AU2002216823B2 - Femoral arterial/venous haemostasis device - Google Patents

Description

WO 02/056775 PCT/AU01/01624 FEMORAL ARTERIAL VENOUS HAEMOSTASIS DEVICE The present invention relates to a haemostasis pressure pad and in particular to a haemostasis pressure pad for a haemostasis clamp. The invention has been developed primarily for invasive cardiac diagnostic surgery and will be described hereinafter with reference to that application. However, it will be appreciated that the invention is not limited to that particular field of use.

Background Art It has been known that applying pressure to a wound in a patient will promote haemostasis, that is, the application of pressure stops or slows bleeding of the wound.

This technique of promoting adequate haemostasis has long been used in the medical field and in surgical procedures. One such procedure in which the technique is often used is during invasive cardiac diagnostic surgery and treatment. In this procedure a catheter and sheath is inserted into an artery and/or vein at a puncture site in a limb of the patient. At the conclusion of the procedure, pressure is applied at the puncture site to facilitate the removal of the sheaths and achieve adequate haemostasis. While pressure can be applied directly by a skilled hand, to do so means that the hand cannot attend to other duties for a significant period of time. To overcome this problem artery damps and pressure pads to directly apply pressure to the catheter entry site have been developed. One type of pad is a simple disc, which is generally made from plastic and which is held in place by a stand or clamp to enable the nurse or other operator to safely and quickly remove the femoral sheath or sheaths. However, the simple round design of there pads makes correct alignment of the disc with the arterial sheath difficult.

SUBSTITUTE SHEET (RULE 26) RO/AU WO 02/056775 PCT/AU01/01624 2 In partial answer to this problem, it has been know to include a narrow alignment notch in the disc to allow visualisation of the puncture site and thus enable alignment.

However, these discs are only designed for use when removing an arterial sheath only.

Patients often have an arterial and venous sheath that need to be removed.

Another problem of the current disc relates to its small size, which minimises the dispersal of pressure and increases patient discomfort throughout the procedure.

Patients have commented in recent surveys that, the sheath removal part is the most discomforting part of the whole interventional cardiac procedure...". Also, the small size of disc means that incorrect disc positioning can place pressure on the femoral nerve that runs along side the femoral artery and vein, which can cause a life-threatening situation called a "vaso vagal". The flow of blood through and the pulse pressure wave play a vital part in the formation and the hardening of the clot to seal the hole. The smaller size disc needs more pressure to be applied to reduce blood flow and allow clot formation. The tolerance of maintaining a comfortable position decreases with more pressure being applied. The risk of femoral complications occurring increases due to the patients discomfort and the likelihood the patient will move instinctively to improve their comfort.

The current design of clamp consists of a base, a vertical pole extending upwardly and a horizontal arm vertically extending to the pole and having a free end for supporting the pad. The horizontal arm can be locked by way of friction cam lock acting on the pole. As the operator gradually removes the sheath their aim is to then apply pressure by pushing down the horizontal arm. When the operator releases pressure from the horizontal arm, the arm locks against the vertical pole and pressure is maintained on the site.

SUBSTITUTE SHEET (RULE 26) RO/AU AUG.02.2007 15:48 +61299255911 GRIFFITH HACK #0947 P.005 /015 -3- 0 o To achieve haemostasis, it is paramount to properly set up the device. If incorrect, the risk of vascular complications, patient trauma, and the overall costs of the cr4 procedure increase. It is also known that an improperly set device will give rise to a o pressure imbalance across the disk surface and the femoral artery.

