Deflatable Retention Catheter

Abstract

An improved safety-deflating retention catheter wherein the balloon empties directly into the drainage lumen through a short passageway under the retention balloon. Temporary blocking means are positioned within or over the passageway, the blocking means being overridden due to the flexible nature of the distal end when that end is stretched by a force which might otherwise pull the balloon into the urethra in its inflated state.

Description

BACKGROUND OF THE INVENTION

In body drainage systems, a significant advance is provided by U.S. Pat. No. 3,482,576, issued to R. E. Ericson, et al. on Dec. 9, 1969. This patent provides safety deflating means on a body cavity drainage device which is retained in the cavity by an inflatable retention balloon, the deflating means serving to prevent inadvertent or accidental removal of the drainage device without deflating the balloon first. The safety deflating mechanism of that patent thus significantly reduces the incidence of injury to the body upon attempted forceable withdrawal of an inflated drainage tube. The specific mechanism of that patent features an ordinarily sealed opening at the proximal end of the device which, when opened, allows drainage of the inflation medium through the inflation lumen.

SUMMARY OF THE INVENTION

This application is directed towards an improvement of the device disclosed in the aforesaid patent whereby a quicker release of the inflation fluid from the retention balloon is obtained. Also, with the present invention, the safety mechanism will be activated only in those circumstances where the force applied to the drainage device is actually transmitted to the retention balloon. More specifically, there is provided a drainage device wherein the releasing means empties the retention balloon directly into the drainage lumen rather than into an inflation lumen, the mechanism being positioned in the distal end of the drainage device so as to be activated only when sufficient tension is applied to the retention balloon as opposed to some other part of the drainage device. The result is an improvement in a drainage device having a proximal end and an open distal end for insertion into an animal body cavity, a drainage lumen connecting the distal and proximal ends for draining the cavity, inflatable retaining means adjacent the distal end for retaining the device within the cavity when inflated, and means for releasing the contents of the retaining means to deflate the same. The improvement features a release passageway or opening through which the retaining means communicates with the drainage lumen, blocking means for blocking the release passageway or opening, and overriding means for overriding the blocking means, the overriding means being activated upon longitudinal tensioning of the device in the area of the retaining means by an amount which is preferably slightly less than that tensioning which would withdraw the retaining means from the cavity with the retaining means still in an inflated state.

Accordingly, it is an object of the invention to provide an improved drainage device having an inflatable retention balloon which will quickly deflate when tension is inadvertently or improperly placed upon the drainage device at the location of the retention balloon, thus eliminating injury to the urethra which might result from withdrawing the drainage device through the urethra while the balloon is fully inflated.

It is a related object of the invention to provide such a drainage device which is so constructed as to be inexpensive to manufacture.

Other objects and advantages will become apparent upon reference to the following drawings and detailed discussion.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a fragmentary, partially sectioned elevational view illustrating the improved drainage device constructed in accordance with the invention;

FIG. 2 is a fragmentary sectional view, partially broken away, of the device shown in FIG. 1 illustrating the device in use;

FIG. 3 is a fragmentary partially broken away sectional view similar to FIG. 2 but illustrating the safety device in operation when the drainage device is under tension;

FIG. 4 is a fragmentary sectional view similar to FIG. 1 but illustrating the state of the device as shown in FIG. 3;

FIG. 5 is a fragmentary sectional view of an alternate embodiment of the device;

FIG. 6 is a fragmentary sectional view, partially broken away, of yet another alternate form of the embodiment shown in FIGS. 1-4;

FIG. 7 is a fragmentary, partially broken away section view similar to FIG. 6 but illustrating the device under tension;

FIGS. 8 and 9 are fragmentary, partially broken away sectional views of still another embodiment of the invention, illustrating, respectively, the relaxed condition and the condition of the device under tension;

FIG. 10 is a fragmentary sectional view, partially broken away, illustrating yet another embodiment of the device;

FIG. 11 is a sectional view taken along the lines 11--11 of FIG. 10; and

FIG. 12 is a fragmentary, partially broken away sectional view similar to FIG. 11, but showing the embodiment in the stretched releasing condition.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The description of preferred embodiments set forth hereinafter concern a Foley-type catheter having a deflation device in accordance with this invention. However, any drainage tube whether of rubber latex, synthetic stretchable polymer or a combination of the two, or stretchable polymer with a non-stretchable, flexible material which has inflatable retaining means and is fitted with the described and claimed deflation device is considered within the invention.

