Patent Application
20060030814
1. Field of the Invention
This invention relates to the field of medical devices, and more particularly to a system and method for locally delivering fluids or agents within the body of a patient. Still more particularly, it relates to a system and method for locally delivering fluids or agents into branch blood vessels or body lumens from a main vessel or lumen, respectively, and in particular into renal arteries extending from an aorta in a patient.
2. Description of Related Art
Many different medical device systems and methods have been previously disclosed for locally delivering fluids or other agents into various body regions, including body lumens such as vessels, or other body spaces such as organs or heart chambers. Local “fluid” delivery systems may include drugs or other agents, or may even include locally delivering the body's own fluids, such as artificially enhanced blood transport (e.g. either entirely within the body such as directing or shunting blood from one place to another, or in extracorporeal modes such as via external blood pumps etc.). Local “agent” delivery systems are herein generally intended to relate to introduction of a foreign composition as an agent into the body, which may include drug or other useful or active agent, and may be in a fluid form or other form such as gels, solids, powders, gases, etc. It is to be understood that reference to only one of the terms fluid, drug, or agent with respect to local delivery descriptions may be made variously in this disclosure for illustrative purposes, but is not generally intended to be exclusive or omissive of the others; they are to be considered interchangeable where appropriate according to one of ordinary skill unless specifically described to be otherwise.
In general, local agent delivery systems and methods are often used for the benefit of achieving relatively high, localized concentrations of agent where injected within the body in order to maximize the intended effects there and while minimizing unintended peripheral effects of the agent elsewhere in the body. Where a particular dose of a locally delivered agent may be efficacious for an intended local effect, the same dose systemically delivered would be substantially diluted throughout the body before reaching the same location. The agent's intended local effect is equally diluted and efficacy is compromised. Thus systemic agent delivery requires higher dosing to achieve the required localized dose for efficacy, often resulting in compromised safety due to for example systemic reactions or side effects of the agent as it is delivered and processed elsewhere throughout the body other than at the intended target.
Various diagnostic systems and procedures have been developed using local delivery of dye (e.g. radiopaque “contrast” agent) or other diagnostic agents, wherein an external monitoring system is able to gather important physiological information based upon the diagnostic agent's movement or assimilation in the body at the location of delivery and/or at other locations affected by the delivery site. Angiography is one such practice using a hollow, tubular angiography catheter for locally injecting radiopaque dye into a blood chamber or vessel, such as for example coronary arteries in the case of coronary angiography, or in a ventricle in the case of cardiac ventriculography.
Other systems and methods have been disclosed for locally delivering therapeutic agent into a particular body tissue within a patient via a body lumen. For example, angiographic catheters of the type just described above, and other similar tubular delivery catheters, have also been disclosed for use in locally injecting treatment agents through their delivery lumens into such body spaces within the body. More detailed examples of this type include local delivery of thrombolytic drugs such as TPA™, heparin, cumadin, or urokinase into areas of existing clot or thrombogenic implants or vascular injury. In addition, various balloon catheter systems have also been disclosed for local administration of therapeutic agents into target body lumens or spaces, and in particular associated with blood vessels. More specific previously disclosed of this type include balloons with porous or perforated walls that elute drug agents through the balloon wall and into surrounding tissue such as blood vessel walls. Yet further examples for localized delivery of therapeutic agents include various multiple balloon catheters that have spaced balloons that are inflated to engage a lumen or vessel wall in order to isolate the intermediate catheter region from in-flow or out-flow across the balloons. According to these examples, a fluid agent delivery system is often coupled to this intermediate region in order to fill the region with agent such as drug that provides an intended effect at the isolated region between the balloons.
The diagnosis or treatment of many different types of medical conditions associated with various different systems, organs, and tissues, may also benefit from the ability to locally deliver fluids or agents in a controlled manner. In particular, various conditions related to the renal system would benefit a great deal from an ability to locally deliver of therapeutic, prophylactic, or diagnostic agents into the renal arteries.
Acute renal failure (“ARF”) is an abrupt decrease in the kidney's ability to excrete waste from a patient's blood. This change in kidney function may be attributable to many causes. A traumatic event, such as hemorrhage, gastrointestinal fluid loss, or renal fluid loss without proper fluid replacement may cause the patient to go into ARF. Patients may also become vulnerable to ARF after receiving anesthesia, surgery, or a-adrenergic agonists because of related systemic or renal vasoconstriction. Additionally, systemic vasodilation caused by anaphylaxis, and anti-hypertensive drugs, sepsis or drug overdose may also cause ARF because the body's natural defense is to shut down, i.e., vasoconstrict, non-essential organs such as the kidneys. Reduced cardiac output caused by cardiogenic shock, congestive heart failure, pericardial tamponade or massive pulmonary embolism creates an excess of fluid in the body, which can exacerbate congestive heart failure. For example, a reduction in blood flow and blood pressure in the kidneys due to reduced cardiac output can in turn result in the retention of excess fluid in the patient's body, leading, for example, to pulmonary and systemic edema.
Previously known methods of treating ARF, or of treating acute renal insufficiency associated with congestive heart failure (“CHF”), involve administering drugs. Examples of such drugs that have been used for this purpose include, without limitation: vasodilators, including for example papavarine, fenoldopam mesylate, calcium-channel blockers, atrial natriuretic peptide (ANP), acetylcholine, nifedipine, nitroglycerine, nitroprusside, adenosine, dopamine, and theophylline; antioxidants, such as for example acetylcysteine; and diuretics, such as for example mannitol, or furosemide. However, many of these drugs, when administered in systemic doses, have undesirable side effects. Additionally, many of these drugs would not be helpful in treating other causes of ARF. While a septic shock patient with profound systemic vasodilation often has concomitant severe renal vasoconstriction, administering vasodilators to dilate the renal artery to a patient suffering from systemic vasodilation would compound the vasodilation system wide. In addition, for patients with severe CHF (e.g., those awaiting heart transplant), mechanical methods, such as hemodialysis or left ventricular assist devices, may be implemented. Surgical device interventions, such as hemodialysis, however, generally have not been observed to be highly efficacious for long-term management of CHF. Such interventions would also not be appropriate for many patients with strong hearts suffering from ARF.
The renal system in many patients may also suffer from a particular fragility, or otherwise general exposure, to potentially harmful effects of other medical device interventions. For example, the kidneys as one of the body's main blood filtering tools may suffer damage from exposed to high density radiopaque contrast dye, such as during coronary, cardiac, or neuro angiography procedures. One particularly harmful condition known as “radiocontrast nephropathy” or “RCN” is often observed during such procedures, wherein an acute impairment of renal function follows exposure to such radiographic contrast materials, typically resulting in a rise in serum creatinine levels of more than 25% above baseline, or an absolute rise of 0.5 mg/dl within 48 hours. Therefore, in addition to CHF, renal damage associated with RCN is also a frequently observed cause of ARF. In addition, the kidneys' function is directly related to cardiac output and related blood pressure into the renal system. These physiological parameters, as in the case of CHF, may also be significantly compromised during a surgical intervention such as an angioplasty, coronary artery bypass, valve repair or replacement, or other cardiac interventional procedure. Therefore, the various drugs used to treat patients experiencing ARF associated with other conditions such as CHF have also been used to treat patients afflicted with ARF as a result of RCN. Such drugs would also provide substantial benefit for treating or preventing ARF associated with acutely compromised hemodynamics to the renal system, such as during surgical interventions.
There would be great advantage therefore from an ability to locally deliver such drugs into the renal arteries, in particular when delivered contemporaneous with surgical interventions, and in particular contemporaneous with radiocontrast dye delivery. However, many such procedures are done with medical device systems, such as using guiding catheters or angiography catheters having outer dimensions typically ranging between about 4 French to about 12 French, and ranging generally between about 6 French to about 8 French in the case of guide catheter systems for delivering angioplasty or stent devices into the coronary or neurovascular arteries (e.g. carotid arteries). These devices also are most typically delivered to their respective locations for use (e.g. coronary ostia) via a percutaneous, translumenal access in the femoral arteries and retrograde delivery upstream along the aorta past the region of the renal artery ostia. A Seldinger access technique to the femoral artery involves relatively controlled dilation of a puncture hole to minimize the size of the intruding window through the artery wall, and is a preferred method where the profiles of such delivery systems are sufficiently small. Otherwise, for larger systems a “cut-down” technique is used involving a larger, surgically made access window through the artery wall.
