Antegrade-retrograde Retention Catheter

Abstract

A catheter has two detachable segments to allow passage of one segment through an orifice in an animal body from a direction opposite to the normal direction, that is, passage from the interior to the exterior of the body. A detachable cap is provided for the leading edge of the segment during its passage through the orifice, after which the cap is removed and the segments are rejoined for normal use.

Parent Case Text

This is a continuation, of application Ser. No. 122,606, filed Mar. 1, 1971 now abandoned.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention comprises a catheter, and more particularly, a catheter capable of passage through an orifice of an animal body from either the interior or the exterior thereof.

2. Prior Art

A catheter serves to conduct fluids, generally body fluids, from a cavity within an animal body. For example, one commonly used catheter, known as a "Foley" retention catheter, has a number of fluid passages extending through a flexible tube, generally of rubber or plastic material. The distal end of the tube is inserted into the body cavity to be drained through an orifice, either natural or artificial, whose diameter is roughly comparable to the inserted end of the catheter. This end has an opening through the side walls at the tip communicating between the body cavity and one or more of the fluid passages, so that fluids may be transferred between these passages and the body cavity. A distensible section communicating with an air passage is also provided in the tip; inflation of the distensible section by a pre-determined amount prevents inadvertent removal of the catheter from the cavity being drained.

The proximal end of the catheter carries a connector for each fluid passage within the catheter. For example, in a typical catheter there is a connector for the fluid drainage passage and another separate connector for the inflation passage leading to the distensible section. The latter connector carries a check valve to maintain the distensible section in the inflated condition as long as desired. An additional passage may be provided for injecting fluid into the body cavity to irrigate it; an additional connector is then also provided for this passage. These connectors branch out from the body of the catheter and present a larger cross section than this body.

The conventional type of catheter so far described is used by passing it from the exterior of the body to the interior thereof through the orifice. Due to the presence of the connectors at the proximal end, the catheter cannot be passed through the body orifice in the reverse direction, that is, from the interior of the body portion to the exterior thereof, since the connectors would not fit through the orifice without substantially enlarging it or without becoming lodged therein. The usefulness of this type of catheter is thereby limited.

A further disadvantage of conventional catheters is that they may severely injure the patient if inadvertently pulled on. For example, when a retention-type catheter is inadvertently pulled on, the distensible tip, which is of large dimension, may rip through body tissue and injure the patient. Further, the catheter must again be implanted in the cavity to be drained and this may cause additional pain or discomfort.

BRIEF SUMMARY OF THE INVENTION

OBJECTS

Accordingly, it is the object of the invention to provide an improved catheter.

A further object of the invention is to provide a catheter capable of retrograde insertion.

Another object of the invention is to provide a catheter which can be inserted in either a retrograde or ante-grade manner.

Yet another object of the invention is to provide a catheter capable of retrograde insertion which is simple to use and inexpensive to manufacture.

A further object of the invention is to provide a catheter which will not injure the patient when inadvertently pulled on.

BRIEF DESCRIPTION OF THE INVENTION

The present invention has two separate segments which are detachably connected to each other. One segment (hereinafter called the "fluid transport segment") has the usual fluid passages terminating in a fluid inlet orifice and a distensible anchoring means, while the other section (hereinafter called the "connector segment") carries corresponding connectors for these passages. In normal use (i.e., while draining or flushing a body cavity), both segments are connected to each other to form a fluid-tight seal. The same is true when the catheter is being inserted in the normal (antegrade) manner.

However, when the catheter is to be inserted in a reverse (retrograde) manner, the connector segment is detached from the transport segment and that end of the transport segment which formerly mated with the connector segment (i.e., the proximal end of the transport segment) is then passed into the body orifice from the inside of the body cavity which is to be drained and is pushed through this orifice to the outside of the body. For example, it may be desirable to insert the catheter in this manner in connection with an operation on a body organ such as the kidney, bladder, prostate, stomach, chest cavity, or other organ. The connector segment is then re-attached to the transport segment and the conventional connections are made to the connector segment to start the drainage, flushing, or other procedure.

