WO2002013893A1

WO2002013893A1 - Skin shield for ultrasonically assisted liposuction

Info

Publication number: WO2002013893A1
Application number: PCT/US2001/041723
Authority: WO
Inventors: Theodore A. D. Novak
Original assignee: Misonix Incorporated
Priority date: 2000-08-15
Filing date: 2001-08-15
Publication date: 2002-02-21

Abstract

A device (50) for protecting skin during a minimally invasive surgical procedure conducted through a skin incision comprises a cannula (52) and adjacent flange (54), together comprising a incision protection part. The incision protection part is further joined to a skin surface protector or shield element (56), encompassing the flange (54) and of significantly thinner and more flexible material. The flange (54) serves to center the cannula (52) in the wound or incision and stop or limit a degree of entry of the cannula into the wound. The shield element (56) in turn protects a larger skin surface than that protected by the flange (54) against accidental contact with a shaft of a probe (100) inserted through a bore (53) of the cannula (52), and is of sufficient flexibility to conform to a larger area of human skin (S), to which it is affixed by a medical grade contact or pressure sensitive adhesive during use. In a related method, a skin incision is first made, into which a projecting length or plug of the cannula (52) is inserted, until abutment of an inside surface of the flange (54) on a patient's skin (S). The shield (56) is then rotated to appropriate angle based on a shape of the shield (56) and an intended medical procedure, and a backing is removed from apre-disposed layer of surgical adhesive for affixing the shield (56) to a patient's skin (S).

Description

SKIN SHIELD FOR ULTRASONICALLY ASSISTED LIPOSUCTION

BACKGROUND OF THE INVENTION

This invention relates to surgery. More specifically, this invention relates to a method

and an associated apparatus for facilitating minimally invasive surgery.

Liposuction, or the subcutaneous aspiration of disrupted adipose tissue, is well-known as a technique of cosmetic surgery. Furthermore, ultrasonic liposuction, or the use of an

ultrasonically active aspirator tip in conducting liposuction, is also known. In the latter

technique an ultrasonically activated probe is inserted beneath the skin through an incision.

Since the ultrasonic transducer is located at a proximal or supracutaneous portion of the

probe, a shaft or extensive element of the probe is also excited in ultrasonic vibration as well

as a subcutaneous tip. It has been found that the shaft can damage the skin at a point of

insertion into a patient, in particular while the probe is being forcefully manipulated during a liposuction procedure. Accordingly, there exists a need for devices and techniques for

obviating or at least reducing damage to the skin at a point of insertion of an ultrasonically

activated probe into a patient undergoing a liposuction procedure.

In creating such devices and techniques, cognizance should be maintained of the need to manipulate a liposuction probe through a full range of motion, approaching a tangential

entry through the skin through at least some range of azimuthal angles, during a fat aspirating

procedure. It is also desirable to provide a seal to prevent a leakage of liquefied tissue and other bodily fluids at a point of incision, so that such fluids are aspirated into a receiving

container rather than being expressed on an exterior of the patient.

SUMMARY OF THE INVENTION This invention is directed to a method and/or an associated device for protecting the

skin during a surgical procedure. Concomitantly, the invention is directed to a method of performing a surgical procedure wherein measures are taken to ensure protection of the skin surface about the region of an incision. The invention is directed to a method, and more

particularly, a surgical method, for protecting the skin in a region of an incision during a

minimally invasive transcutaneous surgical procedure such as a traditional or an ultrasonic

liposuction procedure in which subcutaneous adipose tissue is aspirated from the body. The

problem of protecting the skin is associated with the problem of not unduly interfering with

the use of the surgical instruments. Thus, a method pursuant to the present invention aims

to permit an easy and sufficient range of motion of an inserted surgical instrument. In

addition, the method should provide a seal for bodily fluids which would otherwise be

expressed at an incision made during a minimally invasive surgical procedure.

