Wound Closure Device

1. Field of the Invention

The invention relates to a device to enable the closure of puncture wounds made by trocars during laparoscopic and other minimally invasive surgical procedures. More specifically, the device relates to a hook shaped device which brings together the edges of the deep tissue layers on opposing sides of a puncture wound by passing a suture through the deep tissue structures, under the skin tissue layer on opposite sides of the wound.

2. Description of the Related Art

It is known to suture puncture wounds such as those formed by trocars during laparoscopic and minimally invasive surgical procedures with a J-shaped needle such as the needle disclosed in U.S. Pat. No. 5,336,239. A J-shaped needle may be used to pass a suture through the deep tissue layers on opposing sides of a puncture wound such as the peritoneal membrane and deep abdominal fascia punctured during laparoscopic abdominal surgery. The point of the J-shaped needle may be covered as the needle is inserted into the puncture wound. The needle is then exposed from the cover and drawn outward through the subcutaneous tissue layers and finally through the skin on a side of the wound. The surgeon then threads a length of suture through the eye of the needle and draws the needle back through the skin and tissue into the body. The needle is passed out of the body through the tissue at another location on an opposite side of the wound completing the suture. This process is repeated as necessary to close the wound.

One of the disadvantages of the devices of the prior art such as the one disclosed in U.S. Pat. No. 5,336,239, is that, in order to be insertable through a trocar cannula, the needle profile has to be equal to or less than the internal diameter of the trocar cannula. For example, in currently available devices, if the internal diameter of the trocar cannula is 10 mm, then the width of the J-shaped needle measured from the widest point on the outside of the short leg of the "J", to the outside of the long leg of the "J" must be equal to or less than 10 mm. With this restriction the amount of "bite" that the prior art device can achieve (i.e., the amount of tissue it can capture for suturing) is limited to the maximum gap between the two legs of the "J" shaped needle. This is an unwanted limitation on the ability to secure the tissue under certain circumstances.

Examples of J-shaped needles are disclosed in commonly-owned U.S. patent application Ser. Nos. 08/134,561 and 08/145,855 now U.S. Pat. Nos. 5,468,251 and 5,439,469 respectively. One embodiment of such needles is shown in FIGS. 1A and 1B. The needle 10 is housed in a cylindrical guide member 12 during insertion of the needle into a patient. After insertion, the needle 10 is rotated 180 degrees with respect to the guide member 12 about an axis x of the longer leg of the needle. As shown in phantom lines in FIGS. 1A and 1B, the short leg 16 of J-shaped needle 10 when rotated 180 degrees is positioned at a distance (a) from the guide member 12. The distance (a) is less than the diameter (b) of the guide member 12. As a result, the amount of tissue which can be captured between the short leg 16 and the housing 12 is rather limited.

Other types of needle arrangements are disclosed in WO93/21831, WO92/12674, EP 589409 A1, EP 568098 A2 and U.S. Pat. Nos. 5,222,508, 5,281,237, 5,350,385 and 5,320,632.

The invention provides a wound closure device comprised of an elongated guide member and needle having a needle tip positioned within the guide member in a closed position and positioned outside the guide member in an open position, the guide member and the needle tip being spaced apart by a distance greater than the external diameter of the guide member when the needle is in the open position. The device further includes a retraction mechanism for moving the needle from the open position to the closed position.

The needle preferably comprises a hook shaped needle having a first leg connected to a second leg by a distal end of the needle, the second leg including a needle tip and when the needle tip is in the open position the second leg extends at an angle with respect to the first leg such that a distance between the first leg and the second leg decreases at locations along the second leg away from the tip.

The invention is described with reference to the accompanying drawings in which like elements bear like reference numerals, and wherein:

FIG. 1A is a sectional side view of a comparative wound closure device having a limited "bite";

FIG. 1B is a sectional end view of the device of FIG. 1A;

FIG. 2A is a sectional side view of a wound closure device according to a first embodiment of the present invention;

FIG. 2B is a sectional end view of the device of FIG. 2A;

FIGS. 3A-3E are side views of the operation of a wound closure device according to a second embodiment of the invention;

FIGS. 4A-4E are end views corresponding to FIGS. 3A-3E;

FIG. 5A is a side view of a sleeve for use with a wound closure device according to a third embodiment of the invention;

FIGS. 5B-5F are side views, partly in section, of the operation of a third embodiment of the invention;

FIGS. 6A-6F are end views corresponding to FIGS. 5A-5F;

FIGS. 7A-7C are side views of the operation of a handle useable with the embodiments of FIGS. 5A-5F and 6A-6F; and

FIG. 8 is a side view of a wound closure device according to a fourth embodiment of the invention.