Accordingly, a local renal agent delivery system for contemporaneous use with other retrogradedly delivered medical device systems, such as of the types just described above, would preferably be adapted to allow for such interventional device systems, in particular of the types and dimensions just described, to pass upstream across the renal artery ostia (a) while the agent is being locally delivered into the renal arteries, and (b) while allowing blood to flow downstream across the renal artery ostia, and (c) in an overall cooperating system that allows for Seldinger femoral artery access. Each one of these features (a), (b), or (c), or any sub-combination thereof, would provide significant value to patient treatment; a local renal delivery system providing for the combination of all three features is so much the more valuable.
Notwithstanding the clear needs for and benefits that would be gained from such local drug delivery into the renal system, the ability to do so presents unique challenges as follows.
In one regard, the renal arteries extend from respective ostia along the abdominal aorta that are significantly spaced apart from each other circumferentially around the relatively very large aorta. Often, these renal artery ostia are also spaced from each other longitudinally along the aorta with relative superior and inferior locations. This presents a unique challenge to locally deliver drugs or other agents into the renal system on the whole, which requires both kidneys to be fed through these separate respective arteries via their uniquely positioned and substantially spaced apart ostia. This becomes particularly important where both kidneys may be equally at risk, or are equally compromised, during an invasive upstream procedure—or, of course, for any other indication where both kidneys require local drug delivery. Thus, an appropriate local renal delivery system for such indications would preferably be adapted to feed multiple renal arteries perfusing both kidneys.
In another regard, mere local delivery of an agent into the natural, physiologic blood flow path of the aorta upstream of the kidneys may provide some beneficial, localized renal delivery versus other systemic delivery methods, but various undesirable results still arise. In particular, the high flow aorta immediately washes much of the delivered agent beyond the intended renal artery ostia. This reduces the amount of agent actually perfusing the renal arteries with reduced efficacy, and thus also produces unwanted loss of the agent into other organs and tissues in the systemic circulation (with highest concentrations directly flowing into downstream circulation).
In still a further regard, various known types of tubular local delivery catheters, such as angiographic catheters, other “end-hole” catheters, or otherwise, may be positioned with their distal agent perfusion ports located within the renal arteries themselves for delivering agents there, such as via a percutaneous translumenal procedure via the femoral arteries (or from other access points such as brachial arteries, etc.). However, such a technique may also provide less than completely desirable results.
For example, such seating of the delivery catheter distal tip within a renal artery may be difficult to achieve from within the large diameter/high flow aorta, and may produce harmful intimal injury within the artery. Also, where multiple kidneys must be infused with agent, multiple renal arteries must be cannulated, either sequentially with a single delivery device, or simultaneously with multiple devices. This can become unnecessarily complicated and time consuming and further compound the risk of unwanted injury from the required catheter manipulation. Moreover, multiple dye injections may be required in order to locate the renal ostia for such catheter positioning, increasing the risks associated with contrast agents on kidney function (e.g. RCN)—the very organ system to be protected by the agent delivery system in the first place. Still further, the renal arteries themselves, possibly including their ostia, may have pre-existing conditions that either prevent the ability to provide the required catheter seating, or that increase the risks associated with such mechanical intrusion. For example, the artery wall may be diseased or stenotic, such as due to atherosclerotic plaque, clot, dissection, or other injury or condition. Finally, among other additional considerations, previous disclosures have yet to describe an efficacious and safe system and method for positioning these types of local agent delivery devices at the renal arteries through a common introducer or guide sheath shared with additional medical devices used for upstream interventions, such as angiography or guide catheters. In particular, to do so concurrently with multiple delivery catheters for simultaneous infusion of multiple renal arteries would further require a guide sheath of such significant dimensions that the preferred Seldinger vascular access technique would likely not be available, instead requiring the less desirable “cut-down” technique.
In addition to the various needs for locally delivering agents into branch arteries described above, much benefit may also be gained from simply locally enhancing blood perfusion into such branches, such as by increasing the blood pressure at their ostia. In particular, such enhancement would improve a number of medical conditions related to insufficient physiological perfusion into branch vessels, and in particular from an aorta and into its branch vessels such as the renal arteries.
Certain prior disclosures have provided surgical device assemblies and methods intended to enhance blood delivery into branch arteries extending from an aorta. For example, intra-aortic balloon pumps (IABPs) have been disclosed for use in diverting blood flow into certain branch arteries. One such technique involves placing an IABP in the abdominal aorta so that the balloon is situated slightly below (proximal to) the branch arteries. The balloon is selectively inflated and deflated in a counterpulsation mode (by reference to the physiologic pressure cycle) so that increased pressure distal to the balloon directs a greater portion of blood flow into principally the branch arteries in the region of their ostia. However, the flow to lower extremities downstream from such balloon system can be severely occluded during portions of this counterpulsing cycle. Moreover, such previously disclosed systems generally lack the ability to deliver drug or agent to the branch arteries while allowing continuous and substantial downstream perfusion sufficient to prevent unwanted ischemia.
It is further noted that, despite the renal risks described in relation to radiocontrast dye delivery, and in particular RCN, in certain circumstances local delivery of such dye or other diagnostic agents is indicated specifically for diagnosing the renal arteries themselves. For example, diagnosis and treatment of renal stenosis, such as due to atherosclerosis or dissection, may require dye injection into a subject renal artery. In such circumstances, enhancing the localization of the dye into the renal arteries may also be desirable. In one regard, without such localization larger volumes of dye may be required, and the dye lost into the downstream aortic flow may still be additive to impacting the kidney(s) as it circulates back there through the system. In another regard, an ability to locally deliver such dye into the renal artery from within the artery itself, such as by seating an angiography catheter there, may also be hindered by the same stenotic condition requiring the dye injection in the first place (as introduced above). Still further, patients may have stent-grafts that may prevent delivery catheter seating.
Notwithstanding the interest and advances toward locally delivering agents for treatment or diagnosis of organs or tissues, the previously disclosed systems and methods summarized immediately above generally lack the ability to effectively deliver agents from within a main artery and locally into substantially only branch arteries extending therefrom while allowing the passage of substantial blood flow and/or other medical devices through the main artery past the branches. This is in particular the case with previously disclosed renal treatment and diagnostic devices and methods, which do not adequately provide for local delivery of agents into the renal system from a location within the aorta while allowing substantial blood flow continuously downstream past the renal ostia and/or while allowing distal medical device assemblies to be passed retrogradedly across the renal ostia for upstream use. Much benefit would be gained if agents, such as protective or therapeutic drugs or radiopaque contrast dye, could be delivered to one or both of the renal arteries in such a manner.
Several more recently disclosed advances have included local flow assemblies using tubular members of varied diameters that divide flow within an aorta adjacent to renal artery ostia into outer and inner flow paths substantially perfusing the renal artery ostia and downstream circulation, respectively. Such disclosures further include delivering fluid agent primarily into the outer flow path for substantially localized delivery into the renal artery ostia. These disclosed systems and methods represent exciting new developments toward localized diagnosis and treatment of pre-existing conditions associated with branch vessels from main vessels in general, and with respect to renal arteries extending from abdominal aortas in particular.
However, such previously disclosed designs would still benefit from further modifications and improvements in order to: maximize mixing of a fluid agent within the entire circumference of the exterior flow path surrounding the tubular flow divider and perfusing multiple renal artery ostia; use the systems and methods for prophylaxis and protection of the renal system from harm, in particular during upstream interventional procedures; maximize the range of useful sizing for specific devices to accommodate a wide range of anatomic dimensions between patients; and optimize the construction, design, and inter-cooperation between system components for efficient, atraumatic use.
