CA2074304C

CA2074304C - Drug delivery catheter

Info

Publication number: CA2074304C
Application number: CA002074304A
Authority: CA
Inventors: Cyril J. Schweich, Jr.; Kent D. Harrison; Matthew M. Burns
Original assignee: Scimed Life Systems Inc
Current assignee: Boston Scientific Scimed Inc
Priority date: 1991-08-02
Filing date: 1992-07-21
Publication date: 1996-11-26
Anticipated expiration: 2012-07-21
Also published as: DE69224941D1; US5716340A; CA2074304A1; DE69224941T2; US5554119A; US5558642A; JP3317724B2; EP0526102B1; JPH05184681A; EP0526102A1

Abstract

A drug delivery catheter with an inflatable blood flow lumen is provided. The drug delivery catheter includes a flexible tubular shaft and an inflatable balloon assembly disposed at the distal end of the shaft. The catheter is inserted into a vessel with the balloon assembly in an un-inflated form. The balloon member is positioned at the treatment site and inflated. The balloon member in an inflated form defines a region or pocket between the balloon assembly and the vessel wall which contains the drug separate from blood flow. Apertures are provided in the balloon assembly to provide the drug to the containment pocket. Blood is allowed to flow through the center of the inflated balloon assembly.

Description

207~3~

DRUG DEIIVERY CATEIETER
BACKGROUN~ OF I~TF INVEN~ON
The present invention relates to a drug delivery device and method. More particularly, the present invention relates to a drug delivery device and method that is flexible as to the drug agent employed and the duration of drug ~ ;.... with an emphasis on physician control over d~,uluy~ of both the drug and the device.
Obstructive a~h~los~ u~ic disease is a serions health problem facing our society today. This disease is the result of the deposit of fatty sub-stances on the interior of the walls of the alteries. The build-up or - ' of such deposits results in a narrowing of the inside diameter of the artery which in turn restricts the blood flow through the artery. This disease, wherein the opening or lumen of the artery is narrowed, is known as a~ .uscl~,lu~i~ and the :a~ ' is known as a lesion.
One commonly used procedure for treating an obstruction caused by a~h~u~ulclu~;~ is a procedure Icnown as coronary artery bypass graft surgery ("bypass surgery"). Although bypass surgery has been used with moderate success in the treatment of a~.luscl~u~ it can be extremely invasive and traumatic to the patient.

2~74~

One less invasive and traumatic procedure developed more recently is coronary ~A~,iu,ulaa~y. Coronary angioplasty, and angioplasty in general, is a procedure in which a balloon is positioned in the inside of the artery at the site of the ? I~t~ or lesion and inflated in order to dilate the a~ .u~k,lu~ic lesion and thus open the restricted area of the artery. In order to advance the balloon to the lesion, the balloon is attached to the distal end of a small diameter catheter, which includes means for inflating the balloon from the other end of the catheter. The catheter is v~ d or "steered" through the patient's vessels to the site of the lesion with the balloon in an un-inflated form. When the un-inflated balloon is properly positioned at the lesion, the balloon is then inflated to dilate the restricted area.
While al~;iulJlaa~y has been relâtively successful in treating coronary artery disease, restenosis of the treated site often occurs a,u,u~ / 3 to 6 months following the procedure. It is believed that the primary factor in developing restenosis is the healing that takes place after the injury caused by the il~t~ .. iOII of balloon dilation procedure. The restenosis has close analogy to scar formation in that the histologic result has a similar .liol~ ,lo~y. The histologic response is called ir~tirnal fibrous hy~erplasia. A
main result of the intimal fibrous hyperplasia consists of smooth muscle cells from the vessel wall that proliferate and migrate im the vessel wall. The net result is a thickening of the vessel wall. Over time, this thickening reoccludes or restenosis the vessel to a point where it is clinically significar~t. That is, the blood flow through the vessel is diminished to a rate similar to the rate ~efore

3 2~743~
the angioplasty procedure. The occurrence of this seems to happen approxihna-tely 30-35 % of the time following an af,~,iu~ ly to that specific site.
Several alternative procedures have been attempted to try to affect the occurrence or rate of the restenosis following ill-~ liiUIl to the lesion site in the coronary altery. These procedures have included the use of lasers, mechanical ~ ~Lv~y devices, heated baUoons, and metal , ' ' ' stents. While each of these procedures has shown some success in dealing with the initial lesion, aU have the similar problem of restenosis at a similar or even greater occurrence. Current estimates of restenosis of the lesion site using these alternative procedures ranges between 40-50%. The time frame of restenosis of all of these is generally from 3-6 months after the procedure.
Therefore, it appears that this restenotic healing lesion area is ', ' of the type of ~ lLiv,~dl procedure used. Rather, it is a iologi~ response to any type of injury brought to that lesion site. Because of this intervention ', ' ,UII,~;Vl(J~ response, it is felt by many physicians that potentially the best way to deal with restenosis would be by a ' ~ means, such as a drug agent, targeted at the 1.: - h ~1 events that take place after injury.
To date, most 1' ' "i trials involve either an oral or Ju~l~ injected drug that is delivered throughout the whole body in hopes of trying to effect this small site in the arteries. This type of ~ , treatment is known as a "systemic treatment." Some agents that have been tried in human clinicals include heparin, calcium channel blockers,

4 207~3~-~
inr~n~in converting en;~yme inhibitors, fish oil, and growth peptides. Other agents that may not have been tried in clinicals but are of interest include ~I~UIIII)U~ synthetase inhibitor, serotonin ...-t~.6. , HMGCoA reductase inhibitors, platelet derived growth factors, r~ ~ cell factors, platelet L~ Liun inhibitors, and thrombm inhibitors such as hirudin or its analogs.
The indication for use of most of these has been either in vitro cell culture studies or animal studies. These studies have shown some effect on the smooth muscle cell ~,-uii~ Lion which is a major component of the intimal fibrous hyperplasia that takes place in the restenotic lesion. However, none of the systemic human trials to date has shown a major effect on the occurrence of restenosis.
Even though none of these agents have been completely successful in the in vivo human clinical trials, it is still generally felt that one of these agents or some other new agent, if delivered locally and site specifically to the lesion, would still be able to reduce the proliferative response. One of the problems with systemic techniques is the inability to deliver a high enough, - of the agent locally at the lesion in order to effect the pl-y~iul~g;~, response. In the in vitro studies which have shown some success, a high ~ of the agent was used. Thus, it is believed that if the agent was delivered specifically to the site as opposed to systemically, the agent may be delivered at a high enough I to truly effect the ~Jh.~ h)~;;c res,oonse.

` 5 2a~3~
The reason many of these agents have not been used in a higher r"nrpntr~tinn in vivo in humans is that many of the agents may exhibit "",lr~:".l~lr-. side effects. Thus, if a high ~r~nr,rn~r~tif1n of the agents is given systemically, they may have unwanted pl.~,;ul~,~;ic effects. Therefore, if the drug can be given with lugh locally to the vessel wall while 1" the systemic amount of drug, the desired result of . ~ ;. g the restenotic growth while preventing any unwanted systemic effects may be achieved.
There are other ways known to date in trying to create a site speciflc local delivery of drug to a site. One approach presently ~
is the use of a perforated or sweating balloon. For example, a drug delivery device is disclosed by Wolinsky, H., et al. in the article entitled, Use of a Perforated Balloon Catheter to Deliver C'~l ' Heparin Into the Wall of a Normal Canine Artery, 15 JACC 475 (Feb. 1990). This device is a per-cutaneous t ~ 1 coronary ~u~gio~ "y (PTCA) balloon with several microholes in the balloon for delivery of an agent during balloon dilatation.
The drug is A ' ~ into the same fluid which is used to inflate the balloon.
A major concern with any device with perforated holes is the effect of a jet stream on the wall of the blood vessel. If a balloon with holes is Di~Uli~, a relatively high velocity and/or pressure jet stream may be ~t ~ttt th ugh the holes thett ue ~ h gcahons tt the~ j t st t~ts - ~ 207~304 may cause tissue damage resulting in very severe dissection of the vessel waU
after the dilatation procedure.
Another d;~lv ~ of available devices, such as the one disclosed by Wolinsky et al., is that these devices cause a substantial blockage of blood flow in the subject vessel during the procedure. Thus, such devices may only be used for the fairly short time frame (typically, from one to two minutes), similar to the time frame of the actual v . ' ~/ dilatation.
Other available drug delivery devices are disclosed, for example, in United States Patent Numbers 4,824,436 (Wolinsky) and 4,636,195 (Wolinsky). These devices are directed to a dual occlusion catheter in which a balloon is inflated proximally and distally of the - ' . or lesion creating a space for infusion of a drug. This dual balloon catheter creates a space for infusion of drug separate from the blood flow. This device, however, also can only be used for a short period of time because it occludes blood flow.
Perfusion is very important in developing a suitable type of delivery device. It is necessary that the device provide a la~e latitude in time over which the agent could be delivered and therefore, devices which occlude blood flow may not provide the necessary latitude. Because the basic research into the 1,;~ y and 1' ~,;olc~ic events indicate that the initial events begin ' l~ after mjury and continue intensely for several hours, it is desirable for the drug delivery system to aDow drug delivery for several hours to a day or two beginning - " '~, after intervention. This research also 2~7430~

