U.S. patent number 3,613,684 [Application Number 04/859,413] was granted by the patent office on 1971-10-19 for trocar catheters.
Invention is credited to David S. Sheridan.
United States Patent |
3,613,684 |
Sheridan |
October 19, 1971 |
TROCAR CATHETERS
Abstract
A trocar catheter is formed with a rigid shaftlike stylet and an
encircling catheter made of plastic material. The catheter has a
molded rigid distal end member with a conical shape, a closed
rounded tip fixed to a flexible tube, and at least one fluid
opening through the side. The rigid distal end member has an
interior that conforms to the shape of the stylet tip. The device
may be used in emergency cases where the catheter is forced through
the chest wall of a patient over the stylet which is then withdrawn
to let fluid pass through the catheter or for suprapubic cystostomy
procedures.
Inventors: |
Sheridan; David S. (Argyle,
NY) |
Family
ID: |
25330862 |
Appl.
No.: |
04/859,413 |
Filed: |
September 19, 1969 |
Current U.S.
Class: |
604/264; D24/146;
D24/147; 128/207.29 |
Current CPC
Class: |
A61M
25/09033 (20130101); A61M 25/01 (20130101); A61B
17/34 (20130101); A61B 17/3415 (20130101); A61B
2017/06085 (20130101) |
Current International
Class: |
A61B
17/34 (20060101); A61M 25/01 (20060101); A61B
17/06 (20060101); A61b 017/34 (); A61m
027/00 () |
Field of
Search: |
;128/348-351,347,221,215,214.4 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Truluck; Dalton L.
Claims
The embodiments of the invention in which an exclusive property or
right is claimed are defined as follows:
1. A trocar catheter comprising:
A. a rigid stylet including:
a. a rigid metal shaft of circular cross section,
b. a source square tip on the distal end of the shaft, and
c. an enlarged hand-engaging member attached to the proximal end of
the shaft,
B. a catheter formed of plastic material including:
a. a rigid or semirigid distal end member molded of rigid or
semirigid plastic material with a closed conical-shaped, smoothly
rounded tip,
b. at least one fluid opening through the sidewall,
c. a proximal end portion,
d. a central body portion of cylindrical shape integral with said
proximal end portion and joined to said distal end member,
e. said central body portion being formed of transparent flexible
plastic material,
f. the interior of said distal end member being molded to conform
in shape to the square tip of said rigid stylet, and
g. the interior of said central body portion being formed to
closely encircle the surface of said rigid shaft, and
C. depth penetration limit means including:
a. a slotted tubular member movably embracing the outer surface of
said central body portion, and
b. a slotted radially extending collar fixed upon one end of said
tubular member.
2. A trocar catheter as claimed in claim 1 wherein said tubular
member and collar are formed in complementary half-sections.
3. A trocar catheter as claimed in claim 2 wherein said
half-sections are molded of plastic material.
Description
BACKGROUND OF THE INVENTION
The present invention relates to trocar catheters which are
designed primarily for insertion through a chest or stomach wall of
a patient in order to allow fluid within a body cavity of the
patient to be withdrawn. A procedure of this type is especially
important in emergency cases where patients may require the
withdrawal of blood, air or other fluid in the pleural cavity
because of an accident such as an automobile collision, assault by
a firearm or the like. Also, in suprapubic cystostomy penetration
of the stomach wall may be necessary for drainage of the bladder
when urethal catherization cannot be performed or for the taking of
sterile urine samples.
Situations which require the use of trocar catheters are generally
of an emergency nature requiring prompt relief of the patient's
critical condition which may include a collapsed lung, air or fluid
in the pleural cavity or similar conditions which require creation
of a fluid channel directly through the chest or stomach wall of
the patient. Hence, catheters of this type must be designed for
reliability, but of simple and highly effective construction. To
avoid possible additional damage to the patient, the trocar
catheter must be capable of insertion through the chest or stomach
wall of the patient without flexing or deviation from the desired
path, e.g., passage between a pair of ribs. Further, the
penetration of the catheter must be accomplished with a minimum of
injury to nerves or vessels and without inflicting trauma on the
expanding lung or collapsing bladder. Additionally, it is desirable
for the catheter device to permit anyone using the catheter upon
the patient to estimate the approximate position within the patient
of the distal end of the catheter and to give some indication as to
when the distal end of the catheter has entered the pleural area or
bladder.
