Patent Document

CROSS-REFERENCES TO RELATED APPLICATIONS 
   This application is a divisional of U.S. patent application Ser. No. 11/084,295, filed on Mar. 18, 2005, now U.S. Pat. No. 6,994,700, issued Feb. 7, 2006, which was a continuation of PCT patent application No. PCT/US03/29585, filed Sep. 22, 2003, which claims priority from U.S. Provisional Patent Application Ser. Nos. 60/412,476 filed on Sep. 20, 2002; 60/486,206, filed on Jul. 9, 2003; and 60/502,399 filed on Sep. 13, 2003. The full disclosure of each of the foregoing applications is hereby incorporated by reference. 

   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   This invention relates to the field of medical devices, and more particularly to a system and method for inserting a catheter for locally delivering fluids or agents within the body of a patient. Still more particularly, it relates to a system and method for inserting a catheter that locally delivers 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&#39;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 a 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 in the art 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 an agent that is injected within the body in order to maximize the intended effects locally 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&#39;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 in locations throughout the body 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&#39;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 that uses 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 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. One example of this type of catheter 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 body 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 significantly from the capability of locally delivering therapeutic, prophylactic, or diagnostic agents into the renal arteries. 
   Acute renal failure (“ARF”) is an abrupt decrease in the ability of the kidney to excrete waste from a patient&#39;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&#39;s natural defense is to shut down, i.e., the vasoconstriction of 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&#39;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 the administration of 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. For example, 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&#39;s main blood filtering tools may suffer damage from exposure 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 function of the kidney 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 contemporaneously with surgical interventions, and in particular contemporaneously with radiocontrast dye delivery. However, many such procedures are conducted 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 system and method for inserting an intra-aorta catheter through a delivery sheath contemporaneous 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 particularly valuable. 
   Notwithstanding the clear needs for and benefits that would be gained from such a system and method for inserting an intra-aorta catheter through a delivery sheath, the ability to do so presents unique challenges. 
   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. 
   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. 
   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. 
   However, such previously disclosed designs would still benefit from further modifications and improvements in order to 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 locally isolating delivery of fluids or agents into the renal arteries of a patient from a location within the patient&#39;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 delivering both a local renal drug delivery 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 local renal drug delivery 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 still exists for an improved device configured with the necessary bore, transition angle and fittings to pass one or more devices smoothly into an introducer sheath lumen. 
   A need still exists for adjustable sheaths to allow placement of a local renal drug delivery system and aortic access with commercially available catheters and intervention equipment. 
   BRIEF SUMMARY OF THE INVENTION 
   One aspect of the invention is a method for providing a renal therapy system for use in a local renal therapy procedure in a patient by selecting an introducer sheath based on a length along a catheter that corresponds with a distance between a percutaneous vascular access site and a renal ostium. The introducer sheath is chosen from a plurality of introducer sheaths having different lengths. 
   One mode includes: accessing an abdominal aorta in the patient via the percutaneous access site; inserting the catheter through the percutaneous vascular access site; positioning a distal end of the catheter at a location within the abdominal aorta associated with a renal artery ostium; indicating the relative location of the percutaneous vascular access site on said catheter; and withdrawing said catheter and measuring the length from the percutaneous access point to the distal end of said catheter. 
   Another aspect of the invention is a local renal therapy system that includes an introducer sheath with a tubular wall with a tubular wall with a proximal end portion, a distal end portion that is adapted to be positioned at a location within an abdominal aorta associated with first and second renal ostia of first and second renal arteries, respectively, while the proximal end portion extends externally from the patient, and an introducer lumen that extends along a longitudinal axis between a proximal port along the proximal end portion and a distal port along the distal end portion. A bilateral renal delivery assembly with a local injection assembly that is adapted to be delivered to the location in a first condition through the introducer lumen is also provided. The introducer sheath has an adjustable length between a first configuration and a second configuration. In the first configuration the introducer sheath has a first length that is adapted to deliver the local injection assembly in a first condition to the location. In the second configuration the introducer sheath has a second length that is shorter than the first length and that corresponds with the local injection assembly extending in a second condition distally from the distal port at the location. In addition, in the second condition at the location the local injection assembly is adapted to be coupled to a source of fluid agent externally of the patient and to deliver a volume of fluid from the source bilaterally into each of the two renal arteries. 
   Another aspect of the invention is a system for locally delivering therapy to a renal system in a patient and that includes an introducer sheath in combination with a proximal coupler assembly as follows. The introducer sheath has an elongate tubular body with a proximal end portion, a distal end portion that is adapted to be placed percutaneously into a patient across a vascular access site when the proximal end portion extends externally from the patient, and 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. The proximal coupler assembly has a proximal portion and a distal portion. The distal portion comprises a distal lumen and is coupled to the proximal port with the distal lumen substantially aligned with the longitudinal axis of the delivery lumen. The proximal portion comprises a first branch lumen and a second branch lumen extending proximally from the distal lumen and terminating proximally at first and second entry ports, respectively. The first entry port is adapted to receive a percutaneous translumenal interventional device therethrough into the first branch lumen, whereas the second entry port is adapted to receive a bilateral renal delivery device assembly therethrough and into the second branch lumen. The first and second branch lumens are of sufficient orientation relative to the distal lumen, and the first and second branch lumens and distal and delivery lumens are of sufficient dimension, such that each of the percutaneous translumenal interventional device and the bilateral renal delivery device may be slideably engaged simultaneously within the distal lumen and further within the delivery lumen without substantial mutual interference therebetween. 
