US3314430A

US3314430A - Sump drain catheter

Info

Publication number: US3314430A
Application number: US376879A
Authority: US
Inventors: Ralph D Alley; David S Sheridan
Original assignee: Brunswick Corp
Current assignee: Brunswick Corp; Sherwood Medical Co
Priority date: 1964-04-10
Filing date: 1964-06-22
Publication date: 1967-04-18
Anticipated expiration: 1984-04-18

Description

April 18, 1967 ALLEY ET AL 3,314,430

SUMP DRAIN CATHETER Filed June 22, 1964 2 Sheets-Sheet 1 INVENTORS RALPH D. ALLEY DAVID S. SHERIDAN A ril 18, 1967 R. D. ALLEY E AL 3,314,430

SUMP DRAIN CATHETER Filed June 22, 1964 2 Sheets-Sheet 2 msQ United States Patent 3,314,430 SUMP DRAIN CATHETER Ralph D. Alley, Loudonville, and David S. Sheridan, Argyle, N.Y., assignors to Brunswick Corporation, a corporation of Delaware Filed June 22, 1964, Ser. No. 376,879 16 Claims. (Cl. 128-350) The present disclosure is a continuation-in-part of United States patent application Ser. No. 358,767 filed Apr. 10, 1964, now abandoned, entitled, Intercost-al Catherer, which is in turn a continuation-in-part of United States patent application Ser. No. 171,906, filed Feb. 8, 1962, Patent No. 3,190,290, entitled, Intercostal Catheter, all by the same inventors, Ralph D. Alley and David S. Sheridan.

The present invention relates to sump drains and particularly to sump drains for the operative and postoperative removal of fluid.

In the past, rigid metallic sump drains have been utilized to remove fluid from the body during surgical operations. These would be introduced through surgical incisions utilized during the operation and removed before the surgical incisions wereclosed. Being rigid in structure, they could not remain in the incisions after the operation, for the rigid structure would not only reopen the incision, but it also would rupture surrounding tissue and organs. Since fluids may form in body cavities, after many types of surgical operations, many surgeons have felt that it would be desirable to have available a sump drain which could be placed in a patients body near the termination of a surgical operation and remain therein to accomplish the desired postoperative drainage of the particular body cavity involved. These periods of time required for the postoperative drainage may extend up to several days, or possibly, several weeks. The desired technique for the placement of such a postoperative sump drain is to make a separate stab Wound, introduce the sump drain through a primary incision and to draw the sump drain into a desired location by pulling the proximal 'end out through the stab wound. The metal sump drains which were previously utilized only during a surgical operation, cannot be used in such a desired technique of inserting a postoperative sump drain because their rigidity prevents them from being turned and pulled out through a secondary stab wound after being inserted through a primary incision. In addition their rigidity prevents them from being bent around organs to reach a desired location which cannot be reached in a straight line from a slanted secondary incision. Further, these prior metallic sump drains utilize a projecting abutment-type structure to connect an outer casing to a hollow tube or shaft which serves as an inner cannula and is also constructed of rigid metal.

The present invention fulfills the need for a postoperative sump drain by providing a sump drain structure which is flexible and further has a tapered proximal end which may be drawn out through a secondary stab wound without tearing or coring the body tissues through which it is drawn for placement.

It is therefore an object of the present invention to provide a new and improved sump drain.

An additional object is to provide a flexible sump drain which can be inserted through a primary incision and drawn out through a secondary stab Wound.

A further object is to provide a flexible sump drain which has a tapered proximal end that is devoid of any projections at the point of juncture between an outer casing and an inner cannula.

A principal object is to provide a flexible sump drain which conforms at body temperatures to various irregular drainage terrains.

Another object is to provide a flexible sump drain which can be easily bent around organs in the body Without placing damaging pressure on such organs.