points out that the initial events ~ create a cascade of events that ultimately lead to intimal thickening. While these .. ' or lesions do not become apparent for several months, it is felt that if these initial events can be modulated, blocked, or even ~c~ ~t~A then the subsequent cascade can be altered and a diminished overall thickening could be achieved.
Even in devices where the shaft tubing provides a lumen for blood flow, the blood flow is limited by the diameter of the tube. In fact, when the shaft tubing is used for a blood flow lumen, there is a competing balance of making the shaft large enough to ;.~cr~-~ the larger volume of blood flow while still trying to minimr~e the size so that the catheter can be Illàll~ v~.~tid through the patient's ~la~culail~. This limited blood flow, while providing obvious advantages to no blood flow, may not be completely aali~rd~uly in providing the necessary blood flow to the heart (or other part of the body).
Catheters with expandable devices are also used im other procedures. For example, United States Patent Number 4,183,102 (Guiset) discloses a device which includes a series of toroidal shaped sleeves which conform to a vessel wall~ The device disclosed in this patent is for the treatment of some aortic aneurysms and does not include any means for drug delivery.
Therefore, it is desirable to have a drug delivery device capable of providing the necessary blood flow to the heart for restenosis treatment.
Further, such a device may also be extremely desirable in other procedures 2~7~g where a d~ug is to be delivered to a specific site in a vessel. For example, drug delivery devices may be useful in procedures where a drug or agent is used to dissolve the stenosis in an effort to avoid the use of ,~A.giv~kl~ly or ~Lh~ I~L~J..,~ procedures altogether or to deliver a i' ~ bolyLic agent to dissolve a clot at the lesion site.
It will be recognized from tbis discussion that there is a need for a generic type of drug delivery system which ~ i~, physician control over the deYice and agent. The device should have flexibility as to the agent that is to be delivered and should be capable of delivering any number of agents (either separately or at the same time), or possibly also allow a change in the protocol of the delivery. It should also be flexible with respect to the time frame over which these agents would be delivered. In order to effect this time frame of delivery, the device should also allow a large amount of blood flow by or through the device in order to maintain adequate distal perfusion of cardiac or other muscle during the delivery time.
Therefore, it is a primary object of the present invention to provide a device and method wbich can contain a relatively high ~~
of a drug agent in a selected portion of a vessel, such as a blood vessel.
It is another object of the present invention to provide a device which can be used in a flexible time frame.
It is a further object of this invention to provide a drug delivery catheter which permits a relatively high fluid flow rate through the vessel in which it is inserted while the device is employed.

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It is a still further object of this irlvention to provide a device which is flexible as to the drug and the number of drugs which can be delivered as well as the time frame over which they can be delivered.

Sl~MMARY OF THE lNVEN~ON
To achieve these and other objects, the present invention provides a new and unique drug delivery catheter which may be inserted into a vessel, such as a blood vessel. The drug delivery catheter of the present invention comprises an elongated tubular shaft which includes a drug lumen for delivering a drug to the treatment site and a uniquely configured inflatable balloon assembly. The balloon assembly is disposed at the distal end of the shaft and includes an inflatable balloon member. The balloon member has a ....i~"..,.l;..,. such that when the balloon member is uninflated, the fluid in the vessel (such as blood) may flow around the balloon assembly. This provides an All~...,!j~...l...l~ which may be easily inserted and . 1 1 through the vascular system. When the balloon member is an inflated state, part of the balloon member contacts the vessel wall defining a . pocket between the vessel wall and the balloon assembly. The balloon assembly includes apertures in the . pocket which are in fluid ~ with a drug lumen in order to provide the drug to the . pocket. A flow lumen is also defined through the balloon member when it is inflated in order to allow the fluid in the vessel, such as blood, to flow through the balloon g asgembly. The catheter also includes an inflation lumen which i5 used to inflate the balloon member. The catheter may also include a plurality of drug cr~nt~i -nt pocket6 either in fluid communication with each other or isolated from each other.
The present invention also F-n~ 'lq a method of using the drug delivery catheter to deliver drugs to a treatment site in desired concentrations.
The present invention provides a time frame for drug delivery in relatively high concentrations and which can be used in a relatively flexible time frame. For example the time frame may be greater (or less) than several minutes to possibly several hours or a day to two days.
This time frame of delivery is important in procedures intended to abate the occurrence of restenosis because the time frame needed to favour~bly modulate the restenotic response is variable .
Further, the device and method of the present invention may be advantageously used to deliver a drug agent intended to dissolve a lesion or to dissolve a clot at a lesion site.
BRIEF DESCRIPTION OF THE DR~WINGS
FIGURE 1 shows an ~ of the drug delivery catheter of the present invention.
FIGURE 2a shows a cross section of the ~ _~ir-nt of FIGURE 1 along line 2a-2a.
FIGURE 2b shows a cross section of the c~mho~l i r- t of FIGURE 1 along line 2b-2b.

.~

2~743~

FIGURE 3a shows a cross section of the; ' - ' of FIGURE 1 along lin~ 3a-3a.
FIGI~RE 3b shows a cross sectional slice of the . ~: ' of the device of Figure 1 in a plane ~ . to line 3a-3a.
FIGURE 4 shows another ~ ' ~ " of the drug delivery catheter of the present invention in a deflated form.
FIGURE 5 shows the ' ~1l' of the drug delivery catheter of FIGURE 4 in an inflated forln.
FIGURE 6 shows another e ' " of the drug delivery catheter of the present invention.
FIGURE 7 shows another, ~c ' of the drug delivery catheter of the present invention.
FlGURE 8 shows another . ' " of the drug delivery catheter of the present invention.
FIGURE 8a shows a front view of the ~ ~ " of FIGURE 8.
FIGURE 8b shows a cut-away view of the ' ~ ' of FIGURE 8.
FIGURE 9 shows another; ~ " of the drug delivery catheter of the present invention.
FIGURE 9a shows a cross section of the ~ of FIGURE 9 along line 9a-9a.

207~3~

FIGURE 9b shows a cross section of the .,111~' of FIGURE 9 along Line 9b-9b.

DETAILED DESCRI~ION OF THE PREFERRED EMBODIMENT
Referring to FIGURES 1, 2a, 2b, 3a and 3b, a preferred of the present invention includes a baUoon assembly comprising a single piece of baUoon tubing laced in a manner that wiU be described below to form toroidal or donut-shaped baUoons 10, 12, 14, 16. When inflated the baLloons 10, 12, 14 and 16 are intended to impinge upon or engage the vessel waU 20 as explained in more detail below. The figures depict the baUoons 10, 12, 14, 16 in their inflated form.
In an exemplary ul.ll)od~ , these baUoons 10, 12, 14, 16 are about 3 " (mm) in outside diameter in their inflated form. The balloons, however, can have an outside diameter ranging from about 2 mm to about 20 mm in their uninflated form, depending on the different vessels of the human (or animal) body in which the baLloons wiU be used. The siz~ of the baUoons may also vary for different procedures.
The most distal baUoon 10 and the next most distal baUoon 12 are preferably adjacent to each other as are the most proximal baUoon 16 and the next most proximal baUoon 14. The distance between the next most proximal baUoon 14 and the next most distal balloon 12 may be, for example, about 20 mm.

