated biocompatible solution in a tissue liquefaction system is preferably delivered in a manner optimized for liquefying the target tissue. Variable parameters include, without limitation, the temperature of the solution, the pressure of the solution, the pulse rate or frequency of the solution, and the duty cycle of the pulses or boluses within a stream, the rise rate (i.e., the speed with which the fluid is brought to the desired pressure) of the pulse, and the size of the bolus, which is determined by the specific parameters of the pump dimensions. Additionally, the vacuum pressure applied to the cannula through the vacuum source14can be optimized for the target tissue.

It has been found that for liposuction procedures targeting subcutaneous fatty deposits within the human body, the biocompatible heated solution should preferably be delivered to the target fatty tissue at a temperature between 75 and 250 degrees F., and more preferably between 100 and 140 degrees F. A particular preferred operating temperature for the heated solution is about 115 degrees F., since this temperature appears very effective and safe. Also, for liquefaction of fatty deposits the pressure of the heated solution is preferably between about 200 and about 2500 psi, more preferably between about 600 and about 1300 psi, and still more preferably between about 800 and about 1100 psi. A particular preferred operating pressure is about 900 psi, which provides the desired kinetic energy while minimizing fluid flow. The volume of each bolus (pulse) delivered to each aperture is preferably between about 200 microliters and about 275 microliters, more preferably between about 215 microliters and about 245 microliters, and still more preferably about 230-microliters. The pulse rate of the solution is preferably between 20 and 150 pulses per second, more preferably between 25 and 60 pulses per second. In some embodiments, a pulse rate of about 40 pulses per second was used. And the heated solution can have a duty cycle (i.e., the duration of the pulses divided by the period at which the pulses are delivered) of between 1-100%. In preferred embodiments, the duty cycle can range between 30 and 60%, and more particularly between 30 and 50%.

In preferred embodiments, the rise rate is about 0.1 to 3.0 milliseconds. This can be accomplished by having a standard relief valve that opens once the pressure in the pump chamber reaches the set point (which, for example, can be set to 1100 psi). The pressure increase is almost instantaneous and the fluid exits the fluid supply tube(s)35during a very short time span, as more fully described in the '700 Reference.

Returning now to the suction subsystem5,FIG. 2depicts an expanded cut-away view of an embodiment of the cannula30that includes two (2) apertures37. As shown, the cannula30has two apertures37located near the distal region of the cannula30and proximal to distal tip32. The apertures37can be positioned in various configurations about the perimeter of the distal region of the cannula30. In the illustrated embodiment, the apertures37are on opposite sides of the cannula30, but in alternative embodiments they can be positioned differently with respect to each other. The apertures37are configured to allow fatty tissue to enter the orifices in response to vacuum pressure within the cannula cavity90created by the vacuum supply14. The material that is located in the cavity90(i.e., tissue that has been liquefied and the heated fluid that exited the supply tube35) is then suctioned away in the proximal direction P up through the cannula30, the handpiece20, and into the canister15(all shown inFIG. 1). A conventional vacuum pump (e.g., the AP-III HK Aspiration Pump from HK Surgical Inc. of San Clemente, Calif.) can be used for the vacuum source14, although other types of vacuum pumps can be employed.

In preferred embodiments, the aspiration vacuum that sucks the liquefied tissue (or at least a major portion thereof) back up through the cannula30ranges from 0.33-1.00 atmosphere (1 atmosphere=760 mm Hg). Optionally, the vacuum level can be adjustable by the surgeon during the procedure as needed. Because reduced aspiration vacuum is associated with lower blood loss, the surgeon can prefer to work at the lower end of the vacuum range.

Returning toFIGS. 1-4, the cannula30and handpiece20will now be described in greater detail. Hand piece20has a proximal end21and a distal end22, a fluid supply connection23and a vacuum supply connection24preferably located at the proximal end, and a fluid supply fitting and a vacuum supply fitting at the distal end (to interface with the cannula). The hand piece20routes the heated fluid from the fluid supply to the supply tubes35in the cannula30and routes the vacuum from the vacuum source14to the cavity90in the cannula30, to evacuate material from the cavity90. The handpiece20can have pistol-type configuration, as shown, although in preferred embodiments the handpiece20has a wand-type configuration.

In some embodiments, a cooling fluid supply6can be used to dampen the heat effect of the heated fluid stream in the surgical field. In these embodiments, the handpiece also routes the cooling fluid into the cannula35using appropriate fittings at each end of the handpiece. In these embodiments, a cooling fluid metering device13can optionally be included. The hand piece20can optionally include operational and ergonomic features such as a molded grip, vacuum supply on/off control, heat source on/off control, alternate cooling fluid on/off control, metering device on/off control, and fluid pressure control. Hand piece20can also optionally include operational indicators including cannula aperture37location indicators, temperature and pressure indicators, as well as indicators for delivered fluid volume, aspirated fluid volume, and volume of tissue removed. Alternatively, one or more of the aforementioned controls can be placed on a separate control panel.

The distal end22of hand piece20is configured to mate with the cannula30. The cannula30comprises a hollow tube of surgical grade material, such as stainless steel, that extends from a proximal end31and terminates in a rounded tip at a distal end32. The proximal end31of the cannula30attaches to the distal end22of hand piece20. Attachment can be by means of threaded screw fittings, snap fittings, quick-release fittings, frictional fittings, or any other attachment connection known in the art. It will be appreciated that the attachment connection should prevent dislocation of cannula30from hand piece20during use, and in particular should prevent unnecessary movement between cannula30and hand piece20as the surgeon moves the cannula hand piece assembly in a back and forth motion approximately parallel to the cannula longitudinal axis33.

The cannula30can include designs of various diameters, lengths, curvatures, and angulations to allow the surgeon anatomic accuracy based upon the part of the body being treated, the amount of fat extracted as well as the overall patient shape and morphology. This would include cannula30outer diameters D2of 2.0 mm for delicate precise liposuction of small fatty deposits of about 1 mm in size to cannulas30with outer diameters D2up to 7.0 mm for large volume fat removal (i.e., abdomen, buttocks, hips, back, thighs etc.), and cannula30lengths L1from 2 cm for small areas (i.e., eyelids, cheeks, jowls, face etc.) up to 50 cm in length for larger areas and areas on the extremities (i.e., legs, arms, calves, back, abdomen, buttocks, thighs, etc.). A myriad of cannula30designs include, without limitation, a C-shaped curves of the distal tip alone, S-shaped curves, step-off curves from the proximal or distal end as well as other linear and nonlinear designs. The cannula30can be a solid cylindrical tube, articulated, or flexible.