   Another aspect of the invention is a system for locally delivering therapy to a renal system in a patient that also includes an introducer sheath and a proximal coupler assembly as follows. The introducer sheath has an elongate tubular body with a proximal end portion, a distal end portion that is adapted to be placed percutaneously into a patient across a vascular access site when the proximal end portion extends externally from the patient, and 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. The proximal coupler assembly has a proximal portion and a distal portion. The distal portion comprises a distal lumen assembly and is coupled to the proximal port with the distal lumen assembly substantially aligned with the longitudinal axis of the delivery lumen. The proximal portion comprises a first branch lumen, a second branch lumen, and a third branch lumen coupled to and extending proximally from the distal lumen assembly and terminating proximally at first, second, and third entry ports, respectively. The first entry port is adapted to receive a percutaneous translumenal interventional device therethrough into the first branch lumen. The second entry port is adapted to receive a first delivery member of a bilateral renal delivery system therethrough and into the second branch lumen. The third entry port is adapted to receive a second delivery member of the bilateral renal delivery system therethrough and into the third branch lumen. Accordingly, the first, second, branch lumens are of sufficient orientation relative to the distal lumen assembly, and the first, second, and third branch lumens, distal lumen assembly, and delivery lumens are of sufficient dimension, such that each of the first and second delivery members of the bilateral renal delivery system and the percutaneous translumenal interventional device may be slideably engaged simultaneously within the distal lumen assembly and further within the delivery lumen without substantial mutual interference therebetween. 
   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. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention will be more fully understood by reference to the following drawings which are for illustrative purposes only: 
       FIG. 1  illustrates a standard, single port catheter assembly as is known to exist in the art. 
       FIG. 2  illustrates a proximal coupler assembly in plan view according to the present invention. 
       FIG. 3  is a cross-sectional view of the proximal coupler assembly of  FIG. 2  taken along the lines  3 — 3  of  FIG. 4 . 
       FIG. 4  illustrates the proximal coupler assembly of  FIG. 2  in perspective view. 
       FIG. 5  illustrates a reduced volume proximal coupler assembly embodiment in plan view according to the present invention. 
       FIG. 6  illustrates the proximal coupler assembly of  FIG. 5  in cross-sectional view taken along the lines  6 — 6  of  FIG. 7 . 
       FIG. 7  illustrates the proximal coupler assembly of  FIG. 5  in perspective view. 
       FIG. 8  illustrates the proximal coupler assembly embodiment of  FIG. 2  with an introducer sheath attached at the distal end. 
       FIG. 9  illustrates another embodiment of  FIG. 8  where a side port is positioned between a secondary branch and an introducer sheath. 
       FIG. 10  illustrates a local fluid delivery system according to one embodiment of the invention. 
       FIG. 11A  illustrates a local fluid delivery system as shown in  FIG. 10  in the branch port of a proximal coupler assembly. 
       FIG. 11B  illustrates a local fluid delivery system as shown in  FIG. 11A  with the stiff tube advanced and the tear away sheath separated. 
       FIG. 12  is a stylized illustration of a double Y assembly with two local fluid delivery systems and an intervention catheter disposed in an aorta system of a patient according to the present invention. 
       FIG. 13A  illustrates a proximal coupler assembly similar to that shown in  FIG. 11A  with an introducer sheath inserted in an aorta system of a patient. 
       FIG. 13B  is an illustration of the introducer sheath shown in  FIG. 13A  retracted and pulled away from the insertion point. 
       FIG. 14A  illustrates an adjustable introducer sheath in an expanded state. 
       FIG. 14B  illustrates the adjustable introducer sheath shown in  FIG. 14A  in a compressed state. 
       FIG. 15A  illustrates an adjustable introducer sheath with an external retaining tube positioned over the pleats. 
       FIG. 15B  illustrates the adjustable introducer sheath in  FIG. 15A  with the external retaining tube removed from the pleats. 
       FIG. 16A  illustrates another embodiment of an adjustable introducer sheath in an expanded state with an internal support tube positioned to prevent pleats from folding inward. 
       FIG. 16B  illustrates the adjustable introducer sheath in  FIG. 16A  in a compressed state with the internal support tube removed. 
       FIG. 17A  illustrates another embodiment of an adjustable introducer sheath with pleats, support wires and a locking ring. 
       FIG. 17B  illustrates the adjustable introducer sheath shown in  FIG. 17A  with support wires retracted and the adjustable section compressed. 
       FIG. 18  is a stylized illustration of another embodiment of a proximal coupler system with a local fluid delivery system and a catheter assembly with a rigid tube. 
       FIG. 19A , is a cut away cross-sectional view of  FIG. 18  with the rigid tube advanced through the proximal port. 
       FIG. 19B  is a cross-sectional view of the cut away view of  FIG. 19A  showing the pointed distal tip of rigid tube puncturing the delivery sheath. 
       FIG. 20  illustrates another mode of inserting a catheter in a proximal coupler assembly through the secondary port using a delivery tube with precut holes. 
       FIG. 21  is a cross-sectional view of  FIG. 20  illustrating the hypotube advanced through the delivery sheath and guiding catheter entering through a precut hole in the delivery sheath. 
       FIG. 22  illustrates a renal therapy system including an introducer sheath system, a vessel dilator and a fluid delivery system with a bifurcated renal catheter. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   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 renal flow systems and methods, which are thus generally 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; now U.S. Pat. No. 6,749,598, issued Jun. 15, 2004, 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, now allowed. The disclosures of these prior patent applications are herein incorporated in their entirety by reference thereto. 
   The invention is also generally related to certain aspects of 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. 
   Various particular dimensions, constructions, and materials are herein described according to the various embodiments and are considered highly beneficial. However, it is contemplated that such are illustrative and other modifications may be made to suit a particular need without departing from the intended present scope. 
   Referring more specifically to the drawings, for illustrative purposes the present invention is embodied in the apparatus generally shown in  FIG. 1  through  FIG. 22 . It will be appreciated that the apparatus may vary as to configuration and as to details of the parts, and that the method may vary as to the specific steps and sequence, without departing from the basic concepts as disclosed herein. 
   The description herein provided relates to medical material delivery systems and methods in the context of their relationship in use within a patient&#39;s anatomy. Accordingly, 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. The present embodiments described below generally relate to the local delivery of renal drugs from within the renal arteries themselves; 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. 