The further the disc is away from the vertical pole, the greater the probability of prcssure imbalance and the risk of vascular complications. The problem is _exacerbated by the fact that the ann is made from plastic and able to flex. This flexing often results in a rotation of the face of the disc with respect to the site-giving rise to a pressure imbalance and/or loss of pressure- Additionally, the size of the patient, the correct positioning of the of the disk prior to sheath removal,. and the movement of the patient after sheath removal all increase the risk of the horizontal arm flexing, disc slippage and as a result, loss of pressure over the femoral artery. Correct set-up of the current device is also made difficult because, once the sheath is removed, the operator must hold the horizontal arm still and in postion, and then, with the other hand, tighten the locking nut to stop the arm from slipping up. The two operations can be difficult to coordinate. Moreover, if the patient continues to bleed, repositioning of the clamp will be required- Summary of the Invention An aim of the present invention to overcome or ameliorate at least one of the disadvantages of the prior art, or to provide a useful alternative.

According to the invention provides a pressure pad for a haemostasis clamp, comprising: an elongated body having a major axis, a minor axis; the body having a peripheral intermediate notch formed along the major axis; the notch being wide enough to allow visualization of a pair of proximate femoral or brachial arterial and venous puncture sites- COMS ID No: ARCS-155439 Received by IP Australia: Time 15:45 Date 2007-08-02 AUG.02.2007 15:48 +61299255911 GRIFFITH HACK #0947 P.006 /015 -4- SPreferably the body includes a second surface, which meets the engagement surface at the periphery of the pad and which, at least in part, extends along a substantially elliptical path having a major axis and minor axis. The elongated body Shaving the major and minor axis provides the pad with an effective surface area which minimise dispersal pressure and increase patient comfort.

Ci Preferably the engagement surface is etched to provide a textured, substantially 00 Snon-slip surface.

Ci Preferably the pad has a centrally located mounting boss with a hexagonal Saperture for receiving the end of a locating rod.

The pad further preferably includes strengthening ribs radiating from the mounting boss towards the periphery for resisting deformation of the first surface.

In one form, a haemostasis device is provided that comprises a haemostasis clamp for clamping the limb of a patient, the clamp including: a base for providing a first clamping surface for the limb; .a support post extending upwardly from said base; an arm extending between a first end mounted to the post and second end distal from the post; and a pressure pad according to any form described above mounted to the second end and including a second clamping surface, the pad being displaceable relative to the second end and to the base for moving the surfaces into and out of clamping engagement with the limb.

Preferably the arm is attached to the post at the first end by a releasable clamp and at the second end of the arm, a rod is slidably and rotatably mounted by means of a ratchet mechanism- In turn, the pad is fixedly attached to the other end of the rod.

COMS ID No: ARCS-155439 Received by IP Australia: Time 15:45 Date 2007-08-02 ALTG.02.2007 15:19 461293255911 GIFT AC*97107/1 GRIFFITH HACK #0947 P.007 /015 Brief Description of the Drawings Preferred embodiments of the invention will now be described by way of example only, with reference to the accompanying drawings, in which: o Figure I is a plan view of a pressure pad according to an embodiment of the present invention; Ci Figure 2 is a side elevation of the pressure pad of Figure 1; 00 Figure 3 Is a perspective view from above of the pressure pad of Figure 1; ClFigure 4is aperspective view of a haemnostasis clamp; 0 Fi gure 5 is an enlarged side elevation view of a portion of the clamp of Figure 4; Figure 6 is a plan view of the portion of thc clamp depicted in Figure Figure 7 is an enlarged side elevation of a portion of the clamp of Figure 4;, Figure 8 is a top and Side view of an alternative, embodiment of the arm; and Figure 9 is an exploded view of the rod, handle and pad, with a detail of the rod.

Preferred Mode of Carrying out the Invention Referring to the drawings, and in particular to Figure 4, there is illustrated a haemnostasis clamp I for clamping the limib of a patient (not shown)- Tbe clamp includes a generally rectangular base 2 for providing a substantially planar upwardly facing clamping surface 3 for the limb. A support post 4 of circular cross section extents upwardly from base 2, and an arm 5 extends between. a first end I11 mounted to the post and a second end 12 distal from the post. A pressure pad 13, as shown in Figures 1 to 3, is mounted to end 12 and includes a downwardly facing clamping surface 1.4. The pad .13 is displaceable relative to end 12 and base 2 for moving surfaces 3 and 14 into and out of clamping engagement with the limb- COMS ID No: ARCS-155439 Received by IP Australia: Time 15:45 Date 2007-08-02 WO 02/056775 PCT/AU01/01624 6 Base 2 is fashioned from mild steel plate and is of sufficient weight to promote stabilisation of the camp when in use. Further, base 2 includes two transverse sides and 16, and two longitudinal sides 17 and 18 each having filleted or chamfered edges 19 to reduce the probability of injury to patients and users.