A need still exists for improved devices and methods for diverting blood flow principally into the renal arteries of a patient from a location within the patient's aorta adjacent the renal artery ostia along the aorta wall while at least a portion of aortic blood flow is allowed to perfuse downstream across the location of the renal artery ostia and into the patient's lower extremities.
A need still exists for improved devices and methods for substantially isolating first and second portions of aortic blood flow at a location within the aorta of a patient adjacent the renal artery ostia along the aorta wall, and directing the first portion into the renal arteries from the location within the aorta while allowing the second portion to flow across the location and downstream of the renal artery ostia into the patient's lower extremities. There is a further benefit and need for providing passive blood flow along the isolated paths and without providing active in-situ mechanical flow support to either or both of the first or second portions of aortic blood flow. Moreover, there is a further need to direct the first portion of blood along the first flow path in a manner that increases the pressure at the renal artery ostia.
A need still exists for improved devices and methods for delivering agents such as radiopaque dye or drugs into a renal artery from a location within the aorta of a patient adjacent the renal artery's ostium along the aorta wall, and without requiring translumenal positioning of an agent delivery device within the renal artery itself or its ostium.
A need still exists for improved devices and methods for locally isolating delivery of fluids or agents such as radiopaque dye or drugs simultaneously into multiple renal arteries feeding both kidneys of a patient using a single delivery device and without requiring translumenal positioning of multiple agent delivery devices respectively within the multiple renal arteries themselves.
A need still exists for improved devices and methods for locally isolating delivery of fluids or agents into the renal arteries of a patient from a location within the patient's aorta adjacent the renal artery ostia along the aorta wall, and while allowing other treatment or diagnostic devices and systems, such as angiographic or guiding catheter devices and related systems, to be delivered across the location.
A need still exists for improved devices and methods for locally delivering fluids or agents into the renal arteries from a location within the aorta of a patient adjacent to the renal artery ostia along the aorta wall, and other than as a remedial measure to treat pre-existing renal conditions, and in particular for prophylaxis or diagnostic procedures related to the kidneys.
A need still exists for improved devices and methods for locally isolating delivery of fluids or agents into the renal arteries of a patient in order to treat, protect, or diagnose the renal system adjunctive to performing other contemporaneous medical procedures such as angiograms other translumenal procedures upstream of the renal artery ostia.
A need still exists for improved devices and methods for delivering both a flow diverter system and at least one adjunctive distal interventional device, such as an angiographic or guiding catheter, through a common delivery sheath.
A need also still exists for improved devices and methods for delivering both a flow diverter system and at least one adjunctive distal interventional device, such as an angiographic or guiding catheter, through a single access site, such as a single femoral arterial puncture.
A need also still exists for improved devices and methods for treating, and in particular preventing, ARF, and in particular relation to RCN or CHF, by locally delivering renal protective or ameliorative drugs into the renal arteries, such as contemporaneous with radiocontrast injections such as during angiography procedures.
In addition to these particular needs for diverting blood flow into a patient's renal arteries via their ostia along the aorta, other similar needs also exist for diverting blood flow into other branch vessels or lumens extending from other main vessels or lumens, respectively, in a patient.
In general, various of the aspects of the invention described immediately below provide a local renal infusion system for treating a renal system in a patient from a location within the abdominal aorta associated with abdominal aortic blood flow into first and second renal arteries via respective first and second renal ostia having unique relative locations along the abdominal aorta wall. Moreover, such a system is generally provided with a local injection assembly and a flow isolation assembly.
According to one such aspect, the system includes a local injection assembly is provided in combination with a flow isolation assembly with a tubular wall having a longitudinal axis between a first end and a second end. The flow isolation assembly is adapted to be delivered to the location in a first condition with the tubular wall in a first configuration with a first diameter transverse to the longitudinal axis, and such that the first end is located upstream of the renal ostia and the second end is located downstream of the first end. The flow isolation assembly at the location is adjustable from the first condition to a second condition with the tubular wall in a second configuration as follows. The tubular wall in the second configuration has a second diameter that is greater than the first diameter and that is substantially constant between the first and second ends. According to this arrangement, a first region of abdominal aortic flow within an exterior flow path between the wall and the abdominal aortic wall is substantially isolated from a second region of abdominal aortic flow located within an interior flow path within the tubular wall, and the first and second regions of abdominal aortic blood flow are not substantially diverted by the tubular shaped wall. The local injection assembly is adapted to be fluidly coupled to a source of fluid agent located externally of the patient and to inject a volume of fluid agent from the source and into the first region between the abdominal aortic wall and the tubular wall in the second configuration at the location.
Another such aspect provides a local injection assembly in combination with a flow isolation assembly with a tubular wall having a longitudinal axis extending between a first end and a second end and also with a support member that is substantially ring-shaped and that is coupled to the tubular wall at one of the first and second ends. The flow isolation assembly is adapted to be delivered to the location in a first condition with the tubular wall in a first configuration and with the support member in a radially collapsed condition with a collapsed diameter transverse to the longitudinal axis, and further such that the first end is located upstream of the renal ostia and the second end is located downstream of the first end. At this location, the flow isolation assembly at the location is adjustable from the first condition to a second condition with the tubular wall in a second configuration and the support member in a radially extended condition with an extended diameter that is greater than the collapsed diameter. The support member in the radially extended condition supports the tubular wall at least in part in the second configuration with a tubular shape that is radially expanded relative to the first configuration with respect to the longitudinal axis. Accordingly, the assembly is adapted such that a first region of abdominal aortic flow within an exterior flow path between the tubular wall and the abdominal aortic wall is substantially isolated from a second region of abdominal aortic flow located within an interior flow path within the tubular wall. Of substantial benefit, the support member is constructed from a superelastic metallic wire with two opposite ends and a curved region between the two opposite ends that forms a substantially looped shape around a circumferential path. The wire has a memory shape with the two opposite ends at first and second memory positions relative to each other with respect to the circumferential path such that the curved region has a memory diameter that is less than the extended diameter. The wire in the flow isolation assembly is secured relative to the tubular member in a superelastically deformed condition with the two opposite ends at first and second displaced positions relative to each other such that the support member in the second configuration and with the extended diameter comprises a superelastically deformed condition for the wire. The local injection assembly is adapted to be fluidly coupled to a source of fluid agent located externally of the patient and to inject a volume of fluid agent from the source and into the first region with the flow isolation assembly in the second condition at the location.
Another aspect includes a local injection assembly in combination with a flow isolation assembly with a tubular wall having a longitudinal axis between a first end and a second end as follows. A retraction member is also provided in the system with a proximal end portion and a distal end portion that is coupled to the flow isolation assembly. The flow isolation assembly is adapted to be delivered to the location in a first condition with the tubular wall in a first configuration with a first diameter transverse to the longitudinal axis, and such that the first end is located upstream of the renal ostia and the second end is located downstream of the first end. The flow isolation assembly at the location is adjustable from the first condition to a second condition with the tubular wall in a second configuration. The tubular wall in the second configuration comprises a second diameter that is greater than the first diameter such that a first region of abdominal aortic flow within an exterior flow path between the tubular wall and the abdominal aortic wall is substantially isolated from a second region of abdominal aortic flow along an interior flow path within the tubular wall. Accordingly, the retraction member is adapted to adjust the tubular wall from the second configuration to a third configuration by proximal withdrawal of the proximal end portion of the retraction member externally of the patient. In this third configuration the tubular wall is partially retracted and has a third diameter that is less than the second diameter but greater than the first diameter. In addition, the local injection assembly is adapted to couple to a source of fluid agent located externally of the patient and to inject a volume of fluid agent from the source and into the first region with the flow isolation assembly in the second condition.