To prevent the transport segment from catching or snagging on tissue while passing through the body orifice, a third segment comprising a smooth, generally hemispherical cap mating with the transport segment is provided to cover the exposed face of this segment. This cap fits tightly against the exposed face and thereby provides a smooth "leading edge" for the transport segment as it is pulled through the orifice in the retrograde direction; it also seals the fluid passages of this segment to prevent fluid leakage during placement of the catheter. When the transport segment has passed fully through the orifice to the exterior of the body, this cap is removed so that the connector segment can be attached to the transport segment for fluid transfer.

In addition to allowing insertion in the retrograde direction, the catheter of the present invention prevents injury to patients by readily snapping apart into two segments when sufficient force is exerted on the proximal end of the catheter while it is in place. This prevents damage to tissue which would otherwise occur when retention-type catheters are used, since the force required to separate the segments can be made such as to ensure that no damage is done to the tissue on inadvertent separation. The separating force, of course, is controlled by the selection of materials and by the design of the fastening means holding the sections together.

DETAILED DESCRIPTION OF THE INVENTION

The foregoing features, and other and further objects and features of the invention, will more readily be understood on reference to the following detailed description of the invention, when taken in conjunction with the drawings in which:

FIG. 1 is a sketch of the catheter of the present invention with both the transport and the connector segments firmly connected together;

FIG. 2A is a fragmentary perspective view of one embodiment of the catheter showing the mating connections between the two segments;

FIG. 2B is a fragmentary perspective view of the catheter showing an end cap positioned adjacent the transport segment for sealing off the latter segment;

FIG. 3 is an end view of the cap taken along the lines 3--3 of FIG. 2B;

FIG. 4 is a longitudinal fragmentary sectional view of the mating portions of the transport and connector segments in accordance with an alternative embodiment of the invention;

FIG. 5A is a longitudinal fragmentary sectional view of the transport and connector segments in accordance with another alternative embodiment of the invention; and

FIG. 5B is a view in perspective of the mating face of the connector segment of FIG. 5A.

A retention-type catheter having a single fluid transport passage and a passage for inflating a distensible tip at the distal end will be used to illustrate the invention, but it should be understood that the invention applies to catheters having any number of fluid passages and with or without retention characteristics.

In FIG. 1, the catheter 10 of the present invention has a fluid transport segment 12 detachably connected to a connector segment 14. The segment 12 has the usual tip 16 which carries an orifice 18 communicating with fluid passages within the catheter. The tip also carries a distensible section 20 which connects to a separate air passage extending through the catheter and which is inflatable to hold the catheter within a body cavity when the catheter is properly positioned. Although any number of passages may be provided, for ease of illustration only a single discharge passage and a single air passage are shown.

The connector segment 14 carries a first connector arm 22 for receiving fluid discharge from a body orifice through the catheter and a second connector arm 24 carrying a check valve 26 for inflating the distensible section 20 to anchor the catheter segment 12 firmly within the body orifice.

The transport segment 12 and connector segment 14 are detachably connected from each other at a section 28. The manner in which they are connected is shown more clearly in FIGS. 2 through 5. In FIG. 2A, first and second fluid passages 32A and 34A, respectively, are shown extending through the segment 12. The fluid passage 32A transmits air to the bulbous portion 20 of the tip 16 in FIG. 1 while the fluid passage 34A drains fluid from the body cavity. Corresponding passages 32B and 34B are formed in the segment 14.