As instruments for treatment of both human and animal bodies,
trocars are well known. For example, they are widely used in
embalming (see U.S. Pat. No. 2,639,484). Although they more
generally are employed to introduce or withdraw fluids from a body,
they may be used to extract tissue such as in a biopsy (see U.S.
Pat. No. 2,541,542).
Trocar catheters may be of a single element construction such as a
catheter of rigid or semirigid material with a pointed end capable
of penetrating a body (see U.S. Pat. No. 1,273,542 ). On the other
hand, it is known to employ stylets with catheters to provide the
catheter which is of flexible construction to obtain a sufficient
degree of rigidity to permit the catheter to be properly placed
within a patient's body (see U.S. Pat. No. 2,118,631). The
combination of a rigid stylet and an encircling catheter has been
used in the past in the creation of catheter devices of the general
type to which the present invention pertains, namely, trocar
catheters.
Notwithstanding these prior developments in the field of
medicosurgical devices and particularly trocars and catheters,
further improvements are needed in the construction of trocar
catheters. These include means for insuring correct, effective or
nontraumatic insertion of the catheter through the chest or stomach
wall of a patient and means to insure the catheter penetrates to a
required depth without overpenetration which can cause severe
injury to the patient.
OBJECTS
A principal object of this invention is the provision of new
improvements in construction of trocar catheters.
Further objects include the provision of:
1. Trocar catheter devices which prevent the catheter upon
insertion 6 in a patient from penetrating beyond a required
depth.
2. Such improved catheters which give the surgeon or physician
using the device a visual indication as to when the distal end has
entered the pleural cavity, bladder or other desired body
cavity.
3. Improvements in trocar catheter construction which enable
insertion of the catheter within a patient to be accomplished with
a minimum of danger of bodily injury to the patient.
4. Improved ways of making trocar catheters which permit them to be
manufactured in large numbers at low cost so that they can be
treated as single-use disposable items.
5. Trocar catheters which when inserted in a patient, fill the
entire body puncture, creating effective sealing of the catheter in
the body to reduce possibility of infection and provide for proper
functioning of the catheter.
Other objects and further scope of applicability of the present
invention will become apparent from the detailed description given
hereinafter; it should be understood, however, that the detailed
description, while indicating preferred embodiments of the
invention, is given by way of illustration only, since various
changes and modifications within the spirit and scope of the
invention will become apparent to those skilled in the art from
this detailed description.
SUMMARY OF THE INVENTION
These objects are accomplished according to the present invention
by the provision of trocar catheters which comprise:
A. a rigid stylet including:
a. a rigid shaft of circular cross section,
b. an enlarged hand-engaging member attached to the proximal end of
the shaft, and
B. a catheter formed of plastic material including:
a. a rigid distal end member molded of rigid plastic material with
a smooth, close conical-shaped tip,
b. at least one fluid opening through the sidewall, e.g., near the
distal end,
c. a proximal end portion,
d. a central body portion of cylindrical shape integral with said
proximal end portion and joined to said distal end member,
e. said proximal end portion and central body portion being formed
of flexible plastic material,
f. the interior of said distal end member being molded to conform
in shape to the tip of said rigid stylet, and
g. the interior of said central body portion being formed to
closely encircle the surface of said rigid shaft.
Advantageously, the rigid stylet which constitutes the inner
element of the new catheter devices has a square tip and the stylet
is made of metal. Further, the preferred new catheters have a
distal end member which has an outside surface of the same
circumference as the circumference of the central body portion of
the catheter and both of these are made of plastic material that is
transparent.
In the preferred form of the new trocar catheters, there is
included a depth-penetration-limit means which movably embraces the
outer surface of the central body portion of the catheter.
Advantageously, this comprises a slotted tubular member having a
slotted radially extending collar affixed upon one end. Such
tubular member may be molded in two complementary half-sections of
plastic material. Alternatively, it may be a singular element
having a longitudinal slot permitting the member to be compressed
inwardly to grip the outer surface of the central body portion of
the catheter.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a fragmentary top elevational view of a preferred
embodiment of a trocar catheter in accordance with the
invention.
FIG. 2 is an enlarged fragmentary side view partially in section of
the distal and proximal end portions of the catheter of FIG. 1.
FIG. 3 is an enlarged top exploded view illustrating components
used in making one embodiment of the new trocar catheter.
FIG. 4 is a reduced top elevational view of the catheter of FIG. 1
showing the depth of penetration limit means of the catheter device
embracing the outer surface of the catheter.
