FR2691625A3 - Disposable trochar for use in surgery e.g. to fit drainage tube - made from fibre-reinforced thermosetting plastic e.g. polyester, polyamide, polycarbonate, polystyrene, etc. which is sufficiently hard to take cutting edge - Google Patents

Abstract

The disposable trochar, is made from a fibre-reinforced plastic, produced by injection, compression or vacuum-injection moulding, or from a fibre-reinforced crystalline polymer. The plastic used for the trochar is a thermo-setting plastic selected from e.g. polyesters, polyamides, polycarbonates, polystyrenes and copolymerisates of styrene or other monomers or it can be made from a thermoplastic selected from polyesters, melamine epoxyplastics and polyurethanes. The reinforcing fibres can be of glass, at least 5 mm long and 8-50 microns thick, forming 30-75% by vol. of the plastic. The trochar is in the shape of a bar with one end (1) shaped to receive a drainage tube, a curve (4) and a pointed tip (5) at the other end formed by two flat surfaces at an acute angle. ADVANTAGE - Lower cost, providing suitable replacement for stainless steel which is sufficiently rigid to give a cutting edge and can be thrown away after use.

Description

 The present invention relates to a disposable trocar.

 A trocar is a bar-shaped instrument for medical use which comprises at its front end a blade, and which is provided at its rear end with means for attaching a drainage tube to the trocar.

 During an operation in a body cavity and in which a surgical intervention is performed in the tissue, secretions are usually produced after the operation in the form of blood and other body fluids which must be drawn off. To this end, a drain is usually made in the form of a flexible plastic tube, the wall of which is perforated at the end in order to be located at the operating site, and the opposite end of which is connected via a collecting container. secretion to a suction means for establishing a subatmospheric pressure for withdrawing said secretions from the operating site by suction.

 However, removal of secretions from the operating site can also be done by passive drainage.

 When such a drain is to be positioned, a trocar is passed, the rear end of which is connected to a drainage tube in the body cavity and from there through the tissue and outward through the skin. The drain tube is then pulled in place until the perforated portion thereof is in its correct position relative to the operating site. The drainage tube is then cut near the rear end of the trocar, and the free end is connected to the collecting container mentioned above.

 The front end of the trocar is point-shaped and typically has a triangular cross-sectional shape, one edge of which forms said blade.

 In order to obtain a tip of sufficient strength and a blade sharp enough to cut through the skin, the trocars which have been used until now are made entirely or partially of corrosion-resistant steel.

 The material and production costs associated with steel trocars are comparatively high, and therefore the use of disposable trocars has been unprofitable.

 In order to reduce material and production costs, it has been proposed to manufacture plastic trocars, but so far it has not been possible to successfully produce plastic trocars having blades sufficiently sharp to replace the trocars made of corrosion-resistant steel.

 Surprisingly, we have now found that it is possible to make a plastic trocar with tips of satisfactory rigidity and a sufficiently sharp blade.

 Thus, the trocar according to the invention is characterized in that it is produced from a plastic material reinforced with fibers and in that it is produced by injection molding, compression or vacuum injection.

 The plastic material is preferably a thermoplastic material, a thermosetting material or a crystalline polymer.

 Preferred thermoplastics include polyesters, polyamides such as nylon, polycarbonates and polystyrenes as well as copolymers of styrene and other monomers, such as acrylate and butane diene monomers.

 Preferred thermosetting plastics include polyesters, melamine, epoxyplastics and polyurethanes.

 The fiber reinforcement preferably includes glass fibers, but other inorganic and organic fibers are also suitable reinforcing fibers.

 The fiber reinforcements preferably include elongated fibers, such as fibers having a length of at least 5 mm and a thickness of 8 to 50 µm.

 When manufacturing fiber-reinforced plastic trocars by injection molding, the fibers are first carefully mixed with the plastic material, after which the latter is molded in suitable injection molds.

 The injection of the molding material into the injection molds is preferably carried out at a temperature between 1500C at 250 "C and at a pressure of 60 to 120 MPa.

 The fiber reinforcement preferably comprises 30 to 75% by volume of molding material.

The invention will be better understood and other objects, characteristics, details and advantages thereof will appear more clearly in the explanatory description which follows, made with reference to the appended schematic drawings given solely by way of example illustrating an embodiment. of the invention and in which:
FIG. 1 is a side view of a trocar according to the invention,
- Figure 2 is a trocar according to Figure 2, at an angle of 90 "compared to
Ira view according to Figure 1; and
- Figure 3 is a sectional view, on a larger scale, of the trocar according to Figure 2 along line III-III.

 The trocar shown in the drawings comprises a plastic bar reinforced with fibers, and it is provided at one of its ends (rear) with a hump or protuberance 1 to fix a drainage tube to it. The hump includes a point 2 and two parallel annular ribs 3.

 At its opposite end (front), the trocar shown has a curve 4 and a tip 5. The tip comprises two flat surfaces 6 which together constitute a blade 7.

Claims (7)

 1. Disposable trocar, characterized in that it is produced from a plastic material reinforced with fibers, and in that it is produced by injection molding, compression or vacuum injection.  2. Trocar according to claim 1, characterized in that it is made of a thermoplastic material reinforced by fibers, of a thermosetting plastic material reinforced by. fibers or a fiber-reinforced crystalline polymer.  3. Trocar according to claim 2, characterized in that the thermosetting plastic material is chosen from polyesters, polyamides, polycarbonates, polystyrenes and copolymers of styrene and other monomers.  4. Trocar according to claim 2, characterized in that the thermoplastic material is chosen from polyesters, melamine, epoxyplastics and polyurethanes.  5. Trocar according to one of claims 1 to 4, characterized in that the reinforcement by fibers comprises glass fibers.  6. Trocar according to claim 5, characterized in that the glass fibers have a length of at least 5 mm and a thickness of 8 to 50 clam.  7. Trocar according to claim 6, characterized in that the fibers constitute 30 to 75% by volume of the plastic.