Catheter delivery system and method

A catheter delivery system for delivering an elongated cannula-type catheter, normally including a cannula with an attachment on the tip thereof, to a body of a mammal and for controlling the movement of the cannula in the mammal's body includes both a cannula-control fitting and an enlarged hollow cannula delivery housing. The cannula control fitting has at least three openings therein. A cannula to be delivered to the mammal's body extends through the first and second openings of the cannula-control fitting and pressurized fluid can be inserted into the third opening. A sealing clamp is at the first opening for selectively, sealingly clamping the cannula-control fitting to the cannula. Thus, when the sealing clamp is tightened, fluid introduced at the third opening leaves the cannula-control fitting at the second opening. The hollow cannula delivery housing is attached to the third opening and has a relatively large cavity for receiving gathered portions of the cannula therein. The cannula delivery housing is attached to the third outlet of the cannula-control fitting at an inlet thereof and is attached to a mammal's blood vessel at an outlet thereof. The method of use is that the sealing clamp is tightened and the cannula is gathered in the cannula delivery housing. Pressurized fluid is introduced into the cannula-control fitting to drive the gathered cannula and its attachment from the cannula delivery housing into the mammal's blood vessel. Once all of the gathered cannula has been delivered to the mammal's body the sealing clamp is released and the proximal end of the cannula is controlled manually.

BACKGROUND OF THE INVENTION 
This invention relates broadly to the art of intravenous catheters, and 
more specifically to such catheters including long cannulas for carrying 
out surgical functions in remote parts of mammal bodies. 
This application describes an advantageous method and apparatus, for 
example, for delivering the miniature balloon catheters described in U.S. 
patent application Ser. No. 681,676 of Paul H. Pevsner. 
This invention also relates to U.S. Pat. Nos. 3,703,174 and 3,826,256 to 
Smith. 
Basically, a procedure for using miniature intravenous balloon catheters in 
remote parts of the body involves firstly getting the catheter through a 
main artery of choice and secondly, guiding the catheter on a tortuous 
route to an exact blood vessel to be treated, such as in the brain, for 
example. 
With regard to getting the catheter through the main artery, this can be 
done by first selectively catheterizing an artery of choice, such as the 
axillary, femoral, or common carotid artery using the Seldinger technique. 
In this respect, for example, a number five French polyethelyne catheter, 
or catheterizing tube, 11 (FIG. 1) can be inserted in the artery to extend 
from outside the patient's body to the approximate area to be treated. In 
this regard, it is not unusual for this tube to extend from below a 
patient's waist to above the patient's neck, for example. Next a balloon 
catheter, including a long cannula 13, can be pushed through this 
catheterizing tube 11 by a fluid under pressure. 
In the past, feeding the cannula 13 through the catheterizing tube has been 
unduly cumbersome and messy because it has often been necessary to aid the 
feeding by manual manipulation of the proximal end of the cannula, which 
has allowed the pressurized propelling fluid to escape. Therefore, it is 
an object of this invention to provide a catheter delivery system which 
allows selective manual control of the proximal end of the cannula, where 
necessary, but yet which allows positive feeding of the cannula into a 
blood vessel by a pressurized fluid without significant leakage and 
without the necessity of manual feeding where allowed. 
Once the tip of the cannula 13 passes beyond the distal end of the 
catheterizing tube 11, it must often be guided and manipulated through a 
tortuous system of blood vessels. To accomplish this, the balloon at the 
tip of the cannula 13 is successively inflated and deflated through the 
cannula 13 to be driven by blood flow to a greater or lesser degree as 
desired. During this portion of the procedure, it is essential that the 
doctor have manual control of the proximal end of the cannula. 
Thus, it is an object of this invention to provide a catheter delivery 
system which not only allows positive driving of a cannula by fluid under 
pressure where allowed, but which also allows a doctor to have direct 
manual control of the cannula when either it is or is not being driven by 
a supplied propelling fluid. 
It is a further object of this invention to provide a catheter delivery 
system which provides the above-mentioned advantages, but yet which is 
relatively uncomplicated to manufacture. 
SUMMARY OF THE INVENTION 
According to principles of this invention, an enlarged hollow cannula 
delivery housing is combined with a proximal flushing hub, or a 
cannula-control fitting. The cannula delivery housing has a relatively 
large cavity in which a gathered portion of the cannula can be stored for 
delivering the cannula through a catheterized artery. The cannula-control 
fitting allows positive fluid pressure to be applied to the cannula via 
the cannula delivery housing without leakage of the fluid, but yet also 
selectively allows the cannula to be manually gripped and manipulated when 
desired.