Each of the apertures37includes a proximal end38, a distal end39, and a perimeter edge40. Although the illustrated apertures37are oval, round, or oblong, in alternative embodiments they can be made in other shapes (e.g., egg shaped, diamond or polygonal shaped, or an amorphous shape). As depicted inFIG. 3, the apertures37can be arranged in a longitudinally elongated fashion on one or more sides of the cannula30. Alternatively, the apertures37can be provided in a series along the longitudinal direction L, as depicted inFIG. 4. Optionally, the dimensions or shape of each aperture37can change, for example, from the most distal aperture37to the most proximal aperture37, as illustrated inFIG. 4, where the diameter of each aperture37can decrease in succession from the most distal aperture37to the most proximal aperture37.

The perimeter edge40is configured to present a smooth, unsharpened edge to substantially eliminate shearing, tearing or cutting of the target fatty tissue and also to substantially avoid damage to adjacent non-target tissue caused by shearing, tearing or cutting, particularly for visceral fat removal. Because the target tissue is liquefied, the cannula30does not need to shear tissue.

For targeting visceral fat, the cannula30preferably has between one (1) and three (3) apertures37, although more than three (3) apertures37can optionally be employed. The apertures37can have different shapes, such as round or oblong, by way of non-limiting examples. When oblong apertures37are used, a longitudinal axis33aof the aperture37should preferably be oriented substantially along the longitudinal direction L. Accordingly, the oblong aperture37should have a longitudinal dimension L2(i.e., length) that is greater that a lateral dimension L3(i.e., width) thereof. Stated differently, the aperture37is preferably elongated along the longitudinal direction L. The apertures37should not be too large, because with smaller apertures37less fat is suctioned into the cannula30for a given bolus of energy. On the other hand they should not be too small, to permit the fatty tissue to enter. A suitable size for oblong apertures37, according to one example embodiment, is a width L3of about 0.04 inch and a length L2of about 0.24 inch (i.e., about 0.04 inch wide×0.24 inch long). In further embodiments, the apertures37can be wider than 0.04 inch and longer than 0.24 inch. The size of the apertures37can further be varied for different applications depending on the surgeon's requirements. More extensive areas to be suctioned can require larger apertures37.

It should be appreciated that the interior cavity90of the cannula30defines a suction path for the removal of visceral fat from the subject's body. The suction path90of the embodiments described herein can define a resistance ratio and a surface area per unit length of the suction path as more fully described in the '700 Reference.

Because visceral fat is located on and around organs that are more delicate and more vital than the anatomical structures in which subcutaneous fat is found (skin on one side, muscle on the other side), care must be taken to minimize trauma to the relevant anatomical regions, to permit removal the visceral fat without causing damage or trauma to the adjacent internal organs or to the plethora of blood and lymphatic vessels, and nerves that course throughout the mesenteric fat which supply the bowel. For example, the apertures37need to have perimeter edges40that are rounded, dull, or otherwise blunt so that they present non-cutting surfaces to target and non-target tissue, so as to avoid shearing and cutting of tissue. Additionally, the pressure and temperature ranges should be selected to avoid trauma to non-fat tissue during visceral fat removal.

The cannula30defines a cannula body59that is preferably constructed from cylindrical, elliptical, or flat face tubing, with no exaggerated blunt faces. Suitable materials for the cannula body59include surgical grade metallic materials like 304 and 316 stainless steel, as well as shape memory and super elastic metallic materials like Nitinol. The cannula30can also be made of non-metallic materials like polyetheretherketon (PEEK), polycarbonate (PC), high-density polyethylene (HDPE), nylon, and other high durometer plastics.

Referring now toFIG. 6, in additional embodiments, one or more of the fluid supply tubes35can have a nozzle43that ejects the series of fluid boluses in the distal direction D. In such embodiments, the cannula30can include a cannula body59that defines the interior cavity90and can further define therein a distal end surface92, which can be configured to redirect the loose fat tissue in the proximal direction P and toward the proximal end31of the cannula30. The inventor has observed that the present embodiment, which directs the series of fluid boluses in the distal direction D to impinge against fatty tissue drawn into the interior cavity90, exhibits favorable performance in removing fatty tissue. Furthermore, by locating each nozzle43proximally of the respective aperture37, the need for a manifold (to redirect the fluid delivery tubes35to deliver the boluses in the proximal direction) can be obviated, which can provides a simplified manufacturing process and thereby reduce manufacturing costs. It is also believed that, by locating each nozzle43proximally of the respective aperture37for distal fluid ejection therefrom, the boluses can have a less turbulent, cleaner presentation to the fat, which is believed to enhance the rate of fat extraction.

The cannula30can also include an outer sleeve60disposed around an outer surface62of the cannula body59. As shown, the outer sleeve60is preferably a continuous sheath surrounding the cannula body59from a sleeve proximal end64located at or adjacent the proximal end31of the cannula30to a sleeve distal end66located proximate the distal end32of the cannula30. In other embodiments, the sleeve60can be braided or coiled around the outer surface62of the cannula body59. The sleeve60defines at least one aperture67that is configured to align with at least one aperture37of the cannula30. The aperture67of the sleeve60defines a proximal end68, a distal and69, and a perimeter edge70, in similar fashion to the proximal end38, distal end39, and perimeter edge40of the aperture37of the cannula30. The perimeter edge70of the sleeve60aperture67is configured to present a smooth, unsharpened edge to discourage shearing, tearing or cutting of the target visceral fatty tissue. In some embodiments, the aperture67of the sleeve60can be configured to prevent contact between tissue and any edges40of the aperture37of the cannula30. For example, aperture67of the sleeve60is preferably smaller than aperture37of the cannula30. In this manner, the edges70of the sleeve aperture67can effectively provide relief surfaces for the aperture37of the cannula30. Accordingly, in such embodiments, the cannula body59can be constructed of a hard material, such as stainless steel, and the sleeve60can be configured to prevent contact between edges40and target visceral fat and non-target tissue.

The sleeve60is preferably configured to be disposable, such that the sleeve60can be removed from the cannula30and replaced with a new sleeve60between uses. In other embodiments, the sleeve60can be configured to be detachable and re-attachable to the cannula30for sterilization between uses. In either of these embodiments, the cannula30can be included in a kit that includes a plurality of sleeves60, at least some of which can possess different characteristics, thereby allowing the surgeon to effectively adapt the cannula30according to specific surgical needs by selecting the appropriate sleeve60. The sleeve60and the cannula30can define complimentary mating features for ensuring proper alignment of the apertures37,67thereof. By way of one non-limiting example, the sleeve60can define an inwardly extending protrusion72configured to mate with, such as by being received within, a complimentary receptacle74defined in the outer surface62of the cannula30. Other complimentary mating features are also within the scope of the present disclosure, such as ball-and-detent type mechanisms and the like. The complimentary mating features can also be configured to further retain the sleeve60is position relative to the cannula30during use.

