Cannula for tissue suction

The invention relates to a cannula for suctioning off body tissue, in particular fatty tissue.

Liposuction is a widely used method in plastic surgery to remove excess fatty tissue without major surgery. A cannula is pushed under the skin into the fatty tissue, through which a suction is performed.

According to the prior art, cannulas of the above-mentioned type consist of a thin tube which is closed at the distal end and which has one or more openings in the area of ​​the closed end, which can be designed in the form of a tip. These mostly elongated, oval openings are a few mm long and extend in width at least over half the diameter of the cannula. These suction openings can be arranged linearly one after the other on the cannula shaft, but they can also have an arrangement in the shape of a triangle or an annular arrangement.

Openings in the form of passages surrounding the cannula tube in a spiral shape are also known.

Furthermore, cannulas are known which have an oval opening at the spatula-shaped tip.

All these cannulas mentioned in the prior art, however, have in common that connective tissue, blood vessels and nerves are also sucked out of the areas surrounding the fatty tissue through the openings during aspiration. This aggressive type of suction causes damage to the surrounding tissue, which leads to relatively slow wound healing.

On average, it takes about 3 months for the treated part of the body to heal completely, with the patient only relieving pain after two weeks. The accompanying paresthesia also affects the patient's well-being for up to four months. In addition, the patient is forced to wear pressure bandages and bandages for about five weeks after the operation in order to counteract the postoperative swelling and to promote the firming of the tissue.

The invention aims to shorten the time required for healing and to reduce the period of postoperative pain.

This object is achieved according to the invention in that the distal region of the cannula shaft has a plurality of openings arranged at regular intervals on the underside of the cannula shaft, the diameters of which are less than or equal to 1 mm, the spacing of the openings being between 1 and 3 mm.

With the help of the cannula according to the invention, liposuction can be carried out so gently that the surrounding tissue is almost not impaired. This results in a reduction in the pain period from two weeks to an average of two days and a reduction in the period required for complete healing from three months to two weeks.

The period in which compressive bandages have to be worn is also shortened, which, in contrast to procedures carried out with cannulas according to the prior art, also need to exert less pressure and are therefore more comfortable for the patient to wear. The occurrence of paresthesia after liposuction also decreases to a considerable extent or is limited to a shorter period of time.

Another advantage of the cannula according to the invention is that by using it, the result achieved can be seen immediately after the operation. When cannulas according to the prior art are used, a postoperative fat reduction effect, the so-called fat necrosis, brings about about 40% of the achievable result, whereby a precisely predictable result is not possible, since the end result depends on the fat necrosis which cannot be influenced.

The arrangement of the openings according to the invention also makes it possible to carry out directed suction, that is to say suction which is carried out only in one specific direction, namely in areas only below the openings.

The diameters of all openings in the cannula shaft are advantageously the same, so that the forces acting during aspiration are evenly distributed and gentle suction is ensured in every area.

In a preferred embodiment, the openings on the underside of the cannula shaft are distributed at most over an area of ​​half the circumference of the shaft.

Another preferred embodiment is characterized in that the distances between the openings are between 1 and 2 mm.

The region of the cannula shaft having openings expediently extends over a

AT 408 722 B

Length from 5 to 50 mm, preferably from 10 to 20 mm, viewed from the tip of the cannula to its proximal end. This length enables an optimal ratio between the aspiration speed and the accuracy of the suction.

The cannula shaft particularly advantageously has a diameter of 2 to 3 mm, preferably 2 to 2.5 mm.

The channels in the tissue that arise during liposuction through the cannula, which basically represent injuries to the tissue, are significantly reduced by cannulas with a diameter of less than 3 mm, which accelerates healing.

The cannula is advantageously made of stainless steel.

The invention is explained in more detail below with reference to the drawing, FIG. 1 illustrating a schematic representation of a preferred embodiment of the invention in side view and FIG. 2 illustrating a section along the line II in FIG. 1.

1 shows a cannula shaft 1 which has a plurality of openings 4 of the same size in a longitudinal region 2 which extends from a rounded tip 3 in the direction towards the proximal end (not shown). The openings 4 with a diameter 5 of less than or equal to 1 mm are arranged on the underside 6 of the cannula shaft 1 at regular intervals, the distance 7 between two adjacent openings 4 being in the order of magnitude of the diameter 5 of the openings 4. The diameter 8 of the cannula shaft 1 is between 2 and 3 mm, preferably between 2 and 2.5 mm.

FIG. 2 shows a section through the cannula shaft 1 along the line II of FIG. 1. The underside 6 of the cannula shaft 1, which is formed by an area located below a horizontal plane 9 through the center point of the tube forming the cannula shaft 1, has two openings 4 which are arranged on the underside 6.