US3867945A - Catheter stylets - Google Patents

Abstract

The present invention relates to a new adjunct to the insertion of a urethral catheter. It is a catheter stiffener and former made of a plastic rod which has the properties of being a flexible, resilient member capable of properly stiffening a urethral catheter or the like while also being sufficiently compliant to pre-shaping into various and multiple curvatures to facilitate insertion into a body cavity.

Description

United StatesPatent 1 1 1111 3,867,945 Long Feb. 25, 1975 CATHETER STYLETS 011 1 12335384251} Inventor: Wendell M. g 528 NW. ,5 /1 o erty 3 8 Oklahoma City Okla Primary ExaminerDalton L. Truluck Attorney, Agent, or Firm-Laney, Dougherty, Hessin [22] Filed: May-l4, 1973 & Fish [21] Appl. No.: 359,984

[57] ABSTRACT The present invention relates to-a new adjunct to the gz i g g g insertion of a urethral catheter. it is a catheter stiff- [58] Fieid ener and former made of a plastic rod which has the properties of being a flexible, resilient member capa- [5611 References Cited ble of properly stiffening a urethral catheter or the like while-also being-sufficiently compliant to pre- UNITED STATES PATENTS v shaping into various and multiple curvatures t0 facili 2,l Wappler R {ate insertion into a bod cavit I 2,458,305 1/1949 Sanders 128/348 y 2,463,149 3/1949 Caine... 128/351 8 Clalms, 6 Drawing Figures PATENTED FEB25 5975 l I I. I. I. I. I ,i. I. I. I. I. ll

Ill. ill I. Isl I. h I Ill III III! ibi CATHETER STYLETS BACKGROUND OF THE INVENTION use with the Foley urethral catheter.

2. Description of the Prior Art The prior art includes various types of catheter stylets, not only for use in Foley-type urethral catheters but other catheters as designed for insertion in particular body cavities, i.e. endotrachea catheters, trocar catheters, etc. Generally, the prior forms of stylets have been formed from wire or other rigid metallic materials. The prior art devices, especially as employed for insertion of urethral catheters, had inherent shortcomings due to the very fact of their necessary rigidity. The use of the conventional wire stylets required manipulation and insertion by a trained urologist in performance of the routine as well as the more difficult catheterizations, as the wire guide could very easily force the catheter to pierce the delicate wall of the urethra when not properly avoiding obstructions.

SUMMARY OF THE INVENTION The present invention contemplates a readily expendable catheter stiffener formed of desirably resilient material and it is particularly adapted for use with the Foley urethral catheter. The stiffener and former consists of an elongated portion having the proximal end formed with a pre-selected curvature and a distal portion with an enlarged diameter formed for co-action with the distal end of the Foley catheter. The proximal end of the stylet is formed with a curvature of optimum radius for encounter with the particular obstructions and curvatures present'along the urethral tract.

Therefore, it is an object of the present invention to provide a catheter stylet that is semi-rigid and sufficiently stiff to guide the catheter during insertion and to prevent collapsing of the catheter tube.

It is still another object of the invention to provide a stiffener and former which may be pre-formed into a variety of curves as selected to implement insertion of the catheter device.

It is yet another object of the present invention to provide a catheter stylet having greater resiliency and which is unlikely to damage. the fragile lumen of the urethra when the catheter is inserted.

It is also an object of the present invention to provide a stiffener of simple design having no moving parts which is inexpensive to manufacture and may be disposable after a single usage.

It is therefore an object to provide a stiffener and former compatible with the design of the Foley urethral catheter which may be factory inserted for sale with the Foley catheter as a unit, thereby reducing extra handling and contamination prior to its usage.

Finally, it is an object of the present invention to provide a stiffener and former for use with the Foley catheter which will enable the more routine catheterization to be carried out by nurses or physicians assistants without danger of damage to the urethral tract of the patient.

Other objects and advantages of the invention will be evident from the following detailed description when read in conjunction with the accompanying drawing which illustrates the invention.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a top plan view of the stiffener and former as constructed in accordance with the present invention;

FIG. 2-is a side elevation of the: stiffener of FIG. 1;

FIG. 3 is a side elevation of an alternative form of stiffener;

FIG. 4 is a vertical section ofa Foley urethal catheter as is well-known in the prior art;

FIG. 5 is a vertical section of the Foley catheter with stiffener inserted; and

FIG. 6 is a section taken along lines 6-6 of FIG. 5.,

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawings in greater detail, FIGS. 1 and 2 show a catheter stiffener and former 10 as constructed in accordance with the present invention. The stiffener and former 10 is comprised of arod 12 as securely joined or affixed to what may be termed ahandle 14. Aproximal end portion 16 is then preformed with acurvature 18 of selected radius, generally not too severe but of sufficient curvature to allow optimum probing manipulation during catheter insertion. Aproximal tip 20 ofrod 12 is rounded off to prevent damage to the proximal end portions of the catheter and/or the urethral wall.

