embodiments of the presently disclosed catheter assembly will now be described in detail with reference to the drawings wherein like reference numerals identify similar or identical elements in each of the several views . in the discussion that follows , the term “ proximal ” or “ trailing ” will refer to the portion of a structure that is closer to a user , while the term “ distal ” or “ leading ” will refer to the portion of the structure that is farther from the user . in addition , the term spiral as used in association with the infusion tube and the central member means that the infusion tube extends along and at least partially around the central member in a helical , coiled or like configuration . referring initially to fig1 - 4 , a catheter assembly 10 constructed in accordance with the principles of the present disclosure includes a handle housing 50 , a movable handle 28 , a catheter body 12 , a central member 14 , and an infusion tube 16 . catheter body 12 extends at least partially into a distal end 54 of handle housing 50 and includes a hub 18 at its proximal end that operates to reinforce the coupling of catheter body 12 into the distal end 54 of handle housing 50 . hub 18 may be , for example , flexible shrink wrap tubing encapsulating at least a portion of the distal end 54 of handle housing 50 and at least a portion of a proximal end of catheter body 12 . handle housing 50 includes a first connector 20 at or near its distal end 54 for attaching to a fluid source such as a source of a thrombolytic agent to be delivered through the catheter body 12 and a second connector 21 at or near its distal end 54 for attaching to saline or other liquid for flushing the catheter body 12 . as shown in the cross section of fig2 , the catheter body 12 defines a first lumen 22 that receives the thrombolytic or other agent through the port 20 and delivers it to a proximal end 24 of the infusion tube 16 . the proximal end 24 of infusion tube 16 may be shrink wrapped ( not explicitly shown ) and heated to bond the proximal end 24 of infusion tube 16 to first lumen 22 of catheter body 12 at a mid - joint 60 ( fig1 ) via shrink wrap tubing ( not explicitly shown ). catheter body 12 includes a second lumen 26 which slidably receives the central member 14 which is typically a polymeric tube or the like operably coupled to the handle 28 at its proximal end . using the handle 28 , a physician can axially advance ( see fig5 ) and proximally retract ( see fig7 ) the central member 14 in order to control deployment of the infusion tube 16 , as will be described in more detail with reference to fig3 , 5 , and 7 . the infusion tube 16 is straight in its “ free ” configuration , i . e . where no tension or compression is being applied to the infusion tube 16 . in certain embodiments , the polymeric material ( e . g ., nylon - 12 ) from which the infusion tube 16 is made may possess sufficient stiffness and elasticity without reinforcement to perform as described herein . alternatively , as illustrated in fig4 , a stiffening member or wire 35 that extends through at least a portion of the lumen of the infusion tube 16 may be provided to provide added rigidity to infusion tube 16 . in this scenario , a distal end of the stiffening member or wire 35 is attached at or near its distal end to the distal end of the infusion tube 16 and attached at its proximal end to the catheter body 12 within the infusion lumen 22 , as best seen in fig2 . in other embodiments , however , a proximal end of the stiffening wire 35 is unattached at its proximal end so that the proximal portion of the stiffening wire may move freely within the lumen 22 of the catheter body as the catheter itself is advanced through a body lumen . as best seen in fig1 and 3 , a one - way valve 36 ( e . g ., a duckbill valve ) may be provided at or near the distal end 34 of the central member 14 in order to prevent back - bleed , i . e ., blood flow into central member 14 . one - way valve 36 may be , for example , shrink wrapped or heat - sealed to central member 14 to reduce the cross - sectional profile of catheter assembly 10 and enable catheter assembly 10 to be introduced into a blood vessel or other body lumen . one way valve 36 also facilitates the introduction of a guide wire 38 ( see fig3 a ) or a medical fluid into vasculature via central member 14 . the infusion tube 16 defines a lumen 17 ( see fig3 ) along its length and further includes a plurality of release ports 30 which serve to release fluid from the lumen 17 into a blood vessel bv or other luminal wall . relative to infusion tube 16 , the material from