Another aspect also includes a local injection assembly with a flow isolation assembly with a tubular wall, an inflatable member, and an expandable member. The tubular wall has a first end, a second end, an outer surface, and an inner surface that defines a longitudinal passageway that extends along a longitudinal axis between the first and second ends. The inflatable member is located within the longitudinal passageway of the tubular wall and is adjustable between a deflated condition with a deflated diameter and an inflated condition with an inflated diameter that is greater than the deflated diameter. The tubular wall is adjustable, by inflating the inflatable member from the deflated condition to the inflated condition, from a first configuration with the longitudinal passageway having a first inner diameter transverse to the longitudinal axis to a second configuration with the longitudinal passageway having a second inner diameter that is greater than the first inner diameter. The inflatable member in the inflated condition does not completely occlude the longitudinal passageway of the tubular wall in the second configuration such that at least one flow passageway extends along the longitudinal passageway between the first and second ends. In addition, the expandable member is located on the outer surface of the tubular member and is adjustable between a radially collapsed condition relative to the outer surface and a radially expanded condition that is expanded from the outer surface of the tubular member relative to the radially collapsed condition. Also, the flow isolation assembly is adapted to be delivered to the location in a first condition that is characterized by the inflatable member in the deflated condition, the tubular wall in the first configuration, and the expandable member in the radially collapsed condition, and such that the first end is located upstream of the renal ostia and the second end is located downstream of the first end. The flow isolation assembly at the location is adjustable from the first condition to a second condition that is characterized by the inflatable member in the inflated condition, the tubular wall in the second configuration, the expandable member in the radially expanded condition. In the second condition at the location, the flow isolation assembly is adapted to substantially isolate a first region of abdominal aortic blood flow externally around the tubular member from a second region of abdominal aortic blood flow internally within the tubular member along the at least one flow passageway. The local injection assembly is adapted to couple to a source of fluid agent located externally of the patient and to inject a volume of fluid agent from the source and into the first region when the flow isolation assembly is in the second condition at the location.
Another aspect includes a delivery member with an elongate body with a proximal end portion and a distal end portion with a longitudinal axis and a circumference, and a bilateral local renal delivery assembly comprising a local injection assembly and a flow isolation assembly. The local injection assembly has a plurality of arms that are spaced circumferentially around the distal end portion. Each arm extends along the longitudinal axis between a proximal position and a distal position. The local injection assembly further includes a plurality of injection ports located along the plurality of arms, respectively, between the respective proximal and distal positions. The flow isolation assembly includes a wall assembly coupled to the plurality of arms. Accordingly, the bilateral local renal delivery assembly is adapted to be delivered with the distal end portion to the location in a first condition with the plurality of arms and wall assembly in a radially collapsed condition relative to the elongate body with the proximal end portion extending externally of the patient. The bilateral local renal delivery assembly is thus adjustable at the location from the first condition to a second condition wherein the plurality of arms and wall assembly are in a radially extended condition that is extended from the elongate body relative to the radially collapsed condition. In the second condition the arms and wall assembly form an expanded tubular wall that substantially isolates a first region of abdominal aortic blood flow along an exterior flow path between the tubular wall and the abdominal aortic wall from a second region of abdominal aortic blood flow along an interior flow path extending within the tubular wall between the proximal and distal positions, respectively. Also in the second condition at the location, the plurality of injection ports are fluidly coupled to the first region and are adapted to be fluidly coupled to a source of fluid agent located externally of the patient. The injection ports are adapted to inject a volume of fluid agent from the source and into the first region such that the injected volume flows substantially into the first and second renal arteries via the respective first and second renal ostia.
Another aspect provides a local injection assembly in combination with a flow isolation assembly with a wall that has a first portion and a second portion with a vent. The local injection assembly is adapted to be delivered to the location and to be fluidly coupled to a source of fluid agent located externally of the patient. In a first condition for the flow isolation assembly the wall is in a first configuration and is adapted to be delivered to the location. At the location, the flow isolation assembly is adjustable from the first condition to the second condition. In the second condition at the location, the first portion of the wall is adapted to isolate a first region from a second region of abdominal aortic blood flow at the location. The local injection assembly is adapted to cooperate with the flow isolation assembly so as to inject a volume of fluid agent from the source and into the first region at the location with the flow isolation assembly in the second condition at the location. Furthermore, the vent is adapted to allow the first region to communicate with the second region along the second portion.
Another aspect provides a local injection assembly in combination with a flow isolation assembly with a wall having a first end and a second end. The flow isolation assembly has a first condition with the wall in a first configuration and such that the flow isolation assembly is adapted to be delivered to the location with the first end located upstream of the renal ostia and with the second end located downstream of the first end. The flow isolation assembly at the location is adjustable from the first condition to a second condition wherein the wall is in a second configuration that is angled relative to a longitudinal axis of the abdominal aorta such that the first end is closer to a portion of the abdominal aorta wall than the second end and such that a first region of abdominal aortic blood flow between the wall and the portion is substantially isolated from a second region of abdominal aortic blood flow opposite the first region relative to the wall. The local injection assembly is adapted to couple to a source of fluid agent located externally of the patient and to inject a volume of fluid agent from the source and into the first region with the flow isolation assembly in the second condition at the location.
Another aspect is a local injection assembly in combination with a flow isolation assembly that is adjustable between a first condition and a second condition. The flow isolation assembly in the first condition is adapted to be delivered to the location. The flow isolation assembly at the location is adjustable from the first condition to the second condition. The flow isolation assembly in the second condition at the location is adapted to isolate fluid communication between a first region and a second region of abdominal aortic blood flow. The local injection assembly is adapted to couple to a source of fluid agent located externally of the patient and to inject a volume of fluid agent from the source and into the first region with the flow isolation assembly in the second condition at the location. Further to this aspect, the first region does not include a portion of an outer region of the abdominal aortic blood flow along the abdominal aortic wall.
Another aspect provides a local injection assembly with first and second injection ports in combination with a flow isolation assembly. The flow isolation assembly is adjustable between a first condition and a second condition as follows. In the first condition, the flow isolation assembly is adapted to be delivered to the location. The flow isolation assembly at the location is adjustable from the first condition to the second condition that is adapted to isolate fluid communication between a first region and a second region of abdominal aortic blood flow. The first and second injection ports are adapted to be delivered to first and second positions that are fluidly coupled with the first region when the flow isolation assembly is in the second condition at the location. The first and second injection ports at the first and second positions are adapted to be fluidly coupled to a source of fluid agent located externally of the patient and to simultaneously inject a volume of fluid agent from the source and into the first region such that the injected volume of fluid agent flows substantially into the first and second renal arteries, respectively, via the respective first and second renal ostia.
Another aspect provides a delivery member with an elongate body having a proximal end portion and a distal end portion and also a delivery lumen extending along a longitudinal axis between a proximal port along the proximal end portion and a distal port along the distal end portion, and also provides a local injection assembly that is adjustable between a first configuration and a second configuration The delivery lumen has a proximal portion with a first inner diameter along the proximal end portion, and has a distal portion with a second diameter that is greater than the first diameter along the distal end portion. The local injection assembly in the first configuration is located within the distal portion of the delivery lumen; wherein the distal end portion is adapted to be positioned with the local injection assembly in the first configuration at the location while the proximal end portion extends externally from the patient. The local injection assembly at the location is adapted to be fluidly coupled to a source of fluid agent located externally of the patient. The local injection assembly is adjustable at the location from the first configuration to the second configuration that is extended distally from the distal portion of the delivery lumen through the distal port and into the abdominal aorta at the location. Moreover, the local injection assembly in the second configuration at the location is adapted to inject a volume of fluid agent from the source and substantially into the first and second renal arteries.