The present invention provides a protective medical device or shield for preventing a probe or elongate tubular member of a subcutaneous surgical instrument from contacting

edges of a skin incision, and also for preventing the probe from contacting an unbroken skin

surface surrounding the incision, thereby preventing unnecessary cutaneous injury. The

invention also includes a method of using such a device in a medical procedure, and in

particular during a cosmetic aspiration of subcutaneous fat, or liposuction. The invention

has most particular application to an ultrasonically assisted liposuction procedure, or simply, "ultrasonic liposuction."

A protective medical device in accordance with the present invention has two parts,

namely, an inner section of the device which protects the edges of the skin incision from an

inserted probe, and an outer section which protects unbroken adjacent skin surfaces from

contact with side walls of the probe, in particular when the probe is manipulated through an

acute angle with respect to a skin surface. The inner section of the device or shield is

permanently bonded to the outer section, so that inner and outer sections essentially form a single component part and may optionally constitute a single molded piece.

The inner section of the device essentially takes the form of a tubular member or cannula molded together with a flange, and is constructed to allow easy angular manipulation of an inserted elongate probe. A distal end of the tubular member is tapered or chamfered to allow for an easy entry into a skin incision or wound. The flange provides a surface for assembly of the inner section to the outer section of the device, and also positions the tubular section or cannula axially and radially within the assembly. An outer cylindrical surface of the cannula contacts the wound edges, while the inner cylindrical surface of the tube provides a passage for the probe. The material of the cannula is sufficiently flexible to allow the probe, initially perpendicular, to be positioned at an acute angle, essentially tangential, with respect to a surrounding skin surface, for a grazing insertion of a subcutaneous medical instrument.

The outer section of the shield device provides a dual function of protecting the skin from the probe and anchoring the protective device to the skin. Anchoring maintains the protective device in a proper location during movement of the liposuction probe during a surgical procedure. An anchoring of the outer section of the shield to a patient's skin is achieved by using a medical grade pressure sensitive adhesive, thereby eliminating a need for barbs, threads, or ribs on an outer surface of the cannula, or tubular section, of the device. Protrusions such as barbs or threads on the cannula require initial creation of larger incision and are more traumatic to the wound area than a straight walled insert. Anchoring using an adhesive allows for a smaller skin incision and may significantly reduce skin scarring.

The shield or outer section of the device is made of a material that is flexible and also able to withstand abrasion from an ultrasonically active probe. Preferable materials for the shield include high-strength polymeric compositions such as Teflon or Kevlar, although nylon may also be utilized in a single-use application. The shield section must be sufficiently

large to protect the skin from a probe being used at an acute or shallow angle with the skin,

or in situations where the skin surface protrudes above the incision point, causing the probe

to contact the skin prior to entering the device. The latter situation which may occur in

treatment of an obese patient.

In one embodiment of the invention, the material of the outer section is formed in a

rhomboidal or "deep dish pie" shape. A central, flange, section of the protective device is molded close to an apex of an elongate base section of the pie and is positioned towards an

area of intended operation of the probe during a surgical procedure. In this manner, the

shield is predominantly positioned away from an area of intended operation and in an area where a probe may possibly contact the skin in use, a situation which will be more readily comprehended by inspection of the figures.

In another aspect of this embodiment of the invention, the inner section, in particular

the cannula or tube, incorporates a single lip wiper positioned on an inner bore and contacting

an outside cylindrical surface of a probe inserted into the cannula. This wiper helps minimize leakage of liquids, including both bodily fluids and irrigating fluids which may have been

introduced into the operation site down an irrigating channel in the probe, to be aspirated

along with liquefied fat. The wiper is designed to not restrict a range of motion of a probe

inserted through the cannula into a subcutaneous region.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a plan view of a protective medical device in accordance with the present

invention.

Fig. 2 is a cross section of the device of Fig. 1 taken at plane II-II.

Fig. 3 is an elevational view of the device of Fig. 1. Fig. 4 is a detail section view of the device shown in Fig. 1.

Fig. 5 is a schematic view of the device of Fig. 1, showing a deployment in human

tissue.

Fig. 6 is a further schematic view of a deployment of the device of Fig. 5, showing a different entry angle of an inserted surgical instrument.