The invention provides a wound closure device which can maintain pneumoperitoneum during a laparoscopic surgical operation and allow the surgeon to capture an mount of tissue which is substantially wider than the diameter of the trocar cannula through which the needle is inserted. As shown in FIG. 2A, the suturing device includes a hook shaped needle 20 and a guide member 22. The hook shaped needle 20 includes a long leg 24 which extends to a handle (not shown) and a short leg 26 having an eye 28 for receiving a suture near a sharpened tip of the needle. In the closed position, the needle 20 is fully within guide member 22. The hook shaped needle 20 is designed such that short leg 26 of the needle, in its deployed (open) condition, is tilted or angled, with respect to the long leg 24 of the needle. Therefore, the distance C between the tip of the needle and an adjacent wall of the guide member 22 is greater than the external dimension of guide member 22 and consequently greater than an inner diameter of a trocar cannula (not shown) through which the entire device can be inserted into a patient. In the deployed condition, shown in phantom lines in FIGS. 2A and 2B, a distal curve or bend 30 of the needle 20 is partially exposed outside the guide member 22, the bend 30 having a non-traumatic shape and providing sufficient width between the needle tip and the guide member. Due to the wedge-shaped opening between short leg 26 and guide member 22, tissue captured with the needle during suturing is not severed or excessively compressed within the base of the needle as the device is drawn through the tissue.

The wound closure device can include various retraction mechanisms for deploying the needle to the open position and retracting the needle to the closed position. In the closed position, a trocar cannula can be slid over the device and removed, if desired. If the trocar cannula is removed, a portion of the guide member 22 above the tip of the needle will maintain pneumoperitoneum during the suturing operation.

According to the embodiment of the invention shown in FIGS. 2A and 2B, the needle 20 has the shape shown in phantom in the open, unconstrained stated. As shown in FIG. 2A, the long leg 24 of the hook shaped needle 20 is located in a slot 32 extending along the outer wall of the guide member 22 which restrains the needle longitudinally, but allows rotation of the long leg 24 of the needle with respect to its longitudinal axis. The slot 32 includes a first portion 32a parallel to long leg 24, a second portion 32b receiving portion 25 of the needle and extending at an obtuse angle to the first portion, a third portion 32c perpendicular to the first portion 32a and receiving distal end 30 of the needle and a fourth portion 32d parallel to first portion 32a and receiving short leg 26. The second portion 32b extends in direction y at an acute angle (e.g., .ltoreq.30.degree.) with respect to the central axis of the guide member 22.

Upon rotation of long leg 24, the second portion 32b and first portion 32a cause the portion 25 to elastically bend with respect to long leg 24 and thus orient the short leg 26 parallel to the long leg 24 when the needle 20 is rotated into the closed position. Conversely, to open the needle, the needle 20 is rotated about the axis of long leg 24 to deploy short leg 26 to the open position whereupon the force constraining elastically deformed portion 25 is gradually released until short leg 26 is in the position shown in phantom in FIG. 2A. To accommodate short leg 26 as it rotates into and out of guide member 22, portion 32d of slot 32 includes circumferentially extending recess 34.

In order to facilitate the flexing of the short leg 26 of the needle, the profile of portion 25 could be modified to accommodate bending, for example, by reducing the diameter of the needle. Alternatively, portion 25 could comprise a section of more resilient material than that of long leg 24 and/or short leg 26. Whether or not long leg 24, bend 25, distal end 30 and short leg 26 are of the same material (e.g., stainless steel) or not, when long leg 24 is rotated by a handle (not shown), the point of the needle is rotated in a non-circular path deploying the tip of the needle well outside of the outer surface D of the guide member 22. Preferably, the distance C between the tip of the needle in the open position and the outer surface of the guide member 22 is at least twice the maximum transverse dimension D of the guide member 22. Upon 180.degree. rotation of the long leg 24, the short leg 26 of the needle is flexed inwardly toward the guide member and rotates along recess 34 into portion 32d of slot 32, such that the needle tip is again constrained within the guide member.