2~7~304 Providing the balloons in pairs adv~ulL6~.Jly provides two points of anchoring for each pair. This is IJ~iuulally useful at the ends of the balloon assembly where the two point anchoring reduces the tendency of the balloons to rotate ~ .l.. 1i. . '., to their axis.
The balloons are preferably made of a polyolefin. A suitable polyolefin material is available from E.I. DuPont de Nemours and Co.
(Wilmington, Del.) under the tradename Sur~yn~ Ionomer.
The balloon assembly also imcludes a cylindrical sheath 22 which connects the balloons 10, 12, 14 and 16. The diameter of the sheath 22 is less than the diameter of the balloons. Therefore, when the balloons are inflated, the sheath 22 is attached to the balloons at a point radially mward of the outer diameter of the balloons in order to create a pocket. Preferably, the sheath 22 is disposed tbrough and cormected to the interior portion of the toroidal-shaped balloons. In an exemplary ~ ' t, the sheath 22 is typically 2~i mm from end to end lon~ ly and is preferably about 0.001 inches tbick.
The sheath 22 is situated coaxially to the vessel wall 20 and is open at each end, thereby formmg a l~ IY or blood lumen 24 for the blood to flow through when the balloons are inflated. Thus, the sheath 22 creates a barrier for separation of the drug medium and the blood. The sheath 22 is supported or held open by the tUlUi~ h~r~ balloons 10, 12, 14, 16 and has the capability of having a relatively large internal diameter. For example, the internal diameters may be about 0.060 inches providing a very large volume of blood flow. This internal blood flow lumen 24 formed by the 2Q7~3~

sheath 22 has the capability of being si~";l~,Lly larger than the shaft tubing of the device.
The sheath 22 may be made of Surlyn0 Ionomer. More preferably, the sheath 22 may be made of a polyester copolymer such as a random copo]ymer. The random copolymer used to make the sheath of the present invention may be prepared according to standard procedures from ethylene glycol, and a mixture of dimethyl t~ ' and dimethyl phfhl~' As used in the random copolymer, the ratio of terephthalate to ~50pl th~ fP im the random copolymer may be varied over the range of between 99:1 to 80:20. Suitable cu~l~ are . ~ Jly available and are sold under the tradename SelaP Pr, such as SelaP X257, available from E.I.
Dupont de Nemours and Company (Wilmington, Delaware).
In this C..,IJ- '- t, the blood flow lumen 24 is created by the inflation of the balloons 10, 12, 14, 16 and can be ' i '.y collapsed upon deflation of the balloons 10, 12, 14, 16 (FIGURE 4 illustrates the balloons in a deflated state). The dimensions of the deflated device will, of course, vary depending on the specific use, ,' ~, but suitable sizes range from 0.035 inches to 0.1 inches.
As illustrated best in Figures 1 and 5, when the balloons are inflated, a ,~ pocket or region 26 is defined between the sheath 22 and balloons 12, 14 and the vessel wall 20. When the balloons 12, 14 are inflated they in effect form a seal between the vessel wall 20 and the balloons 12, 14 and thus the balloons 12, 14 define the outer boundary of the -15- 2a74304 pocket 26. The sheath 22, which is bonded to the balloons 12, 14, defines the rest of the ~ pocket 26. This . pocket 26 provides region in the vessel which is isolated or separate from the fluid flowing through the flow lumen 24. Therefore, the drug medium may be contained in this, pocket 26 in the desired ~ for a A period of time without entering the blood stream for that period of time.
The backbone of this; ' - ' is a catheter (or shaft) formed by an elongated tubular shaft 30 into which the balloon tubing is laced in a manner that will be described in detail below to form the toroidal or donut-shaped balloons 10, 12, 14, and 16. The specific size and c.. ~ of the shaft tubing 30 will, of course, vary depending on the specific application for which it is intended. In one exemplary: ' - ' t, the shaft tubing is about 135 ~ (cm) long, about 0.040 inches in distal outside diameter and about 0.050 inches in proximal outside diameter, and has a wall thickness of from about 0.003 inches to about 0.004 inches. The diameter of the tubing 30 can range from about 0.030 inches to about 0.090 inches depending on the . .' ' use. These exemplary ~' are suitable for a catheter intended for use in the coronary arteries. As will be recognized, the dimensions for catheters intended for use m the prostate, urethra, etc. may have other suitable ~' This shaft tubing 30 is preferably made of a flexible material such as a high density ~I~ ,ne OEIDPE!J.

- 16- 2~743~'1 The shaft tubing 30 is advd~ ~u~ly necked at its distal end to allow for variable stiffness or variable flexibility along the shaft. The necking of the shaft tubing 30 may be , ' ' by several ~ " ,. ,~ For example, a necked region, that is a region which is more flexible tban the rest of the tubing, may be provided by reducing the outer diameter of the tubing, by reducing the wall thickness of the tubing, or by providing a section of the tubing made of a more flexible material than the rest of the tubing. The necked portion may also be provided by any . ' of these i ~ ' .
FIGURE 3b best illustrates this necking in one preferred JO~I,- t FIGURE 3b depicts a slice through the plane perr~n~ r to the plane of FIGURF 3a and for purpose of clarity does not depict the structure of the device which is not in this plane. The shaft tubing 30 is ?
bonded to a necked section 30a of proximal shaft tubing. The bonding-152 commercially may be accomplished with an adhesive, such as BiPax~ BA-2135D Tra-Bond available from Tra-Con (Medord, r~- ~ ). The necked section 30a of proximal shaft tubing may have, for example, an outside diameter of about 0.040 inches and a wall thickness of about 0.003 ir~ches.
Proximal to the necked section 30a of proximal shaft tubing, there is a transition section 31 followed by the unnecked section 30b of proximal shaft tubing 30. The uMecked section 30b may have an outside diameter of about 0.050 inches and a wall thickness of about 0.004 inches.
By way of example, the shafting tubing 30 may be about 135 cm long, the necked section 30a of proximal shaft tubing may be about 25 cm - 17- 2~7~30~
long, and the unnecked section 30b of proximal shafting tubing may be about 110 cm long. Preferably, the shaft tubing 30 has a tapered section 33 at its distal end to prevent damage to the vessel walls as it is being inserted.
A necking may be r- L~ ' ' by pulling the tubing through a heated die to elongate it and therefore change its inside and/or outside diameters.
An inner shaft tubing 32 runs coaxially through the shaft tubing 30 in order to ~ ~ ' a PTCA guide wire 34. This type of guide wire is known in the a~t and therefore no further discussion is given here. A
suitable (~nnfi~-~tinn for the inner shaft tubing 32 is a flexible tube made of HDPE which is about 135 cm long, and has a wall thickness of about 0.003 inches.
This inner shafting tubing 32 may also be necked to provide added flexibility to the catheter. As illustrated in FIGURE 3b, in one .
exemplary . lm' the inner shafting tubing 32 has a transition region and ~J
an unnecked proximal portion 32b. The distal, necked portion of the inner shaft tubing 32 may be about 0.021 inches in outside diameter and about 30 cm long. The unmecked proximal portion 32b may be about 0.024 inches in outside diameter and about IOS cm long.
The necked or more flexible portion of the catheter may be provided by necking one or both of the shaft tubing 30 and the inner shaft tubing 32.

3o~
As illustrated there are basically three different lumens through the proximal portion of the shaft tubing 30, one being the inner lumen for the guide wire 34 formed by the inner shaft tubing 32, another being an inflation lumen 36 for the balloon inflation medium which is continuous with the donut-shaped balloons 10, 12, 14, 16 (described in greater detail below), and the final one being the drug delivery lumen 38 formed in the space between the inner shaft tubing 32 and the shaft tubing 30.
In one exemplary f-mhoflimf-n~, the inflation lumen is made at its distal end (where the balloons 10, 12, 14, 16 are formed), from Surlyn~, and has an inside diameter of 0.006 inches and an outside diameter of 0.011 inches.
In a presently preferred ~ the inf~ation lumen is formed of three sections: 1) the section attached to the balloons described above; 2) a middle inflation lumen section 164; and 3) the proximal inflation lumen section 166 which eventually is attached to the manifold (not shown).
Both the middle and proximal inflation lumen sections 164, 166 are preferably made of a polyimide material. The bond 170 of the balloon tubing 36 to the middle inflation lumen section 164 and the bond of 172 of the middle inflation lumen tubing 164 to the proximal inflation lumen tubing 166 is ~f~ ,rA
with a suitable adhesive, such as Loctite~ 405 available from Loctite Corp.

207~30~

(Newington, ('onm~rtitll~), The middle inflation lumen section 164 may have an inside diameter of about 0.012 mches, a wall thickness of about 0.001 inches, and may be aboue 25 cm long. The proximal inflation lumen section may have an inside diameter of 0.016 inches, a wall thickness of 0.001 inches, and may be about 100 cm long. It will be recognized that these dimensions are given by way of example and other suitable sizes may be employed.
The shaft tubing 30 has a number of apertures 40 in order to ac~o...lllo ' the drug flow out of these apertures 40 into the, pocket 26 formed between the two inner balloons 12, 14, the sheath 22, and the vessel wall 24. The apertures 40 are placed k~n~ih~rlir~lly along the shaft hubing 30 between the inner most balloons 12, 14. The apertures 40 are on both sides of the shaft tubing 30 and the area in which they are placed does not come into contact with the vessel wall 20. Preferably, the apertures 40 generally imcrease in diameter from proximal to distal end so that uniform flow out of each aperture 40 is achieved. The apertures are preferably sr~ed such that the drug medium is not pressure injected out of the apertures 40, but rather the vessel tissue is "bathed" with the drug medium. The size of the apertures will, of course, depend on the pressure at which the drug medium is being provided at the proximal end by the drug medium source (not shown).
In an exemplary . :l " t, the more proximal apertures 40 are about 0.003 inches in diameter and the more distal apertures are about 0.005 inches in diameter. These apertures 40 are placed about 2 to 3 mm apart from each other.

2~ 7~30~

This ~ B~ul . ,. .,l is ~ .r~ ulcid by drilling the apertures into the shaft tubiltg 30 and then laciltg non-blown balloon tubing 36 through these apertures in such a way that the tubing is loored around a temporary fornting mandrel (not shown) to form the section in which the sheath will be placed.
~Jpon completion of this lacing, the tubmg is ~ . 1 and dipped into a hot water bath, preferably at 80 C, for expansion of the Ih. .. ~ balloon tubing 36 to form the outer, .'( ~h~ balloons 10, 12, 14, 16.
After this process, another tnin-walled cylindrical balloon is inserted into the interior of the toroidal or donut-shaped balloons 10, 12, 14, 16 to form the sheath 22 which separates the drug and blood mediums. The sheath 22 is then bonded to aD of the ~ ~h~reA balloons 10, 12, 14, 16 and the ends are cut off flush to the most proximal and distal donut-shaped balloon 10, 16. The bonding may be ~. ~o ~ A by the use of a suitable a&esive, such as an epoxy resin with an aliphatic amine hardener. The rO"I, I.lLhJ~ for a suitable epoxy is given below in Table 1.

TABLE I (EPOXY ADHESIVE) Epoxide Wt. Equi~alcnt (in ~elams~ ~t. DescriDtion Araldite GY 508 148.8 (g) 400~55 Bisphenal A based cpoxy tciba Geigy] blendod with polyglycol di-epoxidc Arald~lte GY 506 59.0 (g) 17~-185 Bisphcnal A based epoxy [Ciba Geigy]
Epon 828 9~6 (g) 187.5 Bisphcnal A based cpoxy ~ -21- 2~7~3~4 (Shell) 2~Me~byl-1,5- 32.~ (g) pel~tadiamme A from Dupol~t) Ihe inner shaft tubing 32 is then put through the shaft tubing 30 in order to ~ - ' a guide wire 34. Tttis inner shaft tubing 34 is fastened to the manifold on the proximal end of the catheter with an adhesive bond, such as a urethane adhesive bond available from the 3M Company (M- ~ -'- Mirtnesota) under the tradename ~ - Scotch Weld0 Brand 3549 B/A Urethane Adhesive Kit. The inner shaft tubing 32 is fastened to the outer shaft 30 on the distal end of the catheter using the same urethane adhesive. This bonding material on the distal end may also be used to form the tapered section 33.
As is illustrated in Figure,~, the toroidal-shaped balloons 11 12, 14, 16 are formed from one continuous piece of tubing since they are laced through the shaft tubing 30 and therefore the balloons lO, 12, 14, 16 are all in fluid c, with each other.
T}te proximal end of this catheter comprises a manifold (not shown) known in the art. A suitable manifold is a ~ ~. ' three-port manifold. A vacuum source is placed on the balloon inflation port of the manifold to evacuate air from the balloons. Ttte drug irtfusion port of the manifold is then filled with a sterile liquid to evacuate air.

.

-22- 2~7~3~4 Thus, the blood flow lumen 24 is not an integlal part of the shaft of the device. Rather the lumen is created by inflation of the balloons 10, 12, 14, 16 of the device. Since the blood flow lumen 24 is not an integral part of the shaft, the ultimate diameter of the blood flow lumen 24 is not limited by the diameter of the shaft. When the balloons 10, 12, 14, 16 are deflated, the device is collapsed with essentially no blood flow lumen and therefore small enough in diameter to easily maneuver through the patient's vascular system. As discussed above, in some prior art devices, the lumen was created by the shaft tubing itself thereby limiting the size of the blood flow lumen. Unlike prior alt devices, when the balloon member is inflated, the cross-sectional area of the blood flow lumen 24 is a significant percentage of the cross-sectional area of the blood vessel. It is presently believed that with the present invention, the blood flow through the device will be ahout 60% and may be as much as 80% of the blood flow through a healthy vessel without the device in place.
nifi~ ly, in this ' ' the balloon inflation medium, which may be any suitable inflation medium such as saline and contrast dye, is separate from the drug medium. This separation is imporlant because it provides flexibility as to the amount of drug delivered, the time frame over which it is delivered as well as flexibility as far as d~lu r of the device.
Also, as will be recognr~ed by those skilled irl the art, this, ~ ' minimizes the problem of tissue damage caused by a very high jet stream of the drug being ejected from the catheter. As mentioned above, preferably the 2~3~

apertures 40 are not directed toward the vessel waU 20 and the apertures 40 are d~yluyli~'vly sizeo such that the drug emerges from the apertures to the wall in a slow gentle stream instead of emerging from the apertures 40 in a pressurized stream. Thus, the ~ region 26 created between the shaft tubing 30 and the vessel waU 20 is used to "bathe" the vessel waU 20.
Other r~ O~ of the present invention are illustrated in FIGURE 4, FIGURE~ 5, FIGI~RE 6, and FlGURE 7 with elements similar to the previûus, ' :' numbered similarly. FIGURES 4 and 5 iUustrate this device in the blood vessel 20 both deflated (E'IGURE 4) and inflated (FIGURE 5). As iUustrated in these figures the baUoons in the baUoon assembly may be spaced differently and additional baUoons may be placed at closer intervals. The additional baUoons will aid in keeping the perfusion lumen open. The t nnfif~ ti~-n and plj~;Lio~ g of the toroidal-shaped balloons have multiple l~.J~ More baUoons may be formed between the previously-described toroidal-shaped baUoons 10; and the baUoons 12 and 16 may even be eliminated. (FIGURE 7). For aU of these Pmho~" the distance from the most proximal baUoon 16 to the most distal baUoon 10 can range from about 20-30 mm and the inside baUoons 10' may be disposed about 2-3 mm apart.
The number of baUoons and the spacing between baUoons is important in g, the dyy~ol blood flow through the vessel being treated. It is possible that the flow of blood through the sheath 22 may be cut off by any one of the foUowing: (I) the lesion may deform the sheath; (2) the 207~04 device may be piaced at a bend and the sheath could kink; and/or (3) the pressure of the drug could force the blood lumen shut. Therefore, the radial support needed for the sheath 22 wiU vary depending on the specific conditions of the treatment site and the particular treatment being ad~ ,u.,t~ d. The radial support for the sheath 22 needed to maintain the blood flow lumen 24 through the center of the sheath 22 is provided by the baUoons. The different ~r,. ,l ic,. . ,.~ .C iUustrated may be used to provide more or less radial support as needed. Increasing the number of balloons in the balloon assembly increases the ability of the balloon assembly to maintain the perfusion lumen open.
Referring now to FIGURES 8, 8a, and 8b, another .
of the inventions is shown. In this embodiment the balloon assembly is com-prised of an outer cylindrical sheath 50 and an inner cylindrical sheath 52 sealed to each other at the ends of the sheaths. The cylindrical sheaths 50 and 52 are also '~, sealed to one another at sections 54. An inflation region or pouch 56 is defined between the two sheaths 52 and 54. These seals 54 run along the ~,u. U,llr~ of the cylindrical sheaths 50, 52 except that they are not complete in that spaces are lert at certain points to aUow the inflation medium to migrate from one pouch formed between the cylindrical sheaths 50, 52 to another similar pouch. The method for forming these seals is discussed in greater detail below.
Cutouts 58 are provided in the proximal cone section 60 of the sheaths to allow blood to flow through the center of these sheaths 50, 52. At the proximal portion of the cone, the outer sheath 50 and the inner sheath 52 2Q7~3~4 come to an outer balloon waste 100 and an inner balloon waist 102. The outer balloon waist 100 is bonded with an adhesive, such as Tracon~, to an outer -shaft 104 and the inner balloon waist 101 is bonded with a similar adhesive to an inner shaft 106. The outer and irmer shafts are made in a similar fasbion to the ~ ..,l,~.l - '~ previously described. The inner shaft 106 def~nes a lumen for a guide wire 108. The space between the ~uter and inner shafts 104-defines the d~ /illlL.iion medium lumen.
The double sheath/balloon assembly may be formed for example from . ~ ;~lly available PTCA catheter balloons. The outer sheath 50 and an inner sheath 52 are, however, may also be made from a polyester copolymer such as that described above.
In an exemplary P.mh~' the outer sheath 50 and inner sheath 52 are about 2.9 mm and about 3.0 mm respectively in outside diameter. Depending on the use, however, these diameters may range from about 1.9 mm and about 2.0 mm to about 5.5 mm and about 6.0 mm, respectively. The sheaths 50, 52 are preferably about 20 mm in length, but may vary from about 10 mm to about 30 mm. The length of the total device is d~ / 135 cm, but may range from about 75 to about 150 cm. Tbe seals 54 may be between about 0.005 inches and 0.01 inches wide and about 2 mm away from each other, though other ~ I~..~c,..,~;l,..~ may be employed.
Iu tbis ' ' t, the inflation medium and drug medium are one and the same. When the balloon assembly is inflated, as shown in Figures 8-8b, the outer sheath 50 contacts the wall of the vessel 64 at the areas 2~7~3a4 designated by reference numeral 63. The contact area 63 is defined by the section of the sheath 50 which is not bonded to the other sheath 52. The area 54 where the two sheaths 50, 52 are bonded, however, does not contact the vessel wall 64. Therefore, a, pocket or region 11 for the drug is defined in the space between two adjacent contact areas 63. The outer sheath has apertures or holes 62 in order to deliver the drug to the vessel wall 64 in the c pocket 11. These apertures 62 allow for ~ y of the inflation medium (which contains the drug) out to the vessel wall 64.
Preferably, these apertures 62 are about 0.003 inches in diameter and spaced radially at 90 for each pouch. EIere again other ~I, r~ .. may be suitable as well. For example, both the number and pattern of spacings of the apertures in each pocket defined by adjacent ribs may vary. The polymer that the outer balloon is formed of can either have the apertures 62 as discussed above or alt~ ly may be semi-permeable to the infiation/ drug solution.
This ~ ho~ also provides very good separation of drug from the blood lumen and excellent blood flow because the blood flow lumen 66 is created by the inflation and expansion of the double sheath 50, 52 balloon assembly. The sheaths 50, 52 are inser~ed into the patient in a deflated form (not shown) and when they are positioned properly, they are inflated until the outer balloon 50 comes into contact with the vessel waUs 64. The details for using this ' . are similar to those described below for the; ' "
of FIGURES I, 2a, 2b and 3.

`` 2~7g304 Similar to the other Pmho limPnt~ discussed above, the position and number of inflation pouches 56 may vary for different uses. To r- '` this, the seals between the two cylindrical sheaths 50, 52 can have different ~I-..i;L .~ depending on what type of lifting and expansion force would be needed.
This: ' ~ " of I~IGURES 8, 8a, and 8b, is preferably made by blowing two different sheaths 50, 52, one slightly smaller than the other 52. The second smaller inner sheath 52 is inserted coaxially inside the outer sheath 50. These are then completely sealed distally, creating an occlusive seal 70 between the two sheaths 50, 52. These two sheaths 50, 52 may have seals through the body of the balloon assembly similar to what an inflatable air or water mattress would have; these seals are mcomplete in places, aUowing the inflation medium/drug to flow throughout the device In an exemplary i ' ' t, the seals are 2-3 mm apart with a 0.01 inch wide bond On the proximal end in the cone area 60 of the sheaths 50, 52, there are sealed cutaway portions 58 for blood flow~ This sealing is around the cutaway portions 58 and allows the blood to flow while still ~
inflation space 72 in parts of the cone to the body of the cylindrical sheaths.
The sealing can be done in a number of different ways. One preferred method is by creating a heat seal between the two sheaths. This heat seal can be made by a laser weld, a radio frequency weld, or an ultrasonic weld. Other equivalent methods can be ' J In each case, the polymer ` 207g~0~

of the two cylindrical sheaths would be heated very locally to form a heat bond between the two pieces of the polymer.
Referring now to FIGURES 9, 9a, and 9b, another; ' - ' of the invention ls shown. FIGURE 9a shows a cross section of FIGURE 9 along line A - A' and FIGURE 9b shows a cross section of the ' ' of FIGURE 9 along line B - B' This; ' ' is comprised of an outer polymer cylindrical sheath 72 and an inner polymer cylindrical shedth 74 ~1 sealed to one another at areas 76 to form a balloon assembly with an inflation area 78 being defined between the two sheaths 72 and 74.
This l ..,ho~ is similar to the; ' ' of FIGURES 8, 8a, and 8b except the seals in the balloon assembly are forming welds which are similar to spot welds.
In an exemplary ~ ..,Io~l, .1 the outer sheath 72 and inner sheath 74 are about 2.9 mm and about 3.0 mm ~ ,ly in outside diameter and about 0.001 inches thick. In an exemplary - ~ , the balloon assembly comprised of sheaths 72, 74 is about 20 mm long and the total device is preferably about 135 cm long. The total device length, however, may range from about 75 to about 150 cm long. The outer sheath 72 and an inner sheath 74 are preferably made from the dbu~ .n~ n~A Selal3 copolymer. The seals 76 are d~ y 0.005 inches wide and d~ / 1-2 mm from each other. The method for forming these seals is similar to the methods discussed in greater detail above.

2~74304 - The inflation/drug medium is delivered into the balloon assembly, which comprises the sheaths 72, 74, through shaft tubing 82 that runs lr~n~ih- ' 'Iy along the device. Again, in this . ' ' t, the inflation medium and drug medium are one and the sarne. There are apertures or holes 80 put into the outer sheath in order to deliver drug to the vessel wall. These ~'~
apertures 80 allow for 1~ y of the inflation medium (which contains the drug) out to the vessel wall in a, pocket defined between adjacent areas where the outer sheath contacts the vessel wall. A suitable diameter for these apertures 80 is about 0.003 inches. Apertures 84 in the shaft tubing 82 allow the inflation medium/drug to pass from the shaft tubing 82 to the space 78 between the sheaths 72, 74. These apertures 84 are 0.01 inches in diameter, 0.50 mm apart and run Ir)n~ifllrfin~1ly along the shaft tubing 82. The shaft tubing 82 may also be necked to provide variable stiffness along the length of the shaft.
In an exemplary r~ rl;. \ ..f this shaft tubing 82 is about 135 cm long, about 0.040 inches in outside diarneter, semi-rigid yet flexible, and preferably made of HDPE.
An inner shaft tubing 120 runs coaxially through the shaft tubing 82 in order to ? - ' a guide wire 122. The guide wire 22 may be a PTCA guide wire as is known in the art. In one exemplary ~ L~ " t, this inner shaft tubing 120 is also flexible, about 135 cm long, about 0.021 inches in distal outside diameter, about 0.024 inches in proxirnal outside ` 207430~

diarneter, has a wall thickness of about 0.003 inches, and is made of ~DPE.
This inner shaft tubing 120 may also be necked as described above.
Similar to the other ~ L ' described above, the position and number of inflation pouches and/or seals can have multiple ~
depending on what type of lifting and expansion force would be needed.
This . ' - ' may be made by blowing two cylindrical sheaths 72, 74, one slightly smaller than the other 74. The second smaller inner sheath 74 is inserted inside the outer sheath 72. The sheaths 72, 74 are then completely sealed proximaUy and distally at section 88, creating an occlusive seal between the two sheaths 72, 74. These two sheaths 72, 74 may have il.L~IIlliLhl.L seals 76 through the body of the balloon similar to what an inflatable water mattress would have. The sealing can be formed in a number of different ways as described above.
This; ' - ' also provides good separation of the drug from the blood flow lumen and excellent blood flow because the blood flow lumen 86 is created by the inflation and expansion of the double sheath 72, 74 sleeve/assembly. The balloon assembly is inserted into the patient in a deflated or collapsed form (not shown) and when positioned properly, it is inflated until the unsealed sections of the outer balloon wall 72 come into contact with the vessel wall. Again, details for the use of this; ' ' are similar to those described below for other 1. L
With all of the, ' ' disclosed above, because the blood flow lumen is created by the inflatable balloon assembly (which may consist of 207~3~

any or all of a balloons/sheatb~shaft/etc.) the overall device can be kept to a minimal size. The blood flow lumen is only formed upon inflation of the balloon assembly and the device is in effect collapsed in its uninflated form.
This physical attribute allows the catheter to be of a very small diameter when it is inserted into the patient's body and i~vd to the desired position, yet provides a relatively large blood flow lumen when the balloon member is inflated. Unlike prior art devices the blood flow lumen is not formed by solid tubing, but instead by an inflatable and collapsible means. Since blood is not flowing through the shaft of the device like prior art devices, the competing balance of v the size of the device and making the shaft large enough to ArcommorlA~ the larger volume of blood flow is eliminated. In all of the I,od~ .lL~ disclosed, it is presently believed that when the device is inflated the flow will be at least 60% of what the flow would be without the device in place. Additionally, the drug may be delivered to a pocket which is separate or isolated from the blood flow. This permits the drug to be ~ ' ' at higher ~IJ'.. . I.llA~ and locally at the selected treatment site in the blood vessel.
A preferred use for this device is a method of treating the vessel waD after PTCA and the following description of the use of the invention after PrCA is given so as to provide a practical example of the procedure for using the present invention. One skilled in the art, however, can envision many other uses of the invention for delivering drugs to blood vessel walls or to walls of other ducts or cavities. The following example is given with respect to the r~ of Figure 1. It will be recognized that similar procedures will be used with respect to other embodiments of the invention.
Before use, the drug delivery catheter of the present invention must be prepared. First vacuum is pulled on the balloon inflation port of the manifold to evacuate any air from the balloons. Tben the drug infusion port is filled with a sterile liquid, again to evacuate air therefrom.
Following a typical well known PTCA procedure, the drug delivery catheter of the present invention is exchanged over the existing guide wire 34 used in the PTCA. The drug delivery catheter is slid over the guide wire 34 and positioned at the same site as the balloon dilation was performed.
Tbe balloons are then inflated to between S and 10 ;~ Oa~ ta such that the region is defined as explained above. Drug infusion iâ then initiated through the apertures in the balloon assembly to provide the desired drug to the ~ OIIIA;IIII.~ .,1 pocket or region and thus to the vessel wall. The drug or agent is provided in a thprlrc-lltir~lly effective amount and c.~ for preventing aestenosis. For example, 100 mcglrnl of Heparin may be used, as disclosed in 'IEffect of Controlled Adventitial Heparin Delivery on Smooth Muscle Cell Proliferation'l by Edelman et al., Proc. Natl. Acad. Sci. (USA) Ig90; 87: 3773-3778. The drug is provided at a pressure rangimg from a minimal value over zero to 50 pounds per square inch (depending on the volume and ~ .,1 "~ of drug desired).
Other pressures are ~u- t~ ] for other uses as per the flexible nature of this device. The blood in the vessel continues to flow through the center of the ~' ~

2~7~30~

flow lumen created through the center of the balloons and the sheath. Since the flov. lumen crfated through the center of the balloons and sheath is relatively large (compared to the size of the blood vessel), the illt~ U~)tiUIl of blood flow through the blood vessel is minimized. Further, smce the blood flow is isolated from the, pocket, the drug is only ~
locally and does not enter the blood stream until the balloons are deflated.
This allows for the drug to be provided to the vessel wall in high ~OI~ f ..~ without providing a high of the drug in the blood stream. After the drug has been applied to the vessel wall for the desired time, the device is removed. Because of the large volume of blood flow accommodated by this invention, numerous a~' of the drug may be effected without removing the drug delivery device for a relatively long period of time.
Therefore, the present drug delivery catheter of the present invention may be used to more safely deliver agents intended to eliminate the occurrence of restenosis. Some exemplary agents for this purpose are heparin, calcium channel blockers, ~ul~; converting en~yme inhibitors, fish oil, and growth peptides, lh.u~bu.~ nf, synthetase inhibitor, serotonin :~nt~nict~
HMGCoA reductase inhibitors, platelet derived growth factors, n . y cell factors, platelet ~l~iUII inhibitors, and thrombin inhibitors such as hifudin or its analogs.
The catheter of the present invention may also be used to deliver agents which are intended to dissolve existing stenosis as an altemative to or in 2~7~3Q~

with other procedures such as ~.6iu,ul~aLy or dlh~ u~
procedures. The agents delivered may dissolve thrombus at the lesion site.
Suitable drug agents for the purpose are eisSue 1 ' O activator, ~L~ and urokinase.
The foregoing description of the exemplary and preferred ' ~ ' of the present invention has been presented for purposes of illustration and fl~.~rrir~inn They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many rn~lifin~tinnc and variations are possible in light of the above teachings. The ....I.u.l; ,~
were chosen and described in order to best explain the principle of the invention and its practical applications and to thereby enable others skilled in the art to best utili7e the invention in various, ' ~ ' and with various rnr~iifir:l~jnnc as are suited to the particular use A 1~ It is intended that the scope of the invention be deflned by the following claims, including all eo~uivalents.

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE PROPERTY
OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A drug delivery catheter for insertion into a vessel which contains a first fluid, the drug delivery catheter comprising:
an elongated tubular member having a proximal end and a distal end;
a guide wire lumen for receiving a guide wire, the guide wire lumen running substantially coaxially through the length of the tubular member:
a drug lumen in fluid communication with the distal end of the tubular member for delivering a second fluid;
an inflatable balloon assembly disposed at the distal end of the tubular member, the balloon assembly including an inflatable balloon member having an uninflated state and an inflated state, the balloon assembly having apertures in fluid communication with the drug lumen;
the balloon assembly configured such that 1) when the balloon member is in an uninflated state, the first fluid in the vessel may flow around the balloon assembly, and 2) when the balloon member is in an inflated state, i) sections of the balloon member contact the vessel wall defining a containment pocket for containing the second fluid between the vessel wall and within the contacting sections of the balloon assembly, ii) the apertures are disposed in the containment region, and iii) a flow lumen is defined through the balloon member to allow the first fluid to flow through the balloon member; and an inflation lumen in fluid communication with the balloon member for inflating the balloon member.

2. The drug delivery catheter of claim 1 wherein the containment pocket of the balloon assembly isolates the first fluid from the second fluid.