   In general, the disclosed material delivery systems will include a fluid delivery assembly, a proximal coupler assembly and one or more elongated bodies, such as tubes or catheters. These elongated bodies may contain one or more delivery lumens and generally consist of a proximal region, a mid-distal region, and a distal tip region or regions in the case of multi-tipped embodiments. The distal tip region will typically have means 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 material delivery system of the present invention 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&#39;s groin, typically using a Seldinger technique of percutaneous vessel access or other conventional method. 
     FIG. 1  illustrates a standard, single port catheter assembly  10  as is known to exist in the art with introducer sheath  12  coupled to tubular hub  14 . Side port  16  is in fluid communication with hub  14  and introducer sheath  12  and has tube  18  connected to valve  20  and fitting  22  for introduction of saline or other fluids into catheter assembly  10 . Hemostasis valve  24  is coupled to hub  14  and positioned on the axis  26  of introducer sheath  12  and allows sealable introduction of guide wires, catheters and other interventional devices (not shown) into hub  14 . 
     FIG. 2  through  FIG. 4  illustrate an embodiment of the present invention, a proximal coupler assembly  30 , in plan view, sectional view and perspective view respectively. In the embodiment shown, the Y hub body  32  is configured with an introducer sheath fitting  34  that has outer rib  35  at the distal end  36  of Y hub body  32  and a main adapter fitting  38  at the proximal end  40  of hub body  32 . In an exemplary embodiment, main adapter fitting  38  mates with a hemostasis valve (shown in  FIG. 8 ). Main branch  42  has tubular main channel  44  aligned on axis  46  and fluidly connects introducer sheath fitting  34  and main hemostasis adapter fitting  38 , also aligned on axis  46 . By way of example and not of limitation, main channel  44  may accommodate a 6 Fr Guide catheter (not shown). Side port fitting  48  is positioned on main branch  42  and is fluidly connected to main channel  44 . Secondary branch  50  has tubular branch channel  52  that intersects main channel  44  at predetermined transition angle β. Proximal end  54  of secondary branch  50  has secondary fitting  56 . In a beneficial embodiment, secondary fitting  56  is adapted to mate with a Touhy Borst valve (shown in  FIG. 8 ). In the present embodiment, a channel restriction  58  is molded into introducer sheath fitting  34 . The Y hub body  32  may be molded in one piece or assembled from a plurality of pieces. In one embodiment, (not shown) side port fitting  48  is placed on secondary branch  50  in similar fashion as that shown on main branch  42  in FIG.  1 – FIG. 3 . 
   Turning now to  FIG. 5  through  FIG. 7 , another beneficial embodiment of a reduced volume proximal coupler assembly  60 , in plan view, section view, and perspective view respectively are shown. The Y hub body  62  is adapted with a reduced size main branch  64  and a reduced volume main channel  66 . Secondary branch  68  and secondary channel  70  also present a reduced volume. Introducer sheath fitting  34  at the distal end  36  and side port fitting  48  are the same as in  FIG. 2  through  FIG. 5 . Hemostasis adapter fitting  72  at distal end  40  of main branch  64  is adapted for reduced volume operation. Secondary fitting  74  at proximal end  54  of secondary branch  68  is also adapted for reduced volume operation. 
     FIG. 8  illustrates the proximal coupler assembly  30  as described in  FIG. 2  through  FIG. 4  with proximal end  75  of introducer sheath  76  coupled to introducer sheath fitting  34  of Y hub body  32 . Introducer sheath fits over introducer sheath fitting  34  and is secured by rib  35  (shown in  FIG. 2  through  FIG. 7 ). Distal end  77  of introducer sheath  76  may be adapted with a truncated conical shape to aid insertion and advancement of introducer sheath  76 . In one mode, distal end  77  of introducer sheath is further adapted to accommodate a vessel dilator. In another mode, distal end  77  of introducer sheath is further adapted with a radiopaque marker (not shown). By way of example and not of limitation, introducer sheath may be sized up to about 10 Fr and may be about 8 Fr. In a beneficial embodiment, introducer sheath is about 30 cm in length to about 45 cm in length. Fluid fitting  78  and a fluid valve  80 , such as a stopcock valve, are connected to side port  48  with fluid tube  82 . In one mode, saline solution is introduced into fluid fitting  78  through fluid valve  80  and into Y hub assembly  32 . A hemostasis valve  84  is coupled to main adapter fitting  38 . A Touhy Borst valve  86  is coupled to secondary fitting  56 . It is to be appreciated that proximal coupler assembly  30  with hemostasis valve  84 , Touhy Borst valve  86  and introducer sheath  76  attached, may be configured as a kit. It is also to be appreciated that Touhy Borst valve  86  could be placed in addition or instead on main branch of hub body  32  and likewise hemostasis valve  84  could also be placed in addition or instead on side branch  50 . Similarly, it can be appreciated by one skilled in the art that side port  48  and associated fluid tube  82 , fluid valve  80 , and fluid fitting  78  could be placed in addition or instead on side branch  50  of Y hub body  32 . 
     FIG. 9  illustrates another embodiment of a proximal coupler as shown in  FIG. 8  where the proximal coupler assembly  90  has side port  48  positioned on Y hub assembly  92  between secondary branch  94  and an introducer sheath fitting  96 . Introducer sheath  76  with proximal end  75  and distal end  77  is shown coupled to Y hub assembly  92  at introducer sheath fitting  96 . 
