Stenosis prevention and ablation delivery system

Various aspects of the present disclosure are directed toward apparatuses, systems, and methods for applying ablation therapy to a tissue region. The apparatuses, systems, and methods may include a balloon structure and one or more electrodes arranged on or within the balloon structure and configured to deliver energy to the tissue region.

TECHNICAL FIELD

The present disclosure generally relates to systems and methods for providing a therapy to a patient. More particularly, the present disclosure relates to apparatuses, systems, and methods for ablation delivery to tissue within the heart of the patient and stenosis reduction.

BACKGROUND

Atrial fibrillation is an irregular and often rapid heart rate that commonly causes poor blood flow to the body. Ablation procedures, including ablation of thoracic veins such as the pulmonary vein, may be a treatment for atrial fibrillation. During pulmonary vein ablation, for example, catheters are inserted into the atrium and energy is delivered to the tissue of the pulmonary vein and/or near the ostia of the pulmonary veins in the left atrium.

In certain instances, ablation may cause stenosis (e.g., narrowing of the vessels). Thus, it may be beneficial to include anti-stenotic elements in connection with or during the ablation procedure.

SUMMARY

In Example 1, an apparatus for applying ablation therapy to a tissue region, the apparatus comprising: a catheter sized and shaped for vascular access and including an elongate body extending between a proximal end and a distal end; a balloon structure arranged near the distal end of the elongate body and having a first portion with a first permeability and a second portion with a second permeability, the first permeability differing from the second permeability; and one or more electrodes arranged on or within the balloon structure and configured to deliver energy to the tissue region.

In Example 2, the apparatus of Example 1, wherein the first permeability is greater than the second permeability.

In Example 3, the apparatus of any of Examples 1-2, wherein the first portion of the balloon structure is configured to permeate a liquid therethrough and the second portion of the balloon structure is configured to anchor the elongate body at the tissue region.

In Example 4, the apparatus of Example 3, wherein the liquid comprises at least one of saline, a pharmacological agent, and an anti-stenotic agent.

In Example 5, the apparatus of any of Examples 1-4, wherein the balloon structure includes an external surface, and the first portion and the second portion are arranged along the external surface of the balloon.

In Example 6, the apparatus of Example 5, wherein the first portion of the balloon structure is configured to elute a liquid in response to inflation of the balloon structure.

In Example 7, the apparatus of any of Examples 5-6, wherein the first portion of the balloon structure comprises a plurality of nanostructures configured to contain the liquid.

In Example 8, the apparatus of any of Examples 1-4, wherein the second portion of the balloon structure is arranged within the first portion of the balloon structure.

In Example 9, the apparatus of Example 8, wherein the first portion forms a first chamber of the balloon structure, and the second portion forms a second chamber of the balloon structure.

In Example 10, the apparatus of Example 9, wherein the elongate body includes a first opening arranged within the first chamber and the elongate body includes a second opening arranged within the second chamber.

In Example 11, the apparatus of Example 10, wherein the first portion is configured to elute a liquid therethrough in response to influx of the liquid into the first chamber through the first opening.

In Example 12, the apparatus of Example 11, wherein the second portion is configured to expand and anchor the elongate body at the tissue region in response to influx of a liquid into the second chamber through the second opening.

In Example 13, the apparatus of any of Examples 1-11, wherein the first portion and the second portion form an external surface of the balloon structure.

In Example 14, the apparatus of any of Examples 1-13, wherein the one or more electrodes is arranged within the first portion of the balloon structure.

In Example 15, the apparatus of Example 14, wherein the elongate body includes a lumen, and the one or more electrodes is arranged within the lumen of the elongate body.

In Example 16, an apparatus for applying ablation therapy to a tissue region, the apparatus comprising: a catheter sized and shaped for vascular access and including an elongate body extending between a proximal end and a distal end; a balloon structure arranged near the distal end of the elongate body and having a first portion and a second portion, the first portion of the balloon structure being configured to permeate a liquid therethrough and the second portion of the balloon structure being configured to anchor the elongate body at the tissue region; and one or more electrodes arranged on or within the balloon structure and configured to deliver energy to the tissue region.

In Example 17, the apparatus of Example 16, wherein an external surface of the first portion of the balloon structure is configured to transfer the energy from the one or more electrodes to the tissue region.

In Example 18, the apparatus of Example 17, wherein the one or more electrodes comprises an electrode arranged within the first portion of the balloon structure.

In Example 19, the apparatus of Example 18, wherein the electrode is configured to deliver the energy via the first portion of the balloon structure in response to a direct current applied thereto.

In Example 20, the apparatus of Example 19, wherein the liquid comprises at least one of saline, a pharmacological agent, and an anti-stenotic agent, and the liquid is configured to mitigate against stenosis at the tissue region.

In Example 21, the apparatus of Example 16, wherein the second portion of the balloon structure is arranged within the first portion of the balloon structure.

In Example 22, the apparatus of Example 21, wherein the first portion forms a first chamber of the balloon structure, and the second portion forms a second chamber of the balloon structure.

In Example 23, the apparatus of Example 22, wherein the elongate body includes a first opening arranged within the first chamber and the elongate body includes a second opening arranged within the second chamber, the first portion is configured to elute a liquid therethrough in response to influx of the liquid into the first chamber through the first opening, and the second portion is configured to expand and anchor the elongate body at the tissue region in response to influx of a second liquid into the second chamber through the second opening.

In Example 24, the apparatus of Example 16, wherein the balloon structure is configured to telescope from the elongate body prior to inflation thereof.

In Example 25, the apparatus of Example 16, further comprising a steering mechanism configured to direct at least one of the balloon structure and the elongate body.

In Example 26, the apparatus of Example 25, wherein the steering mechanism comprises at least one wire coupled to a catheter handle.

In Example 27, an apparatus for applying ablation therapy to a tissue region, the apparatus comprising: a catheter sized and shaped for vascular access and including an elongate body extending between a proximal end and a distal end; a balloon structure arranged near the distal end of the elongate body and having a first portion with a first permeability and a second portion with a second permeability, the first permeability differing from the second permeability; and one or more electrodes arranged on or within the balloon structure configured to determine a target location for the ablation therapy and to deliver energy to the tissue region based on the determined location.

In Example 28, the apparatus of Example 27, wherein the first portion of the balloon structure is configured to elute a first liquid therethrough, and the first liquid is configured to mitigate against stenosis at the tissue region.

In Example 29, the apparatus of Example 28, wherein the second portion of the balloon structure is configured to anchor the elongate body at the tissue region in response to a second liquid expanding the second portion.

In Example 30, the apparatus of Example 29, further comprising a visualization element arranged with the elongate body, and the visualization element is configured to observe blood flow through the tissue area.