which the central member 14 is made is more rigid or stiff . for example , central member 14 may be made from a polymer such as a polyimide or polyetheretherketone (“ peek ”). a distal end 32 of the infusion tube 16 is attached near distal end 34 of the central member 14 so that axial advancement of the central member 14 operates to lengthen or elongate the infusion tube 16 , as shown in fig1 , in order to reduce the cross - sectional profile of the infusion tube 16 to enable the infusion tube 16 to be introduced into a blood vessel or other body lumen . conversely , proximal retraction of the central member 14 , as shown in fig3 , radially expands the infusion tube 16 so that it moves outwardly toward the inner wall w of the blood vessel bv or other body lumen . the infusion tube 16 may be spirally or helically wrapped around the central member 14 in its deployment configuration , as shown in fig1 and 3a . as shown in fig1 , 3 and 3 b , one or more radio - opaque markers or bands 19 may be disposed on the catheter body , central member , and / or infusion tube 16 and / or 16 a to allow for clear visualization of the treatment region using fluoroscopic imaging . in addition , to promote visualization of the treatment region , the infusion tube 16 may be comprised of a radiopaque filler such as barium sulfate , for example . referring now to fig5 - 8 , central member 14 extends proximally from catheter body 12 at least partially within handle housing 50 and is operably coupled to a distal end 42 of movable handle 28 . distal end 42 of movable handle 28 is configured to axially reciprocate within proximal end 52 of handle housing 50 to control movement of central member 14 . more specifically and as shown in fig5 , as movable handle 28 is axially advanced , as depicted by directional arrow “ a ”, tension in central member 14 is substantially reduced or eliminated such that infusion tube 16 is lengthened or elongated , as shown in fig1 . as best shown in the cross - section of fig8 , distal end 42 of movable handle 28 includes an annular bushing 45 having an outer surface for sliding engagement with an inner surface of handle housing 50 . annular bushing 45 operates to coaxially stabilize movable handle 28 centrally within handle housing 50 during axial retraction and advancement of handle 28 . in addition , annular busing 45 acts as a seal to allow pressurized flushing of the annular space between central member 14 and catheter body 12 through second connector 21 . as shown in fig7 , as movable handle 28 is axially retracted within handle housing 50 , as depicted by directional arrow “ b ”, infusion tube 16 is compressed by central member 14 such that infusion tube 16 shortens and radially expands toward the inner wall w of the blood vessel bv or other body lumen . as best shown in the cross - section of fig6 , movable handle 28 includes a pair of longitudinal recesses 48 a , 48 b disposed at least partially along opposing sides of the distal end 42 of movable handle 28 . a pair of pins 46 a , 46 b are disposed through opposing sides of handle housing 50 . pins 46 a and 46 b are configured to be received within longitudinal recesses 48 a , 48 b , respectively , of a movable handle 28 . a plurality of indents 44 are incrementally formed within longitudinal recesses 48 a such that upon axial translation of handle 28 , pin , 46 b is configured to be brought into and out of registration with indents 44 . indents 44 may be axially spaced apart in a substantially uniform manner such that proximal retraction and / or axial advancement of movable handle 28 may be incrementally controlled to provide controlled radial expansion and contraction of infusion tube 16 within a blood vessel or other body lumen . in this way , infusion tube 16 may be manipulated in a controlled manner to conform to blood vessels or body lumens of various sizes . in one embodiment , pin 46 b is configured to receive a spring - loaded ball or detent 46 c which allows for distinct engagement with indents 44 . alternatively , other known flexible or resilient engagement devices may be provided to releasably retain movable handle 28 at fixed positions in relation to handle housing 50 . one or both of pins 46 a , 46 b may be , for example , a dowel pin , a threaded fastener , a spring plunger , or the like , and may be adjusted ( i . e ., advanced into handle housing 50 or retracted from handle housing 50 ) as needed . in this manner , the size ( e . g ., circumference ) of the housing and / or handle utilized may be varied without compromising interaction between pins 46 a , 46 b and longitudinal recesses 