     FIG. 10  illustrates a fluid delivery system  100  before insertion. A fluid agent infusion device  102 , shown in phantom, is positioned on the distal end  104  of a stiff tube  106  and compressed in the distal end  108  of delivery sheath  110 . By example and not by limitation, delivery sheath  110  may be about 6 Fr to about 8 Fr in diameter and about 15 cm in length. In another embodiment, stiff tube  106  is made of a Nickel-Titanium alloy. A torque handle  112  is coupled to stiff tube  106  at a mid proximal position  114  on stiff tube  106 . A fluid infusion port  116  is positioned at the proximal end  118  of stiff tube  106 . Fluid infusion port  116  is coupled to an adapter  120  for fluid infusion. Side port fitting  122  is coupled to tube  124  and further coupled to fluid valve  126  and fluid fitting  128 . In an exemplary embodiment, fluid infusion port  116  is adapted for a Luer fitting. In another exemplary embodiment, side port fitting  122  is used for injecting a saline solution. 
   Delivery sheath handle  130  is positioned and attached firmly at the proximal end  132  of delivery sheath  110 . Delivery sheath handle  130  is further comprised of delivery handle tabs  134  and delivery handle cap  136 . In an exemplary embodiment, delivery sheath handle  130  is configured to break symmetrically in two parts when delivery handle cap  136  is removed and delivery handle tabs  134  are forced apart. By way of example and not of limitation, distal end  104  of stiff tube  106  can be configured to couple to bifurcated catheters, flow diverters, and other devices configured to infuse fluids into a major blood vessel or one or more branch blood vessels. By way of example and not of limitation distal end  104  of stiff tube  106  can be configured with radiopaque markers or other diagnostic devices to aid in positioning. 
     FIG. 11A  and  FIG. 11B  illustrate a fluid delivery system  100  as shown in  FIG. 10 , inserted into a Y hub assembly  30  as previously shown in  FIG. 8 . Details of Y hub assembly  30  are omitted for clarity. In  FIG. 11A , delivery sheath  110  is inserted through Touhy Borst valve  86  through secondary branch channel  52  (see  FIG. 3 ) until distal end  108  of delivery catheter  110  (see  FIG. 10 ) stops against channel restriction  58  (see  FIG. 3 ). Force  140  is applied in a distal direction at torque handle  112  to push stiff tube  106  through delivery tube  110 . Fluid agent infusion device  102  (see  FIG. 10 ) travels distally into introduction sheath  76 . 
   In  FIG. 11B , stiff tube  106  has been advanced through introduction sheath  76  and fluid agent infusion device  102  shown in  FIG. 10  is deployed into introduction sheath  76 . In one embodiment, distal end  77  of introducer sheath  76  is positioned above the renal arteries (shown in  FIG. 12 ) prior to deploying fluid agent infusion device  102  shown in  FIG. 10 . In another embodiment, distal end  77  of introducer sheath  76  is retracted in a proximal direction while fluid agent infusion device  102  shown in  FIG. 10  remains positioned proximal the renal arteries. Delivery sheath  110  is retracted from main channel  44  (see  FIG. 3 ) of Y hub assembly  32  to allow a medical intervention device (see  FIG. 12 ) to enter hemostasis valve  84  for further advancement through main channel  44  (see  FIG. 3 ), through introducer sheath  76  and along side stiff tube  106 . In one mode, delivery sheath  110  is removed from Y hub assembly  32  after positioning fluid agent device  102  in introducer sheath  76 . In one exemplary embodiment, delivery sheath  110  is extruded with two thin wall positions about 180 degrees apart on its circumference to facilitate splitting. In one mode, delivery sheath handle  130  is split in two by removing delivery handle cap  136  (see  FIG. 10 ) and pressing inwardly on delivery handle tabs  134 . Delivery sheath may be split by pulling delivery tabs  134  apart. By way of example and not of limitation, delivery sheath  110  may be completely removed through Touhy Borst valve  86  before splitting and removing by tearing away. It is to be appreciated that proximal coupler assembly  30  with introducer sheath  76  and fluid delivery system  100  together may be configured as a kit. 
     FIG. 12  is a stylized illustration of a double Y proximal coupler  150  with two local fluid delivery systems  152 ,  154  and an intervention catheter  156  in an aorta system  158 . Details of local fluid delivery systems  152 ,  154  are shown in  FIGS. 11A and 11B  and are omitted here for clarity. The double Y proximal coupler  150  is constructed similar to a proximal coupler assembly  30  as shown in  FIG. 2  through  FIG. 4  but with another branch port added. Secondary branch  160  accommodates local fluid delivery system  152  for drug infusion in right renal artery  162 . Tertiary branch  164  accommodates local fluid delivery system  154  for drug infusion in left renal artery  166 . Interventional catheter  156  enters double Y proximal coupler  150  through hemostasis valve  168 . Introduction sheath  170  is sized to accommodate local fluid delivery systems  152 ,  154  and catheter  156  simultaneously.  FIG. 12  illustrates secondary branch  160  and tertiary branch  164  on the same side of the double proximal coupler; however, they may be positioned on opposite sides or in another beneficial configuration. By way of example and not of limitation, the cross section of local fluid delivery system  152 ,  154  may be oval shaped. By way of example and not of limitation, double Y proximal coupler  150  may be adapted to advance a wide mix of medical devices such as guide wires, diagnostic catheters, flow diverters and infusion assemblies through introducer sheath  170  and into a vascular system such as aorta system  158 . 
     FIG. 13A  illustrates a proximal coupler with a fluid delivery system attached, designated as coupler assembly  180 , similar to that shown in  FIG. 11A . Coupler assembly  180  is coupled to introducer sheath  182  with a distal end  184  and a proximal end  186 , inserted in aorta system  188  of patient  190  via femoral or iliac arterial access point  192 . Details of proximal coupler assembly  180 , as previously described in  FIG. 11A  and  FIG. 11B , have been omitted for clarity. 
   In  FIG. 13B , introducer sheath  182  has been retracted in direction  194  to deploy a fluid agent infusion device  102  (as shown in  FIG. 10 ) and create transition zone  196 . As a result, proximal end  186  of introducer sheath  182  is pulled away from and outside of insertion point  192  by a length corresponding to the length of transition zone  196 . Interventional catheter  198  must be extended the length of transition zone  196  to reach a target medical location (not shown) distal of fluid agent infusion device  102 , when introducer sheath  182  is in a retracted position. 
     FIG. 14A  illustrates the proximal coupler fluid delivery assembly  180  of  FIG. 13A  with adjustable introducer sheath  204  having a distal end  206 , a proximal end  208  and an adjustable proximal section  210  in an expanded state. Adjustable proximal section  210  of adjustable introducer sheath  204  is composed of a corrugated flexible material to allow compression in total length in “accordion” fashion. 
     FIG. 14B  illustrates adjustable introducer sheath  204 , shown in  FIG. 14A  with adjustable proximal section  210  in a compressed state, such as after deploying a fluid agent infusion device  102  where retraction of distal end  206  of introducer sheath  204  in direction  194  creates transition zone  196 . Proximal end  208  of adjustable introducer sheath  204  is not pulled away from insertion point  192  because of compression of adjustable proximal section  210  by the length of transition zone  196 . Interventional catheter  212  is of adequate length and reaches target medical location (not shown) upstream of fluid agent infusion device  102 . 
     FIG. 15A  illustrates a close up of a proximal coupler assembly  180  with an adjustable introducer sheath  204  coupled at proximal end  208  with adjustable proximal section  210  in an expanded state as shown in  FIG. 14A . A low profile, external retaining tube  220  is positioned snugly over the pleats  222  of adjustable proximal section  210  and prevents pleats  222  from folding outward and thus, prevents adjustable proximal section  210  from contracting. 
     FIG. 15B  illustrates the adjustable introducer sheath  204  shown in  FIG. 15A  with external retaining tube  220  removed from adjustable proximal section  210 . Pleats  222  can fold outward allowing adjustable section  210  to contract in direction  194 . By way of example and not of limitation, external retaining tube  220  can slide to another section of introducer sheath  204  or can be removed in a tear-away fashion. 
     FIG. 16A  illustrates another embodiment of a proximal coupler assembly  180  coupled to an adjustable introducer sheath  204  at proximal end  208  with adjustable proximal section  210  in an expanded state as shown in  FIG. 14A . Internal support tube  224  is positioned in adjustable proximal section  210  such that the outer diameter of internal support tube  224  prevents pleats  222  from folding inward. 
     FIG. 16B  illustrates the adjustable introducer sheath  204  in  FIG. 16A  with internal support tube  224  removed from adjustable proximal section  210 . Pleats  222  fold inward allowing adjustable section  210  to contract. Internal support tube  224  can alternatively be positioned in another section of introducer sheath  204  through external manipulation of adjustable proximal section  210  (not shown). 
     FIG. 17A  illustrates another embodiment of a proximal coupler assembly  180  coupled to proximal end  208  of adjustable introducer sheath  204 . Adjustable section  210  of introducer sheath  204  has pleats  222 , distal end  226  and proximal end  228 . A plurality of adjusting wires  230  are coupled to introducer sheath  204  at distal end  226  of adjustable section  210 . Only one adjusting wire  230  is shown for clarity. Locking ring  232  is positioned between proximal end  228  of adjustable section  210  and proximal end  208  of adjustable introducer sheath  204 , and over adjusting wires  230 . Locking ring  232  is configured to secure adjusting wires  230  from sliding, by radial inward force or other means, and thus keeping adjustable section  210  in an expanded state. 
     FIG. 17B  illustrates the proximal coupler assembly  180  coupled to proximal end  208  of adjustable introducer sheath  204  shown in  FIG. 17A . Locking ring  232  is expanded, or otherwise released, allowing adjusting wires  230  to slide proximally in direction  194  allowing adjustable section  210  to compress. Locking ring  232  may also be adapted with catches or clamps (not shown) to secure and then release adjustable wires  230 . 
     FIG. 18  is a stylized illustration of another aspect of the invention with a proximal coupler assembly  250  coupled to a local fluid delivery system  252  and a catheter assembly  254 .  FIG. 19A  and  FIG. 19B  further illustrate longitudinal cross sections of proximal coupler assembly  250 . Proximal coupler assembly  250  comprises a Y hub body  256 , similar to one shown in  FIG. 2  to  FIG. 5 , with sealable adaptors  258  such as Touhy Borst valves, at the distal port  260 , the proximal port  262  and secondary port  264 . Y hub body  256  has main channel  266  (shown in  FIG. 19A ) connecting distal port  260  and proximal port  262  and secondary channel  268  (shown in  FIG. 19A  connecting secondary port  264  with main channel  266 . 
   Local fluid delivery system  252  has a fluid agent infuser device  102  (shown in  FIG. 13B ), on the distal end of hypotube  270 . Flexible delivery sheath  272  has a proximal handle  274 . Flexible delivery sheath  272  encases the distal end and midsection of hypotube  270 . The proximal end of hypotube  270  is configured for fluid delivery as previously shown in  FIG. 10 . 
   Catheter assembly  254  is similar to that previously shown in  FIG. 1 . A rigid tube  276  is coupled to catheter manifold  278  which is configured to receive catheter  280  and to couple to proximal coupler assembly  250  through proximal port  262  with rigid tube  276 . Catheter  280  enters catheter manifold  278  through proximal port  260  and hemostasis valve  282 . In one beneficial embodiment, catheter  280  is a guiding catheter about 6 Fr in diameter and about 100 cm in length. 
   In  FIG. 18 , flexible delivery sheath  272  is inserted in secondary port  264  through a sealable adapter  258  and advanced past distal port  260 , into a position where the distal end of delivery sheath is proximal the renal arteries. Hypotube  270  of local fluid delivery system  252  is advanced distally until a fluid agent infuser device (shown in  FIG. 13B ) is in position near the renal arteries. Delivery sheath  272  is retracted through proximal coupler assembly  250  and secondary port  264  by pulling handle  274  to create an open transition zone proximal of a fluid agent infuser device as previously shown in  FIG. 13B . In one beneficial mode, delivery sheath is retracted about 10 cm. The sealable adaptor  258  at secondary port  264  is tightened to hold delivery sheath  272  and hypotube  270  firmly in place. 