In Example 31, the apparatus of Example 30, wherein the tissue region is at least one of a pulmonary vein and a renal vein, and the first portion of the balloon structure and the one or more electrodes are configured to elute the first liquid and deliver the energy simultaneously.

In Example 32, a method for applying ablation therapy to a tissue region within a patient's heart, the method comprising: navigating a catheter within the patient's heart, the catheter including an elongate body extending between a proximal end and a distal end; positioning a balloon structure at the tissue region, the balloon structure being arranged near the distal end of the elongate body and having a first portion with a first permeability and a second portion with a second permeability, the first permeability differing from the second permeability; determining a pacing of the tissue region via one or more mapping electrodes arranged on or within the balloon structure to determine a target location for the ablation therapy; delivering energy to the tissue region based on the determined location via one or more electrodes arranged on or within the balloon structure; and eluting a liquid through the first portion of balloon structure during delivery of the energy to the tissue region.

In Example 33, the method of Example 32, further comprising anchoring the elongate body within the tissue region by inflating the second portion of the balloon structure.

In Example 34, the method of Example 33, further comprising visualizing flow within the tissue region subsequent to anchoring the elongate body within the tissue region

In Example 35, the method of Example 32, wherein the liquid comprises at least one of saline, a pharmacological agent, and an anti-stenotic agent, and the liquid is configured to mitigate against stenosis at the tissue region. While multiple embodiments are disclosed, still other embodiments of the present invention will become apparent to those skilled in the art from the following detailed description, which shows and describes illustrative embodiments of the invention. Accordingly, the drawings and detailed description are to be regarded as illustrative in nature and not restrictive.

DETAILED DESCRIPTION

FIG. 1shows an exemplary ablation system100in accordance with embodiments of the disclosure. As shown, the system100includes a catheter102sized and shaped for vascular access. The catheter102has a distal end104and a proximal end106. In one aspect, the proximal end106of the catheter102includes a handle108having a proximal portion110and a distal portion112. A physician may use the manipulate the ablation system100via the handle108during a treatment procedure involving ablation. The handle108may include a plurality of conduits, conductors, and wires to facilitate control of the catheter102and/or mating of the catheter102with a source of fluid, a source of ablative energy, a source of mapping, temperature display, sensors, and/or control software/hardware. The handle108further includes a connection port113through which ablative energy source and a mapping energy source may be operably coupled.

The catheter102can include an elongate body114having a proximal end116and a distal end118. The elongate body114may house electrical conductors/cable assembly (e.g., wires) for transmitting sensed signals and/or ablation energy. In addition, the elongate body114may include a circular cross-sectional geometry. However, other cross-sectional shapes, such as elliptical, rectangular, triangular, and various other shapes, can be provided. In certain instances, the elongate body114may be preformed of an inert, resilient material that retains its shape and does not soften significantly at body temperature; for example, Pebax®, polyethylene, or Hytrel®) (polyester). The elongate body114may be made of a variety of materials, including, but not limited to, metals and polymers. The elongate body114may be flexible and capable of winding through a tortuous path that leads to a target site, i.e., an area within the heart. The elongate body114may also be semi-rigid, i.e., by being made of a stiff material, or by being reinforced with a coating or coil, to limit the amount of flexing.

In certain instances, the movement of the distal end118of the elongate body114(such as to wind through the tortuous path that leads to a target site) can be controlled by a control mechanism122included within the handle108. The system100can include an articulating section of the elongate body114(e.g., near the distal end118) that is controlled via the control mechanism122. The distal end118of the elongate body114may be deflected or bent. The articulation section of the body may facilitate insertion of the catheter102through a body lumen (e.g., vasculature) and/or placement of electrodes at a target tissue location. The articulation may provide one or more degrees of freedom and permit up/down and/or left/right articulation.

The distal end104of the catheter102includes a tip section124positioned at the distal end118of the elongate body114. The tip section124includes a proximal portion134and a distal portion136. In certain instances, portions of the tip section124may be formed from a conductive material. More specifically, the system100includes one or more electrode structures142, formed of the conductive material, on an exterior surface130of the tip section124. The electrode structures142may be arranged around a circumference of exterior surface130of the tip section124. In addition, the electrode structures142may be configured as mapping electrodes and ablation electrodes.

The electrode structures142may be configured to conduct radio frequency (RF) energy or direct current to form lesions during the ablation procedure. The electrode structures142may deliver ablation energy to the myocardial tissues that are the source of arrhythmia, thereby destroying them or a portion thereof through heat. Each of the electrode structures142may be coupled to wires126using suitable means, such as soldering or welding. The number of wires126may be equal to the number of electrode structures142. The wires126can pass through a lumen144extending through the elongate body114of the catheter102and are electrically coupled to the RF generator exteriorly coupled to the ablation system100.

The electrode structures142may also be configured to measure the localized intracardial electrical activity (map) in real time at the point of RF energy delivery. The electrode structures142allow the physician to ascertain lesion formation by measuring the electrical activity of the tissue having been in contact with an ablation electrode (e.g., the lack of electrical activity indicates ablated tissue, whereas the presence of electrical activity indicates live or non-ablated tissue). In certain instances, the wires126, coupled to the electrode structures142, may also be electrically coupled to a mapping signal processor such that electrical events in myocardial tissue can be sensed for the generation of electrograms, monophasic action potentials (MAPs), isochronal electrical activity maps, and the like.

FIG. 2shows an exemplary ablation system at a target tissue region within patient's heart200in accordance with embodiments of the disclosure. More specifically, the heart200shown inFIG. 2may be undergoing a pulmonary vein ablation procedure using a device220in accordance with various aspects discussed herein. The device220may include a catheter having an elongate body222that is connected to a balloon structure224. The device220may be connected to an ablation energy source and controller (e.g., radiofrequency (RF) or direct current (DC) system not shown) and one or more liquid sources (not shown), both of which are located external to the patient. The balloon structure224may be located near the distal end of elongate body222. One or more interior chambers of the balloon structure224may be in fluid communication with a liquid delivery lumen arranged within the elongate body222. The liquid delivery lumen is used to convey the one or more liquids from the source external to the patient into the balloon structure224. The elongate body222and the balloon structure224may be delivered to a tissue region to which ablation energy may be applied.

As shown inFIG. 2, the elongate body222may be positioned in the left atrium202of the patient's heart200. More specifically and in certain instances, the device220may enter the right atrium204of heart200through a femoral vein and the inferior vena cava (not shown). The device220may be passed through a puncture in an atrial septum206to access left atrium202. From the left atrium202, the balloon catheter device220may be positioned through any of the pulmonary vein ostia210,212,214, or216to enter a pulmonary vein such as pulmonary vein218. In certain instances the device220may be an over-the-wire device that is delivered over or on a pre-placed guidewire or a delivery catheter/sheath or rapid exchange catheter may be used to assist in the insertion and placement of the device220.