Another aspect of the invention is a proximal coupler assembly for concurrent use with a bilateral local renal delivery device and percutaneous translumenal interventional device. This is of particular benefit where the bilateral local renal delivery device comprises an elongate body with a proximal end portion and a distal end portion and a local injection assembly located along the distal end portion. The system according to this aspect includes a housing with a distal end and a proximal end. The distal end includes a distal coupler that is adapted to be coupled to an introducer sheath that provides percutaneous translumenal access into a vasculature of a patient that leads to a location within an abdominal aorta associated with renal artery ostia. The proximal end comprises an adjustable hemostatic coupler that is adapted to simultaneously receive the bilateral local renal delivery device and the percutaneous translumenal device into the housing and is substantially aligned along a longitudinal axis with the distal end of the housing. Also included in this system are means for securing the proximal end portion of the bilateral local renal delivery device off-axis relative to the longitudinal axis so as to reduce interference between the percutaneous translumenal interventional device and the bilateral local renal delivery device when the percutaneous translumenal interventional device is manipulated within the hemostatic valve.
Another aspect of the invention is a method for treating a renal system in a patient from a location within the abdominal aorta associated with abdominal aortic blood flow into each of first and second renal arteries via first and second renal ostia, respectively, at unique respective locations along the abdominal aorta wall.
One such method includes positioning a local injection assembly at the location; fluidly coupling to the local injection assembly at the location to a source of fluid agent externally of the patient; and injecting a volume of fluid agent from the source and into the abdominal aorta at the location in a manner such that the injected fluid flows principally into the first and second renal arteries via the first and second renal ostia, respectively, and without substantially occluding or isolating a substantial portion of an outer region of aortic blood flow along a circumference of the abdominal aorta wall and across the location.
Another method aspect includes delivering a flow isolation assembly with a tubular wall having a longitudinal axis between a first end and a second end to the location in a first condition with the tubular wall in a first configuration with a first diameter transverse to the longitudinal axis, and such that the first end is located upstream of the renal ostia and the second end is located downstream of the first end. Also included is adjusting the flow isolation assembly at the location from the first condition to a second condition with the tubular wall in a second configuration that comprises a second diameter that is greater than the first diameter and that is substantially constant between the first and second ends such that a first region of abdominal aortic flow within an exterior flow path between the wall and the abdominal aortic wall is substantially isolated from a second region of abdominal aortic flow located within an interior flow path within the tubular shaped wall, and further such that the first and second regions of abdominal aortic blood flow are not substantially diverted by the tubular shaped wall. Further includes is fluidly coupling a local injection assembly to a source of fluid agent located externally of the patient. Also included is injecting a volume of fluid agent from the source and into the first region between the abdominal aortic wall and the tubular wall in the second configuration at the location.
Another method aspect includes delivering a flow isolation assembly with a tubular wall to the location in a first condition with the tubular wall in a first configuration and with a support member in a radially collapsed condition with a collapsed diameter transverse to a longitudinal axis of the tubular wall, and such that a first end of the tubular wall is located upstream of the renal ostia and a second end of the tubular wall is located downstream of the first end. Another step of this aspect includes adjusting the flow isolation assembly at the location from the first condition to a second condition with the tubular wall in a second configuration and the support member in a radially extended condition with an extended diameter that is greater than the collapsed diameter. Still a further step includes: supporting the tubular wall in the second configuration with the support member in the radially extended condition such that the tubular wall has a tubular shape that is radially expanded relative to the first configuration with respect to the longitudinal axis, and such that a first region of abdominal aortic flow within an exterior flow path between the tubular wall and the abdominal aortic wall is substantially isolated from a second region of abdominal aortic flow located within an interior flow path within the tubular wall. This method is of particular benefit wherein the support member includes a superelastic metallic wire with two opposite ends and a curved region between the two opposite ends that forms a substantially looped shape around a circumferential path, and the support member in the second configuration and with the extended diameter includes a superelastically deformed condition for the wire. Another step includes fluidly coupling the local injection assembly to a source of fluid agent located externally of the patient. A further step is: injecting a volume of fluid agent with the local injection assembly from the source and into the first region with the flow isolation assembly in the second condition at the location.
Another aspect of the invention includes a method for treating a renal system in a patient from a location within the abdominal aorta associated with abdominal aortic blood flow into first and second renal arteries via respective first and second renal ostia having unique relative locations along the abdominal aorta wall. This further method includes: providing a local injection assembly and a flow isolation assembly with a tubular wall having a longitudinal axis between a first end and a second end. Also included is using a retraction member with a proximal end portion and a distal end portion that is coupled to the flow isolation assembly to control the flow isolation assembly. This method further includes delivering a flow isolation assembly to the location in a first condition with a tubular wall in a first configuration with a first diameter transverse to a longitudinal axis within the tubular wall, and such that a first end of the tubular wall is located upstream of the renal ostia and a second end of the tubular wall is located downstream of the first end. Also included is adjusting the flow isolation assembly at the location from the first condition to a second condition with the tubular wall in a second configuration that comprises a second diameter that is greater than the first diameter such that a first region of abdominal aortic flow within an exterior flow path between the tubular wall and the abdominal aortic wall is substantially isolated from a second region of abdominal aortic flow along an interior flow path within the tubular shaped wall. A further step is adjusting the tubular wall from the second configuration to a third configuration by proximal withdrawal of a proximal end portion of a retraction member externally of the patient, wherein a distal end portion of the retraction member is coupled to the tubular wall, and such that in the third configuration the tubular wall is partially retracted and has a third diameter that is less than the second diameter but greater than the first diameter. Still further is coupling a local injection assembly to a source of fluid agent located externally of the patient, and injecting a volume of fluid agent with the local injection assembly from the source and into the first region with the flow isolation assembly in the second condition.
Another method aspect includes as a step: delivering a flow isolation assembly to the location in a first condition that is characterized by an inflatable member within a longitudinal passageway of a tubular wall in a deflated condition with a deflated diameter, the tubular wall in a first configuration, and an expandable member on an outer surface of the tubular wall in a radially collapsed condition, and such that a first end of the tubular wall is located upstream of the renal ostia and a second end of the tubular wall is located downstream of the first end. Also included is the following step: adjusting the flow isolation assembly at the location from the first condition to a second condition by inflating the inflatable member to an inflated condition with an inflated diameter that is greater than the deflated diameter and that expands the tubular wall such that the longitudinal passageway has a second inner diameter that is greater than the first inner diameter, and also by expanding the expandable member to a radially expanded condition that is expanded from the outer surface of the tubular member relative to the radially collapsed condition, and further such that the inflatable member in the inflated condition does not completely occlude the longitudinal passageway of the tubular wall in the second configuration so as to provide at least one flow passageway extending along the longitudinal passageway between the first and second ends. Still a further step includes substantially isolating a first region of abdominal aortic blood flow externally around the tubular member from a second region of abdominal aortic blood flow internally within the tubular member along the at least one flow passageway with the flow isolation assembly in the second condition at the location. Another step is: coupling a local injection assembly to a source of fluid agent located externally of the patient; and injecting a volume of fluid agent with the local injection assembly from the source and into the first region when the flow isolation assembly is in the second condition at the location.
Another method aspect includes providing a delivery member with an elongate body with a proximal end portion and a distal end portion with a longitudinal axis and a circumference; providing a bilateral local renal delivery assembly with a local injection assembly and a flow isolation assembly, wherein the local injection assembly comprises a plurality of arms that are spaced circumferentially around the distal end portion, wherein each arm extends along the longitudinal axis between a proximal position and a distal position, wherein the local injection assembly further comprises a plurality of injection ports located along the plurality of arms, respectively, between the respective proximal and distal positions, and wherein the flow isolation assembly comprises a wall assembly coupled to the plurality of arms; delivering the bilateral local renal delivery assembly with the distal end portion of the elongate body of the delivery member to the location in a first condition with a plurality of arms and wall assembly in a radially collapsed condition relative to the elongate body while a proximal end portion of the elongate body extends externally of the patient; adjusting the bilateral local renal delivery assembly at the location from the first condition to a second condition wherein the plurality of arms and wall assembly are in a radially extended condition that is extended from the elongate body relative to the radially collapsed condition; forming an expanded tubular wall with the arms and wall assembly in the second condition; substantially isolating a first region of abdominal aortic blood flow along an exterior flow path between the tubular wall and the abdominal aortic wall, and a second region of abdominal aortic blood flow along an interior flow path extending within the tubular wall between proximal and distal ports adjacent to and located between the proximal and distal positions, respectively, with the expanded tubular wall at the location. According to another step in the second condition at the location, fluidly coupling the plurality of injection ports to the first region and also to a source of fluid agent located externally of the patient. Further included is injecting a volume of the fluid agent with the injection ports from the source and into the first region such that the injected volume flows substantially into the first and second renal arteries via the respective first and second renal ostia.