The sleeve60is preferably constructed of an electrically insulative material, such as Teflon or other flexible polymeric materials like urethane, nylon, and others. In other embodiments, the sleeve60can be made of thin wall metallic materials like stainless steel and Nitinol in a non-continuous (coil or braid) to provide flexibility. The sleeve60material can be selected to avoid forming sharp edges when contacted against other objects, such as other surgical tools, cleaning instruments, and the like. Avoiding of the formation of sharp edges, such as burs, is important to prevent inadvertent cutting, abrading, scraping, or otherwise harming delicate non-target tissues within or adjacent the visceral fat being removed, such as organ tissue, vascular tissue, and mucosa, by way of non-limiting examples. The sleeve60material can also be selected such that an outer surface76of the sleeve60is smooth and has a low coefficient of friction (both static and sliding friction), thereby avoiding or at least reducing abrasion against delicate tissues within or adjacent visceral fat, such as those delicate tissues mentioned above. The sleeve60can also be subjected to one or more finishing processes to “smooth” or otherwise reduce the surface finish roughness (as measured by root square mean (RMS)) of the outer surface76.

It should also be appreciated that, in other embodiments, the cannula30itself can be disposable. For example, any of the cannulas30disclosed herein can include a cannula body59that is constructed from a polymeric material that provides sufficient rigidity, such as polyetheretherketon (PEEK), polycarbonate (PC), high-density polyethylene (HDPE), nylon, and other high durometer plastics. In such embodiments, the cannula body59material can be selected to avoid forming sharp edges when contacted against other objects, such as other surgical tools, cleaning instruments, and the like. In such embodiments, a surgical kit can include a plurality of cannulas30, each attachable to and non-destructively detachable from the handpiece20.

In additional embodiments, the cannula body59can be constructed of a multi-layer polymer and metallic combination, such as a Teflon base inner body layer with a metallic braid or coil outer layer. In such embodiments, the cannula body59can be fitted with an outer sleeve60, as described above. Such a multi-layer cannula30with sleeve60can be similar to existing coronary guiding catheter technologies like the one used in Cordis Vista Brite Tip Guiding Catheters and endoscopes like the one used in the Olympus Fiber Optic Lines (BF-XP60).

The cannula30can also include at least one cauterizing element78, such as a cauterizing electrode, for mitigating bleeding that can result in some subjects during the visceral fat removal process. As shown inFIG. 6, the cauterizing electrode78can be a single tip electrode located at the distal end32of the cannula30. In such embodiments, the distal end64of the sleeve60can be configured to define a distal opening that exposes the tip electrode78. As shown inFIG. 7, in additional embodiments, the at least one cauterizing element78can include one or more ring electrodes78disposed along the outer surface76of the sleeve60. In such embodiments, the sleeve60can extend over a distal end of the cannula body59and thereby the sleeve60can define the distal end32of the cannula30. In embodiments where the sleeve60is omitted, the one or more ring electrodes78can be disposed along the outer surface62of the cannula body59. In further embodiments, the cannula30can include a distal tip electrode78and one or more ring electrodes78.

The at least one cauterizing element78is in electrical communication with a control element80, such as a foot pedal or optionally a button or trigger located on the handpiece20, by way of non-limiting examples. The control element80can be in electrical communication with the cauterizing electrode78via circuitry, such as one or more wires82, which can extend through a channel or conduit, which can be enclosed and can be located within the cavity90of the cannula30or can be defined in the cannula body59, or can extend between the outer surface62of the cannula30and an inner surface of the sleeve60, by way of non-limiting examples. The physician can activate the at least one cauterizing electrode78as needed to cauterize or otherwise coagulate bleeding in the mesentery during the fat removal process.

Suitable dimensions for the cannula30outer diameter D2range from 2.0 mm for small delicate visceral fatty deposits to 7.0 mm for large volume visceral fat removals as in an omentectomy. For open surgical procedures the entire range of cannula30sizes can be used, including outer diameters D2up to about 20 mm. For laparoscopic or approaches requiring passage through other conduits or trocar sheaths, the cannula30outer diameter D2range (i.e., measured at the outer surface76of the sleeve60or, in embodiments that omit the sleeve60, measured at the outer surface62of the cannula body59) should be from 2.0 mm to 7.0 mm, based on currently used abdominal trocar and access cannula sizes.

Suitable dimensions for the cannula30length L1range from 2.0 cm for open surgical procedures to 50 cm for laparoscopic or procedures requiring access through other cannula sheaths. The cannula30preferably has between one (1) and six (6) apertures37, which can be spaced on the same side of the cannula30or around the circumference of the cannula30. More preferably, between one (1) and four (4) apertures37are used, all positioned on one side, which can be referred to as a “bottom side” or “active side” of the cannula30. A preferred visceral cannula30has one (1), two (2), or three (3) apertures37, all positioned on the bottom side so as to minimize pulling in non-target tissues and provide the surgeon with greater control.

The shapes of the apertures37,67can be circular, elliptical, rectangular, triangular, or many other geometrical shapes. As shown inFIG. 8, the length L2of the apertures37,67is preferably greater than the width L3thereof. Stated differently, the apertures37,67are preferably elongated along the longitudinal direction L. One preferred shape for the apertures37,67is an elliptical shape elongated along the longitudinal direction L. The size of the apertures37,67can vary for any given cannula30diameter and length. The width L3of the apertures37,67is preferably smaller than half (50%) of the cannula30outer diameter D2. The length L2of the apertures37,67can be three quarters (75%) of the cannula diameter 30 or less. An effective cannula aperture37configuration is 1 mm in width L3and 6 mm in length L2, according to one non-limiting example. Apertures37,67configured in this manner (i.e., being longitudinally elongate) can provide increased fat removal efficiency when the surgeon moves the cannula30back and forth in a pivoting or arcing motion along the lateral direction (i.e., a motion analogous to a windshield wiper). Such a range of motion can include a total articulation angle of 90 degrees (i.e., ±45 degrees to either side), but smaller or larger articulation angles can be implemented, e.g., up to a total of 180 degrees (i.e., ±90 degrees to either side).