In order to secure the segment 14 to the segment 12, the fluid passage 32B continues through a tubular extension 36 projecting from a face 38 of the segment 14. This face is formed at an acute angle to a longitudinal axis (not shown) extending through the fluid channel 34B. The tubular extension 36 is tapered in a direction receding from the face 38 and is of such a size as to fit snugly into the fluid passage 32A of segment 12 when the two segments are brought together; the face 38 of segment 14 then butts snugly against a corresponding face 40 of segment 12 to form a fluid-tight seal. The two segments are further held firmly together by means of protuberances 42 extending from the side walls of the interior of fluid passage 34B on segment 14. These protuberances mate with corresponding recesses 44 on the interior of fluid passage 34A on segment 12. The protuberances 42 are preferably somewhat larger than the recesses 44 so as to form a snug fit when the two are brought together, and may be slightly tapered in a direction receding from the face 38 so as to assist in mating the surfaces 38 and 40.

As noted previously the segments 12 and 14 are separated from each other when the catheter 10 is to be inserted in a retrograde direction, that is, from the interior of the body cavity to be drained to the exterior. When used in this manner, the face 40 of the catheter segment 12 forms the "leading edge" of the catheter segment as it is being passed through the body orifice to the exterior of the body. In order to smooth the passage of the face 40 through the body orifice and prevent its catching on body tissue, a smooth cap 50, as shown in FIG. 2B, is fitted to the segment 12. The cap 50 is preferably in the form of a generally semi-hemispheric portion having a face 52 cut at an acute angle to a polar axis and adapted to mate flush against face 40 of segment 12. Protuberances 54 are provided to mate with fluid passage 32A on segment 12, as well as with recesses 44 on this segment to hold the cap 50 snugly against the face 40 during the passage of the segment 12 through the body orifice. In addition to providing a smooth leading edge, the cap also "seals" the segment 12 to prevent drainage through it while it is being positioned.

The catheter segments 12 and 14 may be formed from any of a number of well known materials commonly used for catheters, as well as from numerous other materials. For example, segment 12 may be formed from any rubber, rubber-based, plastic or other material having sufficient flexibility for passage through a body orifice and capable of withstanding the passage of body fluids therethrough. Heretofore, segment 14 was of one piece with segment 12 and therefore was formed from the same material. However, in the present invention, segment 14 is separable from segment 12 and need not be of the same material. Thus, while segment 12 is required to be of material which imparts adequate flexibility to it, there is no such restriction on the segment 14 and this may be molded from a rigid plastic or other material where desired. Alternatively, it can be formed from the same material as the segment 12.

FIGS. 4 and 5 show various modifications of locking arrangements to secure the segments 12 and 14 firmly together and thereby form a fluid-tight seal. In FIG. 4, the face 40' of the segment 12' is cut generally perpendicular to a longitudinal axis extending through the fluid passage 32' B, but has an outer beveled portion 16 which mates with a corresponding reverse bevel 62 on the face 38' of segment 14'. As was previously the case, a tubular protuberance 36' extending from the face 38' snugly fits into fluid channel 32' A. It will be understood that a corresponding tubular protuberance may be placed around the fluid channel 34' B of segment 14' to mate with channel 32' B on segment 12' in order to provide an even tighter fit. However, if this additional protuberance is provided, the liquid passing through the channel 32' B from the segment 12' to the segment 14' will encounter a lip in the channel as it flows from the body cavity. If this is objectionable, the interior walls of the channel 32' B may be widened in the vicinity of the protuberance to the extent of the wall thickness of the protuberance so that the lip will be recessed when placed within the segment 12'; thus an essentially smooth transition will be provided between the segments 12' and 14'.

FIG. 5 shows still another embodiment of the invention having an alternative form of locking means for firmly securing the two catheter segments together when desired. The segment 12" has a face 40" cut perpendicular to a longitudinal axis extending through the fluid passage 34" A and carries protuberances 70 which mate with recesses 72 extending into the face 38" of segment 14". As seen in FIG. 5, the recesses 72 are distributed around the periphery of the face 38" and provide secure seats for the protuberances 70. As was previously the case, the protuberances 70 may be tapered in a direction receding from the face 40" to assist locking them into the recesses 72.

