Angioplasty device with embolic recapture mechanism for treatment of occlusive vascular diseases

An angioplasty device with emboli pull-in mechanism is provided that includes an infusion catheter with a proximal end and a distal end. A balloon catheter having an inflatable cavity formed by an inner wall and an outer wall is disposed coaxially with the infusion catheter. The balloon catheter has a proximal end and a distal end. The distal end of the balloon catheter is sealingly attached to the infusion catheter. And the balloon catheter has at least one communicating channel disposed from the outer wall to the inner wall of the balloon catheter. A suction catheter is disposed between the balloon catheter and the infusion catheter. The suction catheter is in fluid communication with the at least one communicating channel in the balloon catheter.

FIELD OF INVENTION

The present invention relates to a medical device suitable for use in intravascular angioplasty.

BACKGROUND OF THE INVENTION

Release of atherosclerotic debris is the primary cause of ischemic events such as stroke or myocardial infarction during a routine intravascular angioplasty. A standard balloon inflates and deflates via the change in pressure induced by contrast material and saline. The balloon provides a radial force to the surrounding vessel wall resulting in dilation of occlusive lesions in the vessel wall. The process nevertheless releases debris from the site of angioplasty that can migrate distally with the blood flow to occlude small blood vessels resulting in catastrophic outcomes. While the balloon is completely inflated, the loosened plaque particles are compressed against the vessel wall. However, once the balloon is deflated, the plaque particles can move freely with the blood stream into the distal vasculature and embolize arteries of various sizes. Plaque particles of 100 micron or larger can occlude small and medium size vessels. Conventional angioplasty balloons cannot provide protection against debris generated during an angioplasty procedure. In recent years, the use of an embolic protection device is suggested to capture embolic debris during angioplasty. Distal protection devices, such as filters, are under investigation to be placed distal to site of occlusion to block the passage of particles. Different devices are introduced to the market with various degrees of success in capturing plaque particles. However, the use of new embolic protection devices requires insertion and position of the device into the artery distal to the angioplasty site. In many cases the lumen of the artery at the atherosclerotic site is reduced to a point that passage of any extra device is difficult. Furthermore, tortuosity and angulation of the distal vessels prevent successful placement of protection devices. What is needed is a balloon that can perform angioplasty and at the same time prevent the release of embolic debris.

SUMMARY OF THE INVENTION

The present invention meets the above-described need by providing an angioplasty device having a balloon catheter with an embolic recapture mechanism that does not require deployment of a trap located beyond the balloon catheter in the distal direction.

The present invention provides an angioplasty catheter having an infusion catheter with a proximal end and a distal end. A balloon catheter having an inflatable cavity formed by an inner wall and an outer wall is disposed coaxially with the infusion catheter. The balloon catheter has a proximal end and a distal end. The distal end of the balloon catheter is sealingly attached to the infusion catheter. And the balloon catheter has at least one communicating channel disposed from the outer wall to the inner wall of the balloon catheter. A suction catheter is disposed between the balloon catheter and the infusion catheter. The suction catheter is in fluid communication with the at least one communicating channel in the balloon catheter.

DETAILED DESCRIPTION

Referring toFIGS. 1-5generally and initially toFIG. 1, the present invention comprises an angioplasty device11having a suction mechanism for the removal of plaque particles. The device11includes an assembly having three co-axial catheters. The proximal end13of the assembly is connected to a three-way connector16. The center port19of the connector16is coupled to an infusion catheter22which is the most inner catheter. A first side-branch25of the connector16is connected to a balloon catheter28which is the outermost catheter. The first side-branch25is used for inflating and deflating the balloon43. A second side-branch34is connected to a suction catheter37which is located in the middle between the other catheters. The balloon catheter28is furnished with multiple communicating channels40that act as tunnels between the suction catheter37and blood stream. Upon enlargement of the lumen41by balloon43at the atherosclerotic site, suction of the debris is performed through the communicating channels40using a standard syringe (not shown) that is connected to the corresponding port of the three-way connector16. The diameters of communicating channels40are adjusted for the maximum size of the atherosclerotic particles. Their lengths are determined based on the radius of the balloon43in its expanded position. The communicating channels40can be made of elastic material that will be elongated during the expansion of the balloon. Another design of communicating channels40comprises an accordion pleat shape. This design enables the communicating channels to be elongated without exerting any strain on the surface of the balloon43. The communicating channels40can also be made out of fibrous material for reinforcement of its structure to reduce its collapsibility during expansion of the balloon43or suction process. The position of the communicating channels40is adjusted in both the longitudinal and the radial direction on the balloon43to maximize performance of the device. The balloon43is made of asymmetric material with the distal portion49to be thinner such that it allows larger expansion of the balloon43. This larger expansion can restrain the atherosclerotic particles upstream of the balloon portion of the device during deflation phase and ensures all of the particles to be suctioned out into the catheter28and not travel with the blood stream. The deflation of the balloon43because of its design would be stepwise. The distal part49of the balloon43would deflate last to avoid escape of debris particles distal to the site of angioplasty.