After positioning of the device220at the tissue region (within the pulmonary vein218as shown inFIG. 2), the balloon structure224may be expanded. The balloon structure224may be inflated using a liquid (e.g., saline, a pharmacological agent, or a combination thereof) as the inflation medium. In instances where the balloon structure224is positioned within a vessel such as the pulmonary vein218, the inflation of balloon structure224may cause the outer surface of balloon structure224to contact an inner wall of vessel such as the pulmonary vein218. In certain instances, ablation energy may be applied through one or more electrodes (not shown) arranged within the balloon structure224to initiate the modulation of target neural fibers. In addition, one or more portions of the balloon structure224may have a permeability such that a liquid may exude, elute, weep, or otherwise be transmitted from therethrough. In certain instances, the liquid may be an anti-stenotic pharmaceutical agent that may contact the inner wall of pulmonary vein218.

The ablation energy may be applied through one or more portions of the balloon structure224by an electric field generated by the external source/controller and transferred through wires within one or more lumens of the elongate body222to electrodes (not shown) arranged with the balloon structure224. The electric energy can be transmitted to the inner wall of pulmonary vein218directly from the electrodes on the surface of balloon structure224or from the electrodes within the balloon structure224via the liquid (pharmacological agent) that exudes from the exterior surface of balloon structure224. The electric field may modulate the activity along neural fibers within the wall of the pulmonary vein218by at least partially causing apoptotic cell death to the tissue receiving the ablation energy. In certain instances while the electric field for ablation is being applied, transmission of the liquid (pharmacological agent) from the balloon structure224to the tissue can be continued. The ablation process may be performed simultaneously and concurrently with the delivery of an antimitotic pharmacological agent to the tissue receiving the ablation energy or the ablation process can be performed sequentially with the delivery of the liquid.

Delivering the pharmacological agent prior to the ablative energy may provide iontophoresis-like action to drive the agent into the tissue. Delivering the ablative energy prior to the pharmacological agent can provide some electroporative disruption of the endothelial cell-to-cell junction, and thereby promote delivery of the agent. In certain instances, a repetitious cyclic delivery of ablative energy and the pharmacological agent may enhance uptake of the agent. In certain instances, the pharmacological agent can have an ionic base so as to optimize the ablative energy's ability to get the agent beyond the endothelium of the tissue. Paclitaxel is an example of one type of antimitotic pharmacological agent that may be used with the apparatuses, systems, and methods discussed herein. This technique of coordinating the delivery of paclitaxel with the ablation process may prevent or reduce the occurrence of fibrosis, stenosis, and neointimal hyperplasia of the tissue undergoing ablation.

In certain instances, the electric field may be generated by applying direct current to the one or more electrodes arranged within the balloon structure224. Application of direct current, which is athermal, may be less likely to cause stenosis as compared to RF ablation. In certain instances, the amount of anti-stenotic pharmaceutical agent released from the balloon structure224may be tailored based on the type of energy used for ablation (e.g., a greater amount of anti-stenotic for RF ablation as compared to the amount of anti-stenotic for direct current). In addition, the use of direct current may cause apoptotic cell death to the tissue receiving the ablation energy. The direct current may form pores in the cells of the wall of the pulmonary vein218that are irreversible (e.g., the pores do not close). The balloon structure224being in contact with the wall of the pulmonary vein218may provide controlled and direct ablation of a target area while mitigating against down-stream proliferation of the ablation energy.

FIG. 3shows a partial cross-sectional illustration of an exemplary apparatus300for applying ablation therapy to a tissue region in accordance with embodiments of the disclosure. The apparatus300may include a catheter302sized and shaped for vascular access that has an elongate body304extending between a proximal end and a distal end of the catheter302. A distal portion of the catheter302and the elongate body304is shown inFIG. 3. The apparatus300may also include a balloon structure306arranged near the distal end of the elongate body304. The balloon structure306may include a first portion308and a second portion310. The balloon structure306may be configured to inflate in response to a liquid or inflation medium being provided thereto. In certain instances, the first portion308and the second portion310may be separately inflated using two inflation mediums or the first portion308and the second portion310may be inflated using a single inflation medium.

In certain instances, the first portion308of the balloon structure306may include a first permeability and the second portion310of the balloon structure306may include a second permeability. The first permeability may differ from the second permeability. More specifically, the first permeability may be greater than the second permeability. As a result and in certain instances, the first portion308of the balloon structure306may be configured to permeate a liquid therethrough. As the first portion308of the balloon structure306is inflated, the liquid may permeate therethrough. The liquid may be saline, a pharmacological agent, an anti-stenotic agent, or a combination thereof.

In certain instances, the first portion308of the balloon structure306may form a first chamber, and the second portion310of the balloon structure306may form a second chamber. As a result, the first portion308and the second portion310may be separate and distinct structures. More specifically, the second portion310may be a balloon or other similar structure that is arranged within the first portion308. The first portion308may be deposited or attached onto the second portion310.

The apparatus300may also include one or more electrodes arranged on or within the balloon structure306. As shown inFIG. 3, the apparatus includes an electrode312arranged within the balloon structure306. The electrode312may be configured to deliver energy to a tissue region. In certain instances, the electrode312may be configured to delivery energy in response to a direct current applied thereto.

FIG. 4shows an exemplary apparatus400for applying ablation therapy to a tissue region in accordance with embodiments of the disclosure. The apparatus400may include a catheter402having an elongate body404. A distal portion of the catheter402and the elongate body404is shown inFIG. 4. The apparatus400may also include a balloon structure406arranged near the distal end of the elongate body404. The balloon structure406may include a first portion408having a first permeability and a second portion410having a second permeability. The balloon structure406may be configured to inflate in response to a liquid or inflation medium being provided thereto. The first permeability may differ from the second permeability such that the first permeability may be greater than the second permeability. As a result and in certain instances, the first portion408of the balloon structure406may be configured to permeate a liquid therethrough, and the second portion410may mitigate against liquid permeation or eluting. Thus, as the balloon structure406is inflated, the liquid may permeate through the first portion408. The liquid may be saline, a pharmacological agent, an anti-stenotic agent, or a combination thereof.

The apparatus400also includes electrodes412arranged on an exterior surface of the balloon structure406. The electrodes412may be arranged along the elongate body404and configured to deliver energy to a tissue region. The electrodes404may also be arranged uniformly or non-uniformly about the circumference of the balloon structure406. In certain instances, the electrodes412may be configured to delivery energy in response to a direct current applied thereto. Energy may be delivered simultaneously/concurrently on the electrodes412or sequentially across the electrodes412via radiofrequency energy, electroporation, vibration, ultrasound or laser energy.

