A perfusion catheter for use in open heart surgery having an inflatable cuff adjacent the distal end in communication with the lumen of the cathether to self-inflate when perfusion liquid is introduced into the lumen. A reinforcing spine is installed at the cuff area to lend stiffness to the distal end. Flow through passsages in the cuff prevent stagnation and also permit pressure monitoring of the cuff pressure as well as pressure at the distal end of the catheter. An introducer shaft is provided to abut a plug in the lumen, the plug serving to shunt flow through the cuff and also to allow the introducer to apply pressure to the distal end of the catheter when the distal end is being projected into a body organ.

FIELD OF INVENTION 
Cardioplegic catheter for use in open heart surgery and with self-inflating 
retention cuff. 
BACKGROUND AND OBJECTS OF THE INVENTION 
In use of catheters for introduction into a body cavity, a process called 
catheterization, it is common in some instances to include on the catheter 
itself an inflatable balloon or "cuff" which is inflated after 
introduction of the catheter to prevent accidental retraction or rejection 
of the catheter. It is usual to inflate the cuff from an outside source of 
air as, for example, a bulb pump. Representative of the prior art in this 
field is a U.S. Pat. No. 4,573,966 to Weikl et al. 
The present invention is directed to a self-inflating cuff which can be 
used when the catheter is utilized for perfusion of liquid into a body 
cavity. One known means of accomplishing this inflation is to provide the 
catheter with an inflatable cuff surrounding the outside of the catheter 
spaced from the distal end. Openings into the cuff from the lumen are 
provided spaced axially of the lumen, and the sides of distal end of the 
catheter are provided with a plurality of openings for outflow of the 
perfusion liquid. The end of the lumen within the cuff is closed off and 
the openings are designed such that there will be a pressure in the lumen 
which will exert on the interior of the cuff to cause inflation. 
It is an object of the invention to provide an improved self-inflating cuff 
which reduces stagnation of inflating media in the cuff and reduces the 
pressure drop across the cuff. It is a further object to provide an 
optional axial vent which prevents stagnation in the body of the catheter 
under the cuff. A further object is to provide a reinforcement to prevent 
unintentional collapse of the catheter in the cuff area. Pressure 
monitoring is important in the use of a perfusion function and an object 
is also to allow monitoring of the cuff pressure as well as the vessel 
pressure. 
Pressure that approximates the intra-vessel condition in normal operation 
will also register cuff pressure. However, should the pressure monitor 
show an increase as might occur if the distal end of the catheter is 
inadvertently occluded, this would indicate undue pressure in the cuff and 
require immediate attention of the monitoring personnel. Other objects 
include a lumen plug with a design to assist in introducing the distal end 
of the catheter into a vessel. 
Other objects and features of the invention will be apparent in the 
following description and claims in which the invention is described 
together with details to enable persons skilled in the art to practice the 
invention, all in connection with the best mode presently contemplated for 
the invention.

BRIEF DESCRIPTION OF THE INVENTION 
A perfusion catheter having a distal end for introduction into the cavity 
of a body organ, as, for example, introducing cardioplegic liquid into a 
heart organ, which has a lumen blocked at an area of the distal end by a 
plug, the area being surrounded by an inflatable cuff. The interior of the 
cuff is in communication with the lumen to allow flow of liquid into and 
out of the cuff with a sufficient restriction at the distal end of the 
lumen to create an inflating pressure in the cuff when perfusion liquid is 
directed through the catheter. A reinforcing spine overlies the cuff area 
to resist kinking. An introducer shaft projectable into the catheter abuts 
a recess in the plug to allow pressure to be applied to the distal end 
during the introducing phase. 
DETAILED DESCRIPTION OF THE INVENTION AND THE MANNER OF AND PROCESS OF 
USING IT 
The catheter to be described is frequently used in the introduction of 
cardioplegic fluid (cooling fluid) into a heart at the beginning of and 
during an open heart surgical operation. In this procedure, it is 
important not only that the catheter remain in place but that a means be 
provided to prevent the cardioplegic solution from leaking around the 
catheter. Thus the use of the inflatable retention cuff is indicated to 
provide a seal within the heart. It is also important that a surgeon or a 
perfusionist be able to monitor the pressure in the heart cavity receiving 
the cardioplegic liquid. Monitoring pressure in the inflatable cuff is 
also important in instances where cuff pressures may increase 
significantly due to the tip of the catheter being inadvertently occluded 
during manipulation of the heart while delivering in the cardioplegic 
solution. 
WITH REFERENCE TO THE DRAWINGS, in FIG. 1 an elevation of the catheter 
assembly is illustrated. The catheter body 20 is formed of a flexible 
plastic material with a reinforcing coiled spring 21 embedded in the wall 
of the plastic. A connector hub 22 at the proximal end is used to connect 
the catheter to a source of liquid in the use of the catheter for 
infusion. A slip ring 23 serves to aid in the manipulation of the 
catheter. A close-off snap-lock 24 is provided for use in a closing of the 
catheter. A band 26 closes the introduction of a pressure monitoring tube 
28 which also has a connector hub 30. 
