The present invention generally relates to medical devices and treatments for treating intravascular lesions, and more specifically to catheter based treatments of lesions relating to intracranial atherosclerosis disease (ICAD).
Atherosclerosis results from lesions which narrow and reduce the space in the lumen of vessels in the vasculature. Such lesions are usually composed of plaque, which can be fat, cholesterol, calcium, or other components of the blood. Severe occlusion or closure can impede the flow of oxygenated blood to different organs and parts of the body and result in other cardiovascular disorders such as heart attack or stroke. Narrowing of vessels, or stenosis, increases the risk that clots, and other emboli can lodge at such locations, especially in the neurovascular where vessel diameters are already small. ICAD is the narrowing of those arteries and vessels supplying blood to the brain and represents the most common proximate mechanism of ischemic stroke.
Current methods for treating vascular occlusions include utilizing drugs, such as anticoagulants or anti-platelet agents, as well as medical procedures such as surgical endarterectomy, angioplasty, and stenting. Mechanical procedures often involve using medical devices to retrieve an occlusive clot and then utilizing balloons and stents to open a narrowed artery. Following the use of a stentriever or other clot retrieval device, a balloon is delivered to a target site and inflated to dilate the stenosis. The balloon can then be removed and exchanged through a catheter for a stent delivery device. If desirable, once the stent is in place a balloon can be inflated inside the stent to press the struts of the stent scaffold frame firmly against the inner wall of the vessel. Crossing the occlusion with devices such as stentreivers and stents can increase the likelihood that the ICAD ruptures or fragments. Such fragments can include but are not limited to blood clots, plaque, and other thrombi debris. The fragments can lead to vascular occlusions downstream of the lesion, causing extensive stroke or death.
Applicants therefore recognize a need for systems and devices to continue to address and improve treatments for intravascular occlusions, specifically ICAD.
It is an object of the present invention to provide catheter based systems for isolated stenting of an intravascular lesion. Expandable occlusion devices can be expanded in a distal direction and a proximal direction in relation to the lesion to occlude vasculature. A stent can be deployed across the lesion while the occlusion devices are in place. Fragments dislodged during stenting can be aspirated.
An example intravascular treatment system can include a delivery tube, a distal balloon, an angioplasty balloon, a stent, and one or more inflation lumens. The treatment system can also include an expandable element such as a proximal balloon. The treatment system can further include an outer catheter sized to traverse vascular and sized to allow the delivery tube, distal balloon, angioplasty balloon, and stent to traverse therethrough.
The delivery tube can be sized to traverse vasculature.
The expandable element can be disposed on the delivery tube in the proximal direction in relation to the angioplasty balloon. Alternatively, the expandable element can be disposed on the outer catheter. In either case, the expandable element can be a balloon (referred to herein as a “proximal balloon”) inflatable by an inflation lumen of the one or more inflation lumens. Alternatively, the expandable element can be self-expanding or expandable by other means as understood by a person of ordinary skill in the art according to the teachings of the present disclosure. The expandable element can be porous.
The distal balloon can be disposed on the delivery tube. The distal balloon can be disposed near a distal end of the delivery tube. When both the proximal balloon and the distal balloon are inflated by the same inflation lumen, the distal balloon can be expandable at a different pressure than the angioplasty balloon and/or the proximal balloon.
The angioplasty balloon can be disposed on the delivery tube. The angioplasty balloon can be disposed in the proximal direction in relation to the distal balloon. The angioplasty balloon can include an expandable non-compliant wrap configured to expand the stent. Additionally, or alternatively, the angioplasty balloon can include a non-compliant membrane, the stent can restrict expansion of the angioplasty balloon during delivery, and the expanded diameter of the angioplasty balloon can be determined by the shape of the non-compliant membrane. In either case, the angioplasty balloon can be expandable at a different pressure than the distal balloon and/or the proximal balloon when the angioplasty balloon is inflated by the same inflation lumen as the distal balloon and/or proximal balloon.
The stent can be disposed over the angioplasty balloon. The stent can be a balloon expandable stent, meaning inflation of the balloon is necessary to expand the stent, i.e. the stent is not self-expanding.
The delivery tube may be sized to receive a microcatheter so that a thrombectomy device can be used at a more distal location or to use a 0.035″ guidewire to assist access.