   In  FIG. 19A , rigid tube  276  of catheter assembly  254  is inserted into proximal port  262  of proximal coupler assembly  250 . Sealable valves  258  have been removed for clarity. Rigid tube  276  has pointed distal tip  284 , which is advanced through proximal port  262  and into main channel  266 . 
   In  FIG. 19B  pointed distal tip  284  of rigid tube  276  has advanced further distally and punctured delivery sheath  272  at the junction of main channel  266  and secondary channel  268 . Distal tip  284  of rigid tube  276  is shown positioned within the inner lumen of delivery sheath  272  next to hypotube  270 . Sealable adaptor  258  at proximal port  262  (shown in  FIG. 18 ) is tightened to secure rigid tube  276  firmly in place. Catheter  280  is then advanced distally through hemostasis valve  282 , catheter manifold  278  and rigid tube  276  (shown in  FIG. 18 ), then through delivery sheath  272 , and out the distal end of delivery sheath  272  for further medical intervention. 
     FIG. 20  is a plan view and  FIG. 21  is a cut away view of another mode of inserting a catheter adjacent a fluid delivery device wherein Y assembly  300  has distal end  302 , coupled to introducer sheath  304 , a proximal port  306  with hemostasis valve  308  and branch port  310  with a Touhy Borst valve  312  on said branch port. Proximal portion of delivery sheath  314 , made from a stiff material such as stainless steel, having a proximal midsection  316  and a proximal end  318  is inserted in heomostasis valve  308  with distal end (not shown) in introducer sheath  304 . Proximal end  318  of delivery sheath  314  is coupled to a local fluid delivery system  320 , as previously described in  FIG. 10 . Further details of local fluid delivery system are omitted here for clarity. Hypotube  322  extending distally into delivery sheath  314  through Touhy Borst valve  324  on local fluid delivery system  320 . Proximal midsection  316  of delivery sheath  314  has precut holes  326  spaced at predetermined intervals configured to accommodate a guiding catheter  328  introduced through branch port  310 . In a preferred embodiment, guiding catheter  328  is about 100 cm long and about 6 Fr in diameter. Introducer sheath  304  is inserted in an aorta system as previously described in  FIG. 13A . Deployment of a fluid agent infuser device as previously shown in  FIG. 13B  is accomplished by advancing delivery sheath  314  to the desired position and advancing hypotube  322  through delivery sheath  314  to position fluid agent infuser device  102 . As previously shown in  FIG. 13B , a fluid agent infuser device is deployed, delivery sheath  314  is retracted to form a transition zone, which in one embodiment, is about 10 cm. Y hub assembly  300  is advanced distally on the proximal portion of delivery sheath  314  until a preferred precut hole  326 ′ (shown in  FIG. 21 ) is aligned with branch port  310  of Y hub assembly  300 . Guiding catheter  328  is introduced through Touhy Borst valve  312  on branch port  310  and inserted through preferred hole  326 ′ in delivery sheath  320 . 
   Guiding catheter  328  is advanced distally through delivery sheath  314  along side hypotube  322  and finally to a target site as previously described in  FIG. 13B . Y hub assembly  300  may be further modified by extending port  306  proximally to keep all precut holes  326  in delivery sheath  314  sealed inside Y hub assembly  300  and distal of hemostasis valve  308  during medical procedures. 
     FIG. 22  illustrates a further embodiment of a proximal coupler assembly and a fluid delivery assembly as shown in  FIG. 11B . Renal therapy system  350  includes an introducer sheath system  352 , a vessel dilator  354 , and a fluid delivery system  356  with a bifurcated renal catheter  358 . Details of channels, saline systems and fittings as shown previously in  FIG. 2  through  FIG. 4  are omitted for clarity. Introducer sheath system  352  has Y hub body  360  as shown previously in  FIG. 2  through  FIG. 4  configured with various inner structures as shown previously in  FIG. 3 . Y hub body  360  has hemostasis valve  362  on proximal end  366  and Touhy Borst valve  368  on secondary end  370 . Distal end  372  of Y hub body  360  is coupled to proximal end  374  of introducer sheath  376 . Introducer sheath  376  has distal tip  378  that has a truncated cone shape and radiopaque marker band  380 . In one embodiment, introducer sheath  376  is constructed with an inner liner of PTFE material, an inner coiled wire reinforcement, and an outer polymer jacket. Introducer sheath  376  has predetermined length L measured from proximal end  374  to distal tip  378 . 
   Vessel dilator  354 , with distal end  380  and proximal end  382  is a polymer, (e.g. extrusion) tubing with a center lumen for a guide wire (not shown). Distal end  380  is adapted with a taper cone shape. Proximal end  382  is coupled to a Luer fitting  384 . 
   Fluid delivery system  356  has stiff tube  386 , torque handle  388 , and proximal hub  390  as previously described in  FIG. 11A  and  FIG. 11B  with bifurcated catheter  358  coupled at distal end  392 . Bifurcated catheter  358  has two distal extensions  393 ,  394  of a memory shape material. Distal tips  395 ,  396  of each distal extension  393 ,  394  respectively, have a plurality of fluid ports (not shown) and radiopaque marker bands  397 . Polymer tube  398  is positioned proximal of distal extensions  393  and  394  and have radiopaque marker bands  400 . The proximal hub  390  of fluid delivery system  356  has a Luer fitting  402  for infusing a fluid agent, fluidly coupled with the stiff tube  386 . 
   A single lumen, tear-away delivery sheath  404  has a distal end  406 , a proximal end  408 , and slidingly encases stiff tube  386 . Delivery sheath  404  is positioned between the torque handle  388  and the bifurcated catheter  358 . The distal end  406  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  FIG. 3 . The proximal end  408  of the delivery sheath  404  is coupled to a handle assembly  410  with two handles  412  and a tear away cap  414 . 
