WO2003070297A2

WO2003070297A2 - Cauterizing hollow needles and methods of use

Info

Publication number: WO2003070297A2
Application number: PCT/US2003/004466
Authority: WO
Inventors: Enrique Garcia-Valenzuela
Original assignee: Emory University
Priority date: 2002-02-15
Filing date: 2003-02-14
Publication date: 2003-08-28
Also published as: AU2003209146A8; AU2003209146A1; WO2003070297A3

Abstract

Cauterizing needles are disclosed that include a needle having a hollow, electrically conductive needle shaft, and an insulating sheath disposed on the conductive needle shaft. Also disclosed are methods for using the cauterizing needle, one method including passing a cauterizing needle through a vascular tissue, insulating the tissue from the cauterizing shaft of the needle, cauterizing the tissue solely via the tip of the needle shaft, and either withdrawing a substance via a syringe attached to the needle or dispensing a substrate via a syringe attached to the needle. With the apparatus and/or method, specific tissues and/or vessels can be selectively cauterized while using a syringe attached to the cauterizing needle.

Description

CAUTERIZING HOLLOW NEEDLES AND METHODS OF USE

CLAIM OF PRIORITY

This application claims priority to copending U.S. provisional application entitled, "Cauterizing Hollow Needle for Drainage of Fluid and Tissue Biopsy," having serial number 60/357,325, filed February 15, 2002, which is entirely incorporated herein by reference.

BACKGROUND Field of the Invention

The present invention is generally related to needles and syringes, and more particularly, is related to cauterizing needles and methods for using cauterizing needles.

Description of Related Art

For many years, surgeons have employed hollow needles for many different objectives, including fluid aspiration, medication injection, biopsy procedures, and other maneuvers performed in the kidneys, liver, heart, lungs, brain, eyes, and other organs. In some organs, the needle may cut blood vessels it encounters in its path, causing the complication of internal bleeding. Separate cauterizing devices have been used in surgery to reduce this complication. It has also been known to use a particular type of cauterizing needle for biopsy procedures, e.g., U.S. Patent No. 5,578,030 issued to Levin.

An exemplary needle electrode is depicted in FIG. 1. The needle electrode 10 illustrated in FIG. 1, for use with a hypodermic syringe attachment 12, has a tubular hollow needle member 14 of electrically conductive material, such as stainless steel, and a conductor wire 16 in direct electrical communication with an uninsulated portion of the needle member 14. Insulating material such as polypropylene is formed around a portion of the needle member 14 and the conductor wire 16 to form a handle 18. The handle 18 enables convenient and accurate positioning and manipulation of the needle electrode 10.

As shown in FIG. 1, the handle 18 includes a socket connector element 22 for connecting to the hypodermic syringe attachment 12. The connector element 22 also serves to connect the conductor wire 16 to an electric lead 20. The electric lead 20 has a fitting 24 that attaches the electric lead 20 to an electrical supply (not shown).

The needle electrode 10 is used in electromyography in which it is desired to insert an electrode, in the form of a probe, into a patient to locate a particular muscle and then inject a medicine into that muscle. The tubular hollow needle member 14 is electrically conductive and, as such, electrically stimulates all tissue that contacts the needle member 14. Thus, needle electrode 10 is primarily suited for use in tissues that will not be damaged by contacting the electrically conductive needle member 14. Additionally, needle electrode 10 is not adapted for use as a cauterizing device.

Internal bleeding is one possible complication in ocular surgeries and sclera buckle procedures in particular. Briefly, in the scleral buckling procedure, holes in the retinal wall are supported by a band or buckle. The buckle compresses the eye and brings the wall of the eye in contact with the holes, thereby sealing them. During scleral buckling, the subretinal fluid, which keeps the retina detached, is removed and intraocular volume is replaced with air or gas injected into the vitreous cavity to push the retina back into place, hi order to access the subretinal fluid, a needle of a syringe must pass through the scleral and choroidal layers of the eye. The choroid is the most vascular tissue in the body. Thus, bleeding can occur due to passage of the needle. If this bleeding is excessive, loss of vision can result.

Although the cauterizing devices, needle electrodes, and surgical procedures of the prior art may be adequate for their intended purpose, there is a need in the art for improved cauterizing needles. In addition, there is a need to provide improved, novel methods of using cauterizing needles that reduce or eliminate the risk of internal bleeding caused from vessels being nicked by needles used in surgery or damaged by contacting the entire shaft of the cauterizing device.

SUMMARY

Disclosed are embodiments of cauterizing needles, namely hollow insulated cauterizing needles, and methods for using the cauterizing needles.

Briefly described, one embodiment of such a cauterizing needle includes a needle having a hollow, electrically conductive needle shaft, and an insulating sheath disposed on the electrically conductive needle shaft.

