JP2009172390A - Method and low profile apparatus for reducing embolization during treatment of carotid artery disease - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and apparatus for removing emboli from within the carotid arteries during interventional procedures that reduce the risk that emboli are carried into the cerebral vasculature. <P>SOLUTION: The method and apparatus 30 are provided for removing emboli during an angioplasty, stenting, or surgical procedure comprising a catheter 31 having an occlusion element 32, an aspiration lumen, and a blood outlet port in communication with the lumen, a guide wire 35 having a balloon 36, a venous return catheter with a blood inlet port, and tubing that couples the blood outlet port to the blood inlet port. A blood filter, a flow sensor, a flow control valve, and/or a pump may also be included in-line with the tubing to better facilitate filtering of emboli from blood reperfused into the patient and to better monitor and control the quantity of flow reversal. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an apparatus and method for protecting against embolization during vascular interventions (eg, carotid angioplasty, arterial endarterectomy, and stenting). More specifically, the device and method of the present invention induces a controlled reverse flow through the internal carotid artery during an interventional procedure without significant blood loss.

  Carotid stenosis typically occurs in the common carotid artery, internal carotid artery, or external carotid artery, for example, as a pathological narrowing of the vessel wall caused by plaque build-up (which inhibits normal blood flow) ,It is shown. Arterial endarterectomy (open surgical procedure) is traditionally used to treat such stenosis of the carotid artery.

  An important problem encountered in carotid surgery is that emboli can form during the course of the procedure, and these emboli can rapidly flow into the cerebral vasculature and cause ischemic strokes.

  Considerable interest has arisen in the endovascular treatment of carotid artery stenosis in terms of trauma and long recovery times commonly associated with open surgical procedures. In particular, widespread interest has arisen in converting interventional techniques (eg, angioplasty and stenting) developed to treat coronary artery disease for use in the carotid artery. However, such endovascular procedures tend to lead in particular to the formation of emboli.

  Such emboli, for example, allow interventional devices (eg, guidewires or angioplasty balloons) to be forced into or passed through the stenosis, as well as dilatation of the angioplasty balloon and Can be made after contraction or stent placement. Such devices are advanced through the carotid artery in the same direction as the blood flow, and emboli generated by the operation of the device are carried directly to the brain by the antegrade blood flow.

  Seizure rates after carotid stenting vary widely from as low as 4.4% to as high as 30% in different clinical series. One overview of carotid stenting, including data from 24 major intervention centers in Europe, North America, South America and Asia, had combined early failure and combined mortality / stroke rates greater than 7%. Cognitive studies and reports of intellectual changes after carotid stenting show that embolization is a common event that causes potential cerebral damage.

  Some previously known devices and methods attempt to remove emboli formed during intravascular procedures by occluding blood flow and trapping or aspirating the emboli from the target vessel. Try. However, these previously known systems provide a suboptimal answer to the problem of effectively removing emboli. Furthermore, when used in stenting, the elements used to occlude blood flow can interact with the stent in a dangerous manner.

  US Pat. No. 4,921,478 to Solano et al. Describes a cerebral angioplasty method and device, wherein two coaxial shafts are connected at a distal end to a distal opposed funnel balloon. The innermost shaft lumen communicates with the funnel balloon opening at its distal end and is open to atmospheric pressure at its proximal end. In use, the funnel balloon is placed proximal to the stenosis (in the direction of flow) and occludes antegrade flow. An angioplasty balloon catheter passes through the innermost lumen, enters the stenosis, and is then inflated to dilate the stenosis. This patent states that when the angioplasty balloon is deflated, the pressure difference between atmospheric pressure and blood distal to the angioplasty balloon causes a backflow in the vasculature, which is the innermost Flow any emboli formed by the angioplasty balloon through the lumen of the catheter.

  Although superficially an answer to the problem of embolization, some of the disadvantages of the devices and methods described in the Solano et al patent appear to lead to abandonment of that approach. The most important of these problems is the inability of the system to create a reverse flow during placement of the guidewire and angioplasty balloon across the stenosis. Since reverse flow does not occur until after the deflation of the angioplasty balloon, any emboli generated during the placement of the angioplasty balloon will travel very far downstream to There is a substantial risk captured by the reversal. This issue is expected to be discussed further. This is because a relatively small amount of blood is removed by the pressure differential induced after deflation of the angioplasty balloon.

  Applicants have determined another shortcoming of the method described in the Solano patent: the placement of the funnel-shaped balloon in the common carotid artery (“CCA”) from the external carotid artery (“ECA”) to the internal carotid artery (“ICA”). )) Due to the low flow impedance of the ICA. Thus, if a guidewire or interventional device passes across the injury in either ECA or ICA, emboli removed from the stenosis are introduced into the bloodstream and through the ICA to the cerebrum. Carried to the vasculature.

  The shortcomings of insufficient flow, equivalent to the system of the Solano patent, are believed to hinder the development of commercial embodiments of similar systems described in EP Publication 0427429. EP Publication 0427429 describes the use of a separation balloon to occlude the ECA before crossing the lesion in the ICA. However, as with Solano, the publication discloses that flow reversal occurs only when the dilatation balloon in the ICA is deflated.

  Interventional Neuroradiology: Strategies and Practical Technologies (J.J. Describe the use of the system. In particular, a small, deflated occlusion balloon on the wire is introduced at the origin of the ECA, and a guide catheter with a deflated occlusion balloon is placed in the CCA immediately proximal to the ECA origin. The dilatation catheter is advanced through the lumen of the guide catheter and dilated to destroy the stenosis. Prior to dilatation of the dilatation catheter, the occlusion balloon on the guide catheter and within the ECA is dilated to block antegrade blood flow to the brain. The dilatation balloon is then deflated and the dilatation catheter is removed and blood is aspirated from the ICA to remove the embolus.