   Dilator  354  is inserted through Touhy Borst valve  368  on secondary port  370  until distal end  380  protrudes from distal tip  378  of introducer sheath  376  to form a smooth outer conical shape. Distal tip  378  of introducer sheath  376  is positioned in the aorta system near the renal arteries (not shown). Dilator  354  is removed and fluid delivery device  356  is prepared by sliding delivery sheath  404  distally until distal extensions  393  and  394  of bifurcated catheter  358  are enclosed in delivery sheath  404 . Distal end  406  of delivery sheath  404  is inserted in Touhy Borst valve  368  and advanced to the restriction in the main channel of the Y hub body shown in  FIG. 3 . Bifurcated catheter  358  is advanced distally into introducer sheath  376 . Tear away delivery sheath  404  is retracted and removed through Touhy Borst valve  368  as shown previously in  FIG. 11B . Bifurcated catheter  358  is advanced distally out of the distal tip  378  of introducer sheath  376  and distal extensions  393  and  394  expand to their preformed shape to cannulate the renal arteries (not shown). 
   Notwithstanding the particular benefits provided by the various embodiments described above, one particular highly beneficial embodiment of an overall renal therapy system as shown previously in  FIG. 22  is provided as follows in order to further illustrate certain aspects of the invention considered suitable for bi-lateral local renal delivery of therapeutic agents in many circumstances. 
   A Y hub body as shown previously in  FIG. 2  through  FIG. 4  is made of a clear material and is configured with a main channel and a secondary channel that intersects the main channel. The distal end of the main channel is adapted with a channel restriction as shown in  FIG. 3 . The Y hub body has an introducer sheath fitting at the distal end and a port for the introduction of a saline solution into the main channel of the Y hub body. A hemostasis valve is attached to the proximal fitting on the main branch of the Y hub body and is configured to accommodate a nominal 6 French diameter catheter. A Touhy Borst valve is attached to the secondary fitting on the secondary port of the Y hub body. 
   An introducer sheath is coupled to the introducer sheath fitting of the Y hub body and is constructed with an inner liner of TFE material; an inner-coiled wire reinforcement, and an outer polymer jacket. The nominally 8 French introducer sheath has an inner diameter of about 0.116 inches and an outer diameter of about 0.138 inches. The distal tip is shaped as a truncated cone to adapt with the distal tip of a vessel dilator and has a radiopaque marker band. The proximal end of the introducer sheath is comprised of the outer polymer jacket only and is flared to couple to the introducer sheath fitting on the Y hub body. In one highly beneficial embodiment, multiple introducer sheaths are provided with a renal therapy system to accommodate different anatomies. Introducer sheaths with nominal usable lengths L, as shown in  FIG. 22 , of about 30 cm, about 35 cm, about 40 cm, and about 45 cm are typically included, but other suitable lengths can be provided as well. In the present example, the different length introducer sheaths are each coupled to a Y body hub as an integrated introducer sheath system; however, the system may be packaged and sold separately for later assembly. 
   A vessel dilator is used with this renal therapy system to guide the distal tip of the introducer sheath to the proximal region of the renal arteries. The vessel dilator is a polymer extrusion, tapered at the distal end with an inner lumen of about 0.040 inches and adapted for passage of a guide wire of about 0.035 inches to about 0.038 inches in diameter. The vessel dilator length is nominally about 11 cm longer than the usable length of the corresponding introducer sheath used so as to extend from the distal tip of the sheath and also out the appropriate proximal port of the Y hub body. The proximal end of the vessel dilator has a Luer fitting, primarily for flushing the inner lumen with a saline solution. 
   After the position of the renal arteries relative to the percutaneous entry point has been established using a guide wire with a diagnostic catheter and methods known to exist in the art, an integrated introducer sheath system of suitable length is selected. The vessel dilator is introduced through the Touhy Borst valve on the secondary branch of the Y hub and advanced until the distal tip of the vessel dilator protrudes from the distal tip of the introducer sheath resulting in a smooth outer conical shape. A saline flush is introduced through the port on the Y body and the proximal port of the vessel dilator. The introducer sheath with vessel dilator inserted is advanced on the guide wire through the percutaneous entry point and to the region in the aorta of the renal arteries. The marker band on the distal tip of the introducer sheath may be used with fluoroscopy to aid in positioning. When the distal tip of the introducer sheath is positioned at or near the renal arteries, the vessel dilator and guide wire are retracted, and removed, from the Y hub body through the Touhy Borst valve, while the introducer sheath remains in place. 
   A fluid delivery system as previously shown in  FIG. 11A  is prepared for insertion into the Y hub body. In this embodiment, the fluid delivery system has a stiff tube preferably made of Nitinol tubing and is about 77 cm in usable length with a distal end, a mid proximal portion and a proximal end. A bifurcated catheter is coupled at the distal end of the stiff tube. The distal extensions of the bifurcated catheter have a memory shape and are made of a braid-reinforced polymer with an inner core of ribbon wire. Each distal extension in this example has a radiopaque marker band and two infusion ports at or near the distal tip. The outside diameter of each of the distal extensions is nominally about 3 French. There is a polymer tube encasing the bifurcated catheter in a position proximal of the union of the distal extensions. The polymer tube has two radiopaque markers positioned about 1 cm to about 1.5 cm proximal of the union of the distal extensions to aid in relative positioning of the bifurcated catheter and the introducer sheath. 
   The fluid delivery system has a torque handle coupled at the mid proximal portion of the stiff tube and a proximal hub coupled at the proximal end of the stiff tube. The proximal hub has a Luer fitting for infusing a fluid agent and a saline flush port fluidly coupled with the stiff tube. 
