The present invention relates generally to surgical devices for the repair of split portions of tissue, in particular, to surgical devices for closing a severed sternum.
The sternum is an elongated, flattened bone, forming the middle portion of the anterior wall of the thorax. Its upper end supports the clavicles, and its margins articulate with the cartilages of the first seven pairs of ribs. It consists of three parts, named from the neck downward, the manubrium, the body, and the xiphoid process. Its average length in an adult is about 17 cm, and is slightly less in a female adult. The sternum is a composite bone structure with a thin cortical shell surrounding a low-density cancellous core. Cortical bone is ivory-like and is dense in texture without cavities. It is the shell of many bones, surrounding the cancellous bone in the center. Cancellous bone is sponge-like with numerous cavities.
During surgery involving thoracic organs such as the heart, lungs, esophagus and aorta, it may be required to split the sternum to provide sufficient access for the surgeon. A partial or median sternotomy is a procedure by which a saw or other cutting instrument is used to make a midline, longitudinal incision along a portion of, or the entire axial length of the patient's sternum, allowing two opposing sternal halves to be separated laterally. Upon completion of the surgery, the sternum is rejoined and closed.
The two sternal halves are typically closed with stainless steel wire sutures that engage the severed sternal edges in a face-to-face relationship and compress them together while the sternum heals. The wire sutures are wrapped around the sternal halves by passing them through the intercostal spaces adjacent to the sternum. They may also be pierced through both halves of the sternum, particularly near the manubrium. Various piercing and wrapping patterns are used by different surgeons. For example, the wire sutures may be applied in an “X” pattern as viewed from the anterior portion of the sternum, to reduce axial motion of the sternal halves relative to each other. Regardless of the method, the ends of the wire sutures are twisted together to tighten the wire loops to a point where the sternal edges are approximated under tension.
U.S. Pat. No. 3,802,438 discloses sternal closure with wire sutures in conjunction with a splice plate in which the wire sutures are received. Other sternal closure assemblies include one or two metal plates, these plates being provided with rows of openings, through which extend the screws, pins, or metal wire, to bring together the severed portions of the sternum. In U.S. Pat. No. 4,583,541, wire bands are used in concert with an elongated, generally strap-like board, placed at the front of the sternum through which the wires are passed. Knots are then made and the knots then placed within a groove in the board.
Clamps, clasps, bands, and strips have been developed as sternal closure devices. For example, U.S. Pat. No. 4,201,215 discloses the use of a two-piece C-shaped clamp at one side of the sternum, the clamp pieces having hook ends that pass around to the other side of the sternum. Other assemblies completely circle the sternum and employ complex locking mechanisms to effect compression of the two sternal halves together. Representative examples are described in U.S. Pat. Nos. 5,356,417; 5,462,542; and 6,007,538.
There are numerous drawbacks with the use of wire sutures. For example, surgeons typically do not have means for ensuring that the tension in one wire suture is the same as the tension in another. Another drawback is that excessive twisting of the wire suture during tensioning can also result in hardening of the wire suture and breakage during the sternal closure procedure or after the surgical procedure. After being twisted together, the excess wire suture must be cut away, leaving sharp ends which may be palpable through the skin, painful and cosmetically undesirable. Surgeons may also be concerned about the potential for the wire suture to injure small blood vessels or nerves near the underside of the sternum. Moreover, the use of devices such as clamps, etc., that completely wrap around the sternum may irritate or damage tissue and vital structures such as blood vessels, particularly on the underside of the sternum.