  Applicants believe that cerebral injury can still result from the previously known procedure described above, which is similar to the procedure described in EP Publication 0427429, except that the ICA is occluded before the ECA. It was determined. Thus, both of these previously known systems and methods suffer from the same disadvantages (inability to cause flow reversal in a sufficiently large volume during placement of a guidewire and dilatation catheter across the stenosis). Both methods involve the substantial risk that any emboli formed during balloon placement will travel too far downstream and are not captured by flow reversal.

  Regardless of the method of aspiration using the method described in the previous Interventional Neurology paper, Applicants note that there are substantial drawbacks. For example, if natural suction is used (ie, induced by a pressure gradient between atmospheric pressure and an artery), only a relatively small amount of blood is induced after the angioplasty balloon is deflated. It is expected to be eliminated by the difference. On the other hand, when an external pump is used, the collection of these downstream emboli requires a flow rate that cannot be maintained for longer than a few seconds, resulting in insufficient removal of the emboli.

  In addition, using an expansion balloon in place, the occlusion balloon is not expanded until after the expansion of the expansion balloon. Microemboli generated during the progression of the dilatation catheter to the stenosis segment can therefore be carried by retrograde blood flow to the brain before further dilatation, occlusion and aspiration are attempted.

  A still further disadvantage of both devices in EP Publication 0427429 and Interventional Neuroradiology is that if either is used to place a stent in ICA instead of ICA angioplasty, the stent is often ECA and ICA and Extends beyond the branch between. The occlusion balloon placed by the guide wire in the ECA then obstructs the stent during retrieval and the balloon punctures or gets caught in the artery and the emergency balloon is removed to remove the balloon. Requires surgery.

  Imran US Pat. No. 5,833,650 describes a system for treating stenosis, including three coaxial shafts. The outermost shaft comprises a proximal balloon at its distal end, which is deployed proximal to the stenosis and occludes antegrade blood flow. A suction pump then sucks through the lumen of the outermost shaft, causing reversal of flow in the vessel, while the innermost shaft passes across the stenosis. Once placed distal to the stenosis, the distal balloon on the innermost shaft is deployed to occlude the flow distal to the stenosis. Autologous blood taken from the femoral artery using an extracorporeal blood pump is infused through the central lumen of the innermost catheter to provide a continuous antegrade blood flow distal to the distal balloon. The A third coaxial shaft (which comprises an angioplasty balloon) is then advanced through the annulus between the innermost and outermost catheters to inflate the stenosis.

  Like the device in the Solano patent, the device in the Imran patent suffers from the potential removal of emboli that are carried into the cerebral vasculature. In particular, once the Imran innermost shaft distal balloon is deployed, the reversal of flow in the vasculature distal to the distal balloon stops and passes through the central lumen of the innermost shaft. Perfused blood establishes an antegrade flow. Importantly, if emboli are formed during distal balloon deployment, these emboli are carried directly by the perfused blood to the cerebral vasculature and again pose a risk of ischemic stroke. Furthermore, there is some evidence that reperfusion of blood through a small diameter catheter under pressure can contribute to hemolysis and possible removal of emboli.

  In view of these shortcomings of previously known emboli removal systems, methods and apparatus are provided for removing emboli from within the carotid artery during an interventional procedure (eg, angioplasty or carotid artery stenting). It may be desirable to do this, and the method and device reduce the risk that emboli will be carried into the cerebral vasculature.

  It may also be desirable to provide a method and apparatus for removing emboli from within the carotid artery during an interventional procedure (eg, angioplasty or carotid artery stenting), the method and apparatus from the treatment zone. Providing a controlled retrograde blood flow, thereby reducing the risk that emboli will be carried into the cerebral vasculature.

  It would further be desirable to provide an emboli removal method and apparatus that prevents the occurrence of reverse flow from the ECA and antegradeness to the ICA once the CCA is occluded, thereby providing a surgical procedure or interventional Emboli generated by the procedure effectively increase the likelihood of being removed from the vessel.

  It is still desirable to provide an occlusion balloon on the guide wire for placement in the ECA during stenting of the ICA, reducing the risk of catching the stent during removal.

  It would also be desirable to provide a method and apparatus for removal of an embolus between carotid stenting that allows embolus filtration and reduced blood loss while at the same time preventing dangerous interaction between the apparatus and the stent. Is done.

  In view of the above, it is an object of the present invention to remove an embolus from within the carotid artery during an interventional procedure (eg, angioplasty or carotid stenting) that reduces the risk that the embolus will be transported to the cerebral vasculature. A method and apparatus is provided.

  It is also an object of the present invention to provide a method and apparatus for removing emboli from within the carotid artery during an interventional procedure (eg, angioplasty or carotid artery stenting), the method and apparatus comprising: Providing controlled retrograde blood flow from the treatment zone, thereby reducing the risk that emboli will be carried into the cerebral vasculature.

  Once the common carotid artery is occluded, it may prevent the occurrence of reflux between the ECA and the ICA, thereby effectively removing emboli generated by surgical or interventional procedures from the blood vessel It is another object of the present invention to provide an embolus removal method and device that enhances the embolism.

  It is a further object of the present invention to provide a method and apparatus for an occlusion balloon on a guidewire for placement in an ECA during ICA stenting that reduces the risk of catching the stent during removal. is there.

  It is an object of the present invention to provide a method and apparatus for removing emboli during carotid stenting that allows removal of emboli and reduced blood loss while at the same time preventing dangerous interaction between the apparatus and the stent. It is yet another object of the invention.

