DE20022005U1 - Foldable instrument canal sleeve for minimally invasive surgery - Google Patents

Description

Foldable instrument channel sleeve for minimally invasive surgery Introduction :

The invention relates to a sleeve serving as an instrument channel according to the preamble of claim 1.

In minimally invasive surgery, it is first necessary to create access for the rod-shaped instruments in order to be able to reach an operating area inside the body. Usually, the tissue layers are penetrated with a trocar, which consists of a sleeve with a trocar mandrel arranged inside it. The

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The standard external diameter of the instruments to be inserted is 5 to 12 millimeters. The external diameter of the trocar sleeves is therefore approximately 7 to 14 millimeters. Since these trocars are inserted without visual control, there is a risk of injury to blood vessels and internal organs, particularly if they are adherent to the abdominal wall due to adhesions. Various instruments have been developed to reduce these fundamental risks. For example, the abdominal wall can be penetrated under visual control using visual trocars from the Endopath Optiview product range (registered trademark) from Ethicon, Ci. US. (Pat. No. US 5,271,380; 5,685,820; 5,431,151; 6,007,481), but the penetration pressure is high due to the relatively large diameter of the trocars. Before the visual trocars are inserted, a pneumoperitoneum is created with CO2 gas using a Veress needle to distance the internal organs from the abdominal wall. However, inserting this needle also carries the injury risks described above (description in Pat. No. DE 40 35 146 C2). Based on the mechanistic idea that an injury with a smaller diameter trocar would be less serious, techniques were developed to replace a trocar sleeve that was initially inserted with a small diameter with a larger one (diliation set, see Pat. No. DE 198 14 576 Al) or by expanding the elastic wall of a tubular

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To enlarge the sleeve using a dilatation trocar (see Pat. No. US-5,431,676-A). In Pat. No. DE 198 14 576 A1, the diameter of the sleeve is actively changed by movable structural elements in the wall of the sleeve with the aid of operable adjusting devices. However, since the fundamental risk of injury does not depend on the diameter of the trocar, this can only be minimized by visually controlled access through the abdominal wall. In fact, an intestinal injury caused by an instrument with a small diameter is very dangerous, since symptoms indicating an injury only appear after days and the site of the injury is difficult to find. Pat. No. DE 195 47 246 Cl describes an optical Veress needle with which the primary puncture can be made under vision. This needle should have the same diameter as a conventional Veress needle and be able to be inserted with correspondingly low penetration pressure. Since the outer diameter of this needle is about 3-4 millimeters, procedures are necessary to expand the diameter of this puncture channel in order to be able to insert the sleeves for the surgical instruments. Since the expandable sleeves described above significantly increase the diameter of the Veress needle, which has an adverse effect on handling, a sleeve with the thinnest possible wall is required.

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Problem :

The state of the art as described in Pat. No. US 5,431,676-A offers a complex construction with three wall layers. The inner wall layer consists of a braid made of plastic threads, whereby the sleeve length shortens as the diameter increases due to the design. The braid alone offers little stability in the longitudinal axis, but ensures that the dilatation trocars slide well in the braid sleeve. Since this braid does not represent a closed wall, it is covered by an expandable rubber hose, which represents the middle layer and provides additional stability in the longitudinal axis as well as water and gas tightness. This hose absorbs a large amount of energy in the expansion phase, which must be applied to increase its own diameter. Since the rubber hose surrounding the braid slides poorly with its outer surface in the tissue, it is covered with a slippery but material-related non-stretchable outer sheath layer, which consists of a plastic sleeve and bursts at predetermined breaking points in the expansion phase. This results in a relatively large wall thickness of the sleeve due to the wall structure consisting of three different layers.

The sleeve according to the invention, on the other hand, is intended to be variable in diameter by folding and unfolding its single thin wall and, in the folded state, in diameter

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be reduced so that it can ideally be inserted under vision with a Veress needle and the outer diameter of the Veress needle is increased as little as possible in order to keep the penetration pressure in the tissue as low as possible. The sleeve should then be able to be unfolded using a commercially available blunt trocar, whereby the unfolding process of the sleeve itself should require as little force as possible in order to be able to use the force applied to the greatest possible extent to expand the tissue layers. This also contributes to better feedback of the actual penetration pressure and thus to better control of the penetration process for the surgeon. The wall of the sleeve should be stable in the folded state, i.e. with a small inner diameter of the sleeve and during the unfolding process in the longitudinal axis and be protected against kinking. In the unfolded state, the sleeve is stabilized by the inserted trocar sleeve and therefore no longer needs to have any significant inherent stability. The sliding friction force between the outer surface of the dilatation trocar and the inner surface of the sleeve as well as between the outer surface of the sleeve and the tissue to be penetrated should be as low as possible. After removing the trocar sleeve, the sleeve should be reduced to the smallest possible diameter by the surrounding, previously

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stretched tissue is compressed and folded together. Thus, the puncture channel, whose diameter corresponds to the outer diameter of the sleeve that is around the Veress needle, is only temporarily stretched in the tissue of the abdominal wall for the duration of the operation, which represents a maximally atraumatic procedure, and thus returns to its original position after the sleeve of the dilatation trocar is removed. Only a puncture channel with the diameter of the Veress needle is partially sharply cut (fascia and peritoneum) or bluntly penetrated (subcutis, preperitoneal fatty tissue) and then passively expanded, whereby the dilatation trocar does not come into direct contact with the surrounding tissue, as this expands the tissue passively by unfolding the sleeve. After the sleeve of the dilatation trocar is removed, the sleeve wall is folded again by the surrounding tissue pressure, whereby the diameter of the sleeve is reduced again. The previously stretched tissue layers return to their original position due to their elasticity and slide over one another like a backdrop, thereby preventing the formation of scar hernias. Furthermore, in an advantageous design, the sleeve should be fixed in the unfolded state by appropriate shaping of the wall in the longitudinal axis.

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Problem solving:

The sleeve according to the invention can exclude the above-mentioned disadvantages and meet the required properties. It consists of a hollow adaptation element, which serves to adapt the sleeve to a Veress needle, and a thin plastic film with a smooth surface that is folded in the direction of the longitudinal axis and slides well in the tissue and against metal or plastic. The film should be very thin and, when not unfolded, be stabilized by the folds in the longitudinal axis, which stabilize the dilatation trocar in the longitudinal axis during the unfolding process. Since only the folds have to be unfolded, only a small amount of force is required to unfold the sleeve itself, and after the trocar sleeve has been removed, the sleeve can fold back up to a small outer diameter due to the pressure on the tissue. In order to be able to fix the sleeve in the longitudinal axis in the unfolded state in the tissue, a design with shaped elements such as webs that locally increase the circumference in the transverse axis is possible. These webs only reach the outer surface after the sleeve has been unfolded and turn away from the outer surface again when it is folded up.

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Description :

Foldable instrument channel sleeve consisting of a sleeve 4 with an attached adaptation element 1 with a sealing membrane 2 and a sealing valve 3. The adaptation element 1 is used for the reversible adaptation of the sleeve to a Veress needle and, if necessary, for accommodating a valve element which can, for example, consist of a sealing membrane 2 and a sealing valve 3