Another drawback with the use of wire suture is that the amount of force necessary to close the sternum may cause the wire suture, which has a very small load-bearing surface, to cut through the cortical and cancellous portions of sternum. Additionally, the wire suture may cut through the cortical and cancellous portions of the sternum after sternal closure has been achieved, particularly when the wire sutures are subjected to intermittent severe loading due to coughing and other movements of the patient. These loads are transmitted primarily through the wire suture to the cortical component of the sternum. In some cases, this results in a loosening of a wrapped wire suture or an enlargement of the pierced holes in the sternum when the wire suture is pierced through the sternal halves. This loosening of the wrapped wire suture or the enlargement of the holes enables motion of the two halves of the sternum relative to each other. This motion may allow the sternal halves to separate and inhibit proper wound healing. In some cases, this separation may further allow opportunistic organisms to invade the tissue and cause an infection. Such an infection in the sternum is associated with significant morbidity and sometimes death. None of the devices described above that utilize wire sutures offers protection from shear loading and the resultant axial motion of the sternal halves.
Ideally, the device chosen to close a severed sternum must be simple in design, safe and easy to implant and remove, and should not damage adjacent tissue. It should not cause irritation to the patient or be cosmetically unacceptable. It must also be able to provide a secure sternal closure when challenged with post-surgical movement by the patient, particularly coughing. It is therefore an object of the present invention to provide a device and method that overcome the disadvantages of those known in the art.
The invention is generally directed to a device and method for closing a severed sternum. One particular aspect of the invention is directed to a device for joining first and second portions of a severed sternum, each portion having cortical and cancellous surfaces, the device comprising first and second bearing members; a sternum joining member comprising an axis, a first end, and a second end; the first end connected to the first bearing member; the second bearing member adapted to engage the sternum joining member, and the sternum joining member is adapted to traverse the cancellous surfaces of the first and second sternal portions.
Another aspect of the invention is directed to a method for closing a severed sternum having first and second portions, each portion having cortical and cancellous surfaces, comprising the steps of attaching a first bearing member to the first sternal portion; attaching a second bearing member to the second sternal portion; providing a sternum joining member having a first end, a second end, and an axis between the first end and second end; connecting the first bearing member to the first end of the sternum joining member; and attaching the second end of the sternum joining member to the second bearing member; wherein the sternum joining member traverses the cancellous surfaces of the first and second sternal portions.
Yet another aspect of the invention is directed to a kit for closing a severed sternum, the kit comprising at least one of the sternal closure devices mentioned above, means for creating at least one hole in the sternum, a guide, an introducer, a grasping device, and moving means for moving the second bearing member along the axis of the sternum joining member towards the first bearing member, the moving means further comprising means for measuring tension in the sternum joining member.
These and other features, aspects, and advantages of the present invention will become better understood with regard to the following description, appended claims, and accompanying drawings where:
The device will now be described by way of example only and not to limit the spirit or scope of the present invention. Referring now to
Referring now to
The shape of the first 21 and second bearing member 22 may be relatively flat for when the first bearing member 21 is attached to the anterior 18 or posterior surface 19 of the sternum 10. When the device is used on the anterior 18 and posterior surface 19 of the sternum 10, the sternum contacting sides 21b and 22b of the first 21 and second bearing members 22 may be at an oblique angle with respect to the axis 24 of the sternum joining member 23. The sternum contacting side 21b may also have rasps thereon that extend away from the sternum contacting side 21b to provide a secure engagement of the sternum contacting side 21b with the cortical surface 16 of the sternum 10.
The first end 25 of the sternum joining member 23 may be rigidly, integrally, slidably or releasably attached to the sternum contacting side 21b or optionally the protrusion 21c of the first bearing member 21, or in a manner that allows some rotation of the first bearing member 21 about the axis 24. For example, the protrusion 21c may have a lumen 21f that the first end 25 of the sternum joining member 23 is passed through. The first end 25 of the sternum joining member 23 may be flared 25a so as to prevent being pulled out of the lumen 21f when tension is applied during closure. Alternatively, the first end 25 of the sternum joining member 23 may be abutted against the sternum contacting side 21b of the first bearing member 21 while still allowing rotation thereon. This will allow for minor adjustments of the position of the first bearing member 21 on the sternum 10. Alternatively, the protrusion 21c on the first bearing member 21 may be rigidly fixed to the first end 25 of the sternum joining member 23 by welding or having the first bearing member 21 and entire sternum joining member 23 fabricated as a single piece through casting, molding, machining or other means known to those skilled in the art of fabricating small pans.