  The foregoing objects of the invention are achieved by providing an interventional device comprising an arterial catheter, an occlusion balloon placed on a guide wire, and a venous return catheter. In addition, any device may also be provided, including, for example, a blood filter, a flow control valve, a continuous pump, and / or a flow sensor disposed between the arterial catheter and the venous return catheter. The arterial catheter has a proximal end, a distal end, a suction lumen extending therebetween, an occlusion element disposed at the distal end, and a hemostatic port and blood outlet disposed at the proximal end in communication with the suction lumen Provide a port. The aspiration lumen allows an interventional device (eg, an angioplasty catheter or stent delivery system) to be easily passed through this aspiration lumen to the site of stenosis in either the ECA (proximal to the balloon) or ICA. It is sized so that it can be advanced.

  In accordance with the principles of the present invention, an arterial catheter is illustratively placed in the CCA proximal to the ICA / ECA branch and an occlusion balloon on the guidewire is placed in the ECA to occlude reversal of flow from the ECA to the ICA. And the blood outlet port of the arterial catheter is coupled to a venous return catheter with or without additional devices placed therebetween. Arterial pressures higher than venous pressure can cause controlled flow reversals in the ICA, particularly during diastole, for example during interventional procedures (except when the dilatation balloon is inflated) coupled with the flow control valve Allows blood containing the embolus to flow. This blood can then be filtered and reperfused into the body through a venous return catheter. A higher or more uniform rate of blood flow between the arterial and venous catheters can be obtained through the use of a continuous pump, and the flow sensor alerts the health care professional to dangerous blood flow levels. Or provide an auto-start switch for an external pump.

  In stent manipulation applications, the occlusion balloon on the guidewire is puncture resistant to prevent dangerous interactions between the balloon and the stent during retrieval. In a first embodiment, the device comprises a wedge configured to deflect the balloon during contact with the balloon, avoiding contact with the portion of the stent that extends through the ECA / ICA branch. In a second embodiment, the device comprises a balloon that is retracted into a capsule prior to retrieving the balloon from the ECA.

  A method of using the apparatus of the present invention is also provided.

1 is a schematic diagram of a prior art device for protecting against emboli during carotid intervention. FIG. 1 is a schematic diagram of a prior art device for protecting against emboli during carotid intervention. FIG. 1 is a schematic diagram of a device for protecting against emboli during carotid intervention according to the present invention. FIG. 1 is a schematic diagram of an apparatus constructed in accordance with the present invention. FIG. 2 is a detailed side view of the distal end of a device constructed in accordance with the present invention. 2 is a detailed side cross-sectional view of the distal end of a device constructed in accordance with the present invention. FIG. FIG. 3 is a detailed cross-sectional view of the distal end of a device constructed in accordance with the present invention. FIG. 4 is a distal end view of an alternative embodiment of the apparatus of FIG. 3. FIG. 4 is a distal end view of an alternative embodiment of the apparatus of FIG. 3. 4 illustrates a method of using the apparatus of FIG. 3 in accordance with the principles of the present invention. 4 illustrates a method of using the apparatus of FIG. 3 in accordance with the principles of the present invention. 4 illustrates a method of using the apparatus of FIG. 3 in accordance with the principles of the present invention. 4 illustrates a method of using the apparatus of FIG. 3 in accordance with the principles of the present invention. FIG. 4 is a schematic diagram of the alternative embodiment of FIG. 3. FIG. 4 is a cross-sectional view of the alternative embodiment of FIG. FIG. 3 is a side view of a flow control valve for use with the venous return line of the present invention shown in an open position. FIG. 3 is a side view of a flow control valve for use with the venous return line of the present invention, shown in a closed position. FIG. 4 is a schematic view of an alternative embodiment of a guidewire balloon element of the device of FIG. FIG. 4 is a schematic diagram of a method of using the device of FIG. 3 with an alternative embodiment of a guidewire balloon element. FIG. 4 is a schematic view of a further alternative embodiment of the guidewire balloon element of the apparatus of FIG. 3 shown in a deployed configuration. FIG. 4 is a schematic view of a further alternative embodiment of the guidewire balloon element of the apparatus of FIG. 3 shown in a retrieval arrangement. 10 illustrates a method of using the apparatus of FIG. 9 in accordance with the principles of the present invention. 10 illustrates a method of using the apparatus of FIG. 9 in accordance with the principles of the present invention. FIG. 6 is a detailed side cross-sectional view of the distal end of yet another alternative embodiment of the device of the present invention. FIG. 6 is a detailed side cross-sectional view of the distal end of yet another alternative embodiment of the device of the present invention. FIG. 6 is a detailed cross-sectional view of the distal end of yet another alternative embodiment of the device of the present invention. Fig. 4 illustrates a method of using the device of Fig. 3 as an attachment to an embolus filter. Fig. 4 illustrates a method of using the device of Fig. 3 as an attachment to an embolus filter. Fig. 4 illustrates a method of using the device of Fig. 3 as an attachment to an embolus filter.

  Please refer to FIG. 1A and FIG. 1B. The disadvantages of previously known emboli removal catheters are described with respect to performing percutaneous angioplasty of the common carotid artery (CCA) stenosis (S).

  With reference to FIG. 1A, the disadvantages associated with natural suction embolus removal systems (eg, those described in the above patents to Solano and the European Patent Publication) are described. Flow reversal is not induced by these systems until the balloon 10 of the angioplasty catheter 11 is inflated and deflated after it first passes across the stenosis. However, Applicants have noted that once the member 15 of the emboli removal catheter 16 is inflated, the flow within the ECA is reversed and the antegrade flow to the ICA is due to the lower hemodynamic resistance of the ICA. provide. As a result, the embolus (E) generated while the guidewire 20 or catheter 11 passes through the stenosis (S) (reverses the flow in the blood vessel and closes the suction lumen to atmospheric pressure. It can be unrecoverably transported to the cerebral vasculature (before being directed to the suction lumen of the embolus catheter 16 by opening the distal end). Furthermore, natural aspiration cannot remove adequate blood volume to recover even emboli that have not yet been transported to any of the cerebral vasculature.

