US 3508553 A
Description (OCR text may contain errors)
A ril 28, 1970 M. s. KANBAR ET AL 3,508,553
SURGICAL VEIN STRIPPING INSTRUMENT FOR PHLEBECTOMIE$ Filed March 6, 1968 IN TORS Maumcg JQ/YBA/ yam 4? M405) W Ame/v01 United States Patent 3,508,553 SURGICAL VlEIN STRIPPING INSTRUMENT FOR PHLEBECTOMIES Maurice S. Kanbar, 4 E. 77th St. 10021, and Joseph R. Wilder, 1199 Madison Ave. 10028, both of New York, N.Y.
Filed Mar. 6, 1968, Ser. No. 710,976 Int. Cl. A61b 17/00 US. Cl. 128-303 9 Claims ABSTRACT OF THE DISCLOSURE A surgical vein stripping instrument for performing phlebectomies, the stripping being constituted by a molded rod formed of a thermoplastic orientable material, such as nylon, which, except for the end portions, is stretch-oriented to define an elongated mono-filament cable of high strength having unoriented guider tips integral therewith, auxiliary bullet-shaped tips of larger dimension and a handle being connectable to the unoriented guider tips.
This invention relates generally to surgical instruments, and more particularly to a vein stripper of synthetic plastic material for performing phlebectomies.
Veins are vessels or tubular structures in the human body which carry blood from tissues toward the heart. Their highly extensible walls enable veins to expand and to hold large volumes of blood when there is a sudden surge in blood flow through the tissues. Distribution of blood through the venous system depends on flow through the arterioles and capillaries and varies with posture and body activity.
Change from a recumbent to an erect position greatly increases the work required to convey blood from the extremities to the heart, and tends to cause an accumulation of blood in the veins of the extremities. Movement of the body muscles acts to compress the veins, thereby aiding in the propulsion of blood to the heart. This effect is assisted by the presence in the larger veins of valves which prevent back-flow. These valves are formed. by leaflike extensions of the walls of the veins.
Varicose veins are essentially enlarged, tortuous veins which can occur anywhere in the body; but occur most frequently in the superficial veins of the lower extremities. Among the symptoms caused by varicose veins are pain, especially in standing, or cramps in the legs, with swelling of the angles and legs when the condition is marked. Complications consist of thrombophlebitis, varicose vein ulcers and eczema. Varicose veins are caused by any disorder that damages or impairs the vein valves, such as an infection or an increase in venous pressure as a result of a tumor, a pregnant uterus, or constant standing. A tendency toward varicose veins is often due to an inherent weakness in the valve structure. Frequently, varicose veins is a familial disease.
The treatment of varicose veins is often surgical, involving surgical ligation or excision of the damaged veins. In the Atlas of General Surgery by Joseph R. Wilder, 2nd edition, 1964, published by C. V. Mosby Company, there is disclosed and illustrated (page 240 et seq.) a technique for performing a phlebectomy to effect high ligation and total excision of the greater saphenous vein, which is the vein most frequently affected. In this technique, the saphenous vein is excised at the point where it enters the femoral vein, a ligature being applied to the saphenous stump. The greater saphenous vein is then removed by means of a vein stripper.
A conventional vein stripper is constituted of a stainless steel cable about a yard long and having a diameter of 3,508,553 Patented Apr. 28, 1970 "ice approximately one-sixteenth to one-eighth of an inch. Short, externally-threaded plugs are welded to the extremities of the cable and serve as coupling heads. Attachable to one of the plugs is a handle having an internally threaded socket to receive the threaded plug, the handle being used by the surgeon to pull the cable. Attachable to the other plug are bullet-shaped tips to facilitate passage of the cable. A small as well as a large tip is ordinarily provided, the smaller tip having a diameter not much greater than that of the cable, the larger tip having a diameter at least twice as great.
In practice, after an entry incision has been made in the vein to be removed, the surgeon screws on the small leader to one end of the stripper cable and then proceeds to shake the cable through the vein. When the small leader emerges from an exit incision the surgeon places a constricting ligature about the vein attaching it circumferentially to the mechanical stripper and after coupling a handle to the other end of the cable, he slowly withdraws the cable, thereby removing the attached vein. The surgeon, by employing the bullet shaped tips, effectively utilizes this vein stripping instrument.
Stainless steel vein strippers have inherent shortcomings which create problems in carrying out phlebectomies. The cable itself is formed of multiple strands or fila ments of twisted wire. Such cables tend to kink and to have bends or creases therein which make insertion and withdrawal very awkward and difficult. Although it is possible to avoid kinking by the use of finer wire filaments, the resultant cable is limp and lacks sufiicient stiffness to facilitate the necessary snaking action when inserting the cable.