FIG. 5shows a partial cross-sectional illustration of another exemplary apparatus500for applying ablation therapy to a tissue region in accordance with embodiments of the disclosure. The apparatus500includes a catheter having an elongate body502. At or near a distal portion of the elongate body502is a balloon structure504. The balloon structure504may be attached to or formed on the elongate body502.

The balloon structure504may include a first portion506, at least a section of which includes a first permeability, and a second portion508having a second permeability. The balloon structure504may be configured to inflate in response to a liquid or inflation medium being provided thereto. As a result, the first permeability may be greater than the second permeability. Thus, in certain instances, the first portion506of the balloon structure504may be configured to permeate a liquid therethrough (in response to inflation of the balloon structure504) and the second portion508of the balloon structure504may be to anchor the elongate body502at a tissue region. The first portion506and the second portion508are arranged along an external surface of the balloon structure504.

In addition, the first portion506of the balloon structure504may form a first chamber, and the second portion508of the balloon structure504may form a second chamber. The second portion508may be a balloon or other similar structure that is arranged within the first portion506. The first portion506may be deposited or attached onto the second portion508. As noted above, at least a section of the first portion506has a greater permeability than the second portion508. In certain instances, the permeability of the second portion508may be zero such that liquid does not permeate or elute therethrough. Although the entirety of the balloon structure504is configured to inflate, the balloon structure504includes a section, the second portion508, that may be impermeable to liquid. Thus, at least a section510of the balloon structure504that does not include the second portion508may be permeable. The first portion506may be formed of the same permeability such that the entirety of the first portion506may permeate liquid therethrough, or the section510of the first portion506may permeate liquid therethrough.

The balloon structure504may be positioned at a target tissue region for ablation. In certain instances, the tissue region may be a vessel such as a pulmonary vein or a renal vein or other appendage. The balloon structure504may be configured to deploy within the vessel such that the section510contacts the vessel wall. The first portion506may permeate the liquid to the tissue region (e.g., the vessel wall). The liquid may include an anti-stenotic agent that mitigates against stenosis at the tissue region. In addition, the second portion508may be configured to anchor the elongate body502at the tissue region. The second portion508may be impermeable to the liquid.

The apparatus500may also include an electrode512arranged within the balloon structure504. The electrode512may be configured to deliver energy to a tissue region. In certain instances, the electrode512may be arranged within the first portion506and configured to delivery energy in response to a direct current applied thereto. The ablation energy from the electrode512may be applied through an external surface of the first portion506of the balloon structure504by an electric field generated by the external source/controller and transferred through a wire514within the elongate body502. The electric energy can be transmitted to the tissue region (e.g., the vessel wall) via the liquid, which may include an anti-stenotic agent, that exudes from the first portion506of the balloon structure504. The electric field may modulate the activity along neural fibers within the wall of the tissue by at least partially causing apoptotic cell death to the tissue receiving the ablation energy. In certain instances while the electric field for ablation is being applied, transmission of the liquid, including the anti-stenotic agent, from the first portion506of the balloon structure504to the tissue can be continued. The ablation process applied via the electrode512may be performed simultaneously and concurrently with the delivery of an antimitotic pharmacological agent to the tissue receiving the ablation energy or the ablation process can be performed sequentially with the delivery of the liquid.

In certain instances and as noted above, the electric field may be generated by applying direct current to the electrode512. The use of direct current may cause apoptotic cell death to the tissue receiving the ablation energy. The direct current may form pores in the cells of the tissue region such that are irreversible (e.g., the pores do not close). The balloon structure504being in contact with the tissue may provide controlled and direct ablation of a target area while mitigating against down-stream proliferation of the ablation energy.

The apparatus500may also include a tip electrode516that is configured to form a ground or a closed-loop with the electrode512. Similar to the electrode512, the tip electrode516may be coupled to the external source/controller via a wire518within the elongate body502. The external source/controller may apply RF ablation energy or DC current. Thus, the tip electrode516may function as a single point ablation electrode when the external source/controller is configured to apply RF ablation energy.

In certain instances, the electrode512and/or the tip electrode516may also be configured to measure the localized intracardial electrical activity. The wire514and/or the wire518may also be electrically coupled to a mapping signal processor such that electrical events in myocardial tissue can be sensed for the generation of electrograms, monophasic action potentials (MAPs), isochronal electrical activity maps, and the like. The electrode512and/or the tip electrode516may allow the physician to measure the electrical activity of the tissue region (e.g., the lack of electrical activity indicates ablated tissue, whereas the presence of electrical activity indicates live tissue). In certain instances, the tip electrode516may include a hole (e.g., as shown inFIGS. 7-8) centrally a distal end thereof for interfacing with a guide wire or for contrast to be ejected therethrough. In addition, the tip electrode516may be collapsible (e.g., similar to an accordion) after entering into the tissue region. The tip electrode516may stabilize the apparatus500within the tissue region, and collapse if the balloon structure504is moved more distally within the tissue region. Collapsing the tip electrode516may facilitate positioning of the balloon structure504without increasing the pressure within the tissue region. In certain instances, the tip electrode516may be a mesh structure (e.g., formed from Nitinol) that may collapse and disperse the electrical energy over surface area of the mesh.

In other instances, the apparatus500may include pacing electrodes520,522. The pacing electrodes520,522may be arranged within the balloon structure504. In certain instances, the pacing electrodes520,522are arranged within the second portion508of the balloon structure504. The pacing electrodes520,522may be electrically coupled to a mapping signal processor such that electrical events in myocardial tissue can be sensed for the generation of electrograms, monophasic action potentials (MAPs), isochronal electrical activity maps, and the like. The pacing electrodes520,522may allow the physician to measure the electrical activity of the tissue region (e.g., the lack of electrical activity indicates ablated tissue, whereas the presence of electrical activity indicates live tissue). The ablation energy applied via the electrode512may be altered based on the electrical activity measured by the pacing electrodes520,522, used to determine a target location for the ablation therapy.

The illustrative components shown inFIG. 5are not intended to suggest any limitation as to the scope of use or functionality of embodiments of the disclosed subject matter. Neither should the illustrative components be interpreted as having any dependency or requirement related to any single component or combination of components illustrated therein. Additionally, any one or more of the components depicted in any of theFIG. 5may be, in embodiments, integrated with various other components depicted therein (and/or components not illustrated), all of which are considered to be within the ambit of the disclosed subject matter. For example, the pacing electrodes520,522may be used in connection with apparatus300and apparatus400.