One embodiment of a method for using a cauterizing needle includes: passing a cauterizing needle through a vascular tissue, insulating the tissue from the cauterizing shaft of the needle, cauterizing the tissue solely via the tip of the needle shaft, and either withdrawing or dispensing a substance via a syringe attached to the needle. BRIEF DESCRIPTION OF THE DRAWINGS

Many aspects of the disclosed embodiments can be better understood with reference to the following drawings. The components in the drawings are not necessarily to scale. Moreover like reference numerals designate corresponding parts throughout the several views.

FIG. 1 is a perspective view of a prior art needle electrode.

FIG. 2 is a side view illustrating an embodiment of the disclosed cauterizing needle.

FIGs. 3 A and 3B are side views illustrating an alternative embodiment of the disclosed cauterizing needle.

FIG. 4 is an end view illustrating an embodiment of the needle tip of the needle shown in FIG. 3.

FIG. 5 is a side view illustrating an embodiment of a cross-section of the needle tip of FIG. 4. FIG. 6 is a side view illustrating an alternative embodiment of a cross-section of the needle tip of FIG. 4.

FIG. 7 is a side view illustrating an alternative embodiment of a cross-section of the needle tip of FIG. 4.

DETAILED DESCRIPTION

As identified in the foregoing, cauterizing needles and methods for using them are not always sufficient to prevent bleeding from vessels that may be contacted by a needle used in surgery. Furthermore, other cauterizing devices or needles may not be adaptable for multiple uses. For example, lacking is a hollow cauterizing needle that may be used in ocular surgeries or other surgeries in which highly vascular tissue is 3 involved. Therefore, needed are cauterizing needles that provide an efficient cauterizing action on blood vessels that may be cut by the sharp tip of the needle.

Disclosed herein are cauterizing needles and methods of using the cauterizing needles. The disclosed cauterizing needles provide a needle having a hollow, electrically-conductive needle shaft and an insulating sheath disposed on the electrically conductive needle shaft. The disclosed cauterizing needles provide an effective method for preventing excessive bleeding during surgical procedures in which a needle is passed through vascular tissue.

Referring now to the figures, FIG. 2 illustrates an exemplary embodiment of a cauterizing needle 100. The cauterizing needle 100 includes a hollow, electrically- conductive needle shaft 120 that ends with a needle tip 124, and an electrical lead 130 that is connected to the needle shaft 120 at one end 132. The electrical lead 130 connects the electrically-conductive needle shaft 120 to an electrical supply (not shown) at a second end 134. The electrical supply can be any conventional electrocautery supply device. For example, suitable electrocautery supply devices include "Ophthalmic Diathermy TR3000™" manufactured by Dutch Ophthalmic Research Center, Zuidland, The Netherlands, as well as "Accurus™ 400VS/600 DS" manufactured by Alcon Laboratories, Inc., Fort Worth, Texas, USA.

An insulating sheath 122 is disposed upon the conductive needle shaft 120 such that the needle tip 124 is exposed. The needle shaft 120 is connected to a hub

110 at its opposite end. The hub 110 connects the needle 100 to a syringe (not shown) or other dispensing/withdrawing device.

The needle shaft 120 can be made of stainless steel or any other biocompatible material that can be used in surgery. When used in ocular surgeries, the needle shaft 120 is preferably from approximately one (1) to two (2) inches in length. More preferably, the needle shaft 120 is approximately 1.5 inches in length. Additionally, the needle shaft 120 preferably has a gauge of approximately 16 to 30. More preferably, the needle shaft 120 has a gauge of approximately 18 to 23 while, most preferably, the needle shaft 120 has a gauge of approximately 20. It is preferred that the needle tip 124 has a gauge of approximately 20 to 36.

More preferably, the needle tip 124 has a gauge of approximately 25 to 27 with a gauge of approximately 25 being most preferred.

The insulating sheath 122, shown in cross-section in an end view of needle shaft 120 in FIG. 4, is preferably approximately 0.01 to 0.3 millimeters (mm) thick. The insulating sheath 122 is made from silicones, polypropylene, or any other type of biocompatible insulating material and combinations and equivalents thereof. Preferably, the insulating sheath 122 is made of a silicone plastic. The insulating sheath 122 insulates the tissue through which the needle 120 is being inserted from the electrically conductive needle shaft 120. Only the needle tip 124, therefore, cauterizes the desired tissue, not the entire length of the needle shaft 120. Thus, the insulating sheath 122 prevents the needle shaft 120 from inadvertently cauterizing tissue that contacts the shaft 120 apart from its tip 124.