  In FIG. 1B, the system 17 described in the above patent for Imran is shown. As described hereinabove, deployment of the distal balloon 18 and draining blood from the distal end of the internal catheter can remove emboli from the vessel wall at the distal end of the balloon 18. The introduction of antegrade flow through the internal catheter 19 is only expected to exacerbate the problem by pushing the embolus further into the cerebral vasculature. Thus, although the use of aggressive suction in the Imran system can remove emboli located in the restricted treatment area defined by the proximal and distal balloons, such suction can be achieved with the distal balloon 18. It is not expected to provide any benefit for emboli removed distally.

  Reference is now made to FIG. The apparatus and method of the present invention are described. The device 30 comprises a guide wire 35 comprising a catheter 31 comprising an aspiration lumen and an occlusive element 32 and an inflatable balloon 36 disposed at its distal end. In accordance with the principles of the present invention, antegrade blood flow stops when both the occlusive element 32 and the inflatable balloon 36 in the CCA are deployed. Further, the suction lumen of the catheter 31 is connected to, for example, a venous return catheter (described herein below) that is placed in the patient's femoral vein. In this manner, a substantially continuous blood flow is induced between the treatment site and the patient's venous vasculature. As the flow through the artery is directed to the catheter 31, any emboli are removed by advancing the guidewire or angioplasty catheter 33 across the stenosis (S) so that the emboli are aspirated by the catheter 31.

  Unlike previously known naturally aspirated systems, the present invention provides retrograde flow in the ECA of blood and antegrade to the ICA while providing a substantially continuous retrograde blood flow through the ICA. Prevents sexual flow, thereby preventing emboli from being carried to the cerebral vasculature. Because the device and method of the present invention “recycles” blood, including emboli, from the arterial catheter through the blood filter and into the venous return catheter, the patient experiences significantly less blood loss.

  Reference is now made to FIG. 3A. An embolic protection device 40 constructed in accordance with the principles of the present invention is described. The device 40 includes an arterial catheter 41, a guide wire 45, a venous return line 52, a tubing 49 and an optional blood filter 50.

  Catheter 41 includes a distal occlusion element 42, a proximal hemostatic port 43 (eg, a Touhy-Borst connector), an inflation port 44, and a blood outlet port 48. The guide wire 45 includes a balloon 46 that is inflated via an inflation port 47. Tubing 49 connects blood outlet port 48 to filter 50 and blood inlet port 51 of venous return line 52.

  The guidewire 45 and balloon 46 are configured to pass through the hemostatic port 43 and the suction lumen of the catheter 41 (see FIGS. 3C and 3D) so that the balloon can advance to the ECA and occlude the ECA To do. The suction lumen of port 43 and catheter 41 may advance through the suction lumen as additional conventional devices (eg, angioplasty balloon catheters, atherectomy devices and stent delivery systems) are deployed as guidewire 45 is deployed. It is such a size.

  Guidewire 45 preferably comprises a small diameter flexible shaft having an inflation lumen that couples inflatable balloon 46 to inflation port 47. Inflatable balloon 46 preferably comprises a compliant material (eg, those described hereinabove with respect to occlusive element 42 of emboli removal catheter 41).

  The venous return line 52 includes a hemostatic port 53, a blood inlet port 51, and a lumen that communicates the port 53, port 51 and tip 54. The venous return line 52 can be constructed in a manner known per se as a venous introducer catheter. Tubing 49 can include a suitable length of a biocompatible material (eg, silicone). Alternatively, tubing 49 can be omitted and blood outlet port 48 of catheter 41 and blood inlet port 51 of venous return line 52 can be lengthened to engage either end of filter 50 or one another.

  With reference to FIGS. 3B and 3C, the distal occlusion element 42 comprises an expandable bell-shaped or pear-shaped balloon 55. In accordance with manufacturing techniques known in the art, the balloon 55 is made of a compliant material (eg, polyurethane, latex or polyisoprene having a variable thickness along its length to provide a bell shape when inflated. )including. The balloon 55 is secured to the distal end 56 of the catheter 41, for example, by adhesive or melt bonding, so that the opening 57 of the balloon 55 leads to the suction lumen 58 of the catheter 41. The balloon 55 is preferably rolled and heat treated during manufacture so that the distal portion 59 of the balloon extends beyond the distal end of the catheter 41 and is atraumatic tip or bumper relative to the catheter. I will provide a.

  As shown in FIG. 3D, the catheter 41 is preferably a low friction material covered with a layer of flat stainless steel wire blade 61 and a polymer cover 62 (eg, polyurethane, polyethylene, or PEBAX). An inner layer 60 of (e.g., polytetrafluoroethylene ("PTFE")). An inflation lumen 63 is disposed within the polymer cover 62 and connects the inflation port 44 to the balloon 55. In a preferred embodiment of the catheter 41, the diameter of the lumen 58 is 7Fr and the outer diameter of the catheter is about 9Fr.

  Reference is now made to FIGS. 4A and 4B. An alternative embodiment of the closure element 42 of the system of FIG. 3A is described. 4A and 4B, the occlusive element 42 of the emboli removal catheter 41 comprises a self-expanding wire basket 65 covered with an elastic polymer 66 (eg, latex, polyurethane, or polyisoprene). Alternatively, a close-knit self-expanding wire mesh with or without an elastic cover may be used.