An additional object is to provide a flexible sump drain having an inner cannula with a fusiform proximal end section which has an opening edge that is tapered at an angle of less than 30 to a center line of the cannula on the proximal slope of the fusiform portion, and having a flexible casing surrounding the flexible cannula and spaced therefrom, which has a proximal end secured to the distal slope fusiform portion of the cannula so that the juncture of the casing and cannula is free of all projections which might otherwise tear tissue as the proximal end of a cannula and casing are drawn out through a secondary stab wound after being inserted through a primary incision.

Further objects and advantages will become apparent from the following detailed description taken in connection with the accompanying drawings, in which:

FIGURE 1 is a perspective view of an embodiment of the present invention;

FIGURE 2 is an enlarged elevational view of the proximal end of the embodiment of the invention illustrated in FIGURE 1;

FIGURE 3 is a partial sectional view of the distal end of the embodiment of the invention illustrated in FIG- URE 1;

f FIGURE 4 is a sectional view of the embodiment of the invention illustrated in FIGURES 1 and 3, taken along the line 4-4 in FIGURE 3;

' FIGURE 4a is a sectional view taken along the line I 4a.-4a in FIGURE 3;

.casing and their inner cannula.

FIGURE 5 is an action view of the embodiment of the invention illustrated in FIGURES 1-4 as it is entering a secondary stab wound;

endsection is, being drawn through a secondary stab wound; and

FIGURE 7 is an action view of the embodiment of the invention illustrated in FIGURES 1-4 as the proximal end section thereof is emerging from a secondary stab wound.

While this invention is susceptible of embodiment in many different forms, there is shown in the drawings and will herein be described in detail, an embodiment of the invention with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the invention to the embodiment illustrated. The scope of the invention will be pointed out in the appended claims.

Prior designs 'of metallic sump drains would not be practical for use as postoperative sump drains even if any of these designs were constructed of flexible material. It is most undesirable to attempt to retain a sump drain in a primary surgical incision after the completion of an operation. Therefore, the technique of making a secondary stab wound through which a postoperative sump drain is to pass has been developed. However, the sump drains that have been used during surgery in the past have substantial projections created at the juncture of their outer Therefore, even if they were made of material which was flexible enough to be bent around and drawn towards a secondary stab wound, the projections at the juncture of their casings and cannulas would either prohibit the drawing out of the proximal end of such a sump drain or, in doing so, it would badly rip tissue through which it passed. The present invention makes it possible to not only draw the proximal end of a sump drain out through a secondary stab wound, but it also provides a sufficiently flexible sump drain to remain in a patients body for a substantial period of time Without the possibility of further injuring the patient or making him unduly uncomfortable because of a rigid structure remaining in his body. In addition, the present invention provides a method whereby the surgeon can definitely locate by roentgenography a sump drain in the patients'body and periodically check its position in the patients body.

Referring now to the FIGURES 1-4, a flexible transparent plastic cannula has a cannula wall 10, a distal end 11 and a proximal end section 15. The proximal end section 15 is formed in a fusiform shape, as may be most clearly seen in FIGURE 2. The proximal slope of the fusiform section 15 has been cut in a plane forming less than a 30 angle (oz in FIGURE 2) with a center line 36 of the fusiform section to form a cannula proximal end opening 16 whose edge is tapered. A particularly preferred angle is approximately 15, but any angle less than 30 is satisfactory. Thus, the proximal slope of the fusiform section15 forms a tapered section which gradually increases to a maximum diameter of the fusiform section 15. A set of four apertures 19-22 are disposed in the cannula wall 10 near its distal end 11 with each aperture being spaced circumferentially around the cannula at intervals of 90 from the two adjoining apertures.