Moreover, the outer surface of the multi-strand twisted stripper cable, even though the individual filaments are highly polished, is uneven and offers frictional resistance when inserted or withdrawn. Also, because stainless steel strippers are relatively expensive, they are generally reused and must therefore be sterilized before an operation, to avoid contamination. Hence the surgeon must exercise care to be sure before each use, that his stripper is sterile.
In view of the foregoing, it is the primary object of this invention to provide a low-cost, disposable vein striper fabricated of synthetic plastic material.
More specifically, the object of this inevntion is to provide a vein stripper whose cable is formed by an elongated, oriented monofilament of thermoplastic material having high tensile strength and a smooth surface affording a low coefficient of friction.
Still another object of this invention, is to provide a vein stripper in which the end portions of the monofilament cable have guider tips integral therewith, which tips may readily be coupled by a snap action to a handle or to bullet-shaped tips.
A significant advantage of the invention is that the vein stripper may be sterilized after manufacture and packaged in sterile condition, whereby the surgeon is able to make immediate use of the stripper without preliminary sterilization, and may thereafter dispose of the used stripper. Because of the low cost of this plastic stripper in accordance with the invention, no undue expense is involved in the use of a fresh stripper for each phlebectomy.
Briefly stated, these objects are attained by a vein stripper which is formed by injection-molding or otherwise fabricating a realtively short rod of a crystalline resin whose ends are rounded to define the guider tips. The molded rod is then gripped at its ends, the section therebetween being heated to a temperature close to its melting point, and then stretched to several times its initial length to a point of low residual elongation, at which point the resultant cable, which is of reduced diameter, has its highest tensile strength without any loss of flexibility.
The unstretched rounded end portions retain their original diameter, hence a shoulder is formed between the ends and the junction of the cable integral therewith to define guider tip terminals. Attachable to either terminal are bullet-shaped tips of various diameters. A handle is also attachable to the vein stripper. The bullet-tips and handle have a slotted formation making it possible to snap these elements into the cable and to pull the associated guider tip into coupling relationship therewith.
For a better understanding of the invention, as well as other objects and further features thereof, reference is made to the following detailed description to be read in conjunction with the accompanying drawing, wherein:
FIG. 1 illustrates an injection-molded rod which constitutes the blank from which the stripper in accordance with the invention, is made;
FIG. 2 illustrates a vein stripper in accordance with the invention;
FIG. 3 is an enlarged perspective view of the guider tip at one of the stripper cable;
FIG. 4 is a perspective view of an auxiliary bulletshaped tip, attachable to a guider tip;
FIG. 5 is a bottom plan view of the auxiliary bulletshaped tip;
FIG. 6 shows the auxiliary bullet-shaped tip being coupled to the cable of the stripper;
FIG. 7 shows the auxiliary bullet-shaped tip and the associated guider tip in their intercoupled relationship;
FIG. 8 shows a handle which is attachable to a guider tip; and
FIG. 9 illustrates the vein stripper with the handle and the auxiliary bullet-shaped tip coupled thereto.
The material usable for forming a vein stripper in accordance with the invention is any thermoplastic, crystalline resin, preferably of high molecular weight, which is flexible and capable of being stretch-oriented to substantially increase its tensile strength. Among the materials suitable for this purpose are nylon, polypropylene, highdensity polyethylene, and polyvinyl chloride.
The first step in making the stripper involves injectionmolding a rod 10 of the selected material having the configuration shown in FIG. 1 In injection-molding, the raw stock in granular form is fed into a hopper of a screw assembly and drops through the feed throat of the hopper into the channel of a screw rotating within a hardened liner of a screw barrel, the material being forced forwardly by the flight of the screw. As the material moves, it is heated, melted and compressed. The molten stream from the screw assembly fed into a cavity whose configuration is such as to provide the rod 10.
Alternatively, rod 10 may be made by extruding a continuous cylinder, which is thereafter cut and shaped to the desired nonfiguration.
Rod 10 has rounded end portions 10A and 10B whose shape is that of the nose of the guider tips to be thereafter formed. It is known that molecular orientation can be imparted to various synthetic polymers by stretching, this being best done while heating the material. Accordingly, rod 10 is placed in suitable clamps which grip end portions 10A and 10B, the rod then being heated to the desired temperature in the region thereof between the clamped end portions. The clamped ends are then drawn apart to stretch the rod so as to increase its length to several times its original value, to a point of low residual elongation and below the threshold of rupture, at which point it has its highest tensile strength without in any way impairing its flexiblity.