  The catheter 41 is surrounded by a movable sheath 67. The catheter 41 is transluminally inserted with the sheath 67 in the most distal position, and the basket 65 is determined to be in a desired position proximal to the stenosis, with the sheath 67 retracted proximally. As a result, the basket 65 is deployed. At the completion of this procedure, the basket 65 is collapsed within the sheath 67 by moving the sheath again to its most distal position. Operation of the system of FIG. 3A using the emboli removal catheter of FIGS. 4A and 4B, rather than injecting an inflation medium into the balloon 55, except that when the sheath 67 is pulled back, the occlusion element self-expands, Similar to the operations described herein below for FIGS. 5A-5D.

  With reference to FIGS. 5A-5D, the use of the apparatus of FIG. 3 will be described in accordance with the method of the present invention. In FIG. 5, the stenosis (S) is located in the internal carotid artery above the branch between the internal carotid artery (ICA) and the external carotid artery (ECA). In the first step, the catheter 41 is percutaneously and either through a transluminal or surgical incision, at a position proximal to the stenosis (S), without the guide wire 45 passing through the stenosis. Inserted. The balloon 55 of the distal occlusion element 42 is then inflated with a radiopaque contrast solution, preferably via the inflation port 44. This causes a reverse flow from the external carotid artery (ECA) toward the internal carotid artery (ICA), as shown in FIG. 5A.

  A venous return line 52 is then introduced into the patient's femoral vein, either percutaneously or through a surgical incision. The filter 50 is then connected between the blood outlet port 48 of the catheter 41 and the blood inlet port 51 of the venous return line 52 using tubing 49 and any air is removed from the line. Once this circuit is closed, the negative pressure in the venous catheter during the relaxation period causes the patient to pass through the suction lumen 58 of the catheter 41 and through the venous return line 52 as shown in FIG. 5B. Establish a slow continuous flow of blood into the veins.

  The slow continuous flow due to the difference between venous pressure and arterial pressure continues throughout the interventional procedure. Specifically, blood flows through the inhalation lumen 58 and blood outlet port 48 of the catheter 41, through the biocompatible tubular member 49, to the filter 50, and toward the blood inlet port 51 of the venous return line 52. At this blood inlet port 52, blood is reperfused into a remote vein. Filtered emboli can be collected in filter 50 and examined and characterized at the completion of the procedure.

  Continuous blood flow with reperfusion according to the present invention (except during expansion of any dilator) provides effective emboli removal with significantly reduced blood loss. Alternatively, the filter 50 can be removed. In this case, emboli removed from the arterial site are introduced into the venous site and eventually captured in the lung. The use of this filter 50 is preferred because of the low incidence of septal defects (such emboli can reach the left ventricle).

  Referring to FIG. 5C, balloon 55 of occlusion element 42 is inflated, retrograde flow is established with ICA, and guidewire 45 and balloon 46 are advanced through suction lumen 58. For example, when the balloon 46 is placed in an ECA, as determined using a fluoroscope and a radiopaque inflation medium injected into the balloon 46, the balloon 46 is inflated. ECA occlusion prevents antegrade flow from occurring in ICA due to the development of backflow in ECA. Another interventional device (eg, a conventional angioplasty balloon catheter 71 having a balloon 72) is inserted through the hemostatic port 43 and the suction lumen 58 and positioned within the stenosis. The hemostatic port 43 is closed and the device 71 is activated to break the plaque forming the stenosis S.

  As shown in FIG. 5D, the balloon 72 is deflated when a portion of the procedure angioplasty using the catheter 71 is completed. Throughout this procedure, unless the dilatation balloon is fully inflated, the pressure difference between the blood in the ICA and the venous pressure causes the blood of the ICA to go in the retrograde direction of the ICA (aspiration of the emboli removal catheter 41 Flow towards the lumen 58), thereby flowing any emboli from the blood vessel. The blood is filtered and reperfused into the patient's vein.

  If desired, increased volume blood flow through the extracorporeal pathway is achieved by attaching an external pump (eg, a roller pump) to tubing 49. If deemed beneficial, this external pump can be used in conjunction with device 40 at any point during an interventional procedure. Similarly, the flow sensor can be communicated to the tubular member 49 to generate a signal corresponding to the flow rate in the tubular member. This sensor may alert medical personnel to a dangerous level of blood flow through the extracorporeal pathway, or may provide an automatic activation switch for an external pump. The device 71, guide wire 45, emboli removal catheter 41 and venous return line 52 are then removed from the patient to complete the procedure.

  As noted above, the method of the present invention, firstly, prevents any backflow of blood from the ECA to the ICA when the distal occlusion element 42 is inflated, and secondly, from any blood vessels and blood flow. To filter and flow the embolus, it protects against embolization by providing a continuous small volume of blood flow from the carotid artery to a remote vein. Advantageously, the method of the invention makes it possible to remove emboli with little blood loss. This is because blood is filtered and reperfused to the patient. Furthermore, the continuous removal of blood, including emboli, prevents the emboli from moving too far downstream for aspiration.

  With reference to FIG. 6, an apparatus 140 constructed in accordance with the present invention is described. Device 140 is an alternative embodiment of device 40 described hereinabove and includes an arterial catheter 141 having a distal occlusion element 142, a proximal hemostatic port 143, an inflation port 144, and a blood outlet port 148. Guidewire 145 includes a balloon 146 that is inflated through inflation port 147. A biocompatible tubular member 149 connects the blood outlet port 148 to the filter 150 and the blood inlet port 151 of the venous return line 152. Arterial catheter 141, guidewire 145, venous return line 152 and tubular member 149 are constructed as described herein above, except as noted below.

  Guide wire 145 and balloon 146 are constructed to pass through guide wire lumen 164 of catheter 141 (see FIG. 6B) so that the balloon is advanced toward the ECA and occludes the ECA. Can do. In addition, the catheter 141 includes a suction lumen 158. The suction lumen 158 is sized to allow interventional devices (eg, angioplasty balloon catheters, atherectomy devices and stent delivery systems) to be advanced through the port 143 and the suction lumen. As shown in FIG. 6B, one difference between catheters 41 and 141 is the way the guide wire is advanced through the catheter. The guide wire 45 is advanced through the suction lumen of the catheter 41. Meanwhile, the guidewire 145 is advanced through the separation guidewire lumen 164 of the catheter 141.