DETAILED DESCRIPTION 
A catheter delivery system of this invention includes a proximal flushing 
hub or cannula-control fitting 14, in combination with a hollow cannula 
delivery housing 21. 
The cannula-control fitting 14, in the illustrated embodiment, is a spool 
valve basically comprising a sleeve 23 and a hollow spool 25 (such a 
device is sold by Becton-Dickinson as a guide-wire and catheter guide). 
The sleeve 23 forms a coupling member 27 having a passage 15 therethrough 
leading into the interior of the sleeve 23. The sleeve 23 makes sliding, 
sealing contact with O-rings 29 mounted in grooves of the spool 25. A 
shoulder 31 on the spool 25 and a metal C-ring 33 mounted in a groove on 
the spool 25 form stops for the sleeve 23 at limits of its motion along 
the spool. When the sleeve 23 is against the shoulder 31 in the position 
depicted in FIG. 2, the opening 15 communicates with the interior 35 of 
the spool 25 via a passageway 37 in the spool 25. On the other hand, when 
the sleeve 23 is against the C-ring 33, the opening 15 does not 
communicate with the interior 35 of the spool 25 but rather is cut off 
therefrom by the O-rings 29. 
At its left end, (as viewed in FIGS. 1 and 4) the spool 25 has internal 
threads 39 which engage external threads 41 of a wing screw 17. When the 
wing screw 17 is tightened into the threads 39 a resilient washer 43 is 
squeezed between two rigid plastic washers 45 to form a seal between the 
interior wall of the spool 25 and the external wall of a cannula 13 
positioned in the interior 35 of the spool 25. However, when the wing 
screw 17 is loose in the internal threads 39, an internal bore 47 of the 
resilient washer 43 allows the cannula 13 to move easily therethrough. 
The right end of the spool 25 (as viewed in FIGS. 1 and 4) includes a 
mounting hub 49 for attaching the spool 25 to an adaptor 51 of the cannula 
delivery housing 21. 
The cannula delivery housing 21 includes a main cylindrically-shaped 
housing 53 and a circular cap 55. The cap 55 has a hole therethrough at 
which the adaptor 51 is mounted. The cap 55 has a portion 57 that is of 
reduced diameter to fit into a large opening 59 of the 
cylindrically-shaped main housing 53 and forms a seal therewith. The 
portion of reduced size 57 has a slot 61 therein for receiving an O-ring 
63 to form a seal with the interior wall of the cylindrically-shaped main 
housing 53. The cylindrically-shaped main housing 53 has a 
conically-shaped right end 65 (as viewed in FIGS. 1 and 4) converging at a 
mounting protrusion 67 having a passageway therethrough. The mounting 
protrusion 67 is adapted to pass through a hole in a lower portion 69 of a 
spring clamp 71. Tabs 73 of the spring clamp 71 cover the cap 55 and are 
held together by an O-ring 74 to hold the cap 55 on the main housing 53. A 
Touhy-Borst adaptor, for example, 75 attaches the mounting protrusion 67 
to a catheterizing tube 11 which is inserted in a blood vessel. The right 
end of the Touhy-Borst adaptor 75 is shown in greater detail in FIG. 3. In 
this respect, a sealing clamp thereof includes a resilient washer 77, a 
rigid plastic washer 79, and a cap 81. The cap 81 has internal threads to 
engage external threads of a main portion 83 of the adaptor 75 to urge the 
rigid plastic washer 79 against the resilient washer 77 and thereby clamp 
the resilient washer 77 on the catheterizing tube 11. 
In operation, a main artery is punctured and the catheterizing tube 11 
inserted therein. A miniature balloon catheter, including a relatively 
long cannula 13 is extended through the spool valve 25 of the 
cannula-control fitting 14 and the wing screw 17 is tightened to clamp the 
cannula-control fitting 14 to the cannula 13 near the distal end thereof. 
The cannula delivery housing 21 must normally be threaded onto the cannula 
13 in a disassembled state with the O-ring 74 being threaded onto the 
cannula first, the cap 55 second, the main housing 53 third, and the 
spring clamp 71 fourth. The cannula is pulled all the way through these 
members. The mounting hub 49 of the spool 25 is inserted into the adaptor 
51 and screwed tightly therein by means of gripping protrusions 85. 
A syringe, or other pressurized fluid source, 87 is mounted on the coupling 
member 27 of the cannula-control fitting 14 and the sleeve 23 is placed in 
the position shown in FIG. 2, with its opening 15 communicating with the 
interior 35 of the spool 25. Syringe 87 is filled with a propelling fluid, 
such as a heparanized flush solution. This solution is forced by the 
syringe 87 first into the interior 35 of the spool 25 and from there into 
the cavity of the cannula delivery housing 21 to fill this up. The cannula 
13 is then forced, by hand, back through the mounting protrusion 67 to be 
gathered in the cavity of the cannula delivery housing 21. The fluid in 
the cannula delivery housing 21 makes this procedure easier. 
Once the cannula 13 is almost fully gathered in the cannula delivery 
housing 21, the balloon attachment, at the distal end of the cannula 13 is 
inserted into the proximal end of the catheterizing tube 11 and the 
mounting protrusion 67 is mounted onto the Touhy-Borst adaptor 75. The 
proximal end of the cannula is filled with radiopaque contrast media to 
visualize the cannula on a fluroscope. Now fluid is applied under pressure 
from the syringe 87 to drive the catheter 13 into the blood vessel through 
the catheterizing tube 11 until the cannula 13 that is gathered in the 
cannula delivery housing 21 is exhausted. At this point, the doctor 
loosens the wing screw 17 and thereafter manipulates the cannula 13 in the 
blood vessel by gripping the proximal end 13a of the cannula. 
It should be understood by those skilled in the art that the catheter 
delivery system of this invention allows positive fluid propelling of long 
cannula-type catheters while also allowing doctors the flexibility of 
selectively manually manipulating such catheters where necessary or 
desired and significantly increases the speed of cannula delivery. 
Although this invention has been described with reference to a preferred 
embodiment, it should be understood by those skilled in the art that 
various modifications exist thereto within the scope of the invention. For 
example, the main housing could be filled with a fluid prior to putting 
its cap 55 on. Also, the cannula-control fitting 14 does not have to be a 
valve as is disclosed herein but can be merely a hollow housing having 
three openings therein, with one opening thereof including a sealing clamp 
for clamping onto a cannula passing therethrough.