Rod 12 is preferably formed from selected plastic materials having the requisite properties as to resil-' therein to ,be secured through interference fit. While therod 12 andhandle 14 are shown as being formed in two separate pieces, it should be understood that the stiffener and former 10 can be formed unitarily in one piece through conventional plastic molding practices.

While the stiffener and former 10 is shown in FIG. 2 as having acurvature 18, that which is known as the single curved or coude tip, some practitioners prefer, and the exigencies of certain therapeutic applications may demand, a doublecurved tip 24 such as is shown in FIG. 3. Thecurve 24 also subtends a relatively gentle curvature through formation of two distinctangular bends 26 and 28.

FIG. 4 represents a standard form of Foley urethral catheter as is now well-known in the art. The Foley catheter is the particular subject matter of US. Pat. Nos. 2,428,407 and 3,l52,592 and the teachings embodied therein have enjoyed wide application and success. Conventionally, insertion of the Foley catheter has required either the use of a wire-form stylet with its attendant piercing and injury problems, or the attending physician has had to apply excessive lubrication and short stroke insertions of very time-consuming and un- Certain nature.

Briefly, the Foleycatheter 30 consists of adistal portion 32 andtube portion 34, thetube portion 34 being formed to include adrainage lumen 36 and an inflation orcontrol lumen 38. The Foley catheters may be formed as bi-Iuminal or tri-Iuminal tubes, at least one of which, such astube 38, is in communication with aballoon 40 which is sealingly connected abouttube portion 30 proximate the proximal end 42 ofcatheter 30. Dash-lines 44 illustrate in section theballoon 40 after it has been inflated to the attitude wherein it prevents withdrawal oftube portion 34 from the bladder. Thedrainage conduit 36, of larger diameter, is in communication with the fluid drainage holes 46 as formed near the proximal tip 42 ofcatheter 30. At the distal end,catheter 30 is formed with acontrol tube 48 in communication withcontrol lumen 38 and serving to provide inflation and de-inflation control. Aclosure element 50 withincontrol tube 48 serves to maintain in- I flation pressure within the balloon 44 when in use. A

drainage outlet 52 in communication withdrainage lumen 36 provides drainage outlet for urine and collected fluids.

FIGS. 5 and 6 illustrate thecatheter 30 with the stiffener and former 10 inserted therein in operational position. Thus, therod 12 is inserted along the entire length ofdrainage lumen 36 such that itsrounded tip end 20 is fully inserted up to proximal tip 42 ofcatheter 30. Thehandle 14 of stiffener and former 10 is inserted withindrainage outlet 52 to provide a reasonably tight fit to maintain stiffener and former l securely positioned withincatheter 30 during entry manipulation. The length ofrod 12 has been established so as to extend through the length of the catheter shaft ordrainage lumen 36 such that thehandle 14 receives snug fit in the distal end thereof, i.e.,drainage outlet 52. In practice, the catheter is actually stretched slightly to cause it to conform to the shape of the former and to thereby further decrease the diameter of thecatheter 30 itself. This constraint also serves to prevent buckling or collapsing of the catheter during insertion and manipulation.

OPERATION In practice, the relatively resilient-stiffener and former 10 is inserted into thecatheter 30 as shown in FIGS. and 6-. Thereafter, the attending physician, attendant or nurse can then easily manipulate thecatheter 30 for probing entry into the urethra of the requiring patient so that the proximal end 42 and drainage holes 46 are entered sufficiently into the urinary bladder. Thereupon,.inflation control is exercised to inflateballoon 40 thereby to retain proximal end 42 within the bladder confines. Then, the attendant needs only to loosen thehandle 14 fromdrainage outlet 52 to easily withdraw therod 12 of stiffener and former 10. Thecatheter 30 is then in operational placement and the stiffener and former may be discarded.

In practice it is envisioned that such catheters could be supplied to the physician or hospital with the stiffener and former 10 already inserted therein. After one use only, the stiffener and former would then be discarded. Such capability has the obvious advantages of sterilization assurance, and the minimal cost of stiffener andformers 10 should be quite acceptable for the disposability concept.

Some properties which make a catheter and former combination most desirable are (1 a certain degree of stiffness for ease of insertion; (2) some angulation at the tip to allow the tip to ride over obstructions; (3) highest proportion of luminal to catheter diameter ratio; (4) flexibility and softness of the catheter once inserted so as to not to cause undue stress and pressure on the fragile surface of the urethra; (5) inertness of the catheters material; (6) reduced expense; and (7) the facility of use. Previously used wire guides did not have the optimum compromise of qualities and were quite difficult to use safely and handily since the wireguided catheter could not be relied upon to ride over obstructions but rather to constantly endanger piercing of the urethral wall.