  The catheter 141 is preferably an interior of a low friction material (eg, polytetrafluoroethylene (“PTFE”)) covered with a flat stainless steel wire blade 161 and a polymer cover 162 (eg, polyurethane, polyethylene, or PEBAX). Constructed from layer 160. The inflation lumen 163 is disposed within the polymer cover 162 and connects the inflation port 144 to the occlusion element 142. Guidewire lumen 164 is also disposed within polymer cover 142 and is sized to allow guidewire 145 and balloon 146 to pass therethrough. In a preferred embodiment of the catheter 141, the diameter of the inflation lumen 163 is 0.014 inches, the diameter of the guidewire lumen 164 is 0.020 inches, and the diameter of the lumen 158 is 7Fr. . The outer catheter diameter is about 9 Fr. The catheter wall thickness varies with a minimum outer circumference of 0.005 inches at a position 180 degrees away from a maximum of 0.026 inches at the guidewire lumen 164 position.

  With reference to FIGS. 7A and 7B, a flow control valve for use with various venous return lines is described. A flow control valve 175 is illustratively shown coupled to a portion of the biocompatible tubular member 149 of FIG. 6A. The valve 175 includes a pinch foil 177 and a member 179. The member 179 includes a channel 181 and an inclined track 183. The pinch foil 177 includes teeth 178 and is configured to pass through the channel 181 along the track 183. Channel 181 is also configured to receive tubular member 149. The pinch foil 177 can be moved along the track 183 from the first position shown in FIG. 7A, in which the pinch foil 177 does not compress the tubular member 149 and the user shown in FIG. 7B. In a selected second position, the tubular member 149 is compressed to a degree selected by the user to reduce or stop the flow through the tubular member 149.

  When used in combination with the device of the present invention, the valve 175 allows a selected degree of stenosis to be applied to the venous return line. Thus, valve 175 provides selective control over the amount of regurgitation from the carotid artery to the femoral vein. Some patients can tolerate antegrade flow cessation or gradual reflux within the ICA, but cannot tolerate cerebral ischemia associated with complete reflux. Thus, the valve 175 establishes a slow and gentle backflow of antegrade flow, or even a pause, in the ICA. If the flow stops or slightly reverses, the embolus does not move into the brain. Aspiration prior to contraction of the distal occlusion element ensures that emboli located within the carotid artery or sheath are removed.

  Referring to FIG. 8, an alternative embodiment of the guidewire occlusion device of the present invention is described. The occlusion device 190 includes a guide wire 191, an occlusion balloon 192, an inflation lumen 193, and a wedge 194. The wedge 194 may comprise a resilient material (eg, a polymer or a resilient wire) and reduces the risk that the balloon 192 will get caught on a stent that extends beyond the ICA and ECA branches.

  For the reasons described above herein, it is desirable to prevent backflow from the ECA to the ICA when performing a stenting procedure in the ICA to occlude the ECA. Thus, the occlusion balloon on the guidewire is placed in the ECA and inflated to block the artery. The stent is then placed in the ICA to compensate for proper blood flow to the ICA. However, it is often desirable for such a stent to extend beyond the branch between ECA and ICA. As a result, if the occlusion balloon on the guidewire is deflated and removed from the ECA, the risk that the balloon gets stuck on the stent and the balloon punctures or gets trapped in the artery and requires emergency surgery Exists.

  Referring now to FIG. 8B, the occlusion device 190 is exemplarily shown in connection with the catheter 41. Stent 195 extends to the CCA across the branch between ECA and ICA. Balloon 192 is deflated and positioned for retrieval. Since the balloon 192 is placed on the guide wire 191 instead of the conventional larger diameter balloon catheter, the cross-sectional diameter is significantly reduced, thus reducing the risk of the balloon getting caught on the stent 195. The resilient wedge 194 further reduces this risk by moving the balloon outward from the stent during withdrawal of the guidewire 191 and balloon 192. Alternatively, the separating sheath can be advanced into the guide wire 191 and the occlusion balloon 192 to surround these components and thereby reduce the risk of the occlusion balloon or guide wire being caught on the stent.

  With reference to FIGS. 9A and 9B, an alternative embodiment of the guidewire occlusion device of the present invention will be described. The occlusion device 200 has an inflation lumen 202 and terminates proximal to the inflation port 203, a guide wire 201, an occlusion balloon 204, a core wire 205 coupled to the balloon 204, a capsule 206, a radiopaque capsule characteristic portion 207, And a radiopaque balloon characteristic portion 208. The core wire 205 is preferably about 0.010 inches in diameter and is configured to be received within the inflation lumen 202 of the guidewire 201. Guidewire 201 is preferably about 0.018 inches in diameter.

  Balloon 204 may be inflated through inflation lumen 202 with a standard or radiopaque inflation medium. The balloon 204 then extends distally but remains attached to the capsule 206. Upon completion of an interventional procedure (eg, stenting to the carotid artery), the balloon 204 is deflated. Pulling the core wire 205 proximally causes the balloon 204 to be drawn into the capsule 206, thereby preventing it from being caught during retrieval.