FIGs. 3 A and 3B illustrate the cauterizing needle 100 of FIG. 2 with an optional retractable protective sleeve 140 disposed over the shaft 120 of the needle 100. The protective sleeve 140 completely encloses the needle shaft 120, to protect tissue through which the needle 100 is not intended to pass. By preventing the needle tip 124 from contacting this tissue, inadvertent cutting or nicking of vessels in the tissue can be avoided. For example, in ophthalmic surgeries it is often desirable to manipulate the needle 100 into proper position before exposing the needle tip 124. The protective sleeve 140 includes a handle 144 for retracting the sleeve 140 when it is desired to expose the needle tip 124. FIG. 3 A shows the sleeve 140 before it has been retracted, where the sleeve completely covers the needle tip 124. FIG. 3B shows the sleeve 140 after it has been retracted, where the needle tip 124 is exposed. The protective sleeve 140 may further include an optional stopping mechanism

142 that is configured to prevent the protective sleeve 140 from retracting prematurely and thus inadvertently exposing the needle tip 124. The stopping mechanism 142 shown in FIGs. 3 A and 3B includes two protrusions, a first protrusion 143 disposed on an inner surface of the protective sleeve 140 and a second protrusion 145 disposed on an outer surface of the insulating sheath 122 of the needle shaft 120. As can be seen in FIG. 3 A, the first protrusion 143 is disposed closer to the needle tip 124 than the second protrusion 145. After the sleeve 140 has been retracted, however, as shown in FIG. 3B, the second protrusion 145 is disposed closer to the needle tip 124 than the first protrusion 143. The stopping mechanism 142 prevents the protective sleeve 140 from accidentally retracting in that the protective sleeve 140 will only retract when a threshold force is applied to the protective sleeve 140 with handle 144. FIG. 4 illustrates an end view of the needle shaft 120, looking into an aperture 150 in the needle shaft 120. As shown in FIG. 4, the insulating sheath 122 is disposed about the needle shaft 120. An optional rigid outer sheath 160, preferably of a metallic material, such as brass, stainless steel, or any other type of rigid biocompatible material, maybe disposed around the insulating sheath 122. Preferably, the outer sheath 160 is made from brass. The outer sheath 160 is preferably from approximately 0.01 to 0.3 mm in thickness. The outer sheath 160 may be used to impart rigidity and strength to the needle shaft 120. As shown more clearly in FIGs. 5 and 6, and described in more detail below, the outer sheath 160 does not contact with the needle tip 124.

Shown in FIGs. 5-7 are cross-sectional side views of the exemplary configurations for the layers of the needle shaft 120. In FIG. 5, the insulating sheath 122 is disposed on the needle shaft 120 and the outer sheath 160 is disposed on the insulating sheath 122, with the insulating sheath 122 extending longitudinally beyond the outer sheath 160. Thus, the outer sheath 160, which may be electrically conductive, does not contact the conductive cauterizing portion of the needle tip 124. Optionally, as shown in FIG. 6, the insulating sheath 122 and the outer sheath 160 may be tapered in the longitudinal direction of the needle 100 near the tip 124.

The outer sheath 160 may have a first diameter, d_ls and a second diameter, d . The diameter of the outer sheath 160 decreases from the first diameter d to the second diameter d₂, in the direction toward the needle tip 124 so as to form a tapered configuration. Likewise, the insulating sheath 122 may have a first diameter, d , and a second diameter, d₃. The diameter of the insulating sheath 122 decreases from the first diameter d₂ to the second diameter d₃, in the direction toward the needle tip 124 so as to form a tapered configuration. The result, like the configuration of FIG. 5, is that the outer sheath 160, is not in electrical communication with the metallic cauterizing needle tip 124. FIG. 7 illustrates a cross-sectional side view of an alternative arrangement for the layers of the needle shaft 120. In this configuration, the outer sheath 160 is absent and rigidity is instead provided by the needle shaft 120, which includes an enlarged diameter portion 162 that tapers towards the needle tip 124. Thus, the needle shaft 120 may have a first diameter, d₄, and a second diameter, d₅. The diameter of₍the needle shaft decreases from the first diameter d₄ to the second diameter d₅, in the direction toward the needle tip 124.

The cauterizing needle 100 described above is particularly useful in procedures involving passing a needle through vascular tissue. One such method includes passing the cauterizing needle 100 through vascular tissue, insulating the tissue from the cauterizing shaft 120 of the needle 100, cauterizing the tissue solely via the tip 124 of the needle shaft 120, and either withdrawing or dispensing a substance or fluid via a syringe attached to the needle 100. The method may be used to accomplish procedures such as, for example: sclera buckling surgery, fluid aspiration, and tissue biopsy. In the case of ocular surgeries, the vascular tissue is the choroidal tissue of the eye and the substance withdrawn via the syringe is subretinal or vitreous fluid. If the cauterizing needle 100 is used to dispense or inject a substance via a syringe, the substance may be, for example, a medication and/or an anticoagulation agent.