In operation, the device11of the present invention is deployed by means of an introducer sheath(s) having a low profile. As known to those of ordinary skill in the art, the device11is deployed over a guide wire (not shown) to the target area of the vasculature. Once the device reaches the target area, the balloon43is inflated by injecting contrast material and saline into the cavity formed inside the balloon43. The inflation of the balloon43from the state shown inFIG. 1to the state shown inFIG. 2causes the balloon43to expand such that it engages with the inner wall of the lumen41.

InFIG. 4, the balloon43is shown in its deflated state with the co-axial infusion catheter22, suction catheter37, and balloon43. The communicating channels40are formed in the walls of the balloon43such that particles can be suctioned from the vessel lumen through the balloon into the suction catheter37.

InFIG. 5, the balloon43is shown in the inflated state.

InFIGS. 6-9an alternate embodiment of the invention comprises a device100having a balloon catheter103having a suction mechanism for the removal of the plaque particles. The balloon catheter103includes flaps109of nylon or other appropriate biocompatible material. The flaps109are incorporated into the body115of the balloon112. During inflation, the flaps109inflate with the body115of the balloon112while maintaining an airtight seal. A set of strings118connects to the inner wall of the flaps109by means of hooks110(FIGS. 7 and 8) and to the plunger121of the aspirating syringe122(FIG. 9) while passing through the lumen of the balloon catheter103. During deflation, the strings118pull the flaps109back as the plunger121(FIG. 9) is pulled back to aspirate the contrast-saline mixture out of the balloon112. The flaps109are disassociated from the body of the balloon112creating an inflow channel for debris into the lumen of the balloon catheter103and subsequently into the aspiration syringe122. The disassociation of the flaps109precedes the deflation of the rest of the balloon112to prevent inadvertent release of trapped debris. The fluid will be withdrawn in addition to the free material released outside the balloon112from the vessel wall. The deflation of the balloon112because of its design with thinner walls or different material at its distal portion would be stepwise. The distal part of the balloon112would deflate last to avoid escape of debris particles distal to the site of angioplasty.

InFIG. 10, an alternate embodiment is shown. The device200comprises a balloon catheter201and a suction catheter203for the removal of the plaque particles. The device200includes three co-axial catheters. The proximal end206of the device200is connected to a three-way connector209. The center port212of the connector209is coupled to the infusion catheter215(the inner most catheter). One of the side-branches218of the connector is connected to the balloon catheter201(the middle catheter) for inflating and deflating the balloon221. The other side-branch224is connected to the suction catheter203(the outer most catheter). Upon the start of balloon deflating phase, a rapid suction of the debris is performed through at least one orifice227located on the suction catheter203proximal to the angioplasty balloon221. The diameters of orifices227on the suction catheter203are adjusted to allow passage of large debris. The suction is performed using a standard syringe (not shown) connected to the corresponding port of the three-way connector209. The balloon221itself is made of asymmetric material with the distal portion to be thinner that allows larger expansion of the balloon221at the distal segment. This larger expansion restrains the atherosclerotic particles within the balloon segment during deflation phase and ensures all of the particles to be suctioned out into the catheter and not travel with the blood stream. The deflation of the balloon221because of its design would be stepwise. The distal part of the balloon221would deflate last to avoid escape of debris particles distal to the site of angioplasty.

While the invention has been described in connection with certain embodiments, it is not intended to limit the scope of the invention to the particular forms set forth, but, on the contrary, it is intended to cover such alternatives, modifications, and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims.