tracts often encompass only a portion of the lumenal
DRUG DELIVERY APPARATUS AND METHOD circumference. The ducts of the prostate gland communicate with the floor of the urethra; therefore, it would
REFERENCE TO CO-PENDING APPLICATION more efficient to deliver agents (antibiotics, anticancer agents) toward the ducts which access the prostate
This application is a continuation-in-part of U.S. pa- than to cirCUmferentially deliver across the prostatic
tent application Ser. No. 07/937,464, filed Aug. 28, orethra
"1992, which is .« ocm&i^-in-pait of U.S. patent Therefore, a need exists for a drug delivery apparatus
application Ser No 07/705,731 filed May 24, 1991, providing radiany restricted delivery of a drug o?medi
which is d continuation-in-part of U.S. patent apphca- 10. . , ,. , e „ i L A
c„ Vt io-j-ioo n J T i mm Idv v.- I. • cant to a localized area of internal body tissue.
Hon Ser. No. 637,299, filed Jan. 3, 1991ABN, which in'
turn is a continuation-in-part of U.S. patent application SUMMARY OF THE INVENTION
Ser. No. 538,961, filed Jun. 15, 1990ABN. T ,
In accordance with the present invention, an appara
BACKGROUND OF THE INVENTION 15 tus and method is provided for delivering a drug or
1. Field of the Invention combination of drugs selectively and locally to an interThe present invention relates generally to a drug nal ho&y tissue- ^ invention relates to an apparatus
delivery apparatus and method, and more particularly, «nd method for radially restricted delivery of a drug or
to an apparatus and method for selectively and locally combination of drugs substantially transversely to the
delivering a drug to internal body tissue. 20 longitudinal axis of a body passageway such as blood
2. Description of the Prior Art vessel, urinary tract, intestinal tract, reproductive tract, Many techniques currently exist for delivering drugs etc., in order to treat a localized region of the passage
or other medicaments to body tissue. These include, way itself or to treat d localized region or tissue located
among possible others, oral administration, injection adjacent to the passageway.
directly into body tissue such as through an intramuscu- 25 in the preferred embodiment, the apparatus includes
lar injection or the like, topical or transcutaneous ad- a flexible member adapted for insertion into a target
ministration where the drug is passively absorbed, or area of internal tissue, such as a passageway or vessel, a
caused to pass, into or across the skin or other surface drug delivery means including a drug delivery chamber
tissue and intravenous administration which involves connected with ^ member for delivering a drug to a
introducing a selected drug directly into the blood 30 ^get area, and a nonpermeable balloon secured to and
stream. .... about or above the drug delivery chamber for securing
Except for topical or transcutaneous administration, „ . ■ f , ^. T , -.7
,y, jV . * _,» v i.- T the apparatus against internal tissue. In accordance with
the above drug delivery systems tend to be systemic. In ^, . . °. ,. . „ ,. ..
other words, adrmnistration of the drug is delivered the mention, the nonpermeable balloon radially re
throughout the body by the blood stream. 35 st"c's local ... of a dru« l° TM mternal
Over the past several years, the pursuit of devices for The dru8 dehv«y means further mcludes a fluld
localized drug delivery has become exceedingly more delivery lumen or passageway extending from the prox
intense as the advantages of this method of therapy over imal end of the flexible catheter to the drug chamber for
systemic drug administration have become apparent. delivering a selected drug to the drug chamber. The
Because many diseases affect a specific site or organ 40 drug chamber defines a drug delivery area and has a
within the body, it is advantageous to preferentially drug transport wall which is constructed of a material
treat the affected area. This avoids high systemic drug that permits selective transport of a drug therethrough,
levels which may result in adverse side effects and con- i.e. constructed of at least perforated, permeable, micro
centrates therapeutic agents in the local area where they porous or semipermeable material through which the
are needed. By treating just the diseased tissue, the total 45 drug is intended to selectively pass, that is, selectively
quantity of drug used may be significantly reduced, and permeable.
hence the cost of therapy, especially when using newer Transport of the drug across the drug transport wall
genetically engineered drugs. Moreover, local drug ^ ^ facilitated by a driving force such as pressure,
delivery may allow for the use of certain effective ther- iontophoresis or phonophoresis. In preferred embodi
apeutic agents which have previously been considered 50 ments> non.pressure transport forces such as iontopho
too toxic or nonspecific to use systemically. resis or phon0phoresis are empioyed.
Several devices have been developed for the purpose Jn Qne embodinlenti the apparatus includes circum
of accessing specific body lumens or passageways (i.e. ... u ^^tely adjacent the proximal and
blood vessels, gastrointestinal ract, urinary tract) and distal ends of the drug delivery area that act to minimize
delivering therapeutic agents transmurally to specific 55 , f , °. /, . , ,
, ■ c- A J vi u ii *x. * u u movement of a drug beyond the segment of vessel or
subregions of tissue. A double-balloon catheter has been ... «_ _,. LJ. . .
used to administer agents to the area confined by the ho"ow or«an An embodiment of the
balloons. A disadvantage of this system is that drugs [adially restricted local delivery apparatus can also
may be lost through communicating vessels between have a dru8 recovery. lumen extending from the drug
the balloons. Alternatively, a perforated balloon has 60 chamber to the proximal end of the flexible catheter.
been developed to deliver agents directly into the vessel Accordingly, it is an object of the present invention
wall. A major disadvantage with both of these systems t0 provide a drug delivery apparatus and method for
in certain desired applications is that the drug is deliv- radially restricted delivery of a drug or combination of
ered radially in all directions. drugs locally to internal body tissue.
In some therapeutic applications, it can be advanta- 65 This object of the present invention will become
geous to deliver the drug only to one radial section of apparent with reference to the drawings, the descrip
the vessel or passageway. For example, localized neo- tion of the preferred embodiment and method, and the
plasia in the gastrointestinal, urinary or reproductive appended claims.