Irrigating, cutting and aspirating system for percutaneous surgery

Abstract

A percutaneous discectomy system 10 includes a discectomy device 12 having a needle 16 with a port 48 and a flared cutting edge 44 which is actuated past the port 48 to sever tissue provided adjacent thereto. An irrigation device is 18 are provided for irrigating the area adjacent the tip 46 of the needle 16 to assist a vacuum device 22 in aspirating the severed tissue away from the disc. The discectomy system 10 assists in the removal of herniated disc tissue in order to relieve pressure on the nerves located adjacent thereto. In addition, the needle 16 is flexible so that it can be temporarily or permanently bent around other body tissues such as the pelvis in order to access discs which are surgically hard to reach otherwise.

Description

TECHNICAL FIELD

The present invention relates to a surgical cutting device and, in particular, to a percutaneous discectomy device for removing nucleus pulposus from a herniated spinal disc.

BACKGROUND ART

An estimated eight million Americans suffer chronic low back pain due to disc problems requiring a total disability health care expenditure of over twenty billion dollars. The interverebrate disc can be looked upon as an osmotic system. throuhassemble assembly, the diaphragm is positioned so that the slot 50 in the flared cutting edge 44 is located opposite the port 48 at the blunt end 46 of the needle 16.

Another cap 68 is provided adjacent the piston 56 and includes a threaded portion which can be threaded to the body 14 adjacent the threaded ring 66. A chamber 74 is defined between the cap 68 and the diaphragm 58. The cap 68 includes a central bore 70 which guides a portion of the piston 56 and cutting member 42 and which provides a position to seat an O-ring 72, which provides a seal between the elongate tubular cutting member 42 and the another cap 68. The spring 54 biases the piston 56 and the cutting member 42 against the cap 68 so as to keep the flared cutting edge 44 in a first position located adjacent the port 48 as shown in FIG. 2.

The vacuum source device 22 is provided in communication with the central bore 52 of the elongate tubular cutting member 42 by aspiration line 55, and the pulsed pressure device 20 is provided in communication with the chamber 74 through a passage 76 provided in the another cap 68.

The various positions which the cutting edge 44 can occupy relative to the port 48 are shown in FIGS. 2, 3, 4. In FIG. 2, a first position is shown with the port 48 fully open. In FIG. 3, the cutting edge 44 is urged toward the blunt end 46 by pulsed pressure provided to the chamber 74 from the pressure device 20 to capture and sever a piece of disc tissue 78. In FIG. 4, the cutting edge 44 has passed completely by the port 48 and has severed the tissue 78 whereby, with the aid of the irrigating fluid shown by the arrows and the vacuum provided by device 22, the severed tissue is aspirated into a collection bottle of the device 22. A cross-sectional view of the needle including the slot of the cutting edge 44 is depicted in FIG. 5.

In a preferred embodiment, the housing 14 can be comprised of plastic or other suitable materials, and the needle 16 and the tubular cutting member 42 can be comprised of flexible stainless steel tubing with the elongate tubular cutting member 44 42 chrome-plated to prevent galling. The needle and cutting member 42 can be permanently bent to a fixed orientation if desired or can be temporarily bent if it is provided through a bent sleeve as will be described hereinbelow.

In a preferred embodiment, the diameter of the needle 16 is 0.084 inches, or approximately 2 millimeters, while the internal diameter of the central passage 40 of the needle 16 is approximately 0.073 inches with the outer diameter of the tubular cutting member 42 being approximately 0.059 inches. This spacing provides for sufficient irrigating fluid to be provided to slot 50 in order to provide irrigation adjacent the port 48.

It is to be understood that other types of cutting arrangement such as rotating cutters can be used and be within the scope and spirit of the invention.

Alternate embodiments of the invention are depicted in FIGS. 6 and 7. In FIG. 6, an additional elongate tube 80 is provided inside the central bore 52 of the tubular cutting member 42. Irrigation fluid can be provided therethrough into the area adjacent the port 48. In the other embodiment depicted in FIG. 7, apertures 86 are provided through the flared portion of member 42 adjacent cutting edge 44. Apertures 86 provide internal irrigation fluid communication and allow for a strong cutting edge 44.

It is to be understood that with internal irrigation as provided by the present invention, irrigation fluid tends not to pass through port 48 and thus does not interfere with the sucking of tissue into port 48.

It is also to be understood that in addition to pulsing the source of positive pressure to drive diaphragm 58 and thus to drive the cutting edge 44, the irrigation fluid from device 18 as well as the vacuum from device 22 is also pulsed as follows. The irrigation fluid is periodically pulsed off or to a reduced flow with the port 48 open so as not to reduce the vacuuum vacuum and the efficiency thereof in pulling tissue into the port. As cutting is completed and the cutting edge 44 closes port 48, the irrigation fluid is pulsed on to assist in removing the severed tissue through aspiration line 55. The vacuum is pulsed to prevent clogging of tissue in aspiration line 55 by providing an impulse to such tissue.