FIG. 5 is a diagrammatic view illustrating placement of the
catheter through the chest wall of a patient.
FIG. 6 is a perspective enlarged, fragmentary view of the distal
end portion of a catheter of the invention in its course of
manufacture.
FIG. 7 is an enlarged, fragmentary side view of the distal end
portion of a trocar catheter in accordance with the invention.
FIG. 8 is an end elevational view of one form of depth penetration
limit means of the catheter devices in accordance with the
invention.
FIG. 9 is an end elevational view of a modified form of depth
penetration limit means.
DESCRIPTION OF PREFERRED EMBODIMENTS
Referring in detail to the drawings, a preferred embodiment of a
trocar catheter 2 in accordance with the invention comprises a
rigid stylet 4 and a catheter 6 formed of plastic material.
The rigid stylet 4 comprises a rigid shaft 8 of circular cross
section, a capillary groove 10 extending from adjacent the distal
end 12 to the proximal end 14 of the shaft. The proximal end of the
shaft has attached thereto an enlarged hand-engaging member 16
which advantageously is a solid plastic ball threaded upon or
otherwise fixed to the proximal end of the shaft 8.
In the form of catheter shown in FIG. 2, the tip 12 of the stylet 4
has a square tip 18. The end 24 is formed of rigid plastic material
while the remainder of the catheter 6 is formed of flexible plastic
material. In the form of catheter shown in FIG. 2, this
construction is attained by placing a cylindrical piece of rigid
plastic in a heated mold and then forcing a flexible plastic tube
in back of the rigid piece. The combination of heat and pressure
softens the rigid piece, shapes the free end into a rounded tip 26
and welds the other end of the piece to the tube in a smooth
junction. One or more fluid openings 28 extend through the sidewall
30.
In the form of catheter shown in FIG. 3, the catheter 6 comprises a
rigid distal end member 32 having a smooth conical-shaped tip 34.
The member 24 is preferably molded, such as by injection molding,
compression molding, centrifugal casting or the like, of rigid or
semirigid plastic material, e.g., nylon, polyvinyl chloride, or
equivalent plastic materials. Alternatively, the end member 24 may
be formed of metal such as stainless steel by any suitable
metalworking technique. Use of transparent rigid or semirigid
plastic material for forming the distal end member 24 is preferred.
The preformed member 32 is fixed to the tube 36 by cementing,
friction wielding or in any other suitable manner.
The catheter also comprises the central body portion 38 of
cylindrical shape formed integrally with a proximal end portion 40.
These are preferably formed of flexible transparent plastic
material by extrusion although other plastic-forming methods such
as dipping, injection molding, centrifugal casting or the like can
be used to form these portions of the catheter. Unpigmented
plasticized polyvinyl chloride is an advantageous type of plastic
material to use in forming elements 38 and 40 although other
flexible materials such as vinyl ester polymers, e.g., E.V.A., and
the like may be used and, if desired, these may include pigments or
fillers so that the tube is translucent or opaque rather than being
transparent. Such pigments may include X-ray opaque material so
that part or all of the plastic catheter is opaque to X-rays
permitting it position within a patient's body to be readily
determined by X-ray examination.
In the embodiment of catheters shown in FIG. 1, the central body
portion 38 and proximal end portion 40 are made of uniform wall
thickness and constant diameter throughout. Alternatively, the
catheter maybe formed with variation in diameter and wall
thickness, lumen or the like, e.g., the proximal end 40 may be
formed with heavier wall thickness, with a funnel construction 42
to provide a female connector end or with a male connector
construction 45 to permit the catheter to be attached to auxiliary
equipment which may be necessary or desirable in conducting
operations on the patient in accordance with recognized surgical or
clinical practice, e.g., as used with standard thoracic
catheters.
The length of the rigid distal end member 24 or 32 is not critical
although a short length of about 0.5 to 2 cm. is preferred so that
maximum length of flexibility in the catheter can be obtained. In
order that the entire outer surface of the catheter will be
continuously smooth throughout its length, the distal end member 24
or 32 has a circumference identical to the circumference of the
central body portion 38, particularly at the joint between these
two elements.
The interior surface 44 of the distal end member 24 is molded to
conform in shape to the tip 12 of the rigid stylet 4. In the
embodiment shown in FIG. 2, the tip 12 of the stylet 4 is square
ended and the distal end member 24 has an interior shape to
accommodate this square ended stylet.