A second embodiment of the invention is shown in FIGS. 3A-3E and 4A-4E. In this embodiment, the long leg 24 of the hook shaped needle 20 is positioned along the inside wall of the guide member 22 within a slot 36 in the guide member which restrains the needle longitudinally but allows axial rotation of the needle about the long leg. In the fully deployed condition, shown in FIGS. 3A and 4A, the tip of the needle is rotated 180 degrees outside of the guide member 22 such that the tip is positioned at a distance E from the outer surface of the guide member 22, distance E exceeding the dimension D of the guide member.

To close the device, the hook shaped needle 20 is first axially rotated 180 degrees with respect to the body of the device as shown in FIGS. 3B and 4B, causing the curved distal end 30 of the hook to rotate into a recess 38 provided across the diameter of the distal end of the guide member 22. This effectively closes the needle an amount equal to the diameter of the guide member 22, leaving only the angled short leg 26 of the needle exposed beyond the outer surface of the guide member. A retracting mechanism 40 mounted on the outside of the guide member 22 is movable longitudinally and causes an outer, thin-walled ring 42 of the retracting mechanism to slide over the outside diameter of the guide member, over the distal base of the needle, until it engages the exposed, angled short leg 26 of the needle as shown in FIGS. 3C and 4C. On continued axial sliding of the outer retracting mechanism 40 up the guide member 22, the edge of the ring 42, acting as a ramp, elastically deforms the short leg 26 of the needle to flex and bend under the edge of ring 42 as shown in FIGS. 3D and 4D, until the short leg of the needle is elastically deformed into a receiving groove 44 in the side of the guide member 22, as shown in FIGS. 3E and 4E, completely closing the device and allowing the device to be inserted or withdrawn from a surgical site while maintaining peritoneum. If desired, ring 42 can be incorporated in a tubular sleeve having cut-outs for allowing deployment and retraction of short leg 26.

In order to open the needle once the device has been inserted into the body of a patient, the steps shown in FIGS. 3A-3E and 4A-4E are conducted in reverse order. That is, the retracting mechanism 40 is slid distally along the guide member 22 to release the tip of the needle from the ring 42 such that the tip is angled outwardly away from long leg 24. Then the long leg 24 of the needle is rotated 180 degrees with respect to the guide member 22 so that the short leg 26 and the distal end 30 of the needle are entirely outside of the guide member 22.

According to a third embodiment of the invention shown in FIGS. 5A-5F and 6A-6F, the long leg 24 of the hook shaped needle is disposed inside guide member 22 which is positioned inside a sleeve 46. The sleeve 46, as shown in FIGS. 5A and 6A, includes a tubular member configured to fit over the guide member 22. The sleeve 46 has a longitudinal tapered slot 48 through which the short leg 26 of the needle extends. One edge of the longitudinal slot 48 has an arc shape such that the width of the slot increases along the length of the slot, from the distal end to the proximal end of the slot.

In the deployed condition, as shown in FIGS. 5B and 6B, the needle is restrained at its proximal end such that the long leg 24 lies along the inside wall of the sleeve 46, and the short leg 26 of the needle extends out of the slot 48 in the side of the sleeve 46, beyond the outer surface of the device. To close the device, a rotary mechanism (not shown) rotates the guide member 22 with respect to the sleeve 46. The rotation of the guide member 22 moves the long leg 24 laterally away from the slot 48 and draws distal end 30 into the guide member 22, as shown in FIGS. 5C, 5D, 6C and 6D. For instance, this lateral movement can be accomplished by twisting long leg 24 of the needle into a helical shape across the internal diameter of the stationary sleeve 46, as shown in FIGS. 5C and 5D. Such movement partially closes the needle by an amount equal to the internal diameter of the sleeve 46, leaving only the short leg 26 of the needle exposed outside of the slot 48 in the sleeve 46. To complete the closure of the device, the guide member 22 is rotated with respect to sleeve 46 such that the arc shaped side of the slot 48 engages the exposed short leg 26 of the needle, where it acts as a ramp and forces the short leg of the needle to flex under the edge of the arc as shown in FIGS. 5E and 6E. The rotation of the guide member 22 continues until the short leg of the needle is elastically deformed into a receiving groove 50 in the side of the guide member 22, within the diameter of the sleeve 46, completely closing the device.