Some or all of the inflation lumen(s) can extend along the delivery tube. One or more of the inflation lumen(s) can be in communication with the distal balloon and the angioplasty balloon, positioned to inflate the distal and angioplasty balloon. The inflation lumen(s) can be further in communication with the proximal balloon, positioned to inflate the proximal balloon.
The one or more inflation lumens can include a singular inflation lumen in communication with both the distal balloon and the angioplasty balloon, positioned to inflate both the distal balloon and the angioplasty balloon. The singular inflation lumen can further be in communication with the proximal balloon, positioned to inflate the proximal balloon. The pressure at which balloons are expandable can allow multiple balloons to be inflated by a single inflation lumen in a predetermined order. The balloon expandable at a lower pressure can be inflated before the balloon expandable at a higher pressure. For instance, a distal balloon can be expandable at a lower pressure compared to an angioplasty balloon inflatable by the same inflation lumen. In which case the distal balloon can be inflated first. In an instance including a proximal balloon inflatable by the same inflation lumen as the distal balloon and the angioplasty balloon, the distal balloon can be expandable at a lower pressure than the proximal balloon and the angioplasty balloon.
As an alternative to a single inflation lumen in communication with both the distal balloon and the angioplasty balloon, the one or more inflation lumens can include a first inflation lumen in communication with the distal balloon and a second inflation lumen in communication with the angioplasty balloon. Each of the first and second inflation lumens can extend along the delivery tube. The first inflation lumen can be positioned to provide a first flow path to inflate the distal balloon. The second inflation lumen can be positioned to provide a second flow path to inflate the angioplasty balloon. The first and second flow paths can be separated such that the distal balloon and angioplasty balloon are each inflatable independent of each other. In instances where the delivery tube includes a proximal balloon thereon, the first inflation lumen or the second inflation lumen can further be in communication with the proximal balloon, positioned to inflate the proximal balloon. The pressure at which balloons are expandable can allow multiple balloons to be inflated by a single inflation lumen in a predetermined order. As an alternative to the proximal balloon being in communication with an inflation lumen common to the distal balloon or angioplasty balloon, the one or more inflation lumens can further include a third inflation lumen in communication with the proximal balloon. The third inflation lumen can be positioned to provide a third flow path to inflate the proximal balloon. The first, second, and third flow paths can be separated such that the distal balloon, angioplasty balloon, and the proximal balloon are each inflatable independent of each other. The third inflation lumen can extend along the delivery tube; alternatively, the third inflation lumen can extend along a separate tube and/or catheter such as a guide catheter in which the delivery tube is slidably translatable.
An example method for treating an intravascular lesion can include one or more of the following steps presented in no particular order. The method can further include additional steps as appreciated and understood by a person of ordinary skill in the art according to the teachings of this disclosure.
The method can include positioning a delivery tube having a distal balloon, angioplasty balloon, and stent thereon across the lesion. The delivery tube can be positioned such that the distal balloon is in the distal direction in relation to the lesion, the angioplasty balloon crosses the lesion, and the stent crosses the lesion.
The method can include inflating the distal balloon. The distal balloon can be fully inflated before the angioplasty balloon is fully inflated.
The method can include expanding a proximal expandable element positioned in the proximal direction in relation to the lesion. The proximal expandable element can be expanded such that the proximal expandable element circumferentially apposes a blood vessel before the angioplasty balloon is inflated. The proximal expandable element can include a proximal balloon. The proximal expandable element can be disposed on the delivery tube or on a guide catheter through which the delivery tube extends. Where the proximal balloon is disposed on a guide catheter through which the delivery tube is disposed, the proximal balloon can be inflated prior to crossing the lesion to protect the distal vascular bed from becoming blocked should the lesion be ruptured or should a portion of the lesion become dislodged inadvertently. The proximal balloon can also, in its expanded state, support the distal advancement of the delivery tube through the lesion, should the lesion be difficult to cross.
The method can include inflating the angioplasty balloon. The angioplasty balloon can be fully inflated after the distal balloon is fully inflated. The angioplasty balloon can be inflated before the proximal expandable element is expanded to circumferentially appose the blood vessel.
The method can include expanding the stent into the lesion as a result of fully inflating the angioplasty balloon.
The method can include inflating the distal balloon and the angioplasty balloon both via a single inflation lumen. Alternatively, the method can include inflating the distal balloon and the angioplasty balloon through separate inflation lumens.