It will be understood that the various means of locking the two catheter segments together are illustrative only and that any of a number of locking means may be used in addition to, or instead of, those illustrated. It will also be understood that various combinations of bevels or other angled cuts may be used in connection with the locking means to firmly mate the opposing faces of the catheter segment together. Various other changes may be made in the invention by those skilled in the art without departing from either the spirit or the scope of the invention and it is intended that the foregoing material be taken as illustrative only and not in a limiting sense, the scope of the invention being described in the claims.

Claims

Having illustrated and described my invention, I claim:

1. A catheter assembly unit for insertion through a body segment in either an antegrade or a retrograde direction, comprising:

A. a first tubular catheter segment for insertion into an animal body and having an insertion tip and being provided with at least two fluid passages extending longitudinally therethrough, one of said passages communicating with the exterior of the tube through an aperture in the insertion tip for receiving fluid therethrough;

B. a second tubular catheter segment:

i. detachably connected to said first segment and forming a fluid-tight seal therewith when so connected;

ii. having fluid passages therein corresponding to the fluid passages in said first segment and aligned therewith when said segments are connected;

iii. having a portion thereof of larger cross section than any cross section of said first segment and adapted for connection to fluid transfer means; and

C. closure means detachably connectable to said first segment to close said fluid passages when the first segment is to be passed through said animal body in a retrograde direction, said closure means being connected to said first segment upon removal of said second catheter segment from said first catheter segment.

2. A catheter unit according to claim 1 in which one of said segments has at least one recess therein positioned to mate with a corresponding protuberance on the other of said segments and to provide a locking force when so mated.

3. A catheter unit according to claim 1 in which said second segment includes a tubular insert snugly fitting into a corresponding fluid passage in said first segment.

4. A catheter unit according to claim 1 in which at least one of said fluid passages on at least one of said segments has a tubular extension coextensive with the walls defining said passage and projecting beyond said segment for insertion into a corresponding fluid passage on the other of said segments.

5. A catheter unit according to claim 1 in which said closure means is:

i. separable from said first segment but mateable therewith;

ii. has a cross section generally corresponding to that of the first segment;

iii. has a smooth surface on a side facing away from said first segment whereby said third segment may be detachably connected to said first segment for movement therewith through a body orifice without enlarging said orifice.

6. A catheter assembly for fluid drainage from an animal body and adapted to be inserted through a body orifice having a cross section of comparable dimension to the cross section of the catheter segment and in a direction proceeding from the interior to the exterior of said body, said catheter comprising:

A. a first tubular segment:

i. of a length sufficient to extend through said orifice from the interior of said body to the exterior thereof;

ii. having a fluid passage extending therethrough for draining fluid from the interior of said body; and

B. a second tubular segment:

i. having at least a portion thereof of substantially larger cross-section than said orifice whereby its passage through said orifice is prevented;

ii. having a fluid passage therein aligned with the passage in said first segment when said segments are so connected and adapted to receive fluid therefrom;

iii. detachably connected to said first segment and forming a fluid-tight seal therewith when so connected;

iv. whereby said second segment may be detached from said first segment during passage of said first segment through said orifice,

C. a third segment:

i. detachably connectable to said first segment along a first face thereof;

ii. having a cross-section comparable to that of said first segment;

iii. having a generally smooth face opposite said first face;

iv. whereby said third segment forms a smooth leading edge for moving said first segment through said orifice from the exterior of the body when said segments are connected together, and

D. locking means on at least one of said first and second segments for tightly but removably joining said segments together.

7. A catheter according to claim 6 in which said first and second segments have mating faces inclined at an acute angle to a centerline extending longitudinally along said segments.

8. A catheter according to claim 6 in which said second segment has a beveled ring-shaped portion around the outer periphery of a face thereof and in which said first segment has a corresponding beveled portion on a face thereof adapted to mate snugly with said face of said second segment.