Surgical retractor and method of use

Claims

I claim:

1. A surgical retractor comprising:

a rigid remaining element having an aperture defining an operative site, the retaining element having a first section and a second section such that a user can separate the first section from the second section; and

a holder on the retaining element, the holder positioned to receive a connector such that the tissue is compressed between the connector and the retaining element and that the tissue is held stationary relative to the retaining element.

2. The surgical retractor of claim 1 wherein the retaining element comprises a planar section surrounding the aperture.

3. The surgical retractor of claim 1 further comprising a handle attached to the retaining element.

4. The surgical retractor of claim 1 further comprising an irrigation channel in the retaining element.

5. The surgical retractor of claim 4 further comprising a plurality of fluid openings in fluid communication with the channel.

6. The surgical retractor of claim 1 wherein the aperture comprises a longitudinal section, a first lateral section and a second lateral section.

7. The surgical retractor of claim 6 further comprising a connector including a first cord, the first cord extending through the first lateral section, and a second cord extending through the second lateral section.

8. The surgical retractor of claim 7 wherein the cord comprises flexible tape or thread.

9. The surgical retractor of claim 1 wherein the retaining element comprises a compression surface that compresses an artery to control blood flow in the artery.

10. The surgical retractor of claim 9 wherein the compression surface comprises a tab defining an aperture sidewall.

11. The surgical retractor of claim 10 further comprising a connector that extends through a first section of the aperture and a second section of the aperture such that the tab is positioned between the first section and the second section.

12. The surgical retractor of claim 1 further comprising a suction tube.

13. The surgical retractor of claim 1 further comprising a connector and wherein the holder comprises an opening that receives a portion of the connector.

14. The surgical retractor of claim 13 wherein the holder further comprises a second opening that receives a second portion of the connector.

15. The surgical retractor of claim 1 wherein the holder comprises a manually actuated fastener.

16. The surgical retractor of claim 1 wherein the retaining element comprises a plurality of separable sections.

17. The surgical retractor of claim 1 wherein the retaining element comprises a side opening in a base section extending into the aperture.

18. A method of positioning a surgical site during surgery comprising the steps of:

positioning a retaining element at a surgical site, the retaining element having an aperture defined by a first section and a second section such that the aperture exposes the surgical site;

connecting tissue at the surgical site to the retaining element with a connector and exposing a portion of the tissue in the aperture;

performing a surgical procedure; and

removing the retaining element from the surgical site by separating the first section and the second section.

19. The method of claim 18 wherein the connecting step comprises inserting a flexible cord under an artery and connecting the cord to a holder on the retaining element.

20. The method of claim 18 further comprising positioning a surface of the retaining element against an interior surface of a rib.

21. The method of claim 18 further comprising the step of suctioning fluid from the surgical site with a suction tube attached to the retaining element.

22. The method of claim 18 wherein the connecting step further comprises attaching a cord extending through the tissue to a holder on the retaining element.

23. The method of claim 18 further comprising providing a retaining element having a first plate and a second plate and removing the retaining element from the surgical site by separating the first plate from the second plate.

24. The method of claim 18 further comprising occluding an artery at the surgical site by pressing the artery against the retaining element.

25. A surgical retractor for a coronary bypass procedure comprising;

a retaining base having an aperture that exposes an operative site;

a first holder and a second holder on the retaining base; and

a cord that attaches at one side of the aperture to the first holder and at a second side of the aperture to the second holder such that artery tissue can be held stationary relative to the retaining base with the cord.

26. The surgical retractor of claim 25 wherein the retaining element comprises a planar base section surrounding the aperture.

27. The surgical retractor of claim 25 further comprising a handle attached to the retaining element.

28. The surgical retractor of claim 25 further comprising an irrigation channel in the retaining element.

29. The surgical retractor of claim 25 wherein the aperture comprises a longitudinal section, a first lateral section and a second lateral section.

30. The surgical retractor of claim 29 wherein the cord comprises a first cord, the first cord extending through the first lateral section, and further comprising a second cord extending through the section lateral section.