Referring now to FIGS. 1-4, the safety deflating mechanism of the invention is provided in a Foley-type catheter 20 which conventionally has a distal end 22 for insertion in a bladder 21, a drainage eye 24 in that end, a proximal end 26, a main or drainage lumen 28 extending from the distal end 22 to the proximal end 26 and generally formed and surrounded by the exterior catheter wall 29, an inflatable retention balloon 30 adjacent to the distal end 22 and overlying a portion 31 of the wall 29 (FIG. 1), an inflation lumen 32 defined by a wall 33, the lumen 32 extending from the retention balloon to the proximal end of the catheter 20 where it forms a side arm 34, and means in the side arm for inflating the retention balloon 30 through the inflation lumen 32. The entire catheter itself, its distal end or portions thereof, is conveniently formed from a flexible elastomer. The inflating means commonly includes a permanently maintained opening 38 in the wall 29 permitting fluid flow from the lumen 32 into the retention balloon 30, and an inflating balloon 40 forming part of the side arm 34. The balloon 40 contains, when inflated to the position shown in dotted lines in FIG. 1, the inflating fluid which is to fill the balloon 30. A clip 42 closes lumen 32 to retain the inflating fluid in the balloon 40 until such time as the catheter 20 is positioned within a body cavity, such as the bladder. Inflation of balloon 30 is indicated by arrows in the lumen 32, while drainage of the bladder is indicated by the arrow 48.

In accordance with one aspect of the invention, the safety deflating mechanism is provided at the distal end 22 of the catheter so as to give a quick release of the retention balloon 30 when force is applied to the retention balloon in a manner which would otherwise force the withdrawal of the distal end 22 into the urethra with the balloon 30 fully inflated. As shown in FIG. 1, this is accomplished by providing a passageway or opening 50 which extends from the drainage lumen 28 through the catheter wall into the balloon 30 (FIGS. 1 and 4). The passageway 50 is located so that the balloon 30 overlies the passageway in its position in the catheter 20, and preferably the passageway 50 is positioned under the balloon 30 in the proximal half 54 of the wall portion 31 overlaid by balloon 30. The location of the passageway under the proximal half 54 is for a purpose hereinafter stated.

To block flow of inflating fluid from the retention balloon 30 out through the passageway 50, a one-way flap valve 60 is attached at portion 62 to the exterior wall 29 (FIG. 3). As shown in FIG. 1, this attachment is distal to the passageway 50, the flap valve being positioned so as to overlap and cover the passageway 50 when the catheter is normally positioned without any longitudinal stress thereupon. The flap valve 60 thus functions to retain inflating fluid in the balloon 30 after it enters the balloon from the lumen 32, the pressure of the fluid in the direction of the arrow 66 acting upon the valve to keep it closed. FIG. 2 further illustrates the catheter in this normal, unstretched condition with the exterior walls of the retention balloon 30 abutting against the wall of the bladder 21.

Referring now to FIGS. 3 and 4, when tension is longitudinally applied as indicated to the catheter 20 in an amount preferably less than that which would be otherwise sufficient to pull the balloon 30 into the urethra, the catheter and the bladder 21 take the configuration shown. The stretching of the flexible wall 29 of the catheter 20 causes the passageway 50 to stretch so as to override the blocking effect of the flap valve 60. That is, the passageway 50 alters in size and shape so as to extend beyond the area covered by the flap valve 60. In such an arrangement, the inflating fluid flows out of the balloon 30 under pressure and into the drainage lumen 28 where it quickly empties out through the drainage eye 24 or out through the proximal end 26, as indicated by the arrows in FIG. 4. The passageway 50 must be positioned approximately under the proximal half 54 so as to promptly respond to the stretching in the vicinity of the retention balloon, which stretching represents tension which would otherwise be sufficient to pull the retention balloon in its inflated state into the urethra.