The cauterizing needle 100 may be used in ocular surgery, for example, by positioning the needle at the desired location, retracting the protective sleeve 140 by pulling on the handle 144 and exposing the needle tip 142, inserting the needle 100 through the scleral layer of the eye, inserting the needle 100 through the choroidal layer of the eye while cauterizing the vessels in the choroidal layer with the needle tip 124 and also while insulating the choroidal tissue from the needle shaft 120, inserting the needle 100 into the space between the choroid and retina, and withdrawing subretinal fluid. By cauterizing the vascular choroidal tissue while the needle 100 is passing through the choroid, excessive bleeding can be avoided.

It should be emphasized that the above-described embodiments of the cauterizing needle and embodiments of methods for using the cauterizing needle are merely possible example implementations. Many variations and modifications may be made to the above-described embodiment(s). All such modifications and variations are intended to be included herein within the scope of this disclosure and protected by the following claims.

Claims

CLAIMSTherefore, having thus described the invention, at least the following is claimed:

1. A cauterizing needle comprising: a needle having a hollow, electrically conductive needle shaft; an insulating sheath including an insulating material disposed on the electrically conductive needle shaft; and a needle tip on the needle shaft extending longitudinally beyond the end of the insulating sheath.

2. The cauterizing needle of claim 1, wherein the insulating material is chosen from: silicones, polypropylene, and combinations thereof.

3. The cauterizing needle of claim 1, wherein the insulating material has a thickness of approximately 0.01 to 0.3 millimeters.

4. The cauterizing needle of claim 1 , wherein the needle further comprises an outer sheath of rigid material disposed on the insulating sheath.

5. The cauterizing needle of claim 4, wherein the rigid material comprises a metal chosen from: brass, stainless steel, and combinations thereof.

6. The cauterizing needle of claim 4, wherein the outer sheath has a thickness of approximately 0.01 to 0.3 millimeters.

7. The cauterizing needle of claim 4, wherein the outer sheath is tapered longitudinally at the tip of the needle shaft.

8. The cauterizing needle of claim 1, wherein the insulating sheath is tapered longitudinally at the tip of the needle shaft.

9. The cauterizing needle of claim 1, wherein the needle shaft is tapered longitudinally at the tip of the needle shaft.

10. The cauterizing needle of claim 1 , further comprising a retractable protective sleeve disposed on the shaft of the needle, wherein the protective sleeve completely encloses the needle shaft.

11. The cauterizing needle of claim 10, wherein the protective sleeve comprises a handle at an end of the sleeve for retracting the sleeve.

12. The cauterizing needle of claim 10, wherein the protective sleeve comprises a stopping mechanism configured to prevent the protective sleeve from retracting prematurely.

13. The cauterizing needle of claim 10, wherein the stopping mechanism comprises two protrusions, wherein a first protrusion is disposed on an inner surface of the protective sleeve and a second protrusion is disposed on an outer surface of the needle shaft.

14. A cauterizing needle comprising: a needle having a hollow, electrically conductive needle shaft; an insulating sheath disposed on the conductive needle shaft; an outer sheath disposed on the insulating sheath, the inner layer of insulating material extending longitudinally beyond the outer layer of rigid material; a tip on the needle shaft extending longitudinally beyond the insulating sheath; wherein the insulating sheath comprises a material chosen from silicones, polypropylene, and combinations thereof, and the outer layer of rigid material comprises a metal chosen from brass, stainless steel and combinations thereof; wherein the insulating sheath is tapered longitudinally at the tip of the needle shaft, in the direction of the needle tip; and wherein the outer sheath is tapered longitudinally at the tip of the needle shaft, in the direction of the needle tip.

15. A method of using a cauterizing needle, comprising: passing a cauterizing needle through a vascular tissue; insulating the tissue from the cauterizing shaft of the needle; and cauterizing the tissue solely via the tip of the needle shaft.

16. The method of claim 15, further comprising withdrawing a substance via a syringe attached to the needle.

17. The method of claim 16, wherein the vascular tissue is choroidal tissue of the eye and the substance withdrawn is subretinal fluid.

18. The method of claim 15, wherein the method is used to accomplish at least one of the following: sclera buckling surgery, fluid aspiration, and tissue biopsy.

19. The method of claim 15, further comprising dispensing a substance via a syringe attached to the needle.

20. The method of claim 19, wherein the method is used to accomplish injection of at least one of: a medication and an anticoagulation agent.