   A single lumen, tear-away delivery sheath slidingly encases the stiff tube and is positioned between the torque handle and the bifurcated catheter. The delivery sheath is nominally about 15 cm in length with a distal end and a proximal end. The distal end 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  FIG. 3 . The proximal end of the delivery sheath is coupled to a handle assembly with two handles. The handle assembly has a tear away cap on the proximal end and is configured to allow the handle assembly to separate into two portions when the tear-away cap is removed and the handles pulled apart. The circumferential profile of the delivery sheath is configured with opposing thin wall sections to facilitate splitting lengthwise in two pieces when the handles are pulled apart. 
   The fluid delivery system is prepared by flushing saline solution from the saline port in the stiff tube proximal hub through to infusion ports in the distal extension tips of the bifurcated catheter. The bifurcated catheter is loaded into the delivery sheath by pulling the catheter relative to the delivery sheath handle until the tips of the distal extensions of the bifurcated catheter are completely within the delivery sheath. 
   The distal end of the delivery sheath, with the bifurcated catheter loaded, is inserted through the Touhy Borst valve on the secondary port of the Y hub body until the distal end seats in the channel restriction in the main channel. Distal force on the torque handle of the stiff tube advances the bifurcated catheter into the introducer sheath, preferably at least about 15 cm (about the length of the tear away delivery sheath) into introducer sheath to ensure the distal extensions are completely out of the tear away delivery sheath and into the introducer sheath. 
   The tear away delivery sheath is retracted from the Y hub body by pulling in a proximal position on the delivery sheath handle assembly as previously described in  FIG. 11B . During the delivery sheath retraction, the bifurcated catheter remains in position in the introducer sheath. When the distal end of the delivery sheath is removed from the Y hub body, the Touhy Borst valve is tightened on the stiff tube to prevent fluid loss. The tear away cap is removed from the delivery sheath handle assembly and the handles are pulled apart, tearing the delivery sheath longitudinally and into two pieces, which are removed from the stiff tube and discarded. 
   The bifurcated catheter is advanced to the distal tip of the introducer sheath by distal movement of the stiff tube at the torque handle relative to the Y hub body. Using fluoroscopic guidance, the bifurcated catheter is advanced out of the distal tip of the introducer sheath. The bifurcated catheter is manipulated through the torque handle, and the introducer sheath is simultaneously retracted, and the distal extensions bias toward their memory shape in the aorta and cannulate the renal arteries. Once the distal extensions are completely extended out of the distal tip of the introducer sheath and positioned in the renal arteries, the distal tip of the introducer sheath is retracted at least just proximal of the marker bands on the polymer tube of the bifurcated catheter to allow for interventional catheter advancement, while the bifurcated catheter remains in place. With the introducer sheath positioned, the Touhy Borst valve is tightened to prevent further movement of the bifurcated catheter in the introducer sheath. 
   The introducer sheath may be sutured or otherwise positionally controlled at or near the percutaneous entry site to prevent sheath movement during the subsequent procedure. Fluid agent may now be delivered through the proximal port of the fluid delivery system, through the stiff tube and into the renal arteries through the bifurcated catheter similar to that shown in  FIG. 22   
   Medical intervention procedures, such as coronary procedures, are initiated by inserting the appropriate guide wires and catheters through the hemostasis valve on the proximal fitting of the Y hub body. In this example, a nominal 6 French catheter will advance through the introducer sheath and along side the stiff tube without significant resistance. 
   When medical interventions are complete, the intervention catheters and guide wires are retracted and removed from the Y hub body through the hemostasis valve. Fluid agent delivery is often stopped. The Touhy Borst valve is loosened and torque handle of the stiff tube is pulled proximally relative to the Y hub body, withdrawing the distal extensions of the bifurcated catheter out of the renal arteries and into the introducer sheath. The introducer sheath is retracted from the percutaneous entry point and the entry point closed with standard medical procedures. 
   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) arising from diagnostic procedures 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&#39;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 intraveneous 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 intra renal catheters. The required fluoroscopy equipment and auxiliary equipment devices are typically located in a specialized location limiting the in vivo use of the invention to that location. Other modalities for positioning intra renal catheters 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, where fluoroscopy may not be readily available or its use may cause undue radiation exposure to users and others due to a lack of specific radiation safeguards normally present in angiography suites and the like. The use of non-fluoroscopy positioning allows intra renal catheter systems and methods to be used to treat other diseases such as ATN and CHF in clinical settings outside of the angiography suite or catheter lab. 
   In one embodiment, the intra renal catheter 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 intra renal catheter. 
   In another beneficial embodiment, ultrasound sensors are placed on the introducer sheath and the intra renal catheter itself; specifically the tip of the distal extensions, along the distal extensions or at the distal end of the catheter. The intra renal catheter 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 intra renal catheters. 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 ostia. A further advantage of Doppler ultrasongraphy is it is non invasive and uses no x rays. 
   A still further embodiment incorporates optical technology with the intra renal catheter. An optical sensor is placed at the tip of the introducer sheath. The introducer sheath&#39;s 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 intra renal catheter. Once the intra renal catheter is deployed within the aorta, the optic sensor allows visual confirmation of the walls of the aorta. The intra renal catheter 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 intra renal catheter into the renal arteries to a predetermined depth. 
   Another embodiment uses sensors that measure pressure, velocity, and/or flow rate to locate renal ostia without the requirement of fluoroscopy equipment. The sensors are positioned at the tip of distal extensions of the intra renal catheter. The sensors display real time data about the pressure, velocity, and/or flow rate. With the real-time data provided, the physician locates both renal ostia by observing the sensor data when the intra renal catheter is around the approximate location of the renal ostia. In a further mode of this embodiment, the intra renal catheter 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 intra renal catheter 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 intra renal catheter to detect chemical change from one sensor location to another. 
   Additional modifications or improvements may be made by the embodiments shown and described herein without departing from the intended scope of the invention which is considered to be broadly beneficial according to various independent aspects described. For example, various modifications to or combinations with the present embodiments may be made in view of other available information to one of ordinary skill in the art upon review of this disclosure and remain within the intended scope 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.”

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