Clamping surface 3 includes a substantially non-slip section which, in this embodiment, is a substantially planar rubberised mat. However, in other embodiments the mat is textured or roughened to enhance the non-slip function.

Base 2 includes a mounting boss 20 which is disposed adjacent side 15 and equidistant from longitudinal sides 17 and 18 for threadedly receiving one end of post 4.

This allows for convenient disassembly of clamp 1. In further embodiments, support 4 is fixedly attached to base 2 by welding, riveting, an interference fit or similar permanent attachment.

End 11 is slidably and rotatably mounted to post 4 by a releasable clamp 2 1, as best shown in Figures 4 and 5. Clamp 21 allows arm 5 to be selectively lockingly retained at one of an infinite number of relative positions along post 4. Clamp 21 includes a collar 22, which surrounds and receives post 4. A locking screw 23 is threadedly attached to clamp 21 and when tightened acts against post 4 to lock arm 5 in position. A handle 24 is provided for activation of screw 23.

In other embodiments clamp 21 is a releasable compression clamp, as best shown in Figure 8 where corresponding features are denoted by corresponding reference numerals. The clamp includes a collar 25 split into two opposing sides 26 which collectively surround post 4. A quick release cam locking is attached to the sides 27 and configured so that when tightened, the sides are drawn together in releasable damping engagement with post 4. A handle is provided for activation of the locking device.

SUBSTITUTE SHEET (RULE 26) RO/AU WO 02/056775 PCT/AU01/01624 7 In other embodiments, post 4 includes a plurality of discretely spaced apart locking formations for providing a corresponding plurality of locking positions relative to base 2. Arm 5 is a stainless steel tube of similar length to base 2 and includes a ratchet mechanism 26 at end 11. In other embodiments arm 5 is of a polymer based material or of non uniform cross section.

Ratchet 27 includes an aperture 28 which extends parallel to post 4 for receiving a rod 29. Ratchet 27 further includes a lock plate 30 which is mounted to grip plate 34 for horizontal movement with respect to rod 29. Lock plate 30 resiliently biased into engagement with the rod by the offset angle of lock plate 30 resting on the compression coil spring 31. Lock plate 30 can be secured in its position by adjusting the height of lock screw 33. Lock screw 33 threads into post 5. Lock screw 33 allows the operator to lock the position of lock plate 30 to stop the disengagement of rod 29 from lock plate 30 and the loss of pressure at end 14.Depressing lock plate 30 allows rod 29 to freely travel through post 5 in both directions. The lock plate 30 is returned to its original position by the compression coil spring 31 when lock plate 30 is released. Rod 29 automatically engages again against lock plate 30. Rod 29 can only move in one direction through post and will maintain the clamping surfaces 3 and 14 in a fixed spaced apart relationship.

This is best seen in figure 9. This allows rod 29 to be moved toward, but not away from, surface 3. Lock plate 30 is manually moved out of engagement with rod 29 to allow the rod to be moved in the opposite direction. Rod 29 is stainless steel and extends between a lower end 35, nearer surface 3 and 5 an upper end 36, as best shown in Figure 9.

SUBSTITUTE SHEET (RULE 26) RO/AU WO 02/056775 PCT/AU01/01624 8 End 35 may include a hexagonal formation 41 for engaging pad 13 in a fixed rotational relationship. End 36 includes a handle 37 for allowing manual lowering and raising of rod 29. The handle is in the form of a contoured circular disc to complement the palm of the users hand when applying downward pressure. At the end 12 the grip plate 34 allows the operator to ergonomically rest their palm of their hand on handle 37 and place fingers under grip plate 34. Grip plate 34 allows greater control of rod 29 when applying and releasing the pressure being applied. Grip plate 34 is of stainless steel construction secured to end 12 by three dome allen key threaded screws 34a.