31. The surgical retractor of claim 25 wherein the cord comprises flexible tape or thread.

32. The surgical retractor of claim 25 wherein the retaining element comprises a compression surface that compresses an artery to control blood flow in the artery.

33. The surgical retractor of claim 25 wherein the compression surface comprises a tab defining an aperture sidewall.

34. The surgical retractor of claim 33 wherein the connector extends through a first section of the aperture and a second section of the aperture such that the tab is positioned between the first section and the second section.

35. The surgical retractor of claim 25 further comprising a suction tube.

36. The surgical retractor of claim 25 wherein the holder further comprises openings that receive sections of the cord.

37. A method of positioning a coronary artery during bypass surgery comprising the steps of:

positioning a retaining base at a surgical site, the retaining base having an aperture that exposes the coronary artery at the surgical site; and

connecting the coronary artery at the surgical site to the retaining base with a cord such that a portion of the artery is compressed between a surface of the retaining base and the cord; and

grafting a second artery onto the exposed coronary artery positioned in the aperture.

38. The method of claim 37 wherein the connecting step comprises threading a flexible cord under the artery and connecting the cord to a holder on the retaining base, the hold comprising a manually actuated fastener.

39. The method of claim 37 further comprising occluding blood flow in the coronary artery by compressing the artery against the retaining base.

40. The method of claim 37 further including providing a cord comprising a tape or thread connected at two sections to the retaining base on opposite sides of the retainer.

41. A surgical retractor for a coronary bypass procedure comprising;

a retaining base having a compression surface and an aperture that exposes an operative site, the aperture extending along a longitudinal axis of the base;

a plurality of holders on the retaining base such that a first holder is positioned on a first side of the aperture and a second holder is positioned on a second side of the aperture, the compression surface being positioned between the first holder and the second holder; and

an arm attached to the retaining base and extending above the retaining base such that a user can position the retaining base at the operative site with a coronary artery exposed through the aperture.

42. The surgical retractor of claim 41 wherein the retaining element comprises a planar base section surrounding the aperture.

43. The surgical retractor of claim 41 further comprising an irrigation channel in the retaining element.

44. The surgical retractor of claim 41 wherein the aperture comprises a longitudinal section, a first lateral section and a second lateral section.

45. The surgical retractor of claim 44 wherein the cord comprises a first cord, the first cord extending through the first lateral section, and further comprising a second cord extending through the section lateral section.

46. The surgical retractor of claim 41 further comprising a cord held by the first holder and the second holder such that the cord extends through the base around a coronary artery.

47. The surgical retractor of claim 41 wherein the retaining element comprises a compression surface that compresses an artery to control blood flow in the artery.

48. The surgical retractor of claim 41 wherein the compression surface comprises a tab defining an aperture sidewall.

49. The surgical retractor of claim 48 wherein a cord extends between the holders through a first section of the aperture and a second section of the aperture such that the tab is positioned between the first section and the second section.

50. The surgical retractor of claim 41 further comprising a suction tube.

51. A surgical retractor comprising;

a rigid retaining element having an aperture exposing an artery at an operative site, the retraining element further including planar compression surface regions on opposite sides of the aperture; and

a holder on the retaining element, the holder positioned to receive a connector such that the artery is compressed between the connector and the compression surface regions on the retaining element, the compression surface regions occluding a lumen in the artery on the opposite sides of the aperture and holding the artery stationary relative to the retaining element.

52. The surgical retractor of claim 51 wherein the retaining element comprises a planar section surrounding the aperture.

53. The surgical retractor of claim 51 further comprising a handle attached to the retaining element.

54. The surgical retractor of claim 51 further comprising an irrigation channel in the retaining element.

55. The surgical retractor of claim 51 wherein the aperture comprises a longitudinal section, a first lateral section and a second lateral section.

56. The surgical retractor of claim 55 wherein the connector comprises a first cord, the first cord extending through the first lateral section, and a second cord extending through the second lateral section.