Since the illustrated postoperative sump drain is placed by the same general surgical technique as an intercostal catheter, it can have a cannula proximal end section constructured in accordance with the applicants copending application Ser. No. 171,906, filed Feb. 8, 1962, now US. Patent No. 3,190,290 issued June 22, 1965, for an intercostal catheter. That application discloses an intercostal catheter having a fusiform section formed therein adjacent its proximal end which has a distal slope and a proximal slope. The proximal end opening defines a plane at less than a 45 angle with a center line of the fusiform section, which does not lie entirely within the proximal slope. Although this construction minimizes or reduces ripping and tearing of body tissue as the tip is drawn through body tissue, coring of the tissue can be caused by a heel which remains open when drawn through tissue to a secondary incision or stab wound formed at the distal end of the proximal opening. Therefore, as herein disclosed, the proximal end section 15 is preferably constructed in accordance with our continuation-impart application, Ser. No. 358,767, filed Apr. 10, 1964, for an intercostal catheter which is also a copending application and discloses a catheter proximal end section construction which avoids coring of tissue by having a proximal end opening situated entirely within the proximal slope of a fusiform end section which has a warped end surface. The warped end surface 12 has an inwardly inverted heel portion 13 and an outwardly inverted tip 14. The fusiform proximal end section 15 has a maximum diameter indicated at 37 whichseparates a distal slope 38 and a proximal slope 39 of the fusiform section. As aforementioned, the plane of the proximal end opening 16 is at approximately a 15 angle with a center line 36 of the fusiform proximal end section 15. The ratio of a diameter 40 of the fusiform section reasured at the heel 13 to the maximum dimension of the proximal end opening 16 is a ratio of approximately 1:3. While the approximate angle (or in FIGURE 2) between the plane of the proximal end opening 16 and the center line 36 is 15 for an approximate ratio of 1:3, slight variations of this ratio will vary the angle a over a range from approximately 10 to 25. Larger variations of the ratio will vary the angle from approximately to 30. The exact angle to be used for a varies with the composition of the plastic being used to form the cannula, temperature and pressure of the surrounding atmosphere, catheter size, and catheter wall thickness. Therefore, exact angles selected for angle a will probably be within the range of 5 to 30 depending upon these factors. In some circumstances it may be desirable to utilize angles greater than 30 and approaching as high as 45 The cannula is constructed of a plastic which is sufiiciently fiexous at body temperatures to allow the tip 14 to align itself with the center line 36 of the proximal end section 15 when a slight tension is applied to the tip 14. The center line of the proximal end section 15 is identical to the center line of the cannula. Thus, the cannula presents a cone shape for smoothly parting tissue without coring it as is more fully explained in our copending continuation-in-part application.

A flexible, transparent, externally longitudinally grooved or corrugated, plastic tubular casing has a casing wall 25, a distal end 26 which is secured to the cannula distal end 11 and a beveled proximal end 27 which is secured to the distal slope of the fusiform proximal section 15 of the cannula. The relative length of the cannula and the casing are such that the cannula and the casing are spaced from each other even when they are flexed, as illustrated in FIGURE 1. The external land diameter of the wall 25 of the casing (diameter measured between outer surface of opposing lands of the grooved or corrugated casing wall 25) is approximately equal to the maximum diameter of the cannula proximal end section 15. A pair of symmetrically opposing apertures 28 and 29 are formed in the casing wall 25 adjacent the proximal end 27 so that they communicate with the space formed between the cannula wall 10 and the casing. A multiplicity of apertures generally indicated at 30 are formed through the casing wall 25 near the distal end 26 and thereby communicate with the space formed between the cannula and the casing. The outer edge of each aperture 30 is satin smooth with no rough edges and each is located in the valley of a longitudinal corrugation. A longitudinally elongated line of the X-ray opaque material 31 is embedded in the casing wall 25. The line of X-ray opaque material 31 extends from the distal end 26 to the beveled proximal end 27 enclosed under the crest of a corrugation, being interrupted only by a single aperture 32 which is further from the distal end 26 than any of the apertures 30. The X-ray opaque line is placed Within a corrugation in order that it may have as large a cross section of X-ray opaque material as possible.