It is further to be understood that device 18 can also control the irrigation fluid flow rate independently of the above periodic pulsed flow rate. This second control can be adjusted by the operator by observing the flow of irrigation fluid and tissue in the aspiration line 55 which in a preferred embodiment is substantially clear. If the operator observes a fast irrigation fluid flow with little tissue, the operator can decrease generally the flow rate independently of the first periodic pulsed flow rate so that the vacuum can be more efficient in aspirating tissue. If the operator observes a slow irrigation flud flow rate with much tissue, the operator can generally increase the fluid flow rate as a preventative measure so that tissue clogging does not occur.

INDUSTRIAL APPLICABILITY

The operation of the percutaneous discectomy system 10 is as follows. Using CT scan techniques and the like, the needle 16 can be inserted straight-in between the appropriate vertebra and into the herniated disc. Prior to the insertion of the needle 16, a small hole can be prepared through the fibrous annular ring which defines the outer periphery of the disc. The needle is then inserted through this opening.

As the needle 16 is inserted through the hole drilled in the periphery of the disc, the irrigation device, the suction device, and positive pressure device are turned on to operate the guillotine cutting action of the flared cutting edge 44 relative to the port 48 and to aspirate tissue. As the needle is inserted further into and through the disc, additional tissue is severed and aspirated. Also as the needle is rotated in place, the port 48 is exposed to different portions of the disc and additional tissue is severed and aspirated. Once the required amount of tissue is removed, the needle can be moved from the disc.

It is to be understood that if the disc is located in a hard-to-reach area such as between the fifth lumbar and the first sacroiliac vertebrae, then instead of cutting through part of the pelvis or other tissues or bone structures, an introduction and delivery system which includes a curved sleeve or cannula 90 as shown in FIG. 8 can be inserted using known techniques, such as with the aid of the CT scan so as to avoid the bone obstacles. Such an introduction and delivery system using a straight sleeve 92 as shown in FIG. 9 can also be used, if desired, in the above described straight-in procedure. Once the cannula 90,92 is positioned, the flexible needle can be inserted through the cannula into the disc so as to remove disc tissue along a linear path. It is to be understood that the port 48 can also be rotated throughout 360° in order to extract additional tissue. Further it is to be understood that if desired, the needle 16 can be permanently bent, and without the use of a sleeve or cannula 90, 92 can be inserted into this position. However, there is then no opportunity to rotate the port 48 located in the needle 16 in order to sever and aspirate tissue on a 360° basis. It is also to be understood that such an introduction and delivery system can be used generally with this invention and can also include devices for precisely maintaining the position of the probe relative to the body.

From the above it can be seen that the present invention provides for a system for removing tissue from a herniated disc without causing undue trauma to the patient. Additionally the system is flexible so that it can be positioned in otherwise surgically hard to reach areas, plus it provides for irrigation of the severed material to facilitate the aspiration thereof to the collection vessel. The pulsed vacuum creates impulses in the line which act as shock waves to further facilitate the aspiration of the tissue and prevent it from clogging in the needle 16.

Other advantages of the invention can be obtained from a review of the figures and the appended claims. It is to be understood that although the present invention was described relative to a percutaneous discectomy procedure, that a similar system can be used to remove tissue from other portions of the body or for other unrelated purposes and fall within the scope of the invention and the appended claims.

Claims

1. A surgical instrument comprising:

a housing;

a needle supported by said housing, said needle having a forward portion extending distally of said housing;

said needle including a first elongated tubular wall member defining a first bore, and having a port formed entirely within the sidewall of the forward portion of said first tubular wall member;

said needle including a second elongated tubular wall member defining a second bore sized to permit passage of tissue therethrough when said second tubular wall member is connected to a source of suction, the passage within said second bore being unobstructed, said second tubular wall member having a forward portion extending radially outwardly and terminating in a cutting edge;

said second tubular wall member being positioned within said first tubular wall member with said cutting edge in contact with the sidewall defining said first bore, the forward portion of said first bore adjacent said port defining a tissue receiving portion communicating with said second bore;

said first and second tubular wall members being the only tubular wall members in said forward portion of said needle;

the wall of said second tubular wall member spaced inwardly from the wall of said first tubular wall member to define the opposing walls of an annular passageway adapted to be connected to a source of irrigating fluid, said annular passageway being the sole annular chamber in said forward portion of said needle;

said second tubular wall member being disposed for movement within said first tubular wall member to cause said cutting edge to move from a first position where tissue is drawn through said port into said tissue receiving portion of said first bore under suction to a second position where said cutting edge traverses said port to sever the tissue drawn therethrough, and to permit the severed tissue to be captured in said tissue receiving portion;

said second tubular wall member having an opening formed in its sidewall adjacent extending to said cutting edge to provide internal communication between said annular passageway and said second bore to permit direct passage within said needle of irrigating fluid between said annular passageway and said tissue receiving portion and said second bore;

the forward portion of the sidewall of said first tubular wall member having no opening rearward of said cutting edge of said second tubular wall member when said cutting edge is in its first position;

whereby the severed tissue is evacuated through said second bore with the aid of the irrigating fluid.