Several advantages will be seen in the aforedescribed structure. First of all, the extreme shortness and location of the passageway 50 connecting the retention balloon 30 with the drainage lumen 28 permits quick emptying of the retention balloon. The aforesaid location of the passageway also permits the release of the balloon to occur only when sufficient tension is applied in the vicinity of the retention balloon. This is to be contrasted with those arrangements which could permit a release of the balloon when tension is applied to some other portion of the catheter such as the proximal end 26, the tension not being further transmitted to the distal end. A further advantage of the embodiment shown in FIG. 1-4 is that the operation of the deflating device is arrestable. That is, if the accidental tugging on the catheter causing the longitudinal tension is released or terminated before the retention balloon 30 is pulled into the urethra, the catheter will assume its relaxed state as shown in FIG. 2 so that the passageway 50 moves back under the flap valve 60. The result is that any inflating fluid still retained by the balloon 30 will close the flap valve 60, permitting the retention balloon 30 to maintain the catheter in place. Only continued improper stressing or stretching of the catheter 20 will completely empty the balloon 30.

Preferably, the catheter walls 29 and 33 as well as the passageway 50 are formed from a flexible, stretchable polymer such as natural rubber latex, so as to permit the walls to stretch to pull at least a portion of the passageway 50 out from under the flap valve 60. If materials other than rubber are used, the material forming the walls in the distal end of the catheter should be an elastomeric material having a breaking elongation which is similar to that of latex rubber. However, a latex rubber has the further advantage that the mechanisms involved in the aforedescribed structure are easily manufactured. For example, the flap valve 60 is readily formed during the dipping process which is conventional in manufacturing catheters out of the aforementioned latex rubber. That is, a separating material, such as talc, is placed over those portions where the flap valve 60 is not to attach to exterior wall 29 of the catheter, and the dipping process is performed.

ALTERNATE EMBODIMENTS

FIG. 5 illustrates an alternate embodiment wherein the flap valve is attached to the wall of the catheter in a different location and wherein the passage from the main lumen to the retention balloon is direct rather than through an inflation lumen. Parts similar to those previously described bear the same reference numeral to which distinguishing suffix a has been added. Thus, catheter 20a has a distal end 22a, a retention balloon 30a, and a drainage eye 24a as in the previous embodiment, pressure in the direction of arrows 66a being normally effective to keep the balloon inflated. However, this embodiment differs from the previous embodiment in that the drainage lumen 28a is the only lumen within the walls 29a of the catheter. For this reason, the passageway 50a is simply an opening within the wall portion 31a under the balloon 30a and the lumen 28a serves both to inflate the retention balloon and to drain the bladder in the direction of arrow 48a in a manner disclosed and claimed in our copending U.S. Pat. application Ser. No. 187340, filed simultaneously herewith. To this end, there is provided a second flap valve 70 positioned on the interior surface of the wall 29a so as to overlie the drainage eye 24a. The flap valve 70 serves to close off the drainage eye when inflating fluid passes through the lumen 28a and into the retention balloon 30a, while permitting reverse flow of urine from the bladder through the drainage eye 24a and into the drainage lumen 28a.

The other primary distinction in the embodiment shown in FIG. 5 is that the flap valve 60a is attached to the exterior surface of the wall 29a at a portion 62a which is located not distal as in the previous embodiment, but rather proximal to the passageway 50a. It is thus apparent that the location of the attachment of the flap valve 60a is not critical, provided that it is longitudinally displaced from the passageway extending from the drainage lumen to the retention balloon. However, when the portion 62a is located proximally as in FIG. 5, it should attach approximately to the proximal half 54a of the wall portion 31a. This insures prompt release when tension is applied to the balloon by permitting the flap valve 60a to promptly uncover the passageway 50a due to the stretching of the proximal half 54a.