Although the illustrated embodiment of the present invention may be utilized to drain a body cavity through a principal incision during a surgical operation, its principal use is that of a postoperative sump drain. Therefore, the technique of placing the sump drain for the utilization of the sump drain illustrated in the FIGURES 5-7 for postoperative drainage will now be described in greater detail. At the appropriate point of a surgical operation, a secondary stab wound 41 is made and the proximal end section 15 of the sump drain is inserted through a primary incision and is then drawn out through the secondary incision or stab wound 41, usually with the aid of forceps 42 introduced through the secondary stab wound 41 until the distal end 26 is drawn into the operative field to be drained. The jaws of the forceps utilized with the sump drain should be of the elongated type whose maximum diameter is less than that of the maximum diameter of the sump drain. The forceps, when utilized, grasp the cannula proximal tip 14 as shown in FIGURES 57. Since the cannula proximal end section 15 becomes tapered in the form of a cone when it is at body temperatures, and as it is drawn through body tissues, the body tissues will not be torn because there are no projections on the cannula and the taper smoothly parts the tissues to allow the maximum diameter of the fusiform section 15 to pass therethrough. With the proximal end opening 16 lying entirely within the proximal slope of the fusiform proximal end section 15, the entire opening is urged toward closure as body tissue presses upon the surfaceof the cannula around the opening. This easily occurs, for this portion of the cannula is then slack because the tip is approximately aligned with the center of the end section and the strain on the cannula passes through the portion of the proximal slope away from the opening 16. Thus, not only tearing and ripping of tissue is avoided, but also any coring of tissue is avoided.

There is no tearing of the tissue by the proximal end 27 of the casing, for the maximum of the diameter casing does not exceed that of the fusiform section 15 and the proximal end 27 is beveled. Thus, tissue that has been parted by the taper up to the maximum diameter of the fusiform section 15 will smoothly slide over the proximal end 27 of the casing wall 25. This is accomplished even though the tissue may contract around the cannula after the passage of the maximum diameter of the fusiform section 15, with the aid of the beveled casing end 27. Thus, the end section of the cannula smoothly parts tissue without tearing it as it is pulled therethrough and allows the proximal end of the casing to follow through the parted tissue without tearing it.

Once the proximal end of the sump drain has been drawn through the secondary stab wound and the distal end approximately positioned, the surgeon may check the position of the distal end in the patients body, even though he cannot visually observe it, with the aid of X-rays. The X-ray opaque line 31 designates the actual position throughout its length of the sump drain and the interruption of this line by the aperture 32 designates the point along the line at which the

apertures

30 and 32 begin. Therefore, the surgeon observing an X-ray photograph or fluoroscopic view of a sump drain in a patient knows that the apertures 30, which will allow fluid to flow into the space between the cannula and the casing, lie along the short section of the opaque line 31 between the aperture 32 and the casing distal end 26. Thus, a surgeon may be assured that the sump drain is properly positioned and can check its position by X-rays at various times after the primary surgical incisions have been closed. Once the sump drain is in position, fluid may flow through the apertures 30 into the space between the cannula and the casing. Any type of suction device well known to those skilled in the art may be connected to the cannula opening 16 to apply an internal suction to the cannula. This suction will draw fluid from the space between the cannula and casing through the apertures 19-22 in the wall of the cannula and up through the cannula. The two apertures 28 and 29 vent the sump drain when no fluid is being drained. In addition, they prevent body tissues from being drawn through the

apertures

30 and 32 of the casing in the event that excessive suction is applied to the cannula.

The apertures 1922 in the wall of the cannula are larger than the casing eyes 30 so that anything entering the casing will be drawn into the interior of the drain cannula and will not clog the space between the cannula and the casing or any of the apertures 19-22 to interfere with the drainage.