  Referring now to FIGS. 10A and 10B, the use of an occlusion device 200 that combines the arterial catheter 41 and venous return catheter 52 of FIG. 3 during carotid artery stenting will be described. As described herein above, the occlusion device 200 is advanced through the aspiration lumen 58 of the catheter 41 when the balloon 42a of the occlusion element 42 is inflated and retrograde flow is established in the ICA. The capsule 206 is placed in the ECA just as determined using a fluoroscope and radiopaque capsule characteristics 207 as shown in FIG. 10A. The occlusion balloon 204 is then inflated and its location is confirmed, for example, by a fluoroscope and radiopaque balloon feature 208 or a radiopaque inflation medium injected into the balloon 204. ECA occlusion prevents antegrade flow in the ICA from occurring due to the development of backflow in the ECA. Another interventional device (eg, stent 195) is then inserted through the hemostatic port 43 and the inhalation lumen 58 and positioned at the stenosis (S) to compensate for proper blood flow to the ICA.

  Stent 195 may extend beyond the bifurcation between ECA and ICA. As a result, if the guidewire occlusion balloon is deflated and removed from the ECA, there is a risk of the balloon getting caught on the stent, a potentially frightening result.

  As shown in FIG. 10B, when the stenting portion of this procedure is complete, the balloon 204 is deflated and the core wire 205 is withdrawn proximally to retract the deflated balloon 204 into the capsule 206. Since the balloon 204 is placed on the guide wire 201 instead of a conventional large diameter balloon catheter, its cross-sectional diameter is significantly reduced, so there is no risk of the balloon getting caught or punctured on the stent 195. It is reduced. Capsule 206 further reduces this risk by protecting the balloon during withdrawal of occlusion device 200. Device 200, emboli removal catheter 41, and venous return line 52 are then removed from the patient and the procedure is terminated.

  Referring to FIG. 11, a distal end of yet another alternative interventional device suitable for use in the system of the present invention is described. Because the balloon 55 of FIG. 3 is attached to the stepped portion of the catheter 41, the device 40 uses a larger diameter introducer sheath compared to a standard guide catheter without such a balloon. Need. However, when the balloon 55 is attached, the catheter 41 does not require the rotational force, strength or rigidity of a regular guide catheter. The balloon 55 has its own inflation means, and during use, the tip of the catheter 41 is not intubated into the artery.

  With reference to FIGS. 11A and 11B, the distal occlusion element 210 comprises an expandable bell-shaped or pear-shaped balloon 212. The balloon 212 is the same as the balloon 55. In accordance with manufacturing techniques known to those skilled in the art, the balloon 212 includes a flexible material (eg, polyurethane, latex or polyisoprene) having a variable thickness along its length and provides a bell shape when inflated. To do. The balloon 212 is attached to the reduced thickness distal region 216 of the arterial catheter 214, for example, by adhesive bonding or melt bonding, so that the opening 218 of the balloon 212 is attached to the suction lumen 220 of the catheter 214. Leads to Preferably, the balloon 212 is wrapped and heat treated during manufacture so that the distal portion 222 of the balloon extends beyond the distal end of the catheter 214 and provides an atraumatic tip or bumper for the catheter. To do.

  As shown in FIG. 11C, the catheter 214 is preferably a low friction material (eg, polytetrafluoro) covered with a layer of flat stainless steel wire blades 234 and a polymer cover 236 (eg, polyurethane, polyethylene, or PEBAX). An inner layer of ethylene (“PTFE”) 232. An inflation lumen 238 is disposed within the polymer cover 236 and connects an inflation port (not shown) to the balloon 212. In a preferred embodiment of the catheter 214, the tube The diameter of the cavity 220 is 7Fr and the outer diameter of the catheter is about 9Fr.

  The arterial catheter 214 is similar to the catheter 41 of FIG. 3 except in the reduced thickness distal region 216. Preferably, distal region 216 achieves its reduced thickness by omitting wire blade 234 in that region. Thus, when balloon 212 is deflated, the combined delivery profile of distal end 216 and balloon 212 is substantially the same or less than the delivery profile of the remaining catheter 214. Preferably, the device has a delivery profile of about 9Fr (see FIG. 11A). The diameter of lumen 230 remains the same along the entire length of catheter 214 and is preferably about 7 Fr. Thus, the catheter 214 requires an introducer sheath having a diameter that is less than that required by a standard guidewire.

  Referring now to FIGS. 12A-12C, the device of the present invention can also be used as an adjunct to embolization when used with a distally deployed embolic filter. The embolic filter 250 is exemplarily shown with the catheter 41 and includes a guide wire 252 and an expandable mesh 254.

  Catheter 41 may provide auxiliary protection in a variety of ways. For example, as shown in FIG. 12A, backflow through the catheter 41 filters 250 to capture the embolus E that is generated while passing the filter 250 through the stenosis S as described hereinabove. Can be established during deployment. Alternatively, if filter 250 is overfilled with embolus E after deployment, a backflow may be established to provide a pressure differential that draws the embolus from this filter into catheter 41 as shown in FIG. 12B. Also, in the absence of filter 250, for example, back flow may be established during recovery to prevent embolus E or filter fragments from being transported downstream, as shown in FIG. 12C. In addition to the catheter 41, a filter can also be used with the balloon 46 so that, for example, if an embolus E is generated in the ICA, blood flow is not unnecessarily reversed in the ECA.

  Of course, as will be appreciated, the device of the present invention may be used in locations other than the carotid artery. For example, they can be used in the coronary arteries or in any other location deemed useful.

  While preferred exemplary embodiments of the present invention have been described above, it will be apparent to those skilled in the art that various changes and modifications can be made. The appended claims are intended to cover all such changes and modifications as fall within the true spirit and scope of the invention.