Another method aspect includes delivering a flow isolation assembly in a first condition with a wall in a first configuration to the location; fluidly coupling the local injection assembly at the location to a source of fluid agent located externally of the patient; adjusting the flow isolation assembly at the location from the first condition to a second condition wherein a first portion of the wall is adapted to isolate a first region from a second region of abdominal aortic blood flow at the location; injecting a volume of fluid agent with a local injection assembly from the source and into the first region at the location with the flow isolation assembly in the second condition at the location; and allowing the first region to communicate with the second region through a vent located along a second portion of the wall.
Another method aspect includes delivering a flow isolation assembly in a first condition to the location with a wall in a first configuration and a first end of the wall located upstream of the renal ostia and a second end of the wall located downstream of the first end; adjusting the flow isolation assembly at the location from the first condition to a second condition with the wall in a second configuration that is angled relative to a longitudinal axis of the abdominal aorta such that the upstream end is closer to a portion of the abdominal aorta wall than the downstream end and such that a first region of abdominal aortic blood flow between the wall and the portion is substantially isolated from a second region of abdominal aortic blood flow opposite the first region relative to the wall; coupling a local injection assembly to a source of fluid agent located externally of the patient; and injecting a volume of fluid agent with the local injection assembly from the source and into the first region while the flow isolation assembly is in the second condition at the location.
Another method aspect includes delivering a flow isolation assembly in a first condition to the location; adjusting the flow isolation assembly at the location from the first condition to a second condition wherein the flow isolation assembly is adapted to isolate fluid communication between a first region and a second region of abdominal aortic blood flow and wherein the first region does not include a portion of an outer region of the abdominal aortic blood flow along the abdominal aortic wall; coupling the local injection assembly to a source of fluid agent located externally of the patient; and injecting a volume of fluid agent from the source and into the first region while the flow isolation assembly is in the second condition at the location.
Another method aspect includes delivering a flow isolation assembly in a first condition to the location; adjusting the flow isolation assembly at the location from the first condition to a second condition that is adapted to isolate fluid communication between a first region and a second region of abdominal aortic blood flow; delivering first and second injection ports of a local injection assembly to first and second positions that are fluidly coupled with the first region when the flow isolation assembly is in the second condition at the location; fluidly coupling the first and second injection ports at the first and second positions to a source of fluid agent located externally of the patient; and simultaneously injecting a volume of fluid agent from the source and into the first region such that the injected volume of fluid agent flows substantially into the first and second renal arteries, respectively, via the respective first and second renal ostia.
Another method aspect includes providing a delivery member with an elongate body having a proximal end portion and a distal end portion and also a delivery lumen extending along a longitudinal axis between a proximal port along the proximal end portion and a distal port along the distal end portion; providing a local injection assembly that is adjustable between a first configuration and a second configuration. The delivery lumen has a proximal portion with a first inner diameter along the proximal end portion, and has a distal portion with a second diameter that is greater than the first diameter along the distal end portion. Another step is positioning a local injection assembly in the first configuration within the distal portion of the delivery lumen. Still another is delivering the distal end portion with the local injection assembly in the first configuration at the location while the proximal end portion extends externally from the patient. A further step includes fluidly coupling the local injection assembly at the location to a source of fluid agent located externally of the patient; adjusting the local injection assembly at the location from the first configuration to a second configuration that is extended distally from the distal portion of the delivery lumen through the distal port and into the abdominal aorta at the location; and injecting a volume of fluid agent from the source and substantially into the first and second renal arteries with the local injection assembly in the second configuration at the location.
Further aspects of the invention will be brought out in the following portions of the specification, wherein the detailed description is for the purpose of fully disclosing preferred embodiments of the invention without placing limitations thereon.
The invention will be more fully understood by reference to the following drawings which are for illustrative purposes only:
The description herein provided relates to medical methods to divert blood flow from a major blood vessel into one or more branch vessels.
For the purpose of providing a clear understanding, the term proximal should be understood to mean locations on a system or device relatively closer to the operator during use, and the term distal should be understood to mean locations relatively further away from the operator during use of a system or device.
These present embodiments below therefore generally relate to treatment at the renal arteries, generally from the aorta. However, it is contemplated that these systems and methods may be suitably modified for use in other anatomical regions and for other medical conditions without departing from the broad scope of various of the aspects illustrated by the embodiments.
As will be appreciated by reference to the detailed description below and in further respect to the Figures, the present invention is principally related to selective aortic flow diverter systems and methods, which are thus related to subject matter disclosed in the following prior filed, co-pending U.S. patent applications that are commonly owned with the present application: Ser. No. 09/229,390 to Keren et al., filed Jan. 11, 1999; Ser. No. 09/562,493 to Keren et al., filed May 1, 2000; and Ser. No. 09/724,691 to Kesten et al., filed Nov. 28, 2000. The disclosures of these prior patent applications are herein incorporated in their entirety by reference thereto.
The invention is also related to certain subject matter disclosed in other Published International Patent Applications as follows: WO 00/41612 to Libra Medical Systems, published Jul. 20, 2000; and WO 01/83016 to Libra Medical Systems, published Nov. 8, 2001. The disclosures of these Published International Patent Applications are also herein incorporated in their entirety by reference thereto.
In general, the disclosed material delivery systems will include a flow diverter assembly, a proximal coupler assembly and one or more elongated bodies, such as wires, tubes or catheters. These elongated bodies may contain one or more lumens and generally consist of a proximal region, a mid-distal region, and a distal tip region. The distal tip region will typically have means for diverting blood flow from a major vessel, such as an aorta, to a branch vessel, such as a renal artery. The distal tip region may also have a device for delivering a material such as a fluid agent. Radiopaque markers or other devices may be coupled to the specific regions of the elongated body to assist introduction and positioning.
The flow diverter and/or the material delivery system is intended to be placed into position by a physician, typically either an interventionalist (cardiologist or radiologist) or an intensivist, a physician who specializes in the treatment of intensive-care patients. The physician will gain access to a femoral artery in the patient's groin, typically using a Seldinger technique of percutaneous vessel access or other conventional method.
In addition, various of the embodiments are illustrated as catheter implementations, and are further illustrated during in-vivo use. Other techniques for positioning the required flow diverter assemblies described may be used where appropriate, such as transthoracic or surgical placement that either use or don't use percutaneous translumenal catheter techniques. In addition, reference to the illustrative catheter embodiments thus portray specific proximal-distal relationships between the inter-cooperating components of a flow diverter in relation to blood flow and their relative orientations on a delivery catheter platform. For example, some embodiments illustrate or are otherwise described by reference to retrograde femoral approach to renal delivery, such that the distal end of the catheter including the aortic flow diverter is located upstream form the proximal end of the catheter. Other embodiments may show an opposite relative positioning, such as via an antegrade access to the site of renal arteries, e.g. from a brachial or radial arterial access procedure. However, it is to be further understood that such embodiments, though shown or described in relation to one such mode, may be appropriately modified by one of ordinary skill for use in the other orientation approach without departing from the intended scope.
In general, the flow stream 16 is of a higher velocity than flow stream 14 along the wall of aorta 10. It is to be understood that near the boundaries of flow stream 14 with flow stream 16, there can be flow streams into the branching renal arteries 12 as well as down the abdominal aorta 10.