3. The drug delivery catheter of claim 1 wherein the inflation lumen and the drug lumen are the same.

4. The drug delivery catheter of claim 1 wherein the inflation lumen and the drug lumen are not in fluid communication with each other.

5. The drug delivery catheter of claim 1 wherein the balloon assembly comprises a first toroidal balloon, a second toroidal balloon disposed distally of the first toroidal balloon, and a cylindrical sheath connected between the first and second toroidal balloons, wherein the flow lumen is defined through the center of the cylindrical sheath and the first and second toroidal balloons are in fluid communication with each other.

6. The drug delivery catheter of claim 5 wherein the diameter of the cylindrical sheath is less than the diameter of the balloons.

7. The drug delivery catheter of claim 1 wherein the balloon assembly comprises a first cylindrical sheath, a second cylindrical sheath disposed coaxially within the first cylindrical sheath, the first and second cylindrical sheaths being sealed together at their ends to define an inflation space therebetween.

8. The drug delivery catheter of claim 7 wherein the first and second cylindrical sheaths are intermittently sealed to one another at spaced intervals between the sealed ends of the sheaths and a plurality of containment pockets are defined between the sealed sections.

9. The drug delivery catheter of claim 1 wherein the apertures are disposed in the tubular shaft.

10. The drug delivery catheter of claim 1 wherein the apertures are disposed in the balloon member.

11. The drug delivery catheter of claim 8, wherein the apertures are disposed in the balloon member.

12. A drug delivery catheter for insertion into a vessel containing a first fluid, the drug delivery catheter comprising:
an elongated tubular shaft having a distal end and a proximal end;
a balloon assembly including a first toroidal-shaped balloon disposed at the distal end of the tubular shaft, a second toroidal-shaped balloon spaced proximally from the first toroidal-shaped balloon, and a cylindrical sheath attached to the first and second toroidal-shaped balloons, the sheath attached to the toroidal-shaped balloons at a section of the toroidal-shaped balloons radially inward of the outer diameter of the toroidal-shaped balloons, the balloon assembly configured such that when the toroidal-shaped balloons are inflated, (a) the toroidal-shaped balloons lift or expand the sheath, (b) the toroidal-shaped balloons contact the vessel wall thereby defining a containment pocket between the vessel wall, the tubular shaft, the toroidal-shaped balloons, and (c) the sheath forms a flow lumen allowing for substantial flow of the first fluid through the balloon assembly, the balloon assembly further comprising a plurality of toroidal-shaped balloons disposed between the first and second toroidal-shaped balloons:
an inflation lumen in the tubular shaft in fluid communication with the toroidal-shaped balloons; and a drug lumen in the tubular shaft in fluid communication with at least one aperture in the containment pocket for delivering a drug to the containment pocket.

13. The drug delivery catheter of claim 12 further comprising an inner shaft tube running substantially coaxially and longitudinally through the tubular shaft for receiving a guide wire.

14. The drug delivery catheter of claim 12 comprising four toroidal-shaped balloons.

15. The drug delivery catheter of claim 12 wherein: (a) one of the toroidal-shaped balloons disposed between the first and second toroidal-shaped balloons is positioned adjacent the first toroidal-shaped balloon; and (b) another one of the toroidal-shaped balloons disposed between the first and second toroidal-shaped balloons is positioned adjacent the second toroidal-shaped balloon.

16. The drug delivery catheter of claim 12 wherein the apertures are disposed in the tubular shaft.

17. A fluid delivery catheter for insertion into a vessel which contains a first fluid, the fluid delivery catheter comprising:
an elongated tubular shaft having a proximal end and a distal end;
a balloon assembly disposed at the distal end of the tubular shaft, the balloon assembly including an inflatable balloon member having an uninflated state and an inflated state;
the balloon assembly configured such that 1) when the balloon member is in an uninflated state, the first fluid in the vessel may flow around the balloon assembly, and 2) when the balloon member is in an inflated state, (a) sections of the balloon member contact the vessel wall defining a containment pocket for containing a second fluid between the vessel wall and within the containing sections of balloon member, and (b) a single flow lumen is defined through the balloon member to allow the first fluid to pass through the balloon member, wherein the flow lumen allows for substantial flow of the first fluid;
means for inflating the balloon member; and means for providing a second fluid to the containment pocket when the balloon is in an inflated state.

18. The fluid delivery catheter of claim 17 wherein the means for providing a second fluid to the containment pocket comprises a drug lumen provided through the tubular shaft, the drug lumen being in fluid communication with at least one aperture disposed in the distal end of the shaft.

19. The fluid delivery catheter of claim 17 wherein the means for providing a second fluid to the containment pocket comprises a drug lumen provided through the tubular shaft, the drug lumen being in fluid communication with at least one aperture disposed in the balloon member.

20. The fluid delivery catheter of claim 17 wherein the catheter is configured to fit in a blood vessel and further comprising lumen adapted to receive a guide wire.

21. The drug delivery catheter of claim 1 wherein the flow lumen allows for substantial flow of the first fluid.

22. The drug delivery catheter of claim 1 wherein a plurality of containment pockets are formed.

23. The drug delivery catheter of claim 22 wherein the containment pockets are not in fluid communication with each other.

24. The drug delivery catheter of claim 5 wherein the flow lumen allows for substantial flow of the first fluid.

25. The drug delivery catheter of claim 5 wherein a plurality of containment pockets are formed with additional toroidal balloons disposed between the first and second toroidal balloons.

26. The drug delivery catheter of claim 25 wherein the containment pockets are not in fluid communication with each other.

27. The drug delivery catheter of claim 1 wherein the flow lumen is of a greater diameter than the guide wire lumen.

28. The fluid delivery catheter of claim 17 wherein a plurality of containment pockets are formed.

29. The drug delivery catheter of claim 28 wherein the containment pockets are not in fluid communication with each other.

30. A drug delivery catheter for insertion into a vessel which contains a first flowing fluid, the drug delivery catheter comprising:
an elongated tubular member having a proximal end and a distal end;
a drug lumen in fluid communication with the distal end of the tubular member for delivering a second fluid;
an inflatable balloon assembly disposed at the distal end of the tubular member, the balloon assembly including an inflatable balloon member having an uninflated state and an inflated state, the balloon assembly having apertures in fluid communication with the drug lumen;
the balloon assembly configured such that 1) when the balloon member is in an uninflated state, the first fluid in the vessel may flow around the balloon assembly, and 2) when the balloon member is in an inflated state, i) sections of the balloon member contact the vessel wall defining more than one containment pocket for containing the second fluid between the vessel wall and within the contacting sections of the balloon assembly, ii) the apertures are disposed in the containment pocket, and iii) a flow lumen is defined through the balloon member to allow for substantial flow of the first fluid through the balloon member; and an inflation lumen in fluid communication with the balloon member for inflating the balloon member.

31. The drug delivery catheter of claim 30 wherein the balloon assembly comprises a first toroidal balloon, a second toroidal balloon disposed distally of the first toroidal balloon, and a cylindrical sheath connected between the first and second toroidal balloons, wherein the flow lumen is defined through the center of the cylindrical sheath and the first and second toroidal balloons are in fluid communication with each other.

32. A drug delivery catheter for insertion into a vessel containing a first fluid, the drug delivery catheter comprising:
an elongated tubular shaft having a distal end and a proximal end;
a balloon assembly comprising a first toroidal-shaped balloon disposed at the distal end of the tubular shaft, a second toroidal-shaped balloon spaced proximally from the first toroidal-shaped balloon, and a cylindrical sheath attached to the first and second toroidal-shaped balloons, the sheath attached to the toroidal-shaped balloons at a section of the toroidal-shaped balloons radially inward of the outer diameter of the toroidal-shaped balloons, the balloon assembly configured such that when the toroidal-shaped balloons are inflated, (a) the toroidal-shaped balloons lift or expand the sheath (b) the toroidal-shaped balloons contact the vessel wall thereby defining a containment pocket between the vessel wall, the tubular shaft, the toroidal-shaped balloons, and the sheath, and (c) the sheath forms a flow lumen allowing for large amounts of flow of the first fluid through the inflated balloon assembly;
an inflation lumen in the tubular shaft in fluid communication with the toroidal-shaped balloons; and a drug lumen in the tubular shaft in fluid communication with at least one aperture in the balloon assembly for delivering a drug to the containment pocket.