The method can include positioning the proximal balloon in in the proximal direction in relation to the lesion when the delivery tube is positioned across the lesion.
The method can include inflating the proximal balloon such that the proximal balloon is fully inflated after the distal balloon is fully inflated and before the angioplasty balloon is fully inflated.
The method can include inflating the distal balloon, the angioplasty balloon, and the proximal balloon via a single inflation lumen.
When the proximal expandable element is disposed on a guide catheter, the method can include positioning the guide catheter at the lesion such that the proximal expandable element is in the proximal direction in relation to the lesion. The method can include delivering the delivery tube through a guide catheter (e.g. a guide catheter on which the expandable element and/or proximal balloon is disposed) to the lesion. The method can further include aspirating through a guide catheter (e.g. a guide catheter on which the expandable element and/or proximal balloon is disposed).
The method can include deflating the angioplasty balloon. The angioplasty balloon can be deflated before the distal balloon.
The method can include deflating the distal balloon. The distal balloon can be deflated after the angioplasty balloon.
Another example method for treating an intravascular lesion can include one or more of the following steps presented in no particular order. The method can further include additional steps as appreciated and understood by a person of ordinary skill in the art according to the teachings of this disclosure.
The method can include occluding a blood vessel in a proximal direction in relation to the lesion and in a proximal direction in relation to a bifurcation to a first branch blood vessel and a second branch blood vessel. The first branch blood vessel can be in communication with the Circle of Willis.
The method can include occluding a second branch blood vessel in a distal direction in relation to the lesion and the bifurcation.
The method can include stenting the lesion while the second branch blood vessel distal to the lesion is occluded and the blood vessel proximal to the lesion is occluded.
The method can include aspirating in the vicinity of the lesion after stenting the lesion.
The method can include aspirating in the vicinity of the lesion while the second branch blood vessel distal to the lesion is occluded and the blood vessel proximal to the lesion is occluded.
Another intravascular treatment system can include a delivery tube, a first and second balloon, and an inflation lumen. The first and second balloons can be disposed on a distal portion of the delivery tube. The inflation lumen can include a singular inflation lumen in communication with both the first and second balloons to inflate both the first and second balloons. The first balloon can be expandable at a lower pressure than the second balloon to control the order of inflation and deflation of the balloons via the inflation lumen. The treatment system can further include a stent circumscribing the delivery tube 110 and positioned between the first and second balloons. The stent can be self-expandable.
The above and further aspects of this invention are further discussed with reference to the following description in conjunction with the accompanying drawings, in which like numerals indicate like structural elements and features in various figures. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating principles of the invention. The figures depict one or more implementations of the inventive devices, by way of example only, not by way of limitation.
The delivery tube 110 can be sufficiently long such that a proximal end of the delivery tube 110 can be positioned outside the patient when the treatment system 100 is positioned at the lesion P as illustrated in
The distal balloon 114 can be disposed on the delivery tube 110 near a distal end 134 of the delivery tube. The angioplasty balloon 116 can be disposed on the delivery tube 110 in the proximal direction 12 in relation to the distal balloon 114. The stent 118 can be disposed over the angioplasty balloon 116. The proximal occlusion element 112 can be disposed on the delivery tube 110 in the proximal direction 12 in relation to the angioplasty balloon 116.
The proximal occlusion element 112 can include a balloon. Alternatively, the proximal occlusion element can include a self-expandable, mechanically expandable, and/or otherwise expandable occlusion element.