The draw ratio used in stretch-orienting depends, of course, on the choice of material. In practice, the length of the rod may be increased to as much as four to ten times its initial value, thereby forming a flexible cable 11, as shown in FIG. 2, whose ends are provided with 4 guider tips 12 and 13 integral with the cable. Flexible cable 11 is a smooth-surfaced mono-filament having a low coefficient of friction, particularly in the cases of nylon and polypropylene, and monoaxially oriented. The diameter of the filament is approximately three-thirty seconds of an inch, as compared to the original rod diameter, which is about one-quarter of an inch. It is to be understood that these sizes are given only by way of example.
Guider tips 12 and 13, however, retain the original diameter of the rod 10. As shown separately in FIG. 3, each guider tip has a shoulder 12A at the junction of the cable 11 and the guider tip, this tip having a bullet-shape to facilitate passage of the cable.
Attachable to either one of the guider tips are auxiliary bullet-shaped tips, as shown in FIGS. 4 and 5, which are of larger dimension, for carrying out the required surgical procedure mentioned previouslyin which the varicose veins are removed. The auxiliary shaped tips can be molded of the same material as that forming the stripper, or any other suitable material, and is of split construction, the bullet-shaped tips having a longitudinal slot 14A which communicates with a central bore 14B dimensioned to accommodate cable 11, which bore enters the bottom of a cup-shaped socket 14C dimensioned to receive the guider tip.
Thus, as shown in FIG. 6, to attach a bullet-shaped tip 14 to guider tip 12, cable 11 is admitted through slot 14A into central bore 14B, the cable extending through the socket 14C. The width of slot 14A is approximately the diameter of cable 11, but because the split auxiliary bullet-shaped tip is formed of flexible material, the walls of the slot yield to admit the cable, thereby affording a snap action, the cable being retained within the central bore.
The auxiliary bullet-shaped tip 14, which now is slidable on cable 11, is then raised so that the guider tip 12 is received within socket 140, as shown in FIG. 7, the stripper now being in condition for use.
Handle 15, as shown in FIG. 8, is also formed of the same or material similar to the cable, and includes in its split base portion an entry slot 15A, a central bore 15B, and a socket 15C corresponding to those described in connection with FIGS. 4 to 7, to permit attachment of the handle to either one of the guider tips. Thus, as shown in FIG. 9, handle 15 is coupled to guider tip 13, while auxiliary bullet-shaped tip 14 is coupled to guider tip 12.
While there has been described and shown a preferred embodiment of vein stripper in accordance with our invention, it will be appreciated that many changes and modifications may be made therein without, however, departing from the essential spirit of the invention as defined in the annexed claims.
What we claim is:
1. A vein stripper comprising:
(a) a cable formed of a monofilament of synthetic thermoplastic material which is monoaxially oriented to provide high tensile strength, and
(b) a pair of guider tips integral with opposing ends of the cable and formed of the same material in the unoriented state, said guider tips having a bullet formation to facilitate passage of the cable through a vein, and a diameter somewhat greater than that of the cable.
2. A vein stripper as set forth in claim 1, wherein said material is nylon.
3. A vein stripper as set forth in claim 1, wherein said material is polypropylene.
4. A vein stripper as set forth in claim 1, wherein said material is polyethylene.
5. A vein stripper as set forth in claim 1, further including auxiliary bullet-shaped tips of larger diameter attached to said guider tips.
6. A vein stripper as set forth in claim 5, wherein said auxiliary bullet-shaped tips are of split construction including a slot to admit said cable into a central bore dimensioned to accommodate said cable, said central bore 5 6 entering a socket dimensioned to accommodate either one 9. The method as set forth in claim 8, wherein said of said guider tips. material is nylon.
7. A vein stripper as set forth in claim 1, further including a handle attached to one of said guider tips. References Cit d 8. The method of forming a vein stripper, comprising UNITED STATES PATENTS the steps of: 5
(a) molding a rod of synthetic thermoplastic material i gli ei :l u capable of being stretch-oriented, said rod having rounded ends, OTHER REFERENCES (b) clampmg the end portlons of Sand 10 Anchor Plastics Co., Surgery, February 1950, p. 281.
(c) heating the intermediate section of said rod, and
(d) drawing the clamped end portions apart to stretch the heated intermediate section to several times its TRAPP Pnmary Exammer original length to apoint of low elongation, thereby forming a monofilament cable which is monoaxially 15 C XR- oriented and defining guider tips whose noses are the 291 rounded ends of said rod.