Claims (34)

A device for removing emboli during an angioplasty or stenting procedure, the device comprising:
A catheter having a proximal end and a distal end, a lumen extending therethrough, and a blood outlet port in communication with the lumen, the catheter adapted to be placed within a patient's carotid artery A catheter;
An occlusion element disposed on the distal end of the catheter having an opening in communication with the lumen, the occlusion element in a contracted state suitable for transluminal insertion, and the occlusion element being in the artery An occlusion element having an expanded state that occludes antegrade flow in the interior;
A venous return catheter having a proximal end and a distal end, a lumen extending therethrough, and a blood inlet port in communication with the lumen; and tubing connecting the blood outlet port and the blood inlet port A device comprising.   The apparatus of claim 1, further comprising a guide wire having a distal end and a balloon disposed on the distal end, the balloon and the guide wire passing through the lumen of the catheter. Sized to the device.   The apparatus of claim 1, further comprising a flow control valve coupled between the blood outlet port and the blood inlet port.   The apparatus of claim 1, further comprising a blood filter coupled between the blood outlet port and the blood inlet port.   The apparatus of claim 1, wherein the occlusion element is an inflatable member.   6. The device of claim 5, wherein the inflatable member has a pear shape having a wall thickness that varies along the length of the inflatable member.   6. The device of claim 5, wherein a portion of the pear-shaped inflatable member extends beyond the distal end of the catheter in a retracted position to form an atraumatic bumper.   The apparatus of claim 1, wherein the closure element comprises a self-expanding basket.   The device of claim 1, wherein the distal end of the catheter has a step to accommodate the contracted occlusion element. The device of claim 1, wherein the catheter is:
Non-adhesive tubular member;
A device comprising: a layer of wire blades disposed about the non-adhesive tubular member; and a layer of thermoplastic polymer disposed on the layer of wire blades.   11. The device of claim 10, wherein the wire blade layer is omitted in a distal region of the catheter.   The apparatus of claim 2, wherein the catheter further comprises a second lumen, and the guidewire and inflatable balloon can be inserted through the second lumen.   11. The device of claim 10, wherein the device has a substantially uniform cross-sectional diameter when the occlusion element is in a contracted state.   The apparatus of claim 1, wherein the apparatus further comprises a pump that removes blood through the catheter and reperfuses blood through the venous return catheter.   3. The apparatus of claim 2, wherein the means for reducing the risk of puncturing the inflatable balloon disposed on the guidewire and sized to pass through the lumen of the catheter. The apparatus further comprising:   16. The apparatus of claim 15, wherein the guidewire has a proximal end, a lumen extending between the proximal end and the distal end, and the proximal end in communication with the lumen. A device further comprising an inflation port coupled to the balloon, wherein the balloon is in communication with the lumen.   17. The device of claim 16, wherein the means for reducing the risk of puncturing the inflatable balloon comprises a resilient wedge attached to the guidewire proximal to the balloon.   17. The device of claim 16, wherein the means for reducing the risk of puncturing the inflatable balloon is attached to the distal end of the guidewire and to the proximal portion of the inflatable balloon. An apparatus comprising:   The apparatus of claim 18, wherein the inflatable balloon has a deployed state and a withdrawn state. The apparatus of claim 19, comprising:
The balloon is inflated and extends distally of the capsule in the deployed state; and the balloon is deflated and retracted into the capsule in the withdrawn state.   The apparatus of claim 2, wherein the inflatable balloon includes a radiopaque feature.   The apparatus of claim 1, further comprising a flow sensor coupled between the blood outlet port and the blood inlet port, wherein the flow sensor generates a signal corresponding to a flow rate in the tubing. The device is composed of.   The apparatus of claim 1, wherein the distal end of the catheter has a reduced thickness. A device for removing emboli during an angioplasty or stenting procedure, the device comprising:
A guidewire having proximal and distal ends and a lumen extending therebetween;
An inflation port in communication with the guidewire lumen and connected to the proximal end of the guidewire;
An inflatable member in communication with the guidewire lumen and disposed on the distal end of the guidewire; and means for reducing the risk of puncturing the inflatable member disposed on the guidewire An apparatus comprising:   25. The apparatus of claim 24, wherein the means for reducing the risk of puncturing the inflatable member comprises a resilient wedge attached to the guidewire proximal to the inflatable member. .   25. The device of claim 24, wherein means for reducing the risk of puncturing the inflatable member are attached to the distal end of the guidewire and to the proximal portion of the inflatable member. An apparatus comprising:   27. The apparatus of claim 26, wherein the inflatable member has a deployed state and a retrieved state. 28. The apparatus of claim 27, comprising:
The device is inflated and extends distally of the capsule in the deployed state; and the member is deflated and retracted into the capsule in the withdrawn state. 25. The apparatus of claim 24, wherein the apparatus is:
A catheter having a proximal end and a distal end, a lumen extending therebetween, and a blood outlet port in communication with the lumen, the catheter adapted to be placed in a patient's carotid artery; A catheter wherein the guidewire and the inflatable member are configured to pass through the lumen;
An occlusion element disposed on a distal end of the catheter having an opening in communication with the lumen, wherein the occlusion element is in a contracted state suitable for transluminal insertion, and the occlusion element is in the artery An occlusion element having an expanded state that occludes the antegrade flow of
A venous return catheter having a proximal end and a distal end, a lumen extending therethrough, and a blood inlet port in communication with the lumen; and tubing connecting the blood outlet port and the blood inlet port An apparatus further comprising:   30. The apparatus of claim 29, further comprising a blood filter coupled between the blood outlet port and the blood inlet port.   30. The apparatus of claim 29, wherein the apparatus further comprises a pump that removes blood through the catheter and reperfuses blood through the venous return catheter.   32. The apparatus of claim 30, wherein the inflatable member includes a radiopaque feature.   30. The apparatus of claim 29, wherein the capsule includes a radiopaque feature.   30. The apparatus of claim 29, further comprising a flow sensor coupled between the blood outlet port and the blood inlet port, the flow sensor generating a signal corresponding to a flow rate in the tubing. Configured as an apparatus.

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