57. The surgical retractor of claim 56 wherein the cord comprises flexible tape or thread.

58. The surgical retractor of claim 51 wherein the compression surface comprises a tab defining an aperture sidewall.

59. The surgical retractor of claim 58 wherein the connector extends through a first section of the aperture and a second section of the aperture such that the tab is positioned between the first section and the second section.

60. The surgical retractor of claim 51 further comprising a suction tube attached to the retractor.

61. The surgical retractor of claim 51 wherein the holder comprises an opening that receives a portion of the connector.

62. The surgical retractor of claim 61 wherein the holder further comprises a second opening that receives a second portion of the connector.

63. The surgical retractor of claim 51 wherein the holder comprises a manually actuated fastener.

64. The surgical retractor of claim 51 wherein the retaining element comprises a plurality of separable sections.

65. The surgical retractor of claim 51 wherein the retaining element comprises a side opening in a base section extending into the aperture.

BACKGROUND

Numerous devices have been used to position tissue at a surgical site to aid in the performing of surgical procedures. Retractors, for example, have been used to hold an artery in position during operations adjacent to the heart to prevent movement of the artery. This serves to minimize the risk of injury to the artery and adjacent tissue and can facilitate the desired anastomosis.

A recently developed procedure, referred to as the minimally invasive direct coronary artery bypass procedure, has been used to graft onto a coronary artery without cardiopulmonary bypass. This procedure involves the grafting of the left internal mammary artery (LIMA) onto the left anterior descending (LAD) or other artery. As this procedure does not require the use of a heart lung machine to oxygenate and pump blood, the morbidity and mortality associated with this procedure is substantially lower than previous bypass techniques. A problem associated with the minimally invasive procedure, however, is that while the heart continues to pump during the procedure, the motion of the heart can interfere with the surgeon's task of attaching the LIMA to the LAD. There is also a need to stop blood flow in the area of the graft to maintain a clear field of view and provide precise suture placement.

Two basic strategies have been employed to address the problem of operating on a moving site, one being the use of pharmacological agents to limit heart motion, and the other being mechanical, such as a two prong retractor that is pushed down against the heart on both sides of the artery, or alternatively, upward traction away from the moving heart by traction tape or suture thread. Both of these options, however, have problems associated with them. Both options are susceptible to some movement of the vessel grafting site. The use of pharmacological agents is undesirable and impairs circulatory function. Traction by compression of the heart against the spine does serve to immobilize the site but can compromise the ability of the heart to maintain circulation and result in hypotension. Upward traction can involve circumferential compression of the artery to occlude the artery and prevent blood flow, however upward traction that is sufficient to immobilize the site can cause injury, stenosis or occlusion of the vessel.

There is a continuing need however for improvement in devices and methods for retaining tissue at surgical sites to further reduce the risks associated with surgical procedures where the devices and methods are inexpensive, safe and reliable.

SUMMARY

The present invention relates to a surgical retractor for immobilizing tissue at a surgical site and to a method of using the retractor during a surgical procedure. A preferred embodiment of the retractor includes a retaining element having an aperture that exposes the surgical site and a holder that is used to position tissue at the surgical site relative to the retaining element. A handle can be attached to or fabricated with the retaining element or platform so that the user can manipulate the position of the retractor as needed.

In a preferred embodiment of the invention a connector such as elastic tape or thread is used to position tissue at the surgical site within the retractor aperture and to prevent movement of the tissue during the procedure. The connecting cord, thread or tape also aids in the compression of the artery in a grafting procedure to occlude flow on one or both sides of the surgical site. The cord is attached to the holder on the retaining element. A preferred embodiment of the holder can be a plurality of slits or openings positioned on both sides of the retractor that receive and frictionally secure the cord on both sides of the aperture. In another preferred embodiment a mechanical fastener is used to grip both sides of the cord. The fastener can be a spring mounted valve, for example, that allows the user to adjust the tension in the cord.

A preferred embodiment of the invention comprises a retaining element or base having two sections that can be separated after the procedure is complete to permit removal of the retractor from under the grafted artery. Another preferred embodiment uses a side opening in the platform of the retractor that extends to the aperture so that the grafted artery slips through the side opening during removal. During minimally invasive direct coronary artery bypass operations, one or more surface sections of the retractor platform can be positioned against the inner surface or posterior aspect of one or both ribs adjacent to the surgical site. Thus, the size and geometry of the platform are selected to utilize the adjoining ribs where the upper surface of the platform frictionally engages the inner surface one or more ribs to hold the retractor in a fixed position. The retractor can be beneficial in any procedure where it is necessary to stabilize a surgical site. For example, the retractor can also be used for grafting onto the diagonal, right or other coronary arteries without altering the heart's pumping function.

The coronary arteries are about 1-2 mm in diameter, and the pumping heart can move these arteries over distances of several millimeters during each heartbeat. As the movement of even 1 or 2 millimeters can result in a displacement of the grafting site that can substantially interfere with effective anastomosis, it is desirable to restrain movement of the artery at the surgical site in any direction to less than 1 mm. The retractor of the present invention restrains movement in the plane of the base to less than 0.5 mm, and preferably less than 0.2 mm.

In a preferred embodiment of the invention, the handle or articulating arm that is secured to the platform can be held in position by the user, attached to a frame that is fixed around the operative site or simply clipped to a drape around the site.

When used in a minimally invasive coronary bypass procedure, the retractor is positioned to expose the left anterior descending (LAD) artery grafting site after incision, removal of the rib section and dissection of the left internal mammary artery (LIMA) from the chest wall. A pair of cords, for example, sialastic tape (i.e. a silicon elastomer) or suture thread, are passed through the myocardium at two locations flanking the artery grafting site with blunt needles. The four ends of the two cords are connected to the platform holder with sufficient tension to occlude blood flow on both sides of the operative site. The tapes compress the artery against the bottom surface of the platform while they hold the artery grafting site in a fixed position relative to the aperture. The coronary artery is opened longitudinally and the end of the mammary artery is sewn to the graft opening with multiple fine sutures. The cords are released, blood flow is restored and the anastomosis is inspected for hemostatis and other defects and the wound is closed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a surgical retractor in accordance with a preferred embodiment of the invention.

FIG. 2 is a perspective view of a surgical site illustrating a surgical procedure.

FIG. 3 is a perspective view of a surgical retractor for a grafting procedure in accordance with the invention.

FIG. 4 is a bottom perspective view of a surgical retractor in accordance with the invention.

FIG. 5 is a cross-sectional view of a surgical retractor during a surgical procedure.

FIGS. 6A and 6B are partial cross-sectional views of a holder in accordance with the invention.

FIG. 7 is a top view of a two piece retainer in accordance with the invention.

FIG. 8 is a top perspective view of another preferred embodiment of a surgical retractor in accordance with the invention.

FIG. 9 is a top perspective view of another preferred embodiment of a surgical retractor in accordance with the invention.

FIG. 10 is a schematic diagram illustrating a surgical procedure in accordance with the invention.

DETAILED DESCRIPTION

A preferred embodiment of the invention is illustrated in connection with FIG. 1. A retractor 10 includes a retaining element or base 12 having an aperture 16 that is positioned to expose tissue at a surgical site. The base 12 can be made with a metal or a molded plastic material. The retractor 10 can be sterilized after each use, or alternatively, can be disposable after one procedure. A handle 30 or articulating arm can be permanently attached to the base 12, or as described below in connection with other preferred embodiments, can be detachable.

A suction tube 32 can be attached to the handle 30 or integrated therein and is used to remove material such as blood from the operative site. In this particular embodiment the tube 32 is connected at one end to a tube 34 from a suction pump and connected at a second end to a port 36 in fluid communication with a channel within tube 28 that extends around the periphery of base 12. The peripheral tube can have small openings 38 positioned on the sides or top thereof through which fluid such as blood or other debris can be suctioned from the surgical site to maintain a clear field.

A preferred embodiment of the invention can be used at a surgical site 50 such as the example illustrated in FIG. 2. In this particular procedure for a coronary graft without cardiopulmonary by