In an example embodiment, the cannula30can define an outer diameter D2of about 2.0 mm measured at the outer surface76of the sleeve60, and the cannula30and sleeve60can define, in complimentary fashion, a single pair of aligned apertures37,67each having a perimeter edge40,70that is smooth and unsharpened to avoid shearing, tearing or cutting of the target visceral fatty tissue and also to minimize trauma to non-target tissues. The aligned apertures37,67can define a longitudinal length L2greater than their lateral width L3.

In additional embodiments, the distal portion of the cannula30can optionally have two (2) pairs of apertures37,67disposed on opposite sides of the cannula30, similar to the manner shown inFIG. 2. In further embodiments, the cannula30can have different numbers of pairs of apertures37,67, which can be positioned in different configurations along the distal portion of cannula30. In such embodiments, the pairs of apertures37,67are preferably located on the same side of the cannula30, though the pairs of apertures37,67can optionally be angularly offset about the central axis33of the cannula30.

The apertures37are configured to allow fatty tissue to enter the apertures37in response to vacuum pressure within the cannula shaft created by vacuum supply14. Apertures37include a proximal end38, a distal end39, and a perimeter edge40. Apertures37can take a generally circular, oval or egg shape, diamond or polygonal shape, or an amorphous shape. In the illustrated embodiments, the apertures37are oval and are all the same size. In alternative embodiments, the dimensions or shape of the apertures37can vary within a single cannula, like the cannula shown inFIG. 4, in which the diameter of each aperture37decreases in succession from the distal end to the proximal end.

The cannula30can be made of round tubing or tubing with one or more flat surfaces. The distal end32of the cannula30can be integrally formed as a continuation of the cannula30shaft or it can be a two piece construction, with a metal or polymer tip affixed to the end of the shaft. Polymer tips can be advantageous because they are softer than metal. Examples of suitable materials for the tip include, but are not limited to nylon and high density polyethylene.

In further embodiments (not shown), one or more articulation joints can be incorporated into the cannula30. Preferably, these articulation joints are provided proximal to the proximal-most orifice. One suitable way to implement these articulating embodiments is to replace a portion of the cannula from a point that is proximal of the proximal-most orifice with a flexible tubing, and then running that flexible tubing through a conventional articulation joint. In these embodiments, the flexible tubing should be selected or reinforced so as not to collapse under the vacuums expected to be encountered. Examples of suitable articulation joints can be found in U.S. Pat. Nos. 4,108,211 and 7,090,637, each of which is incorporated herein by reference as if set forth herein in its entirety. Other examples include the bending mechanisms used in endoscopes like the Olympus Fiber Optic Lines (BF-XP60) and in other articulating devices like the Medtronic Heart Wall Ablation Catheters (RF Conductr (MC) Series). Any suitable conventional control mechanism can be used to bend the articulation joints, depending on the articulation joint that is used. Examples include foot pedals and hand controls.

When articulation joints with bending mechanisms are incorporated, the operator is able to control the position of the distal end32of the cannula30. For example, if an articulation joint with a single degree of freedom is used, the operator would be able to bend the joint back and forth, like a windshield wiper so as to move the distal end in an arc, as described above.

If an articulation joint with two perpendicular degrees of freedom is used, the operator would be able to bend the joint back and forth, and would also be able to move the distal end of the probe up and down in a direction that is perpendicular to the plane of the wiping motion. These embodiments permit manipulation of the cannula's distal end32in three-dimensional space, providing additional fine-tuned control of movement, which can be particularly desirable when removing visceral fat from around intestinal structures. A suitable range of motion in the up/down direction is 45 degrees of bending, but smaller or larger articulation angles can be implemented, e.g., 80 degrees of bending. Optionally, the bending can be controlled by a mechanized, motorized unit under direct control of the surgeon.

The visceral fatty tissue lipectomy of the present invention should be target tissue-specific so as to remove the visceral fat without damaging the surrounding organs and tissue.

To accomplish this, the temperature of the solution is preferably between 75 and 250 degrees F., more preferably between 75 and 190 degrees F., still more preferably between 100 and 140 degrees F., and most preferably about 115 degrees F.

The stream pressure is preferably between 300 and 2000 psi, more preferably between 600 and 1300 psi, still more preferably between 800 and 1100 psi, and most preferably about 900 psi.

The fluid should preferably be delivered in pulses, with a preferred pulse rate between 25 and 60 pulses per second, more preferably about 40 pulses per second.

The preferred duty cycle for these pulses is between about 30% and 80%, more preferably about 30% to minimize the amount of waste fluid that is generated.

The preferred rise rate for the pulses is between about 0.1 to 3.0 milliseconds.

The aspiration (vacuum) is preferably between ⅓ and 1 atmosphere, and more preferably between ⅓ and ¾ atmosphere.

In the most preferred embodiments for removing visceral fat, the temperature of the solution is between 100 and 140 degrees F., and it is delivered in pulses at a stream pressure between 800 and 1100 psi at a pulse rate between 25 and 60 pulses per second. This combination of parameters provides good tissue differentiation, so as to facilitate removal of the visceral fat without causing trauma to the delicate anatomic structures in the vicinity. It should be appreciated that the foregoing fluid parameters, and those described throughout this disclosure, apply to each pulse of fluid individually. Stated differently, one or more and up to each of the fluid parameters can vary between individual pulses while remaining within the disclosed range(s) for the associated parameter(s).

With reference toFIGS. 9A-9D, additional embodiments of cannulas30having two (2) laterally spaced (i.e., side-by-side) apertures37will now be described. In each of these embodiments, the cannula30includes two nozzles43that respectively direct boluses of fluid toward fatty tissue drawn into the inner cavity90through the apertures37. In these embodiments, the apertures37are preferably the same size and shape, each being oblong and longitudinally elongate. For example, the apertures37can each have a length L2that is about 6 times greater than their width L3, although other length-to-width ratios are within the scope of the present disclosure. The apertures37can also be spaced from each other by an offset distance L4, which can be measured along the circumference of the outer surface of the cannula30. Alternatively, the offset distance L4can be measured along the lateral direction A. The apertures37are also preferably longitudinally offset from each other or “staggered” such that the distal end39of the proximal-most one of the apertures37is longitudinally aligned with a longitudinal mid-point33b(such as along the longitudinal aperture axis33a) of the distal-most one of the apertures37.