We claim:

1. A medical sump drain for use during surgical operations and in postoperative periods comprising:

a flexible, transparent, plastic cannula having a distal end, a proximal end, and a wall, said wall being flared to a larger external and internal diameter near its proximal end,

four inlet apertures disposed in said wall near said distal end circumferentially 90 apart,

an end opening at said proximal end lying substantially in a plane which forms less than a 45 angle with a center line of said proximal end,

a flexible, transparent, exteriorly longitudinally grooved, plastic tubular casing having a distal end, a proximal end and a wall surrounding said cannula and spaced therefrom by having the casing distal end secured tothe cannula distal end and the casing proximal 6 end secured to the flared wall portion of the cannula near the cannula proximal end, said casing having a beveled exterior edge on its proximal end and an exterior land diameter approximately equal to said larger exterior diameter of said cannula,

a plurality of inlet apertures in said casing Wall near said casing distal end of which at least one is located in a longitudinal groove,

a pair of vent holes opposingly spaced in said casing wall near said casing proximal end which communicate with the space between said cannula and easing walls, and

a longitudinal line of X-ray opaque material embedded in said casing.

2. A medical sump drain for use during surgical operations and in postoperative periods comprising:

a flexible, transparent, plastic cannula having a distal end, a proximal end, and a wall,

an inlet aperture disposed in said wall near said distal end,

a flexible, transparent, plastic tubular casing having a distal end, a proximal end and a Wall surrounding said cannula and spaced therefrom by having the casing distal end secured to the cannula distal end and the casing proximal end secured to the wall of the cannula near the cannula proximal end,

a plurality of inlet apertures disposed in said casing wall near said casing distal end,

a vent hole in said casing wall near said casing proximal end which communicates with the space between said cannula and casing walls, and

a longitudinal line of X-ray opaque material embedded in said casing which is interrupted by the casing inlet aperture locate-d furthest from said casing distal end.

3. A medical sump drain for use during surgical operations and in postoperative periods comprising:

a fusiform sec-tion formed in the cannula adjacent the proximal end,

an inlet aperture disposed in said wall near said distal end,

an end opening in said fusiform section lying substantially in a plane which forms less than a 45 angle with a center line of said fusiform section,

a flexible, transparent, plastic tubular casing having a distal end, a proximal end and a wall surrounding said cannula and spaced therefrom by having the casing distal end secured to the cannula distal end and the casing proximal end secured to the fusiform sect-ion of the cannula adjacent the cannula proximal end,

an inlet aperture in said casing wall near said casing distal end, and

a vent hole in said casing wall near said casing proximal end which communicates with the space between said cannula and casing walls.

4. A medical sum-p drain for use during surgical operations and in postoperative periods comprising:

a flexible, plastic cannula having a distal end, a proximal end, and a wall,

a fusiform section formed in the cannula adjacent the proximal end and having an end opening therein,

an inlet aperture disposed in said wall near said distal end,

a flexible, plastic tubular casing having a distal end, a proximal end and a wall surrounding said cannula and spaced therefrom by having the casing distal end secured to the cannula distal end and the casing proximal end secured to the fusiform section of the cannula adjacent the cannula proximal end,

an inlet aperture in said casing wall near said casing distal end, and v a vent hole in said casing wall near said casing proximal end which communicates with the space between said cannula and easing walls.

5. A medical sump drain for use during surgical operations and in postoperative periods comprising:

a cannula having a distal end, a proximal end, and a wall, i

a fusiform section formed in the cannula adjacent the proximal end,

inlet apertures disposed in said wall near said distal end,

a tapering end opening in said fusiform section,

a tubular casing having a distal end, a proximal end and a wall surrounding said cannula and spaced theretherefrom, said casing proximal end being secured to said cannula near the cannula proximal end in an externally smooth junction whereby no projections are present on said cannula or said casing to injure tissue as said cannula tapering end opening is drawn through tissue,

I means for centering said cannula distal end with respect to the tubular casing at the distal end thereof;

a plurality of inlet apertures in said casing wall near said casing distal end,

vent holes in said casing wall near said casing proximal end which communicate with the space between said cannula and casing walls.