DETAILED DESCRIPTION

A medical device 50 used to protect edges of an incision (not shown) and a

surrounding skin surface S (Fig. 5) during a minimally invasive surgical procedure, and

particularly during an ultrasonically assisted liposuction procedure, is shown in Figs. 1-6.

Device 50 comprises a cannula 52 having a through bore 53. The through bore provides an

access point for a liposuction probe 100 or other surgical instrument to pass through the skin. An annular distal surface 55 of cannula 52 is chamfered, so that the cannula may easily be

inserted into an incision causing minimal additional tissue damage to the skin. Cannula 52 is connected to and optionally integral with a flange or pan 54, and in this embodiment, the

cannula is mounted at a right angle with respect to the flange. Flange 54 functions in part to

limit an entry depth of cannula 52 into a wound, through an abutment of an inner surface 62

of the flange with a surrounding skin area.

Through bore 53 passes through flange 54. An outside or proximal circumferential

edge 59 of through bore 52 is rounded, to allow for greater maneuverability of probe 100,

when passed through bore 53. A rounded shape for edge 59 also tends to minimize abrasive damage to the edge during movement of the probe.

A lip wiper 58 is positioned approximately at a midpoint (not designated) of a

thickness d of flange 54. Wiper 58 reduces leakage of bodily or irrigation fluids (not

illustrated) which may otherwise be expressed at the incision. Irrigation fluids may be introduced via a channel in the probe itself and aspirated along with adipose tissue.

A flexible shield 56 comprises a remainder of protective device 50 and is joined to

a periphery of flange 54. Shield 56 is considerably more flexible than flange 54, and in particular, flange 54 does not readily flex to an amount which would permit it to be drawn into a wound, a necessary quality for a stopping or depth limiting function. Shield 56 is, however, sufficiently flexible to conform to a possibly compound curved adjacent skin surface.

Collectively, cannula 52 and flange 54, including rounded edge 59, through bore 53 and lip wiper 58, constitute an incision site protection part 60. The incision site protection part is preferably manufactured from a flexible, elastic, biologically compatible material which also exhibits high abrasion resistance, such as rubber or silicon. Incision protection part 60 is joined at flange 62 to protective pad or shield 56, as mentioned above. The protective pad 56 in this embodiment is configured in a "deep-dish pie" or rhomboidal shape having an upper apex or crown 64, a basal vertex 66, and side-lobe vertices 68, 70. Incision site protection part 60 is mounted on pad 56 symmetrically with respect to side-lobe vertices

68, 70, and towards basal vertex 66 with respect to basal and crown vertices 66, 64; a positioning of part 60 may also be described as located in an apical base of the rhomboid, on an axis of reflective symmetry. Site protection part 60 is permanently attached to pad 56.

It should also be noted from the drawings that site protection part 60 is T-shaped in cross section and mounted with respect to shield 56 so that cannula 52 lies essentially on a single side of the shield. Cannula 52 thus has an appearance of a projecting plug (not designated) on the combined surface of flange 54 and shield 56, which plug is intended for insertion into a surgical incision.

Prior to a surgical use of the device, a lower surface 72 of shield 56, from which the cannula is substantially projecting, is coated with a pressure sensitive adhesive, the adhesive

optionally protected by an adhesive backing (not shown). The adhesive is selected from a

group of known adhesives which are biologically compatible and have good adhesion

characteristics with skin, so that shield or pad 56 does not translate or disengage from the

skin during movements of probe 100 in cannula 52 in a medical procedure. Shield 56 itself

is made out of a flexible, biologically compatible material which exhibits good abrasion

resistance, such as silicon rubber. Incision protection part 60 and shield 56 together

collectively make up the device 50 for preventing contact of a probe with the skin surface S during a liposuction procedure.