Referring now toFIG. 9A, the cannula30with side-by-side apertures37can include first and second supply tubes35with respective nozzles43that are proximally spaced from the proximal ends38of the apertures37and are configured to eject fluid boluses in the distal direction D. The first and second fluid supply tubes35can be connected to two separate pumps19having the same design. Stated differently, in this embodiment, each supply tube35has its own pump19. Each pump19delivers pressurized, heated fluid to the supply tubes35so that series of boluses of the fluid are ejected from the respective nozzles43.

As shown inFIG. 9B, a variation of the cannula30with side-by-side apertures37can include a single (1) main fluid supply tube35ais connected to the pump19. The main fluid supply tube35aterminates distally at a junction35bat which the main fluid supply tube35ais bifurcated into a pair of supply tube branches35cthat have respective nozzles43that are proximally spaced from the proximal ends38of the apertures37and are configured to eject fluid boluses in the distal direction D.

As shown inFIG. 9C, another variation of the cannula30with side-by-side apertures37can include a single (1) main fluid supply tube35athat terminates at a junction35b, as above; however, in this variation the supply tube branches35cdefine bends, such as U-bends41(or an alternative manifold as mentioned above), and include terminal portions that extend proximally to respective nozzles43that are distally spaced from the distal ends39of the respective apertures37and are configured to eject fluid boluses in the proximal direction P.

As shown inFIG. 9D, a further variation of the cannula30with side-by-side apertures37can include first and second fluid supply tubes35that each define a bend, such as a U-bend41, that re-directs the fluid boluses in the proximal direction P. The first and second fluid supply tubes35have nozzles43at their terminal ends that are distally spaced from the distal ends39of the respective apertures37and are configured to eject fluid boluses in the proximal direction P. As above, the first and second fluid supply tubes35can be connected to two separate pumps19that are of the same design.

According to a non-limiting example of the present embodiments, the cannula30can define the following parameters: the cannula30defines an outer diameter D2in a range of about 2.4 mm to about 3.5 mm; the apertures37each have a length L2of about 6 mm and a width L3of about 1 mm; the apertures37are spaced from each other by an offset distance L4of about 0.5 mm (measured along the circumference of the cannula30); the apertures37are longitudinally staggered such that the distal end39of the proximal-most aperture37is longitudinally aligned with a longitudinal mid-point33bof the distal-most aperture37; and the nozzles43each define an inner diameter that tapers to about 0.33 mm (about 0.013 inch).

The cannulas30according to the foregoing non-limiting example parameters can be employed with a pump system19that is configured to deliver boluses of larger volume (such as twice the volume) and similar pulse rates relative to the embodiments described above with reference toFIGS. 1-8. For example, for the cannula30variations shown inFIGS. 9B and 9C, the pump system19can employ a pump that is configured to deliver individual boluses each defining a volume of approximately 460-microliters. In such examples, approximately 460-microliter boluses travel down the single, main fluid supply tube35aand then at the tube's bifurcation point (i.e., junction35b) the boluses split in half resulting in the creation of approximately 230-microliter boluses which travel down each supply tube branch35c; the end result is that approximately 230-microliter boluses are emerging from each of the supply tube nozzles43. Thus, it can be said that the pump system19can deliver to the main fluid supply tube35aa series of approximately 460-microliter boluses, which are divided at the junction35binto respective first and second series of approximately 230-microliter boluses to the first and second supply tube branches35c, which are then ejected from the respective nozzles43. For the cannula30variations shown inFIGS. 9A and 9D, two pumps of the same design are utilized which deliver to each of the first and second fluid supply tubes35a series of boluses each having a volume of about approximately 230-microliters, which are ejected from the respective nozzles43.

Alternatively, the cannulas30shown inFIGS. 9B-9Ccan be employed with a pump that delivers the boluses at a higher pulse rate (such as a pulse rate that is twice as great) and similar bolus volume relative to the embodiments described above with reference toFIGS. 1-8. For example, the pump can be configured to deliver boluses at a pulse rate of about 80 pulses per second and having individual bolus volumes of approximately 230-microliters.

Referring now toFIG. 9E, in further embodiments, the cannula30can have three (3) apertures37. The apertures37are preferably the same size and shape, each being oblong and longitudinally elongate. For example, as above, the apertures37can each have a length L2that is about 6 times greater than their width L3, although other length-to-width ratios are within the scope of the present disclosure. The apertures37can also be spaced from each other by an offset distance L4, which can be measured along the circumference of the outer surface of the cannula30. Alternatively, the offset distance L4can be measured along the lateral direction A. The apertures37can also be longitudinally staggered. For example, the three (3) apertures37can include a first, central aperture37that is distally offset from a second aperture37and a third aperture37. The second and third apertures37can be longitudinally aligned with each other, optionally such that the distal ends39of the second and third apertures37are longitudinally aligned with a longitudinal mid-point33b(such as along the longitudinal aperture axis33a) of the first aperture37. The apertures37can arranged so as to occupy a circumferential span L5along the cannula30, as measured about the longitudinal axis33. The circumferential span L5can be measured from opposite lateral-most edges40of the second and third apertures37, and can be in a range of about 80 degrees to about 180 degrees, and more particularly in a range of about 120 degrees to about 160 degrees, and preferably about 140 degrees. It should be appreciated that other aperture arrangements, including staggered and non-staggered arrangements, are within the scope of the present disclosure.

The three-aperture37cannula30preferably includes three (3) nozzles43that respectively direct boluses of fluid toward fatty tissue drawn into the inner cavity90through the apertures37. For example, the cannula30can include a single (1) main fluid supply tube35athat is connected to the pump19. The main fluid supply tube35aterminates distally at a junction35bat which the main fluid supply tube35ais trifurcated into a trio of supply tube branches35cthat have respective nozzles43that are proximally spaced from the proximal ends38of the apertures37and are configured to eject fluid boluses in the distal direction D. Alternatively, one or more and up to all of the supply tube branches35ccan define a bend, such as a U-bend, that re-directs the fluid boluses in the proximal direction P across the apertures37. The three-aperture cannula30can be employed with a pump system19that is configured to deliver boluses of larger volume (such as three times (3×) the volume) and similar pulse rates relative to the embodiments described above with reference toFIGS. 1-8. For example, the pump system19can employ a pump that is configured to deliver individual boluses each defining a volume of approximately 690 microliters to the main fluid supply tube35a. In such examples, approximately 690-microliter boluses travel down the single, main fluid supply tube35aand then split at the junction35binto substantially equal thirds, resulting in the creation of approximately 230-microliter boluses which travel down each supply tube branch35c; the end result is that approximately 230-microliter boluses are emerging from each of the supply tube nozzles43. Alternatively, the three-aperture cannula30can be employed with a pump that delivers the boluses at a higher pulse rate (such as a pulse rate that is three times (3×) as great) and similar bolus volume relative to the embodiments described above with reference toFIGS. 1-8. For example, the pump can be configured to deliver boluses at a pulse rate of about 120 pulses per second and having individual bolus volumes of approximately 230-microliters. In other embodiments, a three-aperture37cannula30can include a trio of supply tubes each connected to a separate pump. For example, in such embodiments, each separate pump an deliver a respective series of boluses of approximately 230-microliters to the nozzles43for ejecting toward fatty tissue drawn into the cavity90through the apertures37. Thus, the cannulas30of the foregoing multi-aperture embodiments should be matched with a pump configuration tailored to deliver boluses of desired volume from each nozzle43.