FIG. 6shows a partial cross-sectional illustration of another exemplary apparatus600for applying ablation therapy to a tissue region in accordance with embodiments of the disclosure. The apparatus600includes a catheter having an elongate body602. The apparatus600also may include a balloon structure604arranged at or near a distal portion of the elongate body602. The balloon structure604may be configured to inflate in response to a liquid or inflation medium being provided thereto. In addition, the balloon structure604may include a first portion606and a second portion608. In certain instances, the first portion606of the balloon structure604may be configured to permeate a liquid therethrough (in response to inflation of the balloon structure604) and the second portion608of the balloon structure604may be to anchor the elongate body602at the tissue region.

The balloon structure604may be positioned at or within the tissue region for ablation. In certain instances, the tissue region may be a vessel such as a pulmonary vein or a renal vein. The balloon structure604may be configured to deploy within the vessel such that section610contacts the vessel wall. The first portion606may permeate the liquid to the tissue region (e.g., the vessel wall). The liquid may include an anti-stenotic agent that mitigates against stenosis within the vessel. In addition, the second portion608may anchor the elongate body602within the vessel.

In certain instances, the elongate body602includes a first opening624arranged within the first portion606(or chamber) and the elongate body602includes a second opening626arranged within the second portion608(or chamber). The first portion606(or chamber) is configured to elute a liquid therethrough in response to influx of the liquid into the first portion606(or chamber) through the first opening624. In addition, the second portion608may be configured to expand and anchor the elongate body602at the tissue region in response to influx of a liquid into the second portion608(or chamber) through the second opening626. The liquid eluted through the first portion606may be configured to mitigate against stenosis at the tissue region.

In certain instances, the apparatus600may also include an electrode612, arranged within a lumen of the elongate body602, that is configured to deliver energy to a tissue region. In certain instances, the electrode612may be arranged within the first portion606and configured to delivery energy in response to a direct current applied thereto. The ablation energy from the electrode612may be applied through an external surface of the first portion606of the balloon structure604by an electric field generated by an external source/controller and transferred through a wire614within the elongate body602. The apparatus600may also include a tip electrode616that is configured to form a ground or a closed-loop with the electrode612. The tip electrode616may be coupled to the external source/controller via a wire618arranged within the elongate body602. In certain instances and as noted above, the electric field may be generated by applying direct current to the electrode612. The use of direct current may cause apoptotic cell death to the tissue receiving the ablation energy. The direct current may form pores in the cells of the tissue region such that are irreversible (e.g., the pores do not close). The balloon structure604being in contact with the tissue may provide controlled and direct ablation of a target area while mitigating against down-stream proliferation of the ablation energy. In addition, the apparatus600may include a contrast port628arranged with the tip electrode616. The contrast port628may be configured to eject contrast therethrough to assist in visualization of the apparatus600prior to and during ablation. The contrast port628may be off-set from a central axis of the elongate body602. In certain instances, the tip electrode616may include multiple off-set contrast ports628to facilitate guidance into multiple side branch areas.

The electric energy can be transmitted to the tissue region (e.g., the vessel wall) via the liquid that permeates through the first portion606of the balloon structure604. The electric field may modulate the activity along neural fibers within the wall of the tissue by at least partially causing apoptotic cell death to the tissue receiving the ablation energy. In certain instances while the electric field for ablation is being applied, transmission of the liquid from the first portion606of the balloon structure604to the tissue can be continued. The ablation process applied via the electrode612may be performed simultaneously and concurrently with the delivery of an antimitotic pharmacological agent as the liquid (or a saline and antimitotic pharmacological agent combination) to the tissue receiving the ablation energy or the ablation process can be performed sequentially with the delivery of the liquid.

The apparatus600may include pacing electrodes620,622arranged within the balloon structure604. The pacing electrodes620,622may be electrically coupled to a mapping signal processor such that electrical events in myocardial tissue can be sensed for the generation of electrograms, monophasic action potentials (MAPs), isochronal electrical activity maps, and the like. The pacing electrodes620,622may allow the physician to measure the electrical activity of the tissue region (e.g., the lack of electrical activity indicates ablated tissue, whereas the presence of electrical activity indicates live tissue) and determine a target location for the ablation therapy.

In certain instances, the apparatus600may include a steering mechanism630. The steering mechanism630may be configured to direct the balloon structure604, the elongate body602, or both the balloon structure604, and the elongate body602. As shown inFIG. 6, the steering mechanism630is arranged centrally within the elongate body602. The steering mechanism630may direct the balloon structure604and/or the elongate body602in multiple directions based on a force applied thereto. The steering mechanism630may be a wire that is coupled to a catheter handle (e.g., as shown inFIG. 1).

FIG. 7shows a partial cross-sectional illustration of another exemplary apparatus700for applying ablation therapy to a tissue region in accordance with embodiments of the disclosure. The apparatus700includes a catheter having an elongate body702and a balloon structure704attached to the elongate body702. The balloon structure704may be configured to inflate in response to a liquid or inflation medium. In addition, the balloon structure704may include a first portion706and a second portion708. In certain instances, the first portion706of the balloon structure704may be configured to permeate a liquid therethrough (in response to inflation of the balloon structure704) and the second portion708of the balloon structure704may be to anchor the elongate body702at the tissue region.

The balloon structure704may be positioned at or within the tissue region for ablation. In certain instances, the tissue region may be a vessel such as a pulmonary vein or a renal vein. The first portion706may permeate the liquid to the tissue region (e.g., the vessel wall). The liquid may include an anti-stenotic agent that mitigates against stenosis within the vessel. In addition, the second portion708may anchor the elongate body702within the vessel.

Electric energy can be transmitted to the tissue region (e.g., the vessel wall) via the liquid that permeates through the first portion706of the balloon structure704. The electric field may modulate the activity along neural fibers within the wall of the tissue by at least partially causing apoptotic cell death to the tissue receiving the ablation energy. In certain instances while the electric field for ablation is being applied, transmission of the liquid the first portion706of the balloon structure704to the tissue can be continued. The ablation process applied via an electrode712may be performed simultaneously and concurrently with the delivery of an antimitotic pharmacological agent as the liquid (or a saline and antimitotic pharmacological agent combination) to the tissue receiving the ablation energy or the ablation process can be performed sequentially with the delivery of the liquid. The electrode712, arranged with the elongate body702within the first portion704, is configured to deliver energy to a tissue region. The ablation energy from the electrode712may be applied through an external surface of the first portion706of the balloon structure704by an electric field generated by an external source/controller and transferred through a wire714within the elongate body702. In certain instances and as noted above, the electric field may be generated by applying direct current to the electrode712. The use of direct current may cause apoptotic cell death to the tissue receiving the ablation energy. The direct current may form pores in the cells of the tissue region such that are irreversible (e.g., the pores do not close). The balloon structure704being in contact with the tissue may provide controlled and direct ablation of a target area while mitigating against down-stream proliferation of the ablation energy.