Further, the ostia of renal arteries 12 are positioned to receive substantial blood flow from the blood flow near the posterior wall of aorta 10 as well as the side walls. In other words, blood flow 14 is greater than blood flow 16 when along the posterior wall of aorta 10 relative to blood flow in the center of aorta 10 as shown in
Accordingly, in order to maximize the flow of a drug solution into the renal arteries using the natural flow patterns shown in
In
In
In
In
In
In
The dimensions of catheter 310 are determined largely by the size of the blood vessel(s) through which the catheter must pass, and the size of the blood vessel in which the catheter is deployed. In a beneficial embodiment, the length of-the-tubular member 316 is about 50 to about 150 mm, preferably about 80 to about 120 mm. The tubular member 316 has an unexpanded outer diameter of the tubular member of about 1 mm to about 5 mm, preferably about 2 to about 4 mm, and a radially expanded outer diameter of about 40 mm to about 140 mm, preferably about 60 mm to about 120 mm. The radially expanded interior passageway 324 of the tubular member 316 is about 30 mm to about 130 mm, preferably about 50 mm to about 110 mm to provide sufficient perfusion. The interior passageway 324 of the tubular member 316 has a radially expanded inner diameter which is about 1000% to about 6000% larger than the unexpanded inner diameter of the passageway 324. The radially expandable member 318 has a length of about 10 mm to about 50 mm, preferably about 20 mm to about 40 mm. The expanded outer diameter of the radially expandable member 318 is about 10 mm to about 35 mm, preferably about 15 mm to about 30 mm. In this embodiment, the shaft 312 has an outer diameter of about 1 mm to about 5 mm. The inflation lumen 328 (shown in
These embodiments are illustrated schematically and the relationship of the elements may be combined in various combinations and specific modes by one of ordinary skill in the art. For example,
The radially expandable member 318 is expanded by directing inflation fluid into the inflation lumen 328. In the embodiment illustrated in
A variety of suitable imaging modalities may be used to position the catheter in the desired location in the blood vessel, such as fluoroscopy, or ultrasound. For example, radiopaque markers (not shown) on the shaft 312 may be used in positioning the balloon 318 and agent delivery port 334 at the desired location in the blood vessel 10.
A therapeutic or diagnostic agent (hereafter “agent”) is delivered to the renal arteries 10 by introducing the agent into the agent delivery lumen 332 in shaft 312, and out the agent delivery port 334. An agent delivery opening 338 in the tubular member 316 adjacent to the agent delivery port 334 provides a pathway for agent delivery from lumen 332 to external to the tubular member 312. The agent delivery port 334 is up-steam of the renal arteries 12 and proximal to the distal end of the tubular member 316. Thus, the outer blood flow stream 14 has a relatively high concentration of agent and the inner blood flow stream 16 has a relatively low concentration or no agent. Additionally, the balloon 318 in the expanded configuration restricts the flow of blood to decrease the blood flow exterior to the proximal portion of the tubular member 316 down-stream of the renal arteries 12 in comparison to the blood flow stream exterior to the distal portion of the tubular member 316 up-stream of the renal arteries 12. As a result, a relatively large amount of the agent delivered from the agent delivery port 334 is directed into the renal arteries 12, in comparison to the amount of agent which flows down-stream of the renal arteries 12 in the aorta 10. In one embodiment, the outer blood flow stream 14 is substantial.
In one embodiment, the cross-sectional area of the inner lumen 324 of the tubular member 316 is about 4% to about 64% of the blood vessel 10 (i.e., aorta) cross-sectional area, or about 4 mm to about 16 mm for a blood vessel 10 having a 20 mm inner diameter. It should be noted that in some embodiments, the cross-sectional area of the wall of the tubular member 316 is not insignificant in relation to the cross-sectional area of the blood vessel 10. In the embodiment illustrated in
Additionally, the aorta has multiple branch vessels in addition to the renal arteries which effect the total flow in the aorta at a given location therein. Thus, a percentage of the blood flow that enters the abdominal aorta, i.e., past the diaphragm, is delivered in the normal rest state of circulation to the celiac trunk, the superior and inferior mesenteric arteries, and the renal arteries. Nonetheless, the flow segmentation created by the presence of the deployed catheter 310 is such that the blood flow in the outer blood flow stream 14 of a patient at rest is about 10% to about 90% of the total blood flow immediately up-stream of the up-stream or distal most end of the tubular member 316, i.e., of the total blood flow present in the section of the aorta 10 immediately adjacent to the renal arteries 12. Similarly, the blood flow in the inner blood flow stream 16 of a patient at rest is about 10% to about 90% of the total blood flow immediately up-stream of the up-stream or distal most end of the tubular member 316. The flow in the outer blood flow stream 14 is sufficient to provide adequate kidney function, although the flow required will vary depending upon factors such as the presence of drugs which increase flow or increase the ability of the tissue to withstand ischemic conditions.
While the renal arteries 12 are illustrated directly across from one another in
In the embodiment illustrated in
In another embodiment of a tubular member 373, illustrated in
In the inflated configuration, shown in
In
Vessel dilator 954, with distal end 980 and proximal end 982 is a polymer, e.g. extrusion tubing with a center lumen for a guide wire (not shown). Distal end 980 is adapted with a taper cone shape. Proximal end 982 is coupled to a Luer fitting 984.
Fluid delivery system 956 has stiff tube 986, torque handle 988, and proximal hub 990 as previously described in
A single lumen, tear-away delivery sheath 1004 has a distal end 1006, a proximal end 1008, and slidingly encases stiff tube 986. delivery sheath 1004 is positioned between the torque handle 988 and the bifurcated catheter 956. The distal end 1006 has a shape and outer diameter adapted to mate with the channel restriction in the distal end of the main channel of the Y hub body as shown previously in
Dilator 954 is inserted through Touhy Borst valve 968 on secondary port 970 until distal end 980 protrudes from distal tip 978 of introducer sheath 976 to form a smooth outer conical shape. Distal tip 978 of introducer sheath 976 is positioned in the aorta system proximal of the renal arteries (not shown). Dilator 954 is removed and fluid delivery device 956 is prepared by sliding delivery sheath 1004 distally until aortic infusion assembly 958 is enclosed in delivery sheath 1004. Distal end 1006 of delivery sheath 1004 is inserted in Touhy Borst valve 968 and advanced to the restriction in the main channel of the Y hub body shown in
The various embodiments herein described for the present invention can be useful in treatments and therapies directed at the kidneys such as the prevention of radiocontrast nephropathy (RCN) from diagnostic treatments using iodinated contrast materials. As a prophylactic treatment method for patients undergoing interventional procedures that have been identified as being at elevated risk for developing RCN, a series of treatment schemes have been developed based upon local therapeutic agent delivery to the kidneys. Among the agents identified for such treatment are normal saline (NS) and the vasodilators papaverine (PAP) and fenoldopam mesylate (FM).
The approved use for fenoldopam is for the in-hospital intravenous treatment of hypertension when rapid, but quickly reversible, blood pressure lowering is needed. Fenoldopam causes dose-dependent renal vasodilation at systemic doses as low as approximately 0.01 mcg/kg/min through approximately 0.5 mcg/kg/min IV and it increases blood flow both to the renal cortex and to the renal medulla. Due to this physiology, fenoldopam may be utilized for protection of the kidneys from ischemic insults such as high-risk surgical procedures and contrast nephropathy. Dosing from approximately 0.01 to approximately 3.2 mcg/kg/min is considered suitable for most applications of the present embodiments, or about 0.005 to about 1.6 mcg/kg/min per renal artery (or per kidney). As before, it is likely beneficial in many instances to pick a starting dose and titrate up or down as required to determine a patient's maximum tolerated systemic dose. Recent data, however, suggest that about 0.2 mcg/kg/min of fenoldopam has greater efficacy than about 0.1 mcg/kg/min in preventing contrast nephropathy and this dose is preferred.