It should be appreciated that the pump system19should utilize different pump configurations according to the number of apertures37provided on the cannula30. For example, for a two-aperture cannula30having two fluid supply tubes35(FIGS. 9A and 9D), the pump system19employs two fixed-volume pumps each delivering boluses of about 230 microliters to the respective fluid supply tube35. For a two-aperture cannula30having a single fluid supply tube35that is bifurcated into two supply tube branches35c(FIGS. 9B and 9C), the pump system19employs a single, fixed-volume pump that delivers boluses of about 460 microliters to the supply tube35. For a three-aperture cannula30having a single fluid supply tube35that is trifurcated into three supply tube branches35c(FIG. 9E), the pump system19employs a single, fixed-volume pump that delivers boluses of about 690 microliters to the fluid supply tube35. It should be appreciated that the tissue liquefaction system2can be configured to accommodate various pump systems19, particularly those having pump configurations that are tailored for the specific number of apertures37provided by the cannula30(e.g., single pump, two pumps, three pumps). For example, the tissue liquefaction system2can be configured to interchangeably employ various fluid delivery sub-systems3each having an aperture-specific pump system19configurations. In such embodiments, the tissue liquefaction system2can include a fluid delivery kit that includes various fluid delivery sub-systems3that have different, aperture-specific pump systems19. In other embodiments, the tissue liquefaction system2can employ a single fluid delivery sub-system3that itself can house or otherwise accommodate any of the foregoing pump configurations (e.g. single pump, two pumps, three pumps) in interchangeable fashion. In such embodiments, the tissue liquefaction system2can include a pump kit that includes various aperture-specific pump systems19.

The multi-aperture37cannulas30described above provide significant advantages over prior art cannulas. In particular, the inclusion of additional apertures37, such as second and/or third apertures37, can significantly increase the rate of fat extraction by increasing the area through which fat is drawn into the interior cavity90. Additionally, by providing the heated fluid from the fluid delivery sub-system3at the same functioning characteristics (e.g., temperature, pressure, bolus volume, pulse rate, rise rate) to each nozzle43(and thus across each aperture37to the fat drawn into the interior cavity90), the fat extraction rate is further increased, especially relative to single-aperture37cannulas. Thus, the multi-aperture37cannulas30disclosed herein can significantly reduce the time necessary to extract visceral fat, thereby significantly reducing procedure duration.

It should be appreciated that the cannulas30constructed according to the embodiments ofFIGS. 9A-9Ecan be employed with a sleeve60having apertures67that are aligned with the apertures37of the cannula30, similar to the manner described above with reference toFIGS. 6-8. It should also be appreciated that the cannulas30constructed according to the embodiments ofFIGS. 9A-9Ecan be employed with one or more cauterizing elements78, similar to the manner described above.

In further embodiments, the cannula30can define one or more bends, as shown inFIGS. 10A and 10B. In such embodiments, the distal-most bend46is preferably proximal to the proximal-most aperture37. The bends46can be configured to aid the surgeon in the insertion and manipulation of the cannula30, to conform to the particular anatomic region being treated. It should be appreciated that more than two (2) bends can be employed. The bends46can either be abrupt, such as by being defined by intersecting linear portions of the cannula (e.g., bent like a hockey stick), as illustrated inFIGS. 10A and 10B, or can involve radiused portions of the cannula that that define a radius of curvature, depending on the anatomic region being treated. The bends46are preferably proximal to all the apertures37. Each bend46can define a bend angle between 5 degrees and 85 degrees, as described more fully in the '700 Reference.

Visceral fat removal can be done using an open surgical methodology or a laparoscopic one. In an open methodology the cannula30is either inserted into the abdomen, or it is inserted into intra-abdominal anatomical tissues that have been exteriorized outside the abdominal cavity. In a laparoscopic approach, the visceral fat is visualized by a laparoscopic camera, as described in more detail below.

In an example method of an open procedure for removing visceral fat from a patient, the surgeon can make an incision, such as in the abdomen. The incision can be a vertical incision (i.e., an incision along the cranial-caudal direction) substantially down the center or slightly off-center of the abdomen. The incision penetrates the subcutaneous layer, the abdominal muscles, and the parietal peritoneum, providing access to the peritoneal cavity, particularly the mesentery. Retractors can be applied to the incised tissue to widen and maintain an open working channel providing access to the mesentery. The surgeon can insert the cannula30through the working channel and engage target visceral fat in the mesentery, including targeted fat in the omentum (e.g., greater omentum and lesser omentum), transverse mesocolon, small bowel mesentery, and sigmoid mesentery, as needed, by way of non-limiting examples. The surgeon can thereby employ the cannula30to liquefy, loosen, and aspirate the target visceral fat (or at least a major portion thereof) as needed. During this process, the surgeon can optionally externalize at least a portion of the small intestine, repeatedly and sequentially, a process referred to in the art as “running the bowel.”

Additionally or alternatively, the surgeon can use the working channel in the abdomen to access the extraperitoneal space to remove visceral fat from the anterior pararenal space and/or the perirenal space, the latter of which contains the kidneys. Removing visceral fat from the perirenal space (e.g., the perirenal fat capsule that surrounds the kidneys) using the cannula30can be referred to as a perirenal visceral lipectomy. In such a procedure that employs the abdominal working channel to access the perirenal space, the surgeon can make a secondary incision in the anterior renal fascia and can insert the cannula30through this secondary incision. In other embodiments, the surgeon can employ a different surgical approach to the perirenal space, such as a lateral approach, including an antero-lateral, true lateral, or a posterior-lateral approach.