Alternatively, sleeve 46 can be used with the device shown in FIGS. 5A-F. That is, bend 30 can be drawn into the guide member in the manner shown in FIGS. 3A-F by moving long leg 24 along a circumferential path away from slot 48. To complete closure of the needle, sleeve 46 can be used in place of ring 42 to flex short leg 26 into the guide member by engaging short leg 26 with an edge of slot 48. Thus, bend 30 would be moved into and out of the guide member by rotating guide member 22 with respect to sleeve 46 and upon further rotation of sleeve 46 the short leg 26 would be engaged with slot 48.

In the foregoing embodiments, a deployable handle may be attached to the proximal end of the long leg 24 of the needle to provide a secure grasp of the device in the hands of the surgeon and to provide a visual and tactile indication of the orientation of the needle during use. An example of such a handle 52 is shown in FIGS. 7A-7C. The handle 52 is especially useful for identifying the orientation and position of the deployed needle point when it is hidden from view within a body cavity.

The handle 52 is preferably formed as a cylindrical rod whose diameter is less than or equal to the external diameter of the device whereby the device and the handle 52 can pass freely through a trocar cannula in the case where a trocar cannula is used to introduce the guide member 22 into an operative site and the trocar cannula is subsequently removed. The handle 52 may be attached to the needle 20 via a pin 54 which is pressed through a slot 56 in the handle 52. A loop 58 formed at the end of the needle 20 is inserted in the slot 56 and the pin 54 is inserted through the loop. The pin 54 acts as a pivot about which the handle 52 may be rotated with respect to the device to form a "T". The position of the pivot pin 54 and the slot 56 through the handle, are preferably placed off-center such that the two portions of the "T" handle are asymmetrical and provide visual and tactile information as to the orientation of the deployed needle, e.g., the portion of the handle extending further from the pivot indicating the direction of the needle tip. The handle 52 also includes a slot 60 which accommodates the proximal end of the long leg 24 of the needle when the handle is in the closed position.

FIGS. 7A-7C show the operation of the handle 52. In FIG. 7A, the handle is in the closed position parallel to the axis of the guide member to allow removal of a trocar cannula over the device. After insertion of the device into the body, the handle can be pivoted 90 degrees so as to be perpendicular to the axis of guide member 22, as shown in FIG. 7B. Thereafter, the handle is rotated 180 degrees to deploy the needle as shown in FIG. 7C. Rotation of needle 20 with respect to the guide member 22 and sleeve 40 can be limited in any suitable manner, if desired. For instance, a stop member 29 (e.g., pin) attached to guide member 22 can be used to limit longitudinal movement and rotation of the guide member with respect to sleeve 40. As an example, stop member 29 can extend through a circumferentially extending slot 49 in sleeve 40 to limit rotation.

In all of the embodiments discussed above, a variation of the hook shaped needle can be employed, in which the tip of the angled hook of the short leg 26 curves back in towards the body of the device, whilst still maintaining the desired bite width which is greater than the diameter of the closed device. The "recurved" tip 62 is shown in FIG. 8 in which the recurved tip 62 is parallel to the body of the device. This "recurved" tip may aid the surgeon in exiting the tissue at a desired angle during suture placement.

In a preferred embodiment of the invention, a recess (not shown) is incorporated in the guide member of the device, in the region in which the tip and eye of the needle are sheathed when the device is in a completely closed position. This recess extends on both sides of the groove which receives the short leg of the needle. The recess provides clearance for a loop of suture material which is threaded through the eye of the needle and remains attached to the needle in the closed position. This allows the surgeon the option of pre-threading the needle with suture prior to insertion of the device into the patient.

In all embodiments, the device is designed to be completely exchangeable through the bore of the trocar cannula in either direction and designed such that operative pneumo (i.e. pneumoperitoneum or pneumothorax or properitoneal pneumo) is maintained during use. These features result in maximum safety to the patient and allow the surgeon the choice of using the device with the trocar cannula in place or removed.

The foregoing has described the principles, preferred embodiments and modes of operation of the present invention. However, the invention should not be construed as being limited to the particular embodiments discussed. Thus, the above-described embodiments should be regarded as illustrative rather than restrictive, and it should be appreciated that variations may be made in those embodiments by workers skilled in the art without departing from the scope of the present invention as defined by the following claims.