FIGS. 6 and 7 illustrate another embodiment of the invention wherein the safety drainage mechanism is not reversible but instead is maintained in the release configuration when improper stretching at the distal end occurs. Parts similar to those previously described bear the same reference numeral to which the distinguishing suffix b has been added. Thus, FIG. 6 illustrates a catheter 20b positioned in its normal unstretched state in bladder 21b, the retention balloon 30b abutting the bladder walls. As in the previous embodiments, a flap valve 60b covers a passageway 50b extending from the interior of the balloon 30b into a drainage lumen 28b. The instant embodiment is characterized by having an inelastic deformable coiled wire 80 imbedded within the walls 29b and extending distally past 50b of the catheter. Thus, as shown in FIG. 7, when force is transmitted to the distal end, in the direction of the arrows 82 of an amount which would otherwise force the retention balloon to be drawn into the urethra, the following two things occur. The passageway 50b is stretched so as to extend out from under the flap valve 60b as in the previous embodiments, and the coiled wire 80 is permanently deformed to the state shown in FIG. 7. The result is that the retention balloon 30b is caused to completely empty into the drainage lumen, whether or not the force in the direction of the arrow 82 is maintained.

FIGS. 8 and 9 illustrate still another embodiment in which the safety releasing mechanism for the retention balloon is irreversible and which features a plug rather than a flap as the mechanism blocking the passageway between the lumen and the balloon. Parts similar to those previously described bear the same reference numeral to which the distinguishing suffix c has been added. Thus, FIG. 8 illustrates the catheter 20c in the normal unstretched state within the bladder 21c. A retention balloon 30c overlies the release passageway 50c as in the previous embodiments. Unlike the previous embodiments, instead of a flap valve, a plug 90 is positioned within the passageway 50c, the latter occupying a position approximately within the proximal half 54c of the wall portion 31c overlaid by the balloon. The edges of the passageway are beveled so as to hold the plug 90 in position even when external pressure is generated by fluid flowing into the retention balloon 30c through the opening 38c. As shown in FIG. 9, when force is exerted in the direction of arrow 82c, the catheter 20c stretches at the distal end so as to cause the wall portion 31c to pull away from the plug 90, thereby allowing the pressure of the inflating fluid to force the plug 90 into the drainage lumen 28c. The largest dimension of the plug 90 is such as to be substantially less than the diameter of the lumen 28c, thereby permitting the inflating fluid to drain out through the drainage lumen. Preferably, the plug 90 is formed of relatively inelastic material so as to maintain its shape rather than stretch under the influence of the stretched wall portion 31c.

FIGS. 10-12 illustrate yet another embodiment wherein a tongue and groove configuration is utilized to define the release passageway extending from the retention balloon to the drainage lumen. Parts similar to those previously described bear the same reference numeral to which the distinguishing suffix d has been added. Thus, the catheter 20d of this embodiment has a drainage lumen 28d and an inflation lumen 32d for inflating the retention balloon 30d as in the embodiment of FIGS. 1-4. When in the normal unstretched state, the catheter 20d is positioned within the bladder 21d with the retention balloon and the bladder taking the position shown in FIGS. 10 and 11. Unlike the previous embodiments, the passageway 50d extending from the drainage lumen 28d to the retention balloon 30d is formed by a groove or slot 100 approximately within the proximal half 54d of the wall portion 31d. A mating tongue 104 extends from the proximal half 54d into the groove 100, both the tongue and the groove extending generally parallel to the lumen 28d. The surface appearance of the mating tongue and groove can take any configuration, one possible configuration being an C curve 106 as shown in FIG. 10. The mating of the groove 100 and the tongue 104 is therefore in a direction which is longitudinal with the lumen 28d. Therefore, a stretching of the wall portion 31d under tension exerted in the direction of the arrows 82d of an amount sufficient to otherwise withdraw the balloon into the urethra causes a separation as shown in FIG. 12 of the tongue 104 from the groove 100. This separation permits the exiting of the inflation fluid from the retention balloon 30d and into the drainage lumen 28d.

Due to the flexing of tongue 104, reseating of the combination 100-104 is generally impossible. Consequently this embodiment is normally irreversible as are the embodiments shown in FIGS. 6, 7, 8 and 9. As in all the previous embodiments, the walls of the catheter in the distal end 22d must be flexible to permit the stretching necessary to operate the unblocking of the passageway 50d.