The dose level of normal saline delivered bilaterally to the renal arteries may be set empirically, or beneficially customized such that it is determined by titration. The catheter or infusion pump design may provide practical limitations to the amount of fluid that can be delivered; however, it would be desired to give as much as possible, and is contemplated that levels up to about 2 liters per hour (about 25 cc/kg/hr in an average about 180 lb patient) or about one liter or 12.5 cc/kg per hour per kidney may be beneficial.
Local dosing of papaverine of up to about 4 mg/min through the bilateral catheter, or up to about 2 mg/min has been demonstrated safety in animal studies, and local renal doses to the catheter of about 2 mg/min and about 3 mg/min have been shown to increase renal blood flow rates in human subjects, or about 1 mg/min to about 1.5 mg/min per artery or kidney. It is thus believed that local bilateral renal delivery of papaverine will help to reduce the risk of RCN in patients with pre-existing risk factors such as high baseline serum creatinine, diabetes mellitus, or other demonstration of compromised kidney function.
It is also contemplated according to further embodiments that a very low, systemic dose of papaverine may be given, either alone or in conjunction with other medical management such as for example saline loading, prior to the anticipated contrast insult. Such a dose may be on the order for example of between about 3 to about 14 mg/hr (based on bolus indications of approximately 10-40 mg about every 3 hours—papaverine is not generally dosed by weight). In an alternative embodiment, a dosing of 2-3 mg/min or 120-180 mg/hr. Again, in the context of local bilateral delivery, these are considered halved regarding the dose rates for each artery itself.
Notwithstanding the particular benefit of this dosing range for each of the aforementioned compounds, it is also believed that higher doses delivered locally would be safe. Titration is a further mechanism believed to provide the ability to test for tolerance to higher doses. In addition, it is contemplated that the described therapeutic doses can be delivered alone or in conjunction with systemic treatments such as intravenous saline.
It is to be understood that the invention can be practiced in other embodiments that may be highly beneficial and provide certain advantages. For example radiopaque markers are shown and described above for use with fluoroscopy to manipulate and position the introducer sheath and the aortic flow diverter. The required fluoroscopy equipment and auxiliary equipment is typically located in a specialized location limiting the in vivo use of the invention to that location. Other modalities for positioning aortic flow diverters are highly beneficial to overcome limitations of fluoroscopy. For example, non fluoroscopy guided technology is highly beneficial for use in operating rooms, intensive care units and emergency rooms. The use of non-fluoroscopy positioning allows aortic flow diverter systems and methods to be used to treat other diseases such as ATN and CHF.
In one embodiment, the aortic flow diverter is modified to incorporate marker bands with metals that are visible with ultrasound technology. The ultrasonic sensors are placed outside the body surface to obtain a view. In one variation, a portable, noninvasive ultrasound instrument is placed on the surface of the body and moved around to locate the device and location of both renal ostia. This technology is used to view the aorta, both renal ostia and the aortic flow diverter.
In another beneficial embodiment, ultrasound sensors are placed on the introducer sheath and the aortic flow diverter itself; specifically the distal end of the catheter. The aortic flow diverter with the ultrasonic sensors implemented allows the physician to move the sensors up and down the aorta to locate both renal ostia.
A further embodiment incorporates Doppler ultrasonography with the aortic flow diverter. Doppler ultrasonography detects the direction, velocity, and turbulence of blood flow. Since the renal arteries are isolated along the aorta, the resulting velocity and turbulence is used to locate both renal ostium. A further advantage of Doppler ultrasongoraphy is it is non invasive and uses no x rays.
A still further embodiment incorporates optical technology with the aortic flow diverter. An optical sensor is placed at the tip of the introducer sheath. The introducer sheath optical sensor allows visualization of the area around the tip of the introducer sheath to locate the renal ostia. In a further mode of this embodiment, a transparent balloon is positioned around the distal tip of the introducer sheath. The balloon is inflated to allow optical visual confirmation of renal ostium. The balloon allows for distance between the tip of the introducer sheath and optic sensor while separating aorta blood flow. That distance enhances the ability to visualize the image within the aorta. In a further mode, the balloon is adapted to allow profusion through the balloon wall while maintaining contact with the aorta wall. An advantage of allowing wall contact is the balloon can be inflated near the renal ostium to be visually seen with the optic sensor. In another mode, the optic sensor is placed at the distal tips of the aortic flow diverter. Once the aortic flow diverter is deployed within the aorta, the optic sensor allows visual confirmation of the walls of the aorta. The aortic flow diverter is tracked up and down the aorta until visual confirmation of the renal ostia is found. With the optic image provided by this mode, the physician can then track the aortic flow diverter to the renal arteries.
Another embodiment uses sensors that measure pressure, velocity or flow rate to located renal ostium without the requirement of fluoroscopy equipment. The sensors are positioned at the distal tip of the aortic flow diverter. The sensors display real time data about the pressure, velocity or flow rate. With the real time data provided, the physician locates both renal ostium by observing the sensor data when the aortic flow diverter is around the approximate location of the renal ostia. In a further mode of this embodiment, the aortic flow diverter has multiple sensors positioned at a mid distal and a mid proximal position on the catheter to obtain mid proximal and mid distal sensor data. From this real time data, the physician can observe a significant flow rate differential above and below the renal arteries and locate the approximate location. With the renal arteries being the only significant sized vessels within the region, the sensors would detect significant changes in any of the sensor parameters.
In a still further embodiment, chemical sensors are positioned on the aortic flow diverter to detect any change in blood chemistry that indicates to the physician the location of the renal ostia. Chemical sensors are positioned at multiple locations on the aortic flow diverter to detect chemical change from one sensor location to another.
The invention has been discussed in terms of certain preferred embodiments. One of skill in the art will recognize that various modifications may be made without departing from the scope of the invention. Although discussed primarily in terms of controlling blood flow to a branch vessel such as a renal artery of a blood vessel, it should be understood that the catheter of the invention could be used to deliver agent to branch vessels other than renal arteries, or to deliver to sites other than branch vessels, as for example where the catheter is used to deliver an agent to the wall defining the body lumen in which the catheter is positioned, such as a bile duct, ureter, and the like. Moreover, while certain features may be shown or discussed in relation to a particular embodiment, such individual features may be used on the various other embodiments of the invention.
Although the description above contains many details, these should not be construed as limiting the scope of the invention but as merely providing illustrations of some of the presently preferred embodiments of this invention. Therefore, it will be appreciated that the scope of the present invention fully encompasses other embodiments which may become obvious to those skilled in the art, and that the scope of the present invention is accordingly to be limited by nothing other than the appended claims, in which reference to an element in the singular is not intended to mean “one and only one” unless explicitly so stated, but rather “one or more.” All structural, chemical, and functional equivalents to the elements of the above-described preferred embodiment that are known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the present claims. Moreover, it is not necessary for a device or method to address each and every problem sought to be solved by the present invention, for it to be encompassed by the present claims. Furthermore, no element, component, or method step in the present disclosure is intended to be dedicated to the public regardless of whether the element, component, or method step is explicitly recited in the claims. No claim element herein is to be construed under the provisions of 35 U.S.C. 112, sixth paragraph, unless the element is expressly recited using the phrase “means for.”
The present application is a continuation of PCT/US02/29743 (Attorney Docket No. 022352-001200PC) filed Sep. 22, 2003, which claims priority from U.S. provisional application Ser. Nos. 60/412,343 (Attorney Docket No. 022352-000700US), filed on Sep. 20, 2002; 60/412,476 (Attorney Docket No. 022352-000800US), filed on Sep. 20, 2002; and 60/486,349 (Attorney Docket No. 022352-001200US), filed on Jul. 10, 2003. The full disclosure of each of the foregoing applications is hereby incorporated reference.
| Number | Date | Country | |
|---|---|---|---|
| 60412343 | Sep 2002 | US | |
| 60412476 | Sep 2002 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/US02/29743 | Sep 2002 | US |
| Child | 11083802 | Mar 2005 | US |