33. A drug delivery catheter for insertion into a vessel containing a first fluid, the drug delivery catheter comprising:
an elongated tubular shaft having a distal end and a proximal end;
a balloon assembly comprising a first toroidal-shaped balloon disposed at the distal end of the tubular shaft, a second toroidal-shaped balloon spaced proximally from the first toroidal-shaped balloon, at least one additional toroidal shaped balloon positioned between the first and second toroidal shaped balloons, and a cylindrical sheath attached to the toroidal shaped balloons at a section of the toroidal-shaped balloons radially inward of the outer diameter of the toroidal-shaped balloons, the balloon assembly configured such that when the toroidal-shaped balloons are inflated, (a) the toroidal-shaped balloons lift or expand the sheath, (b) the toroidal-shaped balloons contact the vessel wall thereby defining a plurality of containment pockets between the vessel wall, the tubular shaft, the toroidal-shaped balloons, and the sheath, and (c) the sheath forms a flow lumen allowing for flow of the first fluid substantially through the balloon assembly;
an inflation lumen in the tubular shaft in fluid communication with the toroidal-shaped balloons; and a drug lumen in the tubular shaft in fluid communication with at least one aperture in the balloon assembly for delivering a drug to the containment pocket.

34. A drug delivery catheter for insertion into a vessel which contains a first flowing fluid, the drug delivery catheter comprising:
an elongated tubular member having a proximal end and a distal end;
a drug lumen in fluid communication with the distal end of the tubular member for delivering a second fluid;
an inflatable balloon assembly disposed at the distal end of the tubular member, the balloon assembly including an inflatable balloon member having an uninflated state and an inflated state, the balloon assembly having apertures in fluid communication with the drug lumen;
the balloon assembly configured such that 1) when the balloon member is in an uninflated state, the first fluid in the vessel may flow around the balloon assembly, and 2) when the balloon member is in an inflated state, i) sections of the balloon member contact the vessel wall defining a plurality of containment pockets for containing the second fluid between the vessel wall and within the contacting sections of the balloon assembly, ii) the apertures are disposed in the containment pocket, and iii) a single flow lumen is defined through the balloon member to allow the first fluid to flow through the balloon member; and an inflation lumen in fluid communication with the balloon member for inflating the balloon member.

35. The drug delivery catheter of claim 34 wherein the containment pockets of the balloon assembly isolate the first fluid from the second fluid.

36. The drug delivery catheter of claim 34 wherein the inflation lumen and the drug lumen are the same.

37. The drug delivery catheter of claim 34 wherein the inflation lumen and the drug lumen are not in fluid communication with each other.

38. The drug delivery catheter of claim 34 wherein the balloon assembly comprises a first toroidal balloon, a second toroidal balloon disposed distally of the first toroidal balloon, and a cylindrical sheath connected between the first and second toroidal balloons, wherein the flow lumen is defined through the center of the cylindrical sheath and the first and second toroidal balloons are in fluid communication with each other.

39. The drug delivery catheter of claim 38 wherein the diameter of the cylindrical sheath is less than the diameter of the balloons.

40. The drug delivery catheter of claim 34 further comprising a guide wire lumen for receiving a guide wire.

41. The drug delivery catheter of claim 34 wherein the balloon assembly comprises a first cylindrical sheath, a second cylindrical sheath disposed coaxially within the first cylindrical sheath, the first and second cylindrical sheaths being sealed together at their ends to define an inflation space therebetween.

42. The drug delivery catheter of claim 41 wherein the first and second cylindrical sheaths are intermittently sealed to one another at spaced intervals between the sealed ends of the sheaths and a plurality of containment pockets are defined between the sealed sections.

43. The drug delivery catheter of claim 34 wherein the apertures are disposed in the tubular shaft.

44. The drug delivery catheter of claim 34 wherein the apertures are disposed in the balloon member.

45. The drug delivery catheter of claim 42 wherein the apertures are disposed in the balloon member.

46. The drug delivery catheter of claim 34 wherein the flow lumen allows for substantial flow of the first fluid.

47. The drug delivery catheter of claim 34 wherein the containment pockets are not in fluid communication with each other.

48. The drug delivery catheter of claim 38 wherein the flow lumen allows for substantial flow of the first fluid.

49. The drug delivery catheter of claim 38 wherein the plurality of containment pockets are formed with additional toroidal balloons disposed between the first and second toroidal balloons.

50. The drug delivery catheter of claim 49 wherein the containment pockets are not in fluid communication with each other.

51. The drug delivery catheter of claim 34 wherein the flow lumen is of a greater diameter than the guide wire lumen.

52. A drug delivery catheter for insertion into a vessel which contains a first flowing fluid, the drug delivery catheter comprising:
an elongated tubular member having a proximal end and a distal end;

a drug lumen in fluid communication with the distal end of the tubular member for delivering a second fluid;
an inflatable balloon assembly disposed at the distal end of the tubular member, the balloon assembly including an inflatable balloon member having an uninflated state and an inflated state, the balloon assembly having apertures in fluid communication with the drug lumen;
the balloon assembly configured such that 1) when the balloon member is in an uninflated state, the first fluid in the vessel may flow around the balloon assembly, and 2) when the balloon member is in an inflated state, i) sections of the balloon member contact the vessel wall defining at least one containment pocket for containing the second fluid between the vessel wall and within the contacting sections of the balloon assembly, ii) the apertures are disposed in the containment pocket, and iii) a single flow lumen is defined through the balloon member to allow the first fluid to flow through the balloon member; and an inflation lumen in fluid communication with the balloon member for inflating the balloon member;
the balloon assembly comprising a first toroidal balloon, a second toroidal balloon disposed distally of the first toroidal balloon, additional toroidal balloons disposed between the first and second toroidal balloons, and a cylindrical sheath connected between the first and second toroidal balloons, wherein when the toroidal balloons are inflated the flow lumen is defined through the center of the cylindrical sheath and the first and second toroidal balloons are in fluid communication with each other, and wherein a plurality of containment pockets are formed with the additional toroidal balloons disposed between the first and second toroidal balloons.

53. The drug delivery catheter of claim 52 wherein the containment pockets of the balloon assembly isolate the first fluid from the second fluid.

54. The drug delivery catheter of claim 52 wherein the diameter of the cylindrical sheath is less than the diameter of the balloons.

55. The drug delivery catheter of claim 52 further comprising a guide wire lumen for receiving a guide wire.

56. The drug delivery catheter of claim 52 wherein the flow lumen allows for substantial flow of the first fluid.

57. The drug delivery catheter of claim 52 wherein the containment pockets are not in fluid communication with each other.

58. The drug delivery catheter of claim 55 wherein the flow lumen is of a greater diameter than the guide wire lumen.

59. A fluid delivery catheter for insertion into a blood vessel which contains a first fluid, the fluid delivery catheter comprising:
an elongated tubular shaft having a proximal end and a distal end;
a balloon assembly disposed at the distal end of the tubular shaft, the balloon assembly including an inflatable balloon member having an uninflated state and an inflated state;

the balloon assembly configured such that 1) when the balloon member is in an uninflated state, the first fluid in the vessel may flow around the balloon assembly, and 2) when the balloon member is in an inflated state, (a) sections of the balloon member contact the vessel wall defining a plurality of containment pockets for containing a second fluid between the vessel wall and within the containing sections of the balloon member, and (b) a single flow lumen is defined through the balloon member to allow the first fluid to pass through the balloon member;
means for inflating the balloon member; and means for providing a second fluid to the containment pockets when the balloon is in an inflated state.

60. The fluid delivery catheter of claim 59 wherein the means for providing a second fluid to the containment pocket comprises a drug lumen provided through the tubular shaft, the drug lumen being in fluid communication with at least one aperture disposed in the distal end of the shaft.

61. The fluid delivery catheter of claim 59 wherein the means for providing a second fluid to the containment pockets comprises a drug lumen provided through the tubular shaft, the drug lumen being in fluid communication with at least one aperture disposed in the balloon member.

62. The drug delivery catheter of claim 59 wherein the containment pockets are not in fluid communication with each other.