A tip electrode716may also be used to form a ground or a closed-loop with the electrode712. The tip electrode716may also be coupled to the external source/controller. In addition, the apparatus700may include a contrast port710arranged with the tip electrode716. The contrast port710may be configured to eject contrast therethrough to assist in visualization of the apparatus700prior to and during ablation. The contrast port710may be arranged at a distal end of the tip electrode716.

Pacing electrodes720,722arranged within the balloon structure704may be configured to determine electrical activity of the tissue region. The pacing electrodes720,722may be used prior to ablation to estimate an extent tissue damage. In addition, the pacing electrodes720,722may be used after the ablation to determine the extent of the ablation. The pacing electrodes720,722may be electrically coupled to a mapping signal processor such that electrical events in myocardial tissue can be sensed for the generation of electrograms, monophasic action potentials (MAPs), isochronal electrical activity maps, and the like. The pacing electrodes720,722may allow the physician to measure the electrical activity of the tissue region (e.g., the lack of electrical activity indicates ablated tissue, whereas the presence of electrical activity indicates live tissue) and determine a target location for the ablation therapy.

In certain instances, the apparatus700may be steerable and include a first steering wire724and a second steering wire726. The first steering wire724and the second steering wire726may be configured to direct the balloon structure704, the elongate body702, or both the balloon structure704and the elongate body702. The first steering wire724and the second steering wire726are arranged within the elongate body702on either side of a central lumen728. As described in detail above, the central lumen728may include portions that carry liquid to each of the first portion706and the second portion708. The first steering wire724and the second steering wire726may direct the balloon structure704and/or the elongate body702in multiple directions based on a force applied thereto. The first steering wire724and the second steering wire726may be coupled to a catheter handle (e.g., as shown inFIG. 1).

In certain instances, one or both of the first portion706and the second portion708may include a stent support structure730. The stent support structure730may enhance the structural stability of one or both of the first portion706and the second portion708.

FIG. 8shows a partial cross-sectional illustration of another exemplary apparatus for applying ablation therapy to a tissue region accordance with embodiments of the disclosure. The apparatus800includes a catheter having an elongate body802and a balloon structure804attached to the elongate body802. The balloon structure804may include a first portion806and a second portion808. In certain instances, the first portion806of the balloon structure804may be configured to permeate a liquid therethrough and the second portion808of the balloon structure804may be to anchor the elongate body802at the tissue region in response to inflation of the balloon structure804). The balloon structure804may be positioned at or within the tissue region for ablation. In certain instances, the tissue region may be a vessel such as a pulmonary vein or a renal vein. The first portion806may permeate the liquid to the tissue region (e.g., the vessel wall). The liquid may include an anti-stenotic agent that mitigates against stenosis within the vessel. In addition, the second portion808may anchor the elongate body802within the vessel.

Electric energy can be transmitted to the tissue region (e.g., the vessel wall) via the liquid that permeates through the first portion806of the balloon structure804. The electric field may modulate the activity along neural fibers within the wall of the tissue by at least partially causing apoptotic cell death to the tissue receiving the ablation energy. In certain instances while the electric field for ablation is being applied, transmission of the liquid the first portion806of the balloon structure804to the tissue can be continued. The ablation process applied via an electrode812may be performed simultaneously and concurrently with the delivery of an antimitotic pharmacological agent as the liquid (or a saline and antimitotic pharmacological agent combination) to the tissue receiving the ablation energy or the ablation process can be performed sequentially with the delivery of the liquid. The ablation energy from the electrode812may be applied through an external surface of the first portion806of the balloon structure804by an electric field generated by an external source/controller and transferred through a wire814within the elongate body802.

A tip portion810of the apparatus800may be configured to facilitate position of the balloon structure804at the tissue region. The tip portion810may include a central aperture816that may assist in passing the elongate body802and the balloon structure804through a puncture in an atrial septum to access the left atrium of a patient's heart. The central aperture816may pass a guidewire therethrough to assist in positioning of the tip portion810at the septum. Subsequently, a puncture tool may be arranged through the elongate body802and through the central aperture816to puncture the septum. The central aperture816may also be configured to eject contrast therethrough to assist in visualization of the apparatus800prior to and during ablation.

A visualization element824may also be used to assist in visualization. The visualization element824may include a camera and a light source (e.g., a light emitting diode (LED)). The visualization element824may be arranged with the elongate body802and configured to view and provide an image of video to a physician operating the apparatus800. After positioning of the balloon structure804at the tissue region such as within the pulmonary vein (as shown inFIG. 2), the balloon structure804may be expanded. The inflation of the balloon structure804may cause the outer surface of the balloon structure804to contact an inner wall of the vessel. More specifically, the second portion808of the balloon structure804may anchor the elongate body802within the vessel. The visualization element824may be used to observe blood flow through the tissue area. In certain instances, the second portion808may block blood from through the tissue area such that the liquid eluted from the first portion806is directly applied to the tissue area. Blocking blood flow may mitigate against the liquid (e.g., anti-stenotic pharmaceutical agent) being carried from the tissue region. The anti-stenotic pharmaceutical liquid that may contact the tissue region (the inner wall of the vessel) and mitigate against stenosis formation that may result from the application of ablation energy applied via the electrode812.

Pacing electrodes820,822arranged within the balloon structure804may be configured to determine electrical activity of the tissue region. The pacing electrodes820,822may be used prior to ablation to estimate an extent tissue damage. In addition, the pacing electrodes820,822may be used after the ablation to determine the extent of the ablation. The pacing electrodes820,822may be electrically coupled to a mapping signal processor such that electrical events in myocardial tissue can be sensed for the generation of electrograms, monophasic action potentials (MAPs), isochronal electrical activity maps, and the like. The pacing electrodes820,822may allow the physician to measure the electrical activity of the tissue region (e.g., the lack of electrical activity indicates ablated tissue, whereas the presence of electrical activity indicates live tissue) and determine a target location for the ablation therapy.

The illustrative components shown inFIGS. 6-8are not intended to suggest any limitation as to the scope of use or functionality of embodiments of the disclosed subject matter. Neither should the illustrative components be interpreted as having any dependency or requirement related to any single component or combination of components illustrated therein. Additionally, any one or more of the components depicted in any of theFIGS. 6-8may be, in embodiments, integrated with various other components depicted therein (and/or components not illustrated), all of which are considered to be within the ambit of the disclosed subject matter. For example, the pacing electrodes520,522may be used in connection with apparatus300and apparatus400. In addition, apparatus300and apparatus400may include steering mechanisms and/or visualization elements as described with reference toFIGS. 6-8. Further, the tip sections of the apparatuses600-800may be collapsible as described above with reference toFIG. 5.