Referring now toFIG. 11, in an example method of a laparoscopic procedure for removing visceral fat from a patient, the surgeon can make a series of incisions101in the patient's abdomen, including a first incision101, such as for insertion of a hollow needle for inflating the peritoneal cavity103, particularly the abdomen. Thereafter, the surgeon can remove the hollow needle and insert a laparoscope150in the first incision101. The surgeon makes a second incision101in the abdomen and inserts the distal portion of the cannula30through the second incision101and into the inflated abdomen. The surgeon can make a third incision101in the abdomen for introduction of one or more additional surgical tools into the inflated abdomen, such as graspers152and the like for manipulating organs or other peritoneal anatomy as needed to allow the cannula30to access and engage visceral fat while avoiding, minimizing, or at least reducing contact between the cannula30and delicate non-target tissue. It should be appreciated that other instruments can also be inserted into the abdomen through the third incision, such as irrigation tubes for delivering surgical field cleaning fluids to the treatment area as needed, additional camera(s) or visualization instruments, diagnostic instruments, cauterizing and/or suturing tools, and the like. It should also be appreciated that the surgeon can make one or more additional incisions101in the abdomen as needed, such as for insertion of additional instrumentation.

With the laparoscope150and the cannula30inserted within the abdomen, the surgeon can manipulate the cannula30via the handpiece20to target and engage and thereby liquefy, loosen, and aspirate the target visceral fat (or at least a major portion thereof) as needed. As described above, the surgeon can control manipulation tools, such as graspers152and the like, to facilitate the targeting and engaging of visceral fat with the cannula30.

In further examples, the surgeon can insert a first grasper152through a first respective one of the laparoscopic incisions101and can insert a second grasper152through a second respective one of the laparoscopic incisions101. The surgeon can use the first and second graspers152to manipulate anatomy within the mesentery as needed to enhance access to visceral fat for the cannula30. Referring now toFIG. 12, the surgeon can also employ a positioning tool160to control the relative position of the first and second grasper152with respect to each other. The positioning tool160can include pair of arms162that connect to the first and second graspers152. It should be appreciated that the positioning tool160is meant to be used externally to the body, not inside the body. Its purpose is to enable the graspers152to hold the small bowel mesentery segment in a single plane, which facilitates safe extraction of mesenteric fat. For example, by using the graspers152to hold the small bowel mesentery segment in a single plane, the surgeon's hands are free to manipulate instrumentation to liquefy and aspirate visceral fat. Holding that particular segment in one plane allows the surgeon favorable access to the surgical site and favorable control during the fat removal process. Once that segment is completed, the positioning tool160is unlocked, the graspers150are re-positioned to the adjacent segment of the small bowel mesentery and fat removal in that segment is done, and that process can be repeated over and over through the length of the small bowel from distal ileum to proximal jejunum while avoiding the area of the root of the mesentery which is in the area of the proximal jejunum. In particular, the pair of arms can include a first arm162having a first receptacle164for coupling to the first grasper152, and a second arm162having a second receptacle164for coupling to the second grasper152. The positioning tool160can also include a locking mechanism166configured to iterate between a locked configuration, in which the relative position between the first and second arms162are affixed (thereby also affixing the relative position between the first and second graspers152), and an adjustable configuration, in which the relative position between the first and second arms162(and thus also between the first and second graspers152) is adjustable. The positioning tool160can further include an adjustment mechanism168that can be actuated to adjust the relative position between the first and second arms162(and thus also between the first and second graspers152) in a controlled manner, as needed.

In an example method of an alternative laparoscopic technique for removing visceral fat from a patient, the surgeon can make a plurality of laparoscopic incisions in the abdomen, similar to the manner described above. The surgeon can then target and engage a localized segment of the small bowel mesentery with the cannula30to thereby liquefy, loosen, and aspirate the target visceral fat (or at least a major portion thereof) starting at the area of the distal ileum and then progressing in a sequential fashion, segment by segment, traveling in a generally cranial direction (i.e., towards the stomach). In that manner, the surgeon can effectively “run the bowel” laparoscopically inside the inflated abdomen with the one or more graspers (preferably two) to enable removal of visceral fat.

In each of the procedures described above, the visceral fat is preferably removed using a slow, controlled, methodical and precise movement of the cannula30. The surgeon can engage visceral fat by moving the cannula30back and forth in the distal and proximal directions D, P. The surgeon can also move the cannula30in side-to-side motions along the lateral direction. In any of the procedures described above, the surgeon can also pivot the cannula30back and forth using a motion analogous to a windshield wiper. During testing, the inventors observed that such windshield wiper motions were particularly effective at increasing the efficiency of visceral fat removal without increasing potentially harmful contact against delicate non-target tissue. Such gains in efficiency were particularly observed in embodiments where the cannula30employs one or more apertures37having a greater total longitudinal orifice length than total lateral orifice length.

In any of the foregoing procedures, the surgeon can employ the cauterizing electrode(s)78as needed to mitigate any bleeding that might occur. The cauterizing electrode(s)78are particularly helpful because the allow the surgeon to cauterize bleeding as it occurs.

Optionally, surgical field cleaning fluids such as water or saline can be delivered to the site being treated during any of the foregoing procedures. Alternatively or in addition, a small amount of liposuction tumescent fluid (containing, e.g., epinephrine, lidocaine, levorphonal, phenylephrine, athyl-andrianol, ephedrine, or other vasoconstrictors and/or xylocalne, marcaine, nesacaine, Novocain, diprivan, ketalar, ladocaine, or other anesthetic agents and/or other suitable chemicals) can be introduced into the region that is being treated. One suitable way to introduce such fluids into the desired region is to include a dedicated conduit that is built into the cannula, such as with a distal-facing exit port similar, as described more fully in the '700 Reference. In alternative embodiments, a separate irrigation catheter can be used to introduce the desired fluids. These infusions are preferably implemented using low pressure peristaltic type pumping system, at a pressure less than 200 psi, and at an infusion flow rate between 50 and 600 ml min.

Minor bleeding was observed in some test subjects treated with the cannula30. In these subjects, the cauterizing electrode(s)78was shown to quickly and successfully mitigate bleeding. It should be appreciated that other techniques can be employed to control bleeding, including techniques known in the surgical art of laparoscopic or open surgery.

It should be appreciated that any of the surgical techniques described above can be used with robotic assistance.