It will be recognized that all of the preceding embodiments provide the advantage of prompt emptying of the balloon only when sufficient longitudinal force is applied to the balloon. This is accomplished by the location of the passageway under the retention balloon and in a manner such as to empty the balloon by a short traverse from the balloon into the drainage lumen.

Although the invention has been described in connection with certain preferred embodiments, it is not intended that it be limited thereto. To the contrary, it is intended that the invention cover all arrangements, alternate embodiments, and equivalents as may be included within the scope of the following claims.

Claims

What is claimed is:

1. In a drainage device having a proximal end and an open distal end for insertion into an animal body cavity, a main lumen connecting said distal and proximal ends for draining the cavity, inflatable retaining means overlying a portion of the wall of said device adjacent said distal end for retaining said device within the cavity when inflated, and means for releasing the contents of said retaining means so as to deflate the same; the improvement comprising said releasing means including a release passageway adjacent the retaining means and extending from said retaining means to said main lumen, means for blocking said passageway, and means for overriding said blocking means, said overriding means being activated upon longitudinal tensioning of said device responsive to attempted withdrawal of the retaining means, while in its inflated state, from the cavity.

2. The improved device as defined in claim 1, wherein said overriding means is arrestable so as to be effective to release further contents of said retaining means to said main lumen whenever such tensioning is repeatedly applied to said device.

3. The improved device as defined in claim 1, wherein said passageway is relatively short in length compared to said lumen, whereby access time from said retaining means to said lumen is minimized.

4. The improved device as defined in claim 3, wherein no part of said passageway extends longitudinally beyond that portion of said device which mounts said retaining means.

5. The improved device as defined in claim 4, wherein said passageway extends only generally perpendicularly to said lumen.

6. The improved device as defined in claim 1, wherein at least a portion of said passageway is positioned approximately within the proximal half of said wall portion under said retaining means, whereby said overriding means are promptly effective during tensioning to release said retaining means.

7. The improved device as defined in claim 1, wherein said blocking means includes a valve operatively positioned between said passageway and said retaining means, said valve closing off flow from said retaining means to said passageway and wherein said overriding means includes means for altering the shape of said passageway so as to extend the same beyond the effective closing region of said valve.

8. The improved device as defined in claim 8, wherein said valve is a flap valve attached externally to said device operatively between said retaining means and said device, said attachment being longitudinally displaced from said passageway, said valve loosely covering said passageway, and wherein said altering means includes longitudinally flexible walls defining said lumen and said passageway, whereby longitudinal stretching of said walls causes said passageway and said flap valve to longitudinally displace with respect to each other so as to remove said flap valve from its covering relationship to said passageway.

9. The improved device as defined in claim 8 wherein said attachment of said flap valve is distal to said passageway.

10. The improved device as defined in claim 8 wherein said attachment is proximal to said passageway.

11. The improved device as defined in claim 8, wherein said walls at least in part are formed from an elastomeric material having a breaking elongation quality commensurate to that of latex rubber.

12. The improved device as defined in claim 8, wherein said walls defining said lumen include embedded within a portion thereof in the vicinity of said passageway, an inelastic deformable element oriented so as to permanently deform in the presence of said longitudinal stretching.

13. The improved device as defined in claim 12, wherein said element is a coiled inelastic wire.

14. The improved device as defined in claim 7, wherein said effective closing region and said altering means are positioned under said retaining means adjacent to the proximal portion thereof, whereby said overriding means are promptly effective under said tensioning to release said retaining means.

15. The improved device as defined in claim 1, wherein said blocking means includes a plug seated within said passageway, said plug being relatively inflexible, and wherein said overriding means includes relatively flexible walls defining said passageway and said lumen, whereby longitudinal stretching of said device causes said passageway to enlarge in amount sufficient to unseat said plug.

16. The improved device as defined in claim 1, wherein said passageway and said blocking means are defined by at least one grooved slot in a portion of the walls of said device, extending generally parallel to said lumen, and by a mating tongue portion of walls which opposes and extends into said slot.

17. The improved device as defined in claim 16, wherein said mating portion and said slot mate along a direction which is longitudinal to said lumen, and wherein said portions of said walls are flexible, whereby longitudinal stretching of said walls causes said mating portion and said slot to separate, releasing said retaining means.