48 a , 48 b . as can be seen in fig5 and 6 , longitudinal recesses 48 a , 48 b include a pair of distal travel limiting stops 49 a , 49 b , respectively . in use , movable handle 28 may be advanced until pins 46 a , 46 b engage distal travel limiting stops 49 a , 49 b , respectively . similarly , as can be seen in fig7 , longitudinal recesses 48 a , 48 b include a pair of proximal travel limiting stops 49 c ( only one is illustrated ) which engage pins 46 a , 46 b to limit or prevent further axial retraction of movable handle 28 . as movable handle 28 is moved proximally , as illustrated by directional arrow “ b ” in fig7 , the central member 14 is retracted to cause the infusion tube 16 to radially expand into a generally spiral configuration , as shown in fig3 and 3b . since the infusion tube 16 is not pre - shaped , however , the spiral will only form as the infusion tube engages the wall surface w of blood vessel bv , thus allowing the infusion tube to conform to a variety of different diameters and irregularities within and along the surface of the wall surface w of blood vessel . thus , it would not necessarily be expected that the infusion tube 16 will actually achieve the uniform spiral as illustrated in fig3 , instead , it will more often achieve a generally helical or spiral shape which can adapt to match the topography of the wall being engaged . as shown in fig3 b , catheter 10 , in certain embodiments , may include a second infusion tube 16 a in addition to infusion tube 16 . in this scenario , infusion tube 16 a operates substantially as described above with respect to infusion tube 16 . infusion tube 16 a may be spirally wrapped around the central member 14 to interweave with infusion tube 16 in the deployed state ( not explicitly shown ) and to radially expand with infusion tube 16 into a generally spiral configuration upon retraction of movable handle 28 ( fig1 ), as shown in fig3 b . after deployment as shown in fig3 and 3b , the thrombolytic or other agent may be released into the first connector 20 so that it flows through lumen 22 ( fig2 ) and into the infusion tube 16 and / or 16 a for release into the blood vessel bv or other body lumen . saline may be delivered through second connector 21 prior to any procedure to flush lumen 26 . as shown in fig1 , 5 , and 7 , the proximal end 40 of movable handle 28 includes a female luer 39 that provides access to a lumen 29 ( fig5 ) defined through movable handle 28 . lumen 29 communicates with the lumen defined by central member 14 . a male - type cap 43 may be removably fastened ( e . g ., via threading , snap - fit , slide - fit , etc .) into female luer 39 to prevent access or seal the proximal end of lumen 29 . upon removal of cap 43 , a fluid source may be removably coupled to female luer 39 to introduce fluid such as saline into movable handle 28 and central member 14 . further , a guide wire 38 ( see fig3 a ) may be inserted through lumen 29 , and into central member 14 , and through one - way valve 36 to facilitate introduction of infusion lumen 16 ( and / or 16 a ) and central member 14 into the blood vessel bv or other body lumen . although the specific features of the disclosure are shown in some drawings and not in others , this is for convenience only as each feature may be combined with any or all of the other features in accordance with the disclosure . it will be understood that various modifications may be made to the embodiments of the presently disclosed delivery catheters . therefore , the above description should not be construed as limiting , but merely as exemplifications of embodiments . those skilled in the art will envision other modifications within the scope and spirit of the present disclosure .
an infusion catheter includes a catheter body having a proximal end , a distal end , and two or more lumens extending therethrough . the infusion catheter also includes an infusion tube having a proximal end , a distal end , and one or more ports disposed therethrough . the first lumen of the catheter body is in fluid communication with the lumen of the infusion tube . a central member has a distal end connected to the distal end of the infusion tube , a proximal end , and a proximal portion slidably received in the second lumen of the catheter body . the infusion tube is disposed relative to the central member such that axial advancement of the central member relative to the catheter body radially collapses the infusion tube over the central member and axial retraction of the central member relative to the catheter body radially expands the infusion tube about the central member .