6. A medical sump drain for use during surgical operations and in postoperative periods comprising:

a fusiform section formed in the cannula adjacent the proximal end,

an inlet aperture disposed in said wall near said distal end,

an end opening in said fusiform section lying sub stantially in a plane which forms less than a 30 angle with a center line of said fusiform section,

a flexible, transparent, plastic tubular casing having a distal end, a proximal end and a wall surrounding said cannula and spaced therefrom by having the casing distal end secured to the cannula distal end and the casing proximal end secured to the fusiform section of the cannula adjacent the cannula proximal end,

an inlet aperture in said casing wall near said casing distal end, and

a vent hole in said casing wall near said casing proximal end which communicates with the space between said cannula and easing walls.

7. A medical sump drain for use during surgical operations and in postoperative periods comprising:

a flexible, transparent, plastic cannula having a distal end, a proximal end, and a wall, said Wall being flared to a larger external diameter near its proximal end to form a fusifor-m section having a distal slope and a proximal slope,

an inlet aperture disposed in said wall near said distal end,

an end opening as said proximal end defining a plane which intersects only the proximal slope of the fusiform section,

a flexible, transparent, plastic tubular casing having a distal end, a proximal end and a wall surrounding said cannula and spaced therefrom by having the casing distal end secured to the cannula distal end and the casing proximal end secured to the fusiforrn section of the cannula near the cannula proximal end,

an inlet aperture in said casing wall near said casing distal end, and

8. A medical sump drain for use during surgical op? erations and in postoperative periods comprising:

a flexible, transparent, plastic cannula having a distal end, a proximal end, and a wall, said wall being flared to a larger external diameter near its proximal end to form a fusiform section having a distal slope and a proximal slope,

an inlet aperture disposed in said wall near said distal end,

an end opening at said proximal end defining a plane which intersects only the proximal slope of the fusiform section at an angle of approximately 15 to a center line of said section,

a flexible, transparent, plastic tu-bular casing having a distal end, a proximal end and a wall surrounding said cannula and spaced therefrom by having the casing distal end secured to the cannula distal end and the casing proximal end secured to the fusiform section of the cannula near the cannula proximal end,

an inlet aperture in said casing wall near said casing distal end, and

9. A medical sump drain for use during surgical op erations and in postoperative periods comprising:

a cannula of flexible plastic material having a distal end, a proximal end, and a wall,

a fusiform section formed in the tube adjacent the proximal end which has a distal and a proximal slope, an inlet aperture disposed in said wall of said cannula near said distal end,

a proximal end opening defined by a warped end surface having an inwardly inverted heel portion and outwardly inverted tip portion and lying within said proximal slope,

a flexible, plastic tubular casing having a distal end, a proximal end, and a Wall surrounding said cannula and spaced therefrom by having the casing distal end secured to the cannula distal end and the casing proximal end secured to the fusiform section of the cannula adjacent the cannula end,

an inlet aperture in said casing near said casing distal end, and

10. A sump drain as claimed in claim 9 wherein said 11. A medical sump drain for use during surgical operations and in postoperative periods comprising:

a fusiform section having a larger exterior diameter formed in the cannula adjacent the proximal end, an inlet aperture disposed in said wall near said distal end,

a flexible, transparent, plastic tubular casing having a distal end, a proximal end and a wall surrounding said cannula and spaced therefrom by having the casing distal end secured to the cannula distal end and the casing proximal end secured to the fusiform section of the cannula adjacent the cannula proximal end, said casing having a beveled exterior edge on its proximal end and an exterior land diameter approximately equal to said larger exterior diameter of said cannula,

an inlet aperture in said casing wall near said casing distal end, and

12. A sump drain as claimed in claim 11 wherein said 7 casing wall is exteriorly longitudinally grooved.

9 10 13. A sump drain as claimed in claim 12 wherein said 15. A sump drain as claimed in claim 14 wherein a inlet aperture in said casing wall is located in one of said longitudinal line of X-ray opaque material is imbedded longitudinal grooves. in said casing Wall.