Also, in FIG. 1, an introducer shaft 40 has a blunt distal end 42 and a hub 
44 with a first cylindrical section 46 to abut the end 48 of hub 22 and a 
second tapered section 50. This section 50 is dimensioned to move into the 
end 48 of hub 22 in a slip-lock relationship useful in the introduction of 
the catheter into a body organ as will be later described. 
Looking now at FIG. 2, an enlarged area of the distal end of the catheter 
is shown, partially in section, The catheter has a lumen 60 extending from 
the proximal to the distal end. A spine element 62 rigid to semi-rigid, is 
inserted off-center into the wall of the catheter tube at the distal end 
as shown in sectional views FIGS. 3 and 4. The spine element 62 is 
extended from close to the distal end back into the reinforcing coils 
spring area to unify the anti-kink characteristics of the distal end. 
The pressure monitoring tube 28 joins with an incorporated passage 66 in 
the catheter tube wall, this passage being open at 68 to the distal end of 
the catheter. 
Turning now to the inflatable retention cuff 80 shown in FIGS. 1 and 2, the 
cuff, formed of relatively thin flexible membrane that will retain the 
inflationary fluid during use, is enlarged at one end and tapered down to 
the distal end. This cuff compresses, deflates entirely, when the distal 
end of the catheter is introduced to the body organ. 
The cuff 80 has two sleeve ends 82,84 which are snugged and sealed around 
the tube 20 at each end of the cuff. In the lumen 60 between the ends of 
the cuff 80 is inserted a lumen plug 86 which is cylindrical in basic 
shape and symmetrical. Each end has a locator recess 88 as shown in FIG. 5 
for receiving the blunt end of an introducer shaft as will be described. 
The plug is preferably placed toward the distal end of the area enclosed 
by the cuff 80. A shallow axial passage 90 on the surface of the plug 86 
is open to the lumen 60 at each end. While each end of the plug 86 is 
cylindrical in shape with a relatively tight fit with the interior walls 
of the lumen, the central part of the plug is provided with a partial 
girdling recess 92 as shown best in FIG. 3. The purpose of this recess 92 
relates to the installation of the plug 86 near the distal end of the 
lumen. The recess makes it easier to introduce the plug into the lumen. 
Once the plug is properly positioned, a silicon glue (RTV) is introduced 
into the cavity 92 to fill the cavity and lock the plug 86 securely in 
place. 
The lumen 60, as described above, opens to the distal end of the catheter. 
Side opening ports 94 are provided below the cuff sleeve 84 to allow 
perfusion fluid to escape in the event the end of the lumen is closed by 
inadvertent contact with a body part. The lumen, however, also is open to 
the interior of the cuff 80 by side ports 96 at the proximal end of the 
cuff and at the distal end through opposed ports 98 and 100 shown in FIG. 
2. The ports 96,98 and 100 are proportioned in diameter to provide the 
described inflation pressure in the cuff during the use of the catheter. 
In FIGS. 6 and 7, a modification is illustrated in which the same reference 
characters are applied as in FIG. 2 for the same parts. The broken circle 
in FIG. 6 and the sectional view on line 7--7 of FIG. 6 show a short 
radial passage 110 extending from the pressure monitoring passage 66 to 
the lumen 60 within the area covered by the cuff 80. Thus, the pressure 
being monitored in passages 28 and 66 will approximate the pressure at the 
distal end (intra-vessel pressure) in normal operation and intra-cuff 
pressure should the tip be occluded. 
In this embodiment in FIGS. 6 and 7, the passage 90 (FIGS. 3 and 4) is 
eliminated, thus presenting a modified solid plug 86A. 
IN THE OPERATION of the described catheter, the first step in the use is 
the introduction of the catheter into a heart chamber. This is preferably 
accomplished by the use of an introducer shaft 40 having the hub elements 
44,46 and 50. This shaft 40 is projected into the lumen 60 of the catheter 
and moved down so that the blunt end 42 contacts the hollowed recess 88 of 
the plug 86. Pressure is then applied to the hub element 44 to stretch out 
the catheter tube and the tapered element 50 is introduced into the 
catheter stylet 48 in what is referred to as a slip-lock connection. This 
tensioning of the catheter stiffens it for the introduction phase. 
Once the distal end of the catheter is moved through the wall of the body 
element together with the deflated cuff, the introducer shaft may be 
released from the hub 22-48 and withdrawn. The catheter is now ready for 
connection to a perfusion system. The hub 30 of the pressure monitor line 
may then be connected to a pressure monitor system. 
The recess 88 is provided better to translate the axial force created by 
the introducer shaft in stretching (tensioning as above) toward the distal 
tip. The distance between the side ports 96 and the plug 86 is provided so 
that the introducer end 42 will not escape from the lumen into the cuff 
should the end of the catheter buckle unexpectedly during the introduction 
procedure.