In a method of use of the present invention, preparatory to a minimally invasive

surgical procedure a skin incision is made where probe 100 is to enter the body. A health

professional urges a blunt object into the incision in order to enlarge the wound and make a pathway at the incision site for cannula 52 and ultimately for probe 100. Device 50 is

positioned on an enlarged incision site, with the cannula pointing skinward (not illustrated), towards the incision. The cannula is introduced into the incision until skin surface S contacts

lower flange surface 62 of the incision protection part 60 . Device 50 is then further

positioned with crown 64 of the rhomboidal shape pointing away from an area where the

probe will be operating subcutaneously during the surgical procedure. Once the device to

prevent probe contact with the skin is positioned properly, an adhesive backing (not

shown)can be removed from surface 72 of the protection pad 70. Pressure is applied pad 56

to activate the pressure sensitive adhesive, and make a good bond with the skin.

This invention has a unique feature of preventing probe contact with the skin in two

manners. It prevents probe contact with the skin at the edges of the skin incision and it also prevents the skin surface from contacting the sides of the probe when the probe is moved outwards from the incision site. The incision protection part 60 prevents the edges of the skin

incision from contacting the outer diameter of the probe, and the protection pad 56 prevents

the surface of the skin from contacting the sides of the probe. Incision protection part 65 and

protection pad 70 together form a complete protection of the skin from contacting the probe.

Other variations of the present invention will readily occur to the practitioner: For

example, the protective pad or shield may be of alternative shapes adapted to a particular surgical application or bodily position. Starting from an incision site where a probe is likely

to manipulated evenly in all directions, a circular shield is indicated, with a cannula centered in the circular shield. An entry angle of the cannula with respect to the shield may also be

varied, although with sufficiently flexible components, including incision protection part,

a right-angle may be utilized in most circumstances. Multiple lip wipers may also be

employed in order to improve a sealing of bodily and irrigation fluids in the wound site.

Accordingly, the embodiment described herein is to be construed illustrative of the invention, without limiting a scope thereof. A scope of the invention is determined solely

by the attached claims, as supported by specific and general description in the specification,

and not to be limited solely to the specific embodiment disclosed in detail.

Claims

CLAIMS:

1. A surgical protective device, comprising:

a cannula;

a flange joined to said cannula; and a shield, of substantially greater surface area or extent, greater flexibility and lesser

thickness than said flange, operatively joined to and substantially coplanar with said flange.

2. The device of claim 1 wherein said cannula and said flange form essentially a right

angle.

3. The device of claim 2 wherein said shield has a shape taken from the group

consiting essentially of a square, a rectangle, a circle, an ellipse, and a rhomboid.

4. The device of claim 3 wherein said shape of said shield is a rhomboid, and said cannula is located in an apical base of the rhomboid, on an axis of reflective symmetry

5. The device of claim 1 wherein said shield is provided with a pressure sensitive

adhesive coating.

6. The device of claim 5 wherein said pressure sensitive adhesive coating is provided

with a removable adhesive backing.

7. The device of claim 1 wherein said cannula is provided with a lip wiper on an

inner surface for preventing a passage of fluids around a periphery of a surgical instrument inserted through said camiula.

8. A surgical protective device, comprising:

a cannula;

a flexible web member attached to said cannula and disposed in a plane oriented at

an angle relative to said cannula, said web member having two oppositely facing major surfaces; and

an adhesive layer provided along only one of said major surfaces.

9. The device of claim 8 wherein said cannula is eccentrically disposed with respect to said web member.

10. The device of claim 9 wherein said web member has a polygonal shape with a

plurality of apices, said cannula being disposed in one of said apices.

11. The device of claim 8, further comprising a flange connecting said web member to said cannula, said flange being coplanar with said web member, said flange being oriented

substantially perpendicularly to said cannula.

12. The device of claim 8, further comprising a protective backing removably

attached to said adhesive layer, said backing being at least coestensive with said adhesive layer.

13. The device of claim 8 wherein said cannula is provided with a lip wiper or flexible shoulder along an inner surface.

14. A method of conducting a minimally invasive surgical procedure, comprising: providing a protective surgical access device comprising a cannula and a shield in the form of a flexible web attached to said cannula so that said shield is disposable in a plane oriented at a substantial angle to said cannula; creating an incision in a skin surface of a patient; inserting said cannula into said incision so that at least a portion of said cannula extends into the patient; affixing said shield to said skin surface; and after the insertion and the affixation of said shield, inserting at least a portion of a medical instrument through said cannula into said patient.