2. The surgical instrument of claim 1 wherein said first tubular wall member has a cylindrical surface defining said sidewall and a blunt end wall, said port in said sidewall located adjacent said blunt end.

3. The surgical instrument of claim 1 further comprising means for moving said cutting edge of said second tubular wall member between its first and second positions.

4. The surgical instrument of claim 3 wherein said moving means includes a diaphragm associated with said second tubular wall member, and means for exposing said diaphragm to a source of pulsating positive pressure.

5. The surgical instrument of claim 1 further comprising means for providing the irrigating fluid to said annular passageway.

6. The surgical instrument of claim 5 further comprising means for regulating the flow of the irrigating fluid.

7. The surgical instrument of claim 1 further comprising means for providing the source of suction to said second tubular wall member.

8. The surgical instrument of claim 1 wherein the flow of irrigating fluid is "off" when said cutting edge is in its first position and "on" when said cutting edge is in its second position; .

9. The surgical instrument of claim 1 further comprising a cannula adapted to receive said first tubular wall member.

10. The surgical instrument of claim 9 wherein said cannula is curved, said first and second tubular wall members being sufficiently flexible to fit within said curved cannula.

11. The surgical instrument of claim 1 whereinn wherein said instrument is a percutaneous discectomy device.

12. A percutaneous discectomy surgical instrument comprising:

a housing;

a needle supported by said housing, said needle having a forward portion extending distally of said housing;

said needle including a first elongated tubular wall member defining a first bore, and having a port formed within the sidewall of the forward portion of said first tubular wall member;

said needle including a second elongated tubular wall member defining a second bore sized to permit passage of tissue therethrough when said second tubular wall member is connected to a source of suction, the passage within said second bore being unobstructed, said second tubular wall member having a forward portion extending radially outwardly and terminating in a cutting edge;

said second tubular wall member being positioned within said first tubular wall member with said cutting edge in contact with the sidewall defining said first bore, the forward portion of said first bore adjacent said port defining a tissue receiving portion communicating with said second bore;

said first and second tubular wall members being the only tubular wall members in said forward portion of said needle;

the wall of said second tubular wall member spaced inwardly from the wall of said first tubular wall member to define the opposing walls of an annular passageway adapted to be connected to a source of irrigating fluid, said annular passageway being the sole annular chamber in said forward portion of said needle;

said second tubular wall member being disposed for movement within said first tubular wall member to cause said cutting edge to move from a first position where tissue is drawn through said port into said tissue receiving portion of said first bore under suction to a second position where said cutting edge tranverses traverses said port to sever the tissue drawn therethrough, and to permit the severed tissue to be captured in said tissue receiving portion;

means for moving said cutting edge of said second tubular wall member between its first and second positions;

said second tubular wall member having an opening formed in its sidewall adjacent extending to said cutting edge to provide internal communication between said annular passageway and said second bore to permit direct passage within said needle of irrigating fluid between said annular passageway and said tissue receiving portion and said second bore;

the forward portion of the sidewall of said first tubular wall member having no opening rearward of said cutting edge of said second tubular wall member when said cutting edge is in its first position;

means for providing the irrigating fluid to said annular passageway; and

means for providing the source of suction to said second tubular wall member;

whereby the severed tissue is evacuated through said second bore with the aid of the irrigating fluid.

13. A percutaneous discectomy surgical instrument comprising:

a housing;

a needle supported by said housing, said needle having a forward portion extending distally of said housing;

said needle including a first elongated tubular wall member defining a first bore, and having a port formed entirely within the sidewall of the forward portion of said first tubular wall member;

said needle including a second elongated tubular wall member defining a second bore sized to permit passage of tissue therethrough when said second tubular wall member is connected to a source of suction, said second tubular wall member having a forward portion extending radially outwardly and terminating in a cutting edge;

said second tubular wall member being positioned within said first tubular wall member with said cutting edge in contact with the sidewall defining said first bore, the forward portion of said first bore adjacent said port defining a tissue receiving portion communicating with said second bore;

the wall of said second tubular wall member being spaced inwardly from the wall of said first tubular wall member to define the opposing walls of an annulus, said annulus providing the spacing for the forward portion of said second tubular wall member to extend radially outward and provide a cutting edge, said annulus being the sole annular space in said forward portion of said needle, ;

a third elongated tubular wall member positioned in said second bore and defining a passageway adapted to be connected to a source of irrigating fluid, said passageway being in communication with said second bore, said third tubular wall member being the sole element in said second bore;

said third elongated tubular wall member terminating approximately at said cutting edge of said second tubular wall member to provide direct passage within said needle of fluid between said third tubular wall member and said second bore;

said second tubular wall member being disposed for movement within said first tubular wall member to cause said cutting edge to move from a first position where tissue is drawn through said port into said tissue receiving portion of said first bore under suction to a second position where said cutting edge traverses said port to sever the tissue drawn therethrough, and to permit the severed tissue to be captured in said tissue receiving portion;

the forward portion of the sidewall of said first tubular wall member having no opening rearward of said cutting edge of said second tubular wall member when said cutting edge is in its first position;

whereby the severed tissue is evacuated through said second bore with the aid of the irrigating fluid.