The catheter 2 preferably includes a depth penetration limit means
48. This may assume various forms but advantageously comprises a
tubular member 50 having a longitudinal slot 52 and a radially
extending collar 54 which is similarily slotted. The tubular member
50 may have more than one slot and as seen in FIG. 9 a pair of
slots 52a and 52b may be used thereby dividing the tubular member
50 into a pair of complementary half-sections 50a an 50b In the
embodiment of the limit means shown in FIG. 8, the tubular member
50 has only a single slot 52. Such limit means can be molded of
plastic material such as polyvinyl chloride, polystyrene, nylon or
the like or alternatively, it may be cast, machined or otherwise
formed of metal.
An alternative method of forming the new trocar catheters is shown
in FIGS. 6 and 7. A cylindrical plug 60 of rigid plastic material
is placed in the end 62 of the tube 64 made of a flexible
formulation of polyvinyl chloride. This assembly is then placed in
a mold (not shown) of the desired shape and is heated to a
temperature, e.g., 250.degree.-350.degree. F., that melts the
plastic and the tube 64 is pushed into the mold to provide pressure
to make the softened plastic take the shape of the mold. This
creates the distal end 66 in which the rounded tip 68 is rigid with
a gradual transition in rigidity the region 70 toward the flexible
tube 64. The openings or holes 28 may be formed by known cutting or
punching methods before or after the molding operations as
described.
Since the trocar catheters of the invention are by their nature
often used for emergency cases and under conditions where
sterilization equipment is unavailable, it is advantageous for the
assembly to been closed in a sealable package in which it can be
sterilized such as by exposure to ethylene oxide vapors, gamma
radiations or similar techniques known to medicosurgical equipment
manufacturers so that the catheter assembly will remain within the
package in sterile condition and immediately available in this form
upon opening of the package for safe use by the surgeon, physician
or other party in attendance of the emergency patient. Also,
suitable markings can be formed by printing, staining or the like,
on a surface of the stylet or the catheter to indicate any
appropriate distance from the pointed tip 68 or one of the openings
28 as may be preferred or required by the surgeon or other party
who would use the device. X-ray indicator tips or eyes may also be
formed in the catheter.
The method of use of the catheter is illustrated in FIG. 5 in an
intercostal penetration to the pleural cavity. The surgeon or other
user estimates the distance along the central body portion 38 that
penetration into the pleural cavity 72 of the patient, the catheter
is to be inserted. A slight incision is made with a scapula or
knife in the skin. The penetration limit member 48 is then placed
along the catheter so that the collar 54 is located at this
critical position on the catheter 6. The user then grasps the
penetration limit member 48 in one hand 74, exerting sufficient
pressure on the unit 48 so that it tightly grasps the outer surface
of the catheter 6. The proximal end ball 16 is then palmed in the
other hand 76 of the operator and the rounded point 24 of the
catheter 6 is then placed in the skin incision positioned between a
pair of ribs 78 and 80 of the patient in known manner so that the
intercostal penetration can be made. This is accomplished by
exerting simultaneous force through the hands 74 and 76 until the
distal end member 24 of the catheter 6 penetrates the chest wall 82
of the patient and enters the pleural cavity 72. Once the skin is
cut, the slightly blunted tip of the new trocar is quite easily
forced through the rest of the tissue into the body cavity.
Accidental overpenetration is prevented by the collar 54 of limit
means 48 coming to rest against the skin on the chest of the
patient. A visual indication is given to the surgeon or other
operator that the distal end opening 28 has entered the pleural
area since blood or other fluid appears at the proximal end of the
catheter by passing along the channel 10. This is not essential,
however, and the channel 10 may be omitted in the construction of
the stylet. At this point, the stylet 4 is partially withdrawn from
the interior of the catheter. The catheter is then clamped off and
the stylet is completely withdrawn. To complete the procedure, the
proximal end 40 of the catheter will be connected to a closed
underwater seal system or any other auxiliary equipment required
for the patient under the particular circumstances and the
patient's injury or disease and the clamp is removed.
The smooth rigid tip construction of the new trocar catheters
permits necessary penetration of the chest or stomach wall to be
accomplished without inflicting trauma on the expanding lung or
collapsing bladder. Further, with sharp pointed needles or trocar
of prior types there is always the danger of puncturing the far
wall of the bladder or the lung during the thorocotomy. This is
obviated by the rounded rigid tip of the new catheters. Also, where
the catheter must dwell in the patient for an extended period, the
rounded tip mitigates possibility of puncture or other trauma.
* * * * *