14. A medical sump drain for use during surgical op- 16. A sump drain as claimed in claim 14 wherein said erations and in postoperative periods comprising: 5 casing wall near said distal end and said cannula Wall a flexible plastic cannula of flexible plastic material near said distal end each have a plurality of inlet aperhaving a distal end, a proximal end, and a wall, tures, and wherein said inlet apertures in said casing wall a fusiform section formed in the cannula adjacent are smaller than said inlet apertures in said cannula the proximal end which has a distal slope and a wall. proximal slope, 10 References Cited by the Examiner an inlet apctlerurle 1dispgsed in said wall of said cannula UNITED STATES PATENTS near sai 1s a en a proximal end opening lying within said proximal slope, 11045326 11/1912 Ruflu} 128 349l a flexible plastic tubular casing having a distal end, a 1799765 4/1931 Schnelder et 174 83 proximal end, and a wall surrounding said cannula 15 1879249 9/1932 Honsalmr 128 239 and spaced therefrom by having the casing distal end 2857915 10/1958 Schendan 128 349 secured to the cannula distal end and the casing 3/1960 "128 350 proximal end secured to the fusiform section of the 104L044 7/1962 Sheridan 128348 cannula adjacent the cannula proximal end, 10/1963 Overment 128' 35O an inlet aperture in said casing wall near said casing 20 3115138 12/1963 McElvwny 128278 distal end, and 3,1 6,316 6/1964 Beall 128350 a vent hole in said casing wall near said casing proximal end which communicates with said space between RICHARD GAUDET Primary Exammer' said cannula and easing wall. DALTON L. TRULUCK, Examiner.

Claims

1. A MEDICAL SUMP DRAIN FOR USE DURING SURGICAL OPERATIONS AND IN POSTOPERATIVE PERIODS COMPRISING: A FLEXIBLE, TRANSPARENT, PLASTIC CANNULA HAVING A DISTAL END, A PROXIMAL END, AND A WALL, SAID WALL BEING FLARED TO A LARGER EXTERNAL AND INTERNAL DIAMETER NEAR ITS PROXIMAL END, FOUR INLET APERTURES DISPOSED IN SAID WALL NEAR SAID DISTAL END CIRCUMFERENTIALLY 90* APART, AN END OPENING AT SAID PROXIMAL END LYING SUBSTANTIALLY IN A PLANE WHICH FORMS LESS THAN A 45* ANGLE WITH A CENTER LINE OF SAID PROXIMAL END, A FLEXIBLE, TRANSPARENT, EXTERIORLY LONGITUDINALLY GROOVED, PLASTIC TUBULAR CASING HAVING A DISTAL END, A PROXIMAL END AND A WALL SURROUNDING SAID CANNULA AND SPACED THEREFROM BY HAVING THE CASING DISTAL END SECURED TO THE CANNULA DISTAL END AND THE CASING PROXIMAL END SECURED TO THE FLARED WALL PORTION OF THE CANNULA NEAR THE CANNULA PROXIMAL END, SAID CASING HAVING A BEVELED EXTERIOR EDGE ON ITS PROXIMAL END AND AN EXTERIOR LAND DIAMETER APPROXIMATELY EQUAL TO SAID LARGER EXTERIOR DIAMETER OF SAID CANNULA, A PLURALITY OF INLET APERTURES IN SAID CASING WALL NEAR SAID CASING DISTAL END OF WHICH AT LEAST ONE IS LOCATED IN A LONGITUDINAL GROOVE, A PAIR OF VENT HOLES OPPOSINGLY SPACED IN SAID CASING WALL NEAR SAID CASING PROXIMAL END WHICH COMMUNICATE WITH THE SPACE BETWEEN SAID CANNULA AND CASING WALLS, AND A LONGITUDINAL LINE OF X-RAY OPAQUE MATERIAL EMBEDDED IN SAID CASING.