FIG. 9Ashows a partial cross-sectional illustration of another exemplary apparatus900for applying stenosis prevention to a tissue region having a first multiple chamber configuration in accordance with embodiments of the disclosure. The apparatus900may include an elongate body902and a balloon structure904. In the first multiple chamber configuration shown inFIG. 9A, the balloon structure904may include two chambers906,908that are configured to anchor the elongate body902at the tissue region. The chambers906,908may be impermeable to liquid applied to inflate the balloon structure904. The balloon structure904may also include a third chamber910that is configured to permeate a liquid therethrough. The liquid may be an anti-stenotic agent and may prevent stenosis formation at the tissue region.

FIG. 9Bshows the apparatus900for applying stenosis prevention, as shown inFIG. 9A, having a second multiple chamber configuration in accordance with embodiments of the disclosure. In the second multiple chamber configuration shown inFIG. 9B, the balloon structure904may include two chambers906,908that are configured to anchor the elongate body902at the tissue region. The chambers906,908may be impermeable to liquid applied to inflate the balloon structure904. The third chamber910that is configured to permeate a liquid therethrough. The liquid may be an anti-stenotic agent and may prevent stenosis formation at the tissue region. The chambers906,908are smaller than the first configuration chambers906,908to allow for a larger third chamber910.

FIG. 9Cshows the apparatus900for applying stenosis prevention, as shown inFIGS. 9A-B, having a third multiple chamber configuration in accordance with embodiments of the disclosure. In the third multiple chamber configuration shown inFIG. 9B, the balloon structure904may include three chambers906,908,912that are configured to anchor the elongate body902at the tissue region. The chambers906,908,912may be impermeable to liquid applied to inflate the balloon structure904. The apparatus includes the third chamber910configured to permeate a liquid therethrough and a fourth chamber914that is also configured to permeate a liquid therethrough. The liquid may be an anti-stenotic agent and may prevent stenosis formation at the tissue region. In the third configuration, the apparatus900includes two regions of permeability916,918through which the liquid (e.g., the anti-stenotic agent) may permeate. Any of the first, second, and third configurations of the apparatus900may also include electrodes that are configured to apply ablation energy, as described in detail above. The electrodes may be arranged within the chambers that permeate the liquid.

FIG. 10shows another exemplary apparatus1000for applying stenosis prevention to a tissue region having a multiple chamber configuration in accordance with embodiments of the disclosure. The apparatus1000includes three chambers1002,1004,1006along an elongate body1008of a catheter. Each of the three chambers1002,1004,1006may be configured to permeate an anti-stenotic liquid therethrough. In certain instances, the entirety of the three chambers1002,1004,1006may be permeable to the liquid, and in other instances, only a portion of the three chambers1002,1004,1006may be permeable to the liquid. The permeability (or lack thereof) may differ between the three chambers1002,1004,1006. Any of the three chambers1002,1004,1006. may also include electrodes that are configured to apply ablation energy, as described in detail above.

FIG. 11Ashows another exemplary apparatus1100for applying ablation therapy to a tissue region accordance with embodiments of the disclosure. The apparatus1100may include a catheter having an elongate body1102and a balloon structure1104attached to the elongate body1102. The balloon structure1104may be configured to telescope from the elongate body1102prior to inflation thereof. As shown inFIG. 11A, the balloon structure1104is arranged in a first configuration prior to telescoping from the elongate body1102.

A second balloon structure1106may be arranged with the elongate body1102. The second balloon structure1106may house a visualization element1108. The visualization element1108may also be used to assist in visualization during the application of ablation therapy. The visualization element1108may include a camera and a light source (e.g., a light emitting diode (LED)). The visualization element1108may be configured to view and provide an image of video to a physician operating the apparatus1100.

In the first configuration, the elongate body1102and the catheter may be navigated to a tissue region. More specifically, the elongate body1102and the catheter may be navigated within the patient's heart. After navigating to the patient's heart (e.g. as described above with reference toFIG. 2), the balloon structure1104may be positioned at the tissue region. In certain instances, the tissue region may be a vessel such as a pulmonary vein. In these such instances, the balloon structure1104is arranged within the vessel.

FIG. 11Bshows the apparatus1100for applying ablation therapy, as shown inFIG. 11A, in a second configuration in accordance with embodiments of the disclosure. In the second configuration, the balloon structure1104has been telescoped from the elongate body1102and has not yet been inflated. The positioning of the balloon structure1104at the tissue region (within the blood vessel) may occur during transition of the balloon structure1104between the first configuration and the second configuration, or after transition of the balloon structure1104to the second configuration. The balloon structure1104may include a section arranged within the elongate body1102that connects to a catheter handle. This section may be configured to slide within the elongate body1102to telescope the balloon structure1104therefrom.

FIG. 11Cshows the apparatus1100for applying ablation therapy, as shown inFIGS. 11A-Bin a third configuration in accordance with embodiments of the disclosure. In the third configuration, the balloon structure1104has been inflated. The balloon structure1104may include a first portion1110and a second portion1112. In certain instances, the first portion1110of the balloon structure1104may be configured to permeate a liquid therethrough and the second portion1112of the balloon structure1104may be to anchor the elongate body1102at the tissue region in response to inflation of the balloon structure1104). Thus, the first portion1110of the balloon structure1104may include a first permeability, and the second portion1112of the balloon structure1104may include a second permeability, with the first permeability being greater than the second permeability. The balloon structure1104may be positioned at or within the tissue region for ablation. In certain instances, the tissue region may be a vessel such as a pulmonary vein or a renal vein. The first portion1110may permeate the liquid to the tissue region (e.g., the vessel wall). The liquid may include an anti-stenotic agent that mitigates against stenosis within the vessel. In addition, the second portion1112may anchor the elongate body1102within the vessel.

An ablation process applied via an electrode1114may be performed simultaneously and concurrently with the delivery of an antimitotic pharmacological agent as the liquid (or a saline and antimitotic pharmacological agent combination) to the tissue receiving the ablation energy or the ablation process can be performed sequentially with the delivery of the liquid. Electric energy can be transmitted to the tissue region (e.g., the vessel wall) via the liquid that permeates through the first portion1110of the balloon structure1104. The electric field may modulate the activity along neural fibers within the wall of the tissue by at least partially causing apoptotic cell death to the tissue receiving the ablation energy. In certain instances, while the electric field for ablation is being applied, transmission of the liquid the first portion1110of the balloon structure1104to the tissue can be continued. The ablation energy from the electrode1114may be applied through an external surface of the first portion1110of the balloon structure1104by an electric field generated by an external source/controller and transferred coupled to the electrode1114.