The proximal occlusion element 112, distal balloon 114, and angioplasty balloon 116 are configured to expand to appose vascular walls in a blood vessel BV as illustrated in
As a variation on the treatment system 100 illustrated in
Referring collectively to
When the angioplasty balloon 116 includes a compliant membrane, the compliant membrane can expand as pressure within the angioplasty balloon 116 increases. The non-compliant membrane can expand to one specific size or size range, even as internal pressure within the distal balloon 114 increases, and the distal balloon 114 can require less pressure to inflate to occlude the blood vessel BV compared to the compliant membrane of the angioplasty balloon 116. To reduce the risk of overexpansion of the compliant membrane of the angioplasty balloon 116, the angioplasty balloon 116 can further include and a non-compliant wrap configured to restrict the expanded diameter of the angioplasty balloon 116. As an alternative to using a non-compliant distal balloon 114, the distal balloon 114 can include a complaint membrane that inflates at a lower pressure compared to the compliant membrane of the angioplasty balloon 116. In such a case, to reduce the risk of overexpansion of the compliant membrane of the distal balloon 114, the distal balloon 114 can also include a non-compliant wrap configured to restrict the expanded diameter of the distal balloon 114. Additionally, or alternatively, to reduce the risk of overexpansion of the distal balloon 114, the distal balloon can include a thick walled elastomeric material resistant to expansion compared to the angioplasty balloon's desired expansion. While pressure to fully expand the distal balloon 114 can depend primarily on the material properties of its' balloon membrane, pressure to inflate the angioplasty balloon 116 can depend on the properties of its' balloon membrane in addition to compression force from the stent 118, resistance of the plaque P, and resistance of the blood vessel BV to expansion.
Regardless as to whether the distal balloon 114 is non-compliant or includes a compliant membrane, the angioplasty balloon 116 can be deflated before the distal balloon 114. The membrane of the angioplasty balloon 116 can be sufficiently resilient to press inflation fluid from the angioplasty balloon 116 at a faster rate than inflation fluid is expelled from the distal balloon 114 when inflation pressure is reduced.
When the angioplasty balloon 116 includes a non-compliant membrane, the stent 118 can provide a force to inhibit expansion of the angioplasty balloon 116. The distal balloon 114, being uninhibited by a stent, can thereby inflate at a lower pressure compared to the angioplasty balloon 116. Pressure effective to inflate the angioplasty balloon 116 can be determined based on mechanical properties of the stent 118 which cause the stent 118 stent to be resistant to expansion.
In examples where the proximal occlusion element 112 includes a balloon, the proximal balloon 112 can be expanded via the singular inflation lumen 120 illustrated in
In examples where the proximal occlusion element 112 includes a balloon, the proximal balloon 112 can further be configured to inflate before, after, or simultaneously with the distal balloon 114. For instance, the distal balloon 114 can be inflated at a lower pressure than both the angioplasty balloon 116 and the proximal balloon 112 to allow the distal balloon 114 to inflate before both the proximal balloon 112 and the angioplasty balloon 116. To accomplish this, the distal balloon can be non-compliant, and both the proximal and angioplasty balloons 112, 116 can be compliant with a non-compliant wrap. Alternatively, the distal balloon 114 can include a compliant membrane that is configured to expand at a lower pressure than both the proximal balloon 112 and the angioplasty balloon 116.
In some treatments it can be advantageous to inflate the distal balloon 114 first to block blood flow downstream of the lesion P, inflate the proximal balloon 112 second to block blood flow to the lesion P, and inflate the angioplasty balloon 116 third, to expand the stent 118. The distal balloon 114 can anchor the delivery tube 110 in place and block the blood vessel BV while still providing access for other treatment devices to reach the lesion P from the proximal direction 12.
In some treatments it can be advantageous to expand the proximal occlusion element 112 (e.g. inflate a balloon of the proximal occlusion element 112) before inflating the distal balloon 114 and angioplasty balloon 116 to block blood flow to the lesion P. Inflating the proximal balloon 112 first can be particularly advantageous when the angioplasty balloon 116 and/or distal balloon 114 are translatable to cross the lesion P after the proximal occlusion element 112 is expanded to thereby inhibit fragments dislodged during crossing of the lesion P from being carried elsewhere in the vasculature by blood flow.
In another example, the proximal balloon, distal balloon and the angioplasty balloon include non-compliant wraps such that higher pressures can be used to compress the lesion. In yet another example, the proximal balloon, distal balloon and the angioplasty balloon can include a non-compliant balloon so that higher pressures can be used to compress plaque and wherein the sequence of expansion of each balloon is controlled by using compliant wraps, each compliant wrap being configured to release each of the non-compliant balloons in a predetermined sequence as discussed above.
The system 100 can additionally, or alternatively be configured such that the proximal occluding element 112 is expandable at the same time or prior to the distal balloon 114. In some examples, the balloon of the proximal occluding element 112 can be expanded at same pressure as distal balloon 114 or the angioplasty balloon 116. Preferably, the proximal and distal balloons are both compliant and inflated at the same pressure so that a compliant (elastomeric) balloon can be used for each such that each balloon has a low profile and does not require wrapping (e.g. with the stent to restrict expansion) like a non-compliant angioplasty balloon 116.