The second bearing member 22 may be slidably or releasably engaged with the axis 24 of the sternum joining member 23. For example, the second end 26 of the sternum joining member 23 may be adapted to engage a lumen 22f in the protrusion 22c of the second bearing member 22. The sternum joining member 23 may have means disposed along its axis 24 that facilitate movement of the second bearing member 22 towards the first bearing member 21. As illustrated in
The second end 26 of the sternum joining member 23 may include a hole 27 that can be used, along with a grasping instrument or hooking device, to help draw the second end 26 through the cortical 16 and cancellous portions 17 of the sternum 10. In alternative embodiments, the second end 26 may have a hook, flared end, or indentation that would also facilitate passing it through the sternum 10. The axis 24 of the sternum joining member 23 is adapted to traverse the cancellous surface 17 of the first 10a and second portion 10b of the severed sternum, obliquely in one or more directions or perpendicularly traversing the sternal incision margins created when the sternum was severed into two portions. The adaptation is made by having sufficiently long axis 24 with a diameter or cross-sectional area small enough to avoid undue interruption of the cancellous bone within the sternum. It should also be large enough to afford sufficient sternum joining strength. Preferably, the length of the axis 24 is 1-30 cm. The excess portion of the axis 24 can be removed at the end of the procedure. The diameter of the axis 24 is preferably between 1 mm-5 mm. If an axis 24 with a non-circular cross-section is utilized, the preferred cross-sectional area would be 1-25 mm2.
Referring now to
Yet another embodiment is illustrated in
Referring now to
Alternatively, as shown in
Preferably, each of the components described in the embodiments discussed thus far in
Illustrated in
The kit is further comprised of a punch guide 73 that can be applied to the sternal incision margins or severed edge of the sternal portions so as to provide a means for accurate and reproducible hole sizes, angle, depths, etc. The punch guide has holes 73b drilled in it to serve as the path for the bone punch 71. The punch guide 73 may also have a stop 73a thereon to prevent the bone punch from puncturing or damaging any vital structures, i.e., the depth of the hole created will be limited. The kit is further comprised of a moving means such as a tensioning tool 74 that grabs the second end 26 of the sternum joining member 23 while simultaneously pushing the second bearing member 22 along the axis of the sternum joining member 23 towards the first bearing member 21. The tensioning tool preferably has means 74a for setting the desired tension to be applied to the sternum joining member 23 and means disposed on its distal end 74b for cutting excess portions of the sternum joining member 23 away. The kit may optionally be further comprised of instructions for use.
One method of implanting the sternal closure device of the present invention will now be described in detail. The traditional incision of the sternum involves cutting the sternum with a fine-toothed saw that is applied perpendicular to the plane of the anterior surface of the sternum. After the sternal incision is made, the cancellous surface of each sternal portion is exposed. A retractor is then used to provide sufficient exposure to the organs in the thoracic cavity so that a surgical procedure can be performed therein. After the surgical procedure has been completed, the retractor is removed and the two portions of the severed sternum are now ready to be secured together.
As shown in
Also illustrated in
Alternatively, the method of closing the severed sternum comprises placing holes within the intercostal spaces on each portion of the severed sternum and using the sternal closure device 50 illustrated in
The number of devices of the type shown in
It is understood that various modifications and changes in form or detail could readily be made without departing from the spirit of the invention. It is therefore intended that the invention be not limited to the exact forms described and illustrated, but should be constructed to cover all modifications that may fall within the scope of the appended claims. Thus, the device and method could be used to close other bones such as cranial defects, fractures of bones in the skull, vertebral fractures, fractures of in the arms and legs, and fractures of bones in the hands and feet.