The embodiments described herein, particularly those for removing visceral fat, can be employed for treating one or more medical conditions in a subject, such that the subject experiences at least a reduction of symptoms of the medical condition. Examples of such medical conditions include metabolic syndrome (MS) (also referred to as “insulin resistance syndrome”), hypertension, cardiovascular disease, type II diabetes mellitus, obesity, Alzheimer's disease, dementia, cancer, aging, non-alcoholic fatty liver disease, and non-alcoholic steatohepatitis. For example, the embodiments that are optimized for removing visceral fat can be used during gastric bypass surgeries, or as stand-alone procedures for overweight or obese patients who do not qualify for gastric bypass surgery, especially for individuals with poorly controlled diabetes mellitus type II. Additionally, visceral fatty tissue lipectomy described in connection with these embodiments can be performed as a medical procedure for the prevention of diabetes mellitus type II and cardiovascular disease in patients with significant stores of visceral fat.

It should be appreciated that the embodiments described above can also be used in various liposuction procedures including, without limitation, liposuction of the face, neck, jowls, eyelids, posterior neck (buffalo hump), back, shoulders, arms, triceps, biceps, forearms, hands, chest, breasts, abdomen, abdominal etching and sculpting, flanks, love handles, lower back, buttocks, banana roll, hips, saddle bags, anterior and posterior thighs, inner thighs, mons pubis, vulva, knees, calves, shin, pretibial area, ankles and feet. They can also be used in revisional liposuction surgery to precisely remove residual fatty tissues after previous liposuction.

The embodiments described above can also be used in conjunction with other plastic surgery procedures in which skin, fat, fascia and/or muscle flaps are elevated and/or removed as part of the surgical procedure. This would include, but is not limited to facelift surgery (rhytidectomy) with neck sculpting and submental fat removal, jowl excision, and cheek fat manipulation, eyelid surgery (blepharoplasty), brow surgery, breast reduction, breast lift, breast augmentation, breast reconstruction, abdominoplasty, body contouring, body lifts, thigh lifts, buttock lifts, arm lifts (brachioplasty), as well as general reconstructive surgery of the head, neck, breast abdomen and extremities. It will be further appreciated that the embodiments described above have numerous applications outside the field of liposuction.

The embodiments described above can be used in skin resurfacing of areas of the body with evidence of skin aging including but not limited to sun damage (actinic changes), wrinkle lines, smokers' lines, laugh lines, hyper pigmentation, melasma, acne scars, previous surgical scars, keratoses, as well as other skin proliferative disorders.

The embodiments described above can target additional tissue types including, without limitation, damaged skin with thickened outer layers of the skin (keratin) and thinning of the dermal components (collagen, elastin, hyaluronic acid) creating abnormal, aged skin. The cannula would extract, remove, and target the damaged outer layers, leaving behind the healthy deep layers (a process similar to traditional dermabrasion, chemical peels (trichloroacetic acid, phenol, croton oil, salicyclic acid, etc.) and ablative laser resurfacing (carbon dioxide, erbium, etc.) The heated stream would allow for deep tissue stimulation, lightening as well as collagen deposition creating tighter skin, with improvement of overall skin texture and/or skin tone with improvements in color variations. This process would offer increased precision with decreased collateral damage over traditional methods utilizing settings and delivery fluids which are selective to only the damaged target tissue.

Other implementations include various distal tip designs and lighter pressure settings that can be used for tissue cleansing particularly in the face but also applied to the neck, chest and body for deep cleaning, exfoliation and overall skin hydration and miniaturization. Higher pressure settings can also be used for areas of hyperkeratosis, callus formation in the feet, hands knees, and elbows to soften, hydrate and moisturize excessively dry areas.

Additional tissue removal procedures can be accomplished by various other embodiments. For example, viable fat cells (adipocytes) can be extracted and processed for re-injection into areas of fat deficiency. This would include, without limitation, areas around the face, brow, eyelids, tear troughs, smile lines, nasolabial folds, labiomental folds, cheeks, jaw line, chin, breast, chest abdomen, buttocks, arms, biceps, triceps, forearms, hands, flanks, hips, thighs, knees, calves, shin, feet, and back. A similar method can be used to address post liposuction depressions and/or concavities from over aggressive liposuction. Other procedures utilizing a similar method include; without limitation, breast augmentation, breast lifts, breast reconstruction, general plastic surgery reconstruction, facial reconstruction, reconstruction of the trunk and/or extremities.

Additional uses include tissue removal in the spine or spinal nucleotomy. The cannula used in spinal nucleotomy procedures includes heated solution supply tubes within the cannula as described above. The cannula further includes a flexible tip capable of moving in multiple axes, for example, up, down, right and left. Because of the flexible tip, a surgeon can insert a cannula through an opening in the annulus fibrosis and into the central area, where the nucleus pulpous tissue is located. The surgeon can then direct the cannula tip in any direction. Using the cannula in this manner the surgeon is able to clean out the nucleus pulpous tissue while leaving the annulus fibrosis and nerve tissue intact and unharmed.

In another implementation, the present design can be incorporated in to an endovascular catheter for removal of vascular thrombus and atheromatous plaque, including vulnerable plaque in the coronary arteries and other vasculature.

In another implementation, a cannula using the present design can be used in urologic applications that include, but are not limited to, trans-urethral prostatectomy and trans-urethral resection of bladder tumors.

In another implementation, the present design can be incorporated into a device or cannula used in endoscopic surgery. An example of one such application is chondral or cartilage resurfacing in arthroscopic surgery. The cannula can be used to remove irregular, damaged, or torn cartilage, scar tissue and other debris or deposits to generate a smoother articular surface. Another example is in gynecologic surgery and the endoscopic removal of endometrial tissue in proximity to the ovary, fallopian tubes or in the peritoneal or retroperitoneal cavities.

In yet a further implementation to treat chronic bronchitis and emphysema (COPD), the cannula can be modified to be used in the manner a bronchoscope is used; the inflamed lining of the bronchial tubes would be liquefied and aspirated, thereby allowing new, healthy bronchial tube tissue to take its place.

The various embodiments described each provide at least one of the following advantages: (1) differentiation between target fatty tissue and delicate non-target tissue to an extent allowing clinical removal of visceral fat, which to the inventors' knowledge had not been possible without significant risk to the health of the patient; (2) a reduction in the level of suction compared to traditional liposuction, which mitigates damage to non-target tissue; (3) a significant reduction in the time of the procedure and the amount of cannula manipulation required; (4) a significant reduction in surgeon fatigue; (5) a reduction in blood loss to the patient; and (6) improved patient recovery time because shearing of tissue is not the enabling mechanism of fat removal, liquefaction is instead; shearing and suction of sheared tissue pieces is replaced with liquefaction and suction of liquefactant.

Although the present invention has been described in detail with reference to certain implementations, other implementations are possible and contemplated herein. All the features disclosed in this specification can be replaced by alternative features serving the same, equivalent, or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.