Pad 13 includes a plastics body 38 having a substantially planar elongate engagement surface defined by surface 14 for abutting a limb of the patient. Pad 13 further includes a pair of integral extensions 42 and 43 which project from body 38 to respective free ends 44 and 45. These extensions 42 and 43 form respective continuations of surface 14 and define an intermediate notch 51 which has its largest dimension at ends 44 and 45. Pad 13 has a periphery 52 which at least in part extends along a substantially elliptical path having a major axis 53 and a minor axis 54. In this embodiment the width Lo of the pad on the minor axis 54 is approximately and the length Lm,, of the pad on the major axis 53 is approximately 70mm. However in other embodiments the width Lio, is between 50% and 90% of that of length Ljo, The width of notch 51 at ends 44 and 45 of extensions 42 and 43 is approximately 15mm and the depth of notch 51 is approximately 10mm. Thus, notch 51 is of sufficient dimension to allow visualisation of at least two proximate puncture sites in the limb. Surface 14 includes a textured finish to facilitate non-slip abutment with the limb.

SUBSTITUTE SHEET (RULE 26) RO/AU AUG.02.2007 15:49 +61299255911 GRIFFITH HACK #0947 P.006 /015 -9- Body 38 also includes an opposite surface 55, which meets surface 14 at a periphery in the form of a rounded edge 56- The edge provides a surface 14 devoid of sharp comers- Surface 55 includes mounting means, in the form of a centrally located ci o mounting boss 57, for mounting pad 13 to formation 41. Boss 57 includes a hexagonal locating aperture 61 for complementarily receiving end 35 of rod 29 in fixed rotational engagement Surface 53 includes five radially diverging strengthening ribs 62 for resisting ci C,1 deformation of surface 14. Ribs 62 radiate from boss 55 and terminate at periphery 52.

0 I other embodiments a different number and or configuration of ribs are used.

Moreover, in still further embodiments, pad 13 does not include ribs and gains sufficiently rigidity to resist the deformation commonly encountered by other means.

For example, through the use of thicker and stiffer plastic material.

Clamp I is designed for any procedure where a catheter and sheath have been inserted into the artery and/or vein of a patient. During removal of the sheath, clamp 1 is applied to the limb so that surface 14 abuts the limb at or adjacent to the entry or puncture site. Once the sheath is removed surface 14 applies adequate pressure to promote haemostasis. The clamp is suitable for use in conjunction with either Femoral or Brachial sheaths- Surface 14 includes a large area for ensuring that significant portions of the arterial and/or venous vessels are compressed thus ensuring adequate haemostasis to allow clot formation. This also minimises the risk of both haematoma development and generalised bruising at that site.

COMS ID No: ARCS-155439 Received by IP Australia: Time 15:45 Date 2007-08-02 WO 02/056775 PCT/AU01/01624 In use, the base 2 is positioned between the patient (not shown) and the bottom of the mattress (not shown). The weight of the patient assists in the stabilisation of clamp 1 Prior to a clamping operation; pad 13 is mounted to end 35 of rod 29. The rod is positioned so that pad 13 is immediately adjacent to end 12 of arm 5. Arm 5 is then moved relative to support post 4 both vertically and horizontally until pad 13 is appropriately positioned above the femoral artery at the puncture site. Notch 51 is used to allow ready visualisation of the catheter puncture site before pad 13 touches the limb.

Prior to removal of the catheter sheets, following cardiac surgery for example, rod 29 is lowered until surface 14 comes into contact with the limb of the patient. As the catheter or catheters are removed; pad 13 is gradually progressed downwardly, to apply controlled pressure at the puncture site. Ratchet mechanism 27 allows pressure to be applied and maintained with one hand so that pad 13 remains under pressure until relieved.