Number | Name | Date | Kind |
---|---|---|---|
309350 | Hayden | Dec 1884 | A |
3802438 | Wolvek | Apr 1974 | A |
4122989 | Kapitanov et al. | Oct 1978 | A |
4201215 | Crossett et al. | May 1980 | A |
4210148 | Stivala | Jul 1980 | A |
4279248 | Gabbay | Jul 1981 | A |
4512346 | Lemole | Apr 1985 | A |
4535764 | Enert | Aug 1985 | A |
4548202 | Duncan | Oct 1985 | A |
4583541 | Barry | Apr 1986 | A |
4730615 | Sutherland et al. | Mar 1988 | A |
4802477 | Gabbay | Feb 1989 | A |
4813416 | Pollak et al. | Mar 1989 | A |
4896668 | Popoff et al. | Jan 1990 | A |
5089012 | Prou | Feb 1992 | A |
5098433 | Freedland | Mar 1992 | A |
5139498 | Astudillo Ley | Aug 1992 | A |
5163598 | Peters et al. | Nov 1992 | A |
5318566 | Miller | Jun 1994 | A |
5330489 | Green et al. | Jul 1994 | A |
5356412 | Golds et al. | Oct 1994 | A |
5356417 | Golds | Oct 1994 | A |
5366461 | Blasnik | Nov 1994 | A |
5417698 | Green et al. | May 1995 | A |
5423821 | Pasque | Jun 1995 | A |
5437685 | Blasnik | Aug 1995 | A |
5462542 | Alesi, Jr. | Oct 1995 | A |
5722976 | Brown | Mar 1998 | A |
5830234 | Wojciechowicz et al. | Nov 1998 | A |
5849012 | Abboudi | Dec 1998 | A |
5893879 | Hirshowitz et al. | Apr 1999 | A |
5968077 | Wojciechowicz et al. | Oct 1999 | A |
5972006 | Sciaino, Jr. | Oct 1999 | A |
6007538 | Levin | Dec 1999 | A |
6008535 | Jean et al. | Dec 1999 | A |
6033429 | Magovern | Mar 2000 | A |
6045572 | Johnson et al. | Apr 2000 | A |
6051007 | Hogendijk et al. | Apr 2000 | A |
6080185 | Johnson et al. | Jun 2000 | A |
6200318 | Har-Shai et al. | Mar 2001 | B1 |
6217580 | Levin | Apr 2001 | B1 |
6302899 | Johnson et al. | Oct 2001 | B1 |
6312431 | Asfora | Nov 2001 | B1 |
6358270 | Lemer | Mar 2002 | B1 |
6368342 | Lemer | Apr 2002 | B1 |
6692497 | Toermaelae et al. | Feb 2004 | B1 |
6712821 | Gabbay | Mar 2004 | B2 |
6921401 | Lerch et al. | Jul 2005 | B2 |
7094239 | Michelson | Aug 2006 | B1 |
20020143336 | Hearn | Oct 2002 | A1 |
20020161439 | Strobel et al. | Oct 2002 | A1 |
20020165548 | Jutley | Nov 2002 | A1 |
20030040746 | Mitchell et al. | Feb 2003 | A1 |
20030083694 | Miller, III | May 2003 | A1 |
20030114856 | Nathanson et al. | Jun 2003 | A1 |
20030153947 | Koseki | Aug 2003 | A1 |
Number | Date | Country |
---|---|---|
0464480 | Jan 1992 | EP |
2199288 | Feb 2003 | RU |
WO 8701270 | Mar 1987 | WO |
WO 0064366 | Nov 2000 | WO |
WO 0122989 | Apr 2001 | WO |
WO 02067795 | Sep 2002 | WO |
WO 2004028412 | Apr 2004 | WO |
Number | Date | Country | |
---|---|---|---|
20050240189 A1 | Oct 2005 | US |