In another example, all balloons 112, 114, 116 can be elastomeric. The balloon 116 used to expand the stent 118 can be made using a thicker or stiffer material such that the proximal and distal balloons 112, 114 expand first (due to thinner wall and thus lower inflation pressure) and when the stent balloon 116 expands, the proximal and distal balloons 112, 114 begin to roll out longitudinally.
In another example, a composite or hybrid balloon can be used. The composite balloon can be constructed of an elastomeric material with non-compliant threads or braid that prevents the balloon from expanding past a certain diameter. The hybrid balloon can be constructed of an inner non-compliant balloon with an elastomeric outer sleeve that holds the non-compliant inner balloon in a compressed configuration for low profile delivery.
As an alternative to the system 300 illustrated in
In step 404, a proximal expandable element can be positioned in a proximal direction in relation to the lesion. The proximal expandable element can be a proximal occlusion element 112, 212, 312 as illustrated and described herein, a variation thereof, or an alternative thereto as appreciated and understood by a person of ordinary skill in the art according to the teaching herein. The proximal expandable element can be positioned on the delivery tube or can be positioned on a separate device. The proximal expandable element can be fixed a predetermined distance from the distal balloon and/or angioplasty balloon or the proximal expandable element can be slidably translatable in relation to the distal balloon and/or angioplasty balloon.
In step 406, the distal balloon can be inflated. The distal balloon can be inflated through an inflation lumen as described herein or otherwise inflated appreciated and understood by a person of ordinary skill in the art according to the teaching herein.
In step 408, the proximal expandable element can be expanded. The proximal expandable element can be inflated, unsheathed to self-expand, or otherwise expanded as appreciated and understood by a person of ordinary skill in the art according to the teaching herein. Step 408 can be performed before or after step 406 according to the needs of the treatment.
In step 410, the angioplasty balloon can be inflated, thereby expanding the stent into the lesion. The angioplasty balloon can be an angioplasty balloon 116, 216, 316 as illustrated and described herein, a variation thereof, or an alternative thereto as appreciated and understood by a person of ordinary skill in the art according to the teaching herein. The stent can be a stent 118, 218, 318 as illustrated and described herein, a variation thereof, or an alternative thereto as appreciated and understood by a person of ordinary skill in the art according to the teaching herein. The angioplasty balloon can be inflated while both the distal balloon and the proximal expandable element remain expanded. Inflation of the angioplasty balloon can additionally widen the blood vessel.
In step 412, the angioplasty balloon can be deflated. The angioplasty balloon can be deflated while the distal balloon and the proximal expandable element remain expanded.
In step 414, the blood vessel can be aspirated in the vicinity of the lesion. Aspiration can occur while one or both of the proximal expandable element and distal balloon remains expanded.
In step 416, the distal balloon can be deflated. The distal balloon can be deflated via an inflation lumen as illustrated and described herein or otherwise deflated as understood by a person of ordinary skill in the art according to the teaching herein. Step 416 can be performed before or after step 412 according to the needs of the treatment.
In step 418, the proximal expandable element can be collapsed. The proximal expandable element can be deflated, retracted into a sheath, or otherwise collapsed as understood by a person of ordinary skill in the art according to the teaching herein. Step 418 can be performed before or after steps 412 and 416 according to the needs of the treatment.
In step 504, one of the two branch vessels can be occluded in a distal direction in relation to the lesion and the bifurcation.
In step 506, a stent can be expanded into the lesion. The stent can be positioned and expanded while vasculature remains occluded as in steps 502 and 504.
In step 508, vasculature can be aspirated in the vicinity of the lesion. The lesion can be aspirated while the vasculature remains occluded as in steps 502 and 504. The non-occluded branch vessel can provide a path for backflow of blood during aspiration.
The descriptions contained herein are examples of embodiments of the invention and are not intended in any way to limit the scope of the invention. As described herein, the invention contemplates many variations and modifications of the intravascular treatment system, including alternative materials, alternative device structures, alternative treatment steps, etc. Modifications apparent to those having ordinary skill in the art to which this invention relates and are intended to be within the scope of the claims which follow.