RETRACTOR RAKE FOR VASCULAR GRAFT SURGERY

BACKGROUND OF THE INVENTION

When an aortic arch vessel is damaged (e.g., an abdominal aortic aneurysm (AAA) or vessel wall intima), total replacement of the arch may be conducted surgically. In this surgical procedure, the arch is removed and an artificial vascular graft is sutured end-to-end with severed ends of the aorta. The graft also has branches for connecting to the branch vessels that lead off from the arch (e.g., the

brachiocephalic, left common carotid, and left subclavian arteries). The graft typically includes a fourth branch that is temporarily used during the surgery by a perfusion system for supplying temperature-controlled oxygenated blood to the patient.

As a result of pressure of the perfused blood acting on the arch graft, the graft tends to move towards an upper right direction away from the surgical site and becoming masked behind the rib cage. This movement increases the difficulty for the surgeon to suture the branches of the graft to the target vessels.

SUMMARY OF THE INVENTION

The invention provides a tool that enables the surgeon to pull down the arch vessel in order to bring it into the working area with good visibility and space while having adjustability of location and angulations.

In one aspect of the invention, a surgical rake useful for aortic arch replacement surgery comprises a base formed of molded thermoplastic. A plurality of arched fingers are integrally molded with the base, each conforming to a

predetermined arc. The fingers define at least one slot adapted to receive a branch vessel of an aortic arch graft. The predetermined arc substantially conforms to an outside diameter of the graft. A mounting feature is arranged at an end of the base opposite from the fingers.

In another aspect of the invention, a method is provided for anastomosing an aortic graft to replace an excised aortic arch in a patient. An end of the aortic graft is sutured to a descending aorta of the patient. Perfusion of blood is initiated through the graft from an auxiliary perfusion branch of the graft to the descending aorta.

Movement of the graft resulting from the perfusion of the blood is counteracted by grasping the graft with a molded rake comprising a base and a plurality of arched fingers extending from the base and each conforming to a predetermined arc, wherein the fingers define at least one slot adapted to receive a branch vessel of the aortic graft, and wherein the predetermined arc substantially conforms to an outside diameter of the graft. Then the branch vessel is sutured to an artery of the patient. BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a diagram showing an aortic arch.

Figure 2 is a diagram showing aorta and side branches remaining after dissecting the arch.

Figure 3 is a plan view showing an aortic arch graft.

Figure 4 is a plan view showing the suturing of one end of the graft to the descending aorta.

Figures 5 and 6 are plan views showing subsequent steps of suturing of the graft wherein perfusion of pumped blood is conducted.

Figure 7 is a plan view showing a surgical rake of the present invention during anastomosis with the rake mounted to a support arm.

Figure 8 is a plan view of an adjustable support arm.

Figures 9A-9I are surgical rakes of the invention of various sizes and with various numbers of arched fingers.

Figure 10 is a perspective view of a base and fingers for one preferred embodiment of the invention having four fingers.

Figure 11 is a perspective view of one embodiment of a support pin for attaching to the base of Figure 10.

Figure 12 is a perspective view of one embodiment of a ring nut for attaching the support pin of Figure 11.

Figure 13 is another perspective view of the support pin of Figure 11. Figure 14 is a rear perspective view of the base and fingers of Figure 10.

Figure 15 is an end perspective view of the base and fingers of Figure 10.

Figures 16 and 17 are perspective views of a base and fingers in an embodiment having two fingers.

Figures 18 and 19 are perspective views of a base and fingers in an embodiment having three fingers.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Figure 1 shows an aorta 10 including an aortic arch 11 between the ascending and descending aorta, together with branch arteries. As a result of aneurysm or vessel wall intima, it may be indicated to replace arch 11. As shown in Figure 2, a diseased arch may be removed (i.e., dissected) by severing from the ascending and descending aorta and from the side branches. Throughout a surgical procedure, a supply of perfusion blood is given to the patient, with the blood supply at least initially provided directly to one or more side arteries as shown.

Figure 3 shows a graft 15 for replacing the aortic arch including a main body 16, upper side branches 17, 18, and 19 for joining with the patient's arteries, and an auxiliary side branch 20 which may be temporarily used for introducing perfusion during certain portions of a surgical procedure.

Figure 4 shows one end of graft 15 being sutured to a descending aorta 21 wherein a supplemental collar or sleeve 22 may also be sutured in place for more reliably joining the graft with the vessel. Suturing thread 23 has a suturing needle 24 at one end (e.g., swaged onto the end of thread 23).

As shown in Figure 5, as the surgical procedure progresses a source of perfusion may be supplied to the auxiliary side branch. With one end of graft 15 sutured to the descending aorta, a perfused blood flow can be supplied to auxiliary branch 15 after the other end of graft 15 and side branches 17-19 have been clamped off using clamps 25-28. The pressure of the perfused blood introduced via auxiliary branch 20 may cause a tendency for the graft to roll in the direction indicated, making it more difficult to continue suturing other connections to graft 15. For example, the procedure may continue with a side vessel 31 which is temporarily clamped off by a clamp 30 being sutured to side branch 19 of graft 15. The rolling reaction may be counteracted using the rake of the present invention in order to keep the interface between vessel 31 and branch 19 more accessible to the surgeon. As shown in Figure 6, another subsequent step in anastomosing graft 15 includes attachment to an ascending aorta 32. Then branches 17 and 18 are sutured to their respective vessels. It would be desirable to simultaneously hold graft 15 and side branches 17-19 in an accessible position using minimal effort and setup time.

To counteract the tendency of the graft to roll during the procedure, a rake 40 shown in Figure 7 may be mounted to a support arm 41, wherein rake 40 has a base (i.e., root) 43 and a plurality of tines or fingers 42 adapted to grasp graft 15 between and among the side branches. As shown in Figure 8, support arm 41 has a mounting structure 44 at one end for connecting to a support frame such as a sternal retractor (not shown) and has an end connector 45 which may preferably include a ball quick- connect or latching mechanism as known in the art (e.g., the Hercules™ Stabilizing Arm available from Terumo Cardiovascular Systems of Ann Arbor, Michigan).

Figures 9A-9I show various embodiments of the rake of the present invention having two, three, or four arched fingers. Each arched finger or tine is formed as a predetermined arc that substantially conforms to an outside diameter of a respective graft size. In addition, the arched fingers are spaced according to an arrangement of side branches to be accommodated within the rake. Extending from each respective base, in a direction opposite the fingers, a support shaft extends to a locking ball to be received in the support arm.

Figure 10 shows four finger rake 40 with base region 43 supporting curved fingers 46-49. Each pair of adjacent fingers 46-49 defines an intervening slot adapted to receive a branch vessel of the aortic arch graft. A socket 50 is provided for receiving a support pin 55 shown in Figures 11 and 13. Socket 50 has a recess 51 with a noncircular shape and an inner bore 52 that passes through base 43. Pin 55 has a flange 56 matching the shape of recess 51 and a shaft 57 adapted to pass through bore 52. Thus, pin 55 extends substantially transverse to an outer surface of base 43. Pin 55 has a ball 58 which is grasped by the support arm in a manner of a ball joint as known in the art.

In order to accommodate auxiliary branch 20, rake 40 may preferably include a recess 53 cut into base 43 in a region below fingers 48 and 49. A reduced profile of base 43 allows it to be positioned between auxiliary branch 20 and the row of side branches 17-19 as best shown in Figure 7.

Figure 12 shows a ring nut 60 with a central opening 61 for receiving shaft 57 of pin 55 on the opposite side of base 43. As shown in Figure 14, the second side of base 43 may include a circular recess 62 for receiving ring nut 60. Central opening 61 is adapted to secure shaft 57 (e.g., by an interference fit, heat staking, or other mechanical connection).

Figures 15-19 show additional perspective views of rakes having various numbers of fingers. The rake main body (i.e., integrally molded base and fingers), support pin, and ring nut may preferably be molded using a biocompatible

thermoplastic (e.g., TPE or TPO).