TROCAR

Abstract: Trocar (1) intended to be used in gasless laparoscopy and comprising a tube (2) with a collar (3) at one end. The tube is composed of plastic or metal and has a constant open slit (4) through which an instrument, for example the blades (10, 11) of a pair of scissors (9) or hemostatic forceps can be introduced without expanding the tube.

Description: Troakar The present invention relates to a trocar, for use during laparoscopy, comprising a tube with a collar at one end and an axial longitudinal slit. A trocar is known, for example from WO 94/22357 which has a slit tube. The tube consists of a flexible material and because of the slit can be expanded radially in order to permit the introduction of an instrument with a larger outer diameter than the inner diameter of the tube. When the tube does not contain an object which strives to expand the tube the slit is closed so that its end edges are in contact with each other. The trocar is intended to be used during laparoscopy and permits the use of instruments with large differences in size. However, the construction is so that it is not possible to identify, grip and suture tissues through the slit because there is no free opening through the slit. In gasless laparoscopy holes can be made in the abdominal wall, through which lift rods can be inserted under the abdominal wall and lifted upwardly with a lifting means in order to expand the hole in the abdomen through which instruments can subsequently be fed. A gastight introduction port with especially adapted instruments is not needed. During longer operations where different instruments are introduced through the same hole there is, however, a risk for increasing traumatisation and damage to the tissues which border the hole. The object of the present invention is to provide in the first instant a trocar intended for gasless laparoscopy which permits the use and facilitates the introduction of instruments intended for open abdomen surgery which take up a lot of room and which in this connection protects the tissues around the hole without changing the circumstances of how the instruments are manipulated. This is achieved according to the invention by the tube being composed of a rigid semi-rigid material and that the slit being so large that a part of a surgical instru¬ ment introduced in the trocar can be taken out through the slit without expanding t tube. Through the invention a trocar is provided which holds apart the tissues of the hole and guides the instruments so that these follow the right path through the abdomina wall at the same time as the different tissue layers of the abdominal wall can be identified through the slit. The slit allows for example the cutting blades of a pair o scissors to be opened and closed through the slit. The invention is described more closely with reference to the embodiment shown o the appended drawings, where Fig. 1 shows a perspective view of an embodiment o a trocar according to the invention, Fig. 2 shows a side view of the trocar placed o a mandrel and Fig. 3 shows a cross-section through an abdomen wall with a trocar introduced through the wall. The trocar 1 according to the invention comprises a cylindrical tube 2 of rigid or semi-rigid material, for example metal or a suitable plastic material, for example PVC. At one end of the tube 2 is a collar 3 formed in one piece with the tube. The tube 2 has an axial slit 4 which extends over the whole length of the tube and continues into a slit 5 in the collar 3. In Fig. 1 the width of the slit 4 is approximately 25% of the inner diameter of the tube 1. In practice the inner dia¬ meter of the tube can be approximately 5-15 mm depending on the area of use and the width of the slit can be up to approximately 75% of the inner diameter of the tube. It is most important that the width of the slit is less than the inner diameter so that the trocar can be held in place on for example a mandrel. Fig. 2 shows the trocar 1 closed on a mandrel 6 by means of which the abdominal wall 7 is penetrated (see Fig. 3) in order to introduce the trocar into the abdominal hole 8. Fig. 3 shows a pair of scissors 9 introduced into the trocar 1. One of the cutting blades 10 of the pair of scissors is accommodated in the trocar while the other blade 11 extends out through the slit 4. As can be seen from Fig. 3 the hinge 12 of the blades 10, 11 lies at the level of the abdominal wall 7. The trocar 1 according to the invention is in the first instance intended to be used during gasless laparoscopy but it can also be used as a holder of a normal trocar for normal laparoscopy and permits quick changes between gas and gasless laparoscopy respectively the opposite. The collar 3 at the upper end of the tube 2 prevents the trocar 1 from sliding into the abdominal hole 8 and can be used in order to fasten the troakar to the skin, for example with a clamp or through sewing the collar 3 to the skin.

Claims: Claims 1. Trocar for use during laparoscopy, comprising a tube with a collar at one end an an axial longitudinal slit, characterised in that the tube (2) consists of a rigid or semi-rigid material and that the slit (4) is so wide that a part (11) of said instrume introduced into the troakar can be brought out through the slit without expanding t tube. 2. Trocar according to claim 1, characterised in that the width of the slit (4) is les than the inner diameter of the tube (2). 3. Trocar according to claim 2, characterised in that the width of the slit (4) is between 25% and 75% of the inner diameter of the tube (2). 4. Trocar according to one of claims 1-3, characterised in that the slit (4) extends over the whole length of the tube. 5. Trocar according to claim 4, characterised in that the collar (3) has a slit (5) which forms a continuation of the slit (4) in the tube (2).

Inventors: BERGSTROEM BO S, BERGSTROEM, BO, S.
Applicants: BERGSTROEM BO S, BERGSTROEM, BO, S.
Application year: 1996
Main classification: A61B17
IPC codes: A61B1, A61B17