Once the pressure has been applied for sufficient length of time to promote haemostasis, the pressure of pad 13 on the limb is gradually released by manually extracting pin 30 from engagement with rod 29 in gradual increments every five minutes over a 20-40 minute period. If bleeding or swelling is detected pad 13 can be easily re applied by ratchet mechanism 27. The process is repeated until pad 13 has reached its starting position. Arm 5 and pad 13 are then moved upward, out of damping engagement, and damp 1 removed from under the buttock of the patient. Manual pressure is applied proximal to pad 13 prior to removing Arm 5 and pad 13 from its damping engagement. The pad, being disposable, is discarded. Clamp 1 is then sterilised in an appropriate manner and provided with a new sterilised pad equipped for re-use.

SUBSTITUTE SHEET (RULE 26) RO/AU WO 02/056775 PCT/AU01/01624 11 The major advantages of the pad of the preferred embodiments are: the pad provides for removal of more than one catheters by having a wide notch the pad has a large surface area which distributes the load over a larger area to reduce the risk of vascular complications and improve patient comfort; and the shape and size of the pad compresses a greater number of vessels, slowing blood flow and dispersing the arterial pulse wave.

The clamp of the preferred embodiment has the major advantages of.

Having adjustment at the clamping end of the arm as well as the support end to allow accurate control of the pressure applied at the puncture site; providing automatic locking of the rod and pad via a ratchet mechanism at the pad end of arm to allow one handed operation once the clamp is in place; having a rigid arm which has negligible flex under normal working loads for minimising pad slippage; allowing direct pressure to be gradually applied to the artery and/or vein; and allowing pressure to be gradually released, as required.

Although the invention has been described with reference to specific examples it will be appreciated by those skilled in the art that the invention may be embodied in many other forms.

SUBSTITUTE SHEET (RULE 26) RO/AU

Claims (9)

1. A pressure pad for a haemostasis clamp, comprising: an elongated body having a major axis, a minor axis; Sthe body having a peripheral intermediate notch formed along the major axis; the notch being wide enough to allow visualization of a pair of proximate femoral or C brachial arterial and venous puncture sites. 00 (O N

2. A pressure pad according to claim 1, wherein the body is surrounded by a 0 rounded edge and have a centrally located mounting boss.

3. The pad of claim 2, wherein: the body further comprises reinforcing ribs which radiate out from the mounting boss to the rounded edge.

4. The pad of either of claims 1, 2 or 3, wherein: the body further comprises a pair of extensions which define the notch.

The pad of any of one of the preceding claims whercin: the body is generally elliptical, but for the notch-

6. A haemostasis device comprising; a pressure pad according to any preceding claims; and a haemostasis clamp comprising; a base; a support post attached to one end of the base; an arm having a releasable post locking engagement at a first end for slidably receiving COMS ID No: ARCS-155439 Received by IP Australia: Time 15:45 Date 2007-08-02 AUG.02.2007 15:49 +61299255911 GRIFFITH HACK #0947 P.010 /015 -13- O the post and having at a second end, a rod locking device which releasably secures a rod having a knob or handle at one end and adapted at the other end, to engage the pressure pad; Sthe rod locking device readily allowing the rod to be urged by manual pressure toward the base but only allowing rod movement away from the base when the locking device Cl is disabled. 00 (O l

7. The device of claim 6, wherein: 0 0 the rod locking device comprises a locking plate, the plate having an opening for receiving the rod, the plate having an offset angle with respect to the rod and being resiliently biased into engagement with the rod; the plate being manually disengageable from the rod by manual pressure acting against the resilient bias.

8. The device of claim 7, further comprising: a grip plate mounted onto the second end of the anm, wherein the rod locking device is pivotally mounted onto the grip plate.

9. A pressure pad substantially as herein described with reference to the drawings. A haemostasis device as substantially herein described with reference to the drawings. COMS ID No: ARCS-155439 Received by IP Australia: Time 15:45 Date 2007-08-02