With the present shortage of qualified doctors, more and more catheterizations are done by nurses and physicians assistants, and generally speaking they do not have sufficient training or qualifications to perform difficult catheterizations which require the use of a stylet or, more important, they do not recognize the complications which may result from the use of the conventional style'ts. Thus, the present invention converts the usual Foley catheter into an instrument capable of performing many of the more difficult as well as the row tine catheterizations safely.

In summary, the aims and design of the catheter stiffener and-former permit the use of a soft pliable urethral catheter. with a large drainage lumen as compared to the catheter diameter. The catheter walls can be made thinner to increase the ratio of lumen to catheter size, thus allowing more free drainage of urine from the bladder during operative usage. The stiffener and former will permit easy passage of the catheter through the normal urethral canal or when narrowed, angulated, or otherwise obstructed through disease, such passage being made safely without buckling or collapsing of the drainage channels. The catheter stiffener is designed to be cheap and amenable to mass production as it can be packaged already within the catheter and ready for the insertion procedure.

Changes may be made in the combination, arrangement and size as heretofore set forth in the specification and shown in the drawings; it being understood that changes may be made in the embodiments disclosed without departing from' the spirit and scope of the invention as defined in the following claims.

What is claimed is:

1. An improvement for use in combination with urethral catheters of the type having a drainage lumen and a reduced diameter inflation lumen disposed in parallel through the length thereof, a proximal end for insertion in the urinary bladder, and a distal end including an enlarged diameter drainage outlet communicating with the drainage lumen and an inflation control outlet communicating with said inflation lumen, the improvement consisting of a stiffener and former device comprising:

rod means of uniform cross-sectional configuration and reduced length relative to said drainage lumen and extending from proximal to distal ends and having a diameter which is substantially less than that of said drainage lumen for insertion therein throughout the length thereof, said proximal end being formed with an optimal curvature;

a handle portion secured to the distal end of said rod means, said handle portion being formed with uni- 6 form cross-section slightly larger than said drainage said plastic material is nylon. outlet; 5. The improvement as set forth in claim 3 which is whereby said rod means may be inserted throughout further characterized in that:

the entire length of said drainage lumen with said said rod means and said handle means are unitarily handle means tightly received within the drainage 5 formed as uniform, round elements having preoutlet of said urethral catheter to stiffen the cathedetermined respective diameters. ter while reducing its overall circumference for 6. The improvement as set forth in claim 5 which is urethral insertion. further characterized in that: 2. The improvement as set forth inclaim 1 which is said rod means has a diameter of approximately Ill 6 further characterized in that: 10 inch and said handle means has a diameter of apsaid rod means proximal end curvature is formed as proximately three-eights inch. 7

two substantially equal angular bends subtending 7. The improvement as set forth in claim 6 which is an arc defining said optimal curvature. further characterized in that: 3. The improvement as set forth inclaim 1 which is said rod means and said handle means are unitarily further characterized in that: formed from nylon.

said rod means and said handle means are formed 8. The improvement as set forth inclaim 1 wherein: I from resilient plastic material said urethral catheter is the type known as the Foley 4. The improvement as set forth in claim 3 which is urethral catheter. further characterized in that:

Claims (8)

1. An improvement for use in combination with urethral catheters of the type having a drainage lumen and a reduced diameter inflation lumen disposed in parallel through the length thereof, a proximal end for insertion in the urinary bladder, and a distal end including an enlarged diameter drainage outlet communicating with the drainage lumen and an inflation control outlet communicating with said inflation lumen, the improvement consisting of a stiffener and former device comprising: rod means of uniform cross-sectional configuration and reduced length relative to said drainage lumen and extending from proximal to distal ends and having a diameter which is substantially less than that of said drainage lumen for insertion therein throughout the length thereof, said proximal end being formed with an optimal curvature; a handle portion secured to the distal end of said rod means, said handle portion being formed with uniform cross-section slightly larger than said drainage outlet; whereby said rod means may be inserted throughout the entire length of said drainage lumen with said handle means tightly received within the drainage outlet of said urethral catheter to stiffen the catheter while reducing its overall circumference for urethral insertion.

2. The improvement as set forth in claim 1 which is further characterized in that: said rod means proximal end curvature is formed as two substantially equal angular bends subtending an arc defining said optimal curvature.

3. The improvement as set forth in claim 1 which is further characterized in that: said rod means and said handle means are formed from resilient plastic material.

4. The improvement as set forth in claim 3 which is further characterized in that: said plastic material is nylon.

5. The improvement as set forth in claim 3 which is further characterized in that: said rod means and said handle means are unitarily formed as uniform, round elements having pre-determined respective diameters.

6. The improvement as set forth in claim 5 which is further characterized in that: said rod means has a diameter of approximately 1/16 inch and said handle means has a diameter of approximately three-eights inch.

7. The improvement as set forth in claim 6 which is further characterized in that: said rod means and said handle means are unitarily formed from nylon.

8. The improvement as set forth in claim 1 wherein: said urethral catheter is the type known as the Foley urethral catheter.

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