After positioning of the balloon structure1104at the tissue region such as within the pulmonary vein (as shown inFIG. 2), the inflation of the balloon structure1104may cause the outer surface of the balloon structure1104to contact an inner wall of the vessel such. More specifically, the second portion1112of the balloon structure1104may anchor the elongate body1102within the vessel. The visualization element1108may be used to observe blood flow through the tissue area. In certain instances, the second portion1112may block blood from through the tissue area such that the liquid eluted from the first portion1110is directly applied to the tissue area. Blocking blood flow may mitigate against the liquid (e.g., anti-stenotic pharmaceutical agent) being carried from the tissue region. The anti-stenotic pharmaceutical liquid that may contact the tissue region (the inner wall of the vessel) and mitigate against stenosis formation that may result from the application of ablation energy applied via the electrode1114.

In addition, the balloon structure1104may include pacing electrodes1116,1118arranged therein. The pacing electrodes1116,1118may be configured to determine electrical activity of the tissue region. The pacing electrodes1116,1118may be used prior to ablation to estimate an extent tissue damage. In addition, the pacing electrodes1116,1118may be used after the ablation to determine the extent of the ablation. The pacing electrodes1116,1118may be electrically coupled to a mapping signal processor such that electrical events in myocardial tissue can be sensed for the generation of electrograms, monophasic action potentials (MAPs), isochronal electrical activity maps, and the like. The pacing electrodes1116,1118may allow the physician to measure the electrical activity of the tissue region (e.g., the lack of electrical activity indicates ablated tissue, whereas the presence of electrical activity indicates live tissue).

In certain instances, when balloon structure1104is deployed (e.g., inside the pulmonary vein) the balloon structure1104may be positioned therein as distally as possible toward the bifurcation where the pulmonary vein splits. At this point, the second portion1112may be inflated first to anchor the elongate body1102therein. Inflation of the second portion1112may stop blood flow to the left atrium, which may be verified by the visualization element1108. Subsequently, the pacing electrodes1116,1118may measure the electrical activity of the pulmonary vein. The measurement by the pacing electrodes1116,1118may provide a baseline for the ablation therapy. Ablation therapy may be applied via the electrode1114, based on the measurement of the pacing electrodes1116,1118, along with release of an anti-stenotic via the liquid permeated through the first portion1110. In certain instances, the liquid may be permeate through the first portion1110prior to the application of ablation therapy. The visualization element1108and/or an ultrasound may verify that the liquid (e.g., saline and the anti-stenotic) is flowing to the vessel wall prior to the application of ablation via the electrode1114.

After ablation is applied, the pacing electrodes1116,1118may be used again to measure the electrical activity. If the desired level of ablation has occurred based on the reading of the balloon structure1104may be deflated and removed from the pulmonary vein. In certain instances, the balloon structure1104may be moved along the pulmonary vein to a second ablation site. The second portion1112may remain inflated during repositioning of the balloon structure1104. The electrical activity of the second ablation may be measured by the pacing electrodes1116,1118, and the liquid permeation and ablation may occur. This process may be repeated until the desired level of ablation is achieved. The movement to the second ablation site (e.g., 5 mm) may be determined based on a change in the electrical activity measured by the pacing electrodes1116,1118. In addition the electrode1114may apply electrical energy via direct current applied thereto at various pulse width patterns and amplitudes (e.g., 1-30 microsecond pulses at 1000-3000 volts). For further detail regarding the ablation procedure, including mapping use the pacing electrodes1116,1118, reference may be made to theFIG. 1and the related discussion.

The illustrative components shown inFIGS. 11A-Care not intended to suggest any limitation as to the scope of use or functionality of embodiments of the disclosed subject matter. Neither should the illustrative components be interpreted as having any dependency or requirement related to any single component or combination of components illustrated therein. Additionally, any one or more of the components depicted in any of theFIGS. 11A-Cmay be, in embodiments, integrated with various other components depicted therein (and/or components not illustrated), all of which are considered to be within the ambit of the disclosed subject matter.

FIG. 12shows an exemplary balloon structure1200for applying stenosis prevention to a tissue region in accordance with embodiments of the disclosure. The balloon structure1200may include a permeability portion1202and non-permeability portion1204. The permeability portion1202may include a plurality of nanostructures1206. In certain instances, the nanostructures1206may be hollow fibers that act as a core material to contain a liquid, such as an anti-stenotic drug. In other instances, the plurality of nanostructures1206may contain a liquid, such as an anti-stenotic drug, in gaps between the plurality of nanostructures1206. The plurality of nanostructures1206in either instance may form a cross-hatched network within the permeability portion1202.

The plurality of nanostructures1206may be arranged on the balloon structure1200by fiber deposition, fiber sintering (thermal or chemical), hydrophilic or hydrophobic coating, or other similar processes. In addition, the permeability portion1202may include multiple layers such that one layer may include the plurality of nanostructures1206, and another layer is arranged thereon to mitigate against release of the liquid from the plurality of nanostructures1206. The liquid may release from the plurality of nanostructures1206, with or within the layer arranged thereon, in response to inflation of the balloon structure1200. The liquid, such as the anti-stenotic drug, may be delivered to a tissue region by diffusion into the tissue, or may be driven by ionophoresis by an electrical force originating from an electrode (not shown) arranged within the balloon structure1200. In other instances, the plurality of nanostructures1206may be replaced with a coating on the balloon structure1200of the anti-stenotic drug. This may include combing the anti-stenotic drug with water or saline (e.g., 4.86% 80/20 ptx/ATBC in 40/40/20 EtOH/Acetone/water). In certain instances, the balloon structure1200may have multiple layers. One or more anti-stenotic drugs, saline or other pharmacological agents may be impregnated within the different layers of the balloon structure1200. Sequential delivery of the anti-stenotic drugs, saline or other pharmacological agents may be delivered via the different layers of the balloon structure1200. In addition, the balloon structure1200may have different layers in different portions thereof for sequential delivery of the anti-stenotic drugs, saline or other pharmacological agents.

The illustrative components shown inFIG. 12are not intended to suggest any limitation as to the scope of use or functionality of embodiments of the disclosed subject matter. Neither should the illustrative components be interpreted as having any dependency or requirement related to any single component or combination of components illustrated therein. Additionally, any one or more of the components depicted in any of theFIG. 12may be, in embodiments, integrated with various other components depicted therein (and/or components not illustrated), all of which are considered to be within the ambit of the disclosed subject matter. For example, the nanostructures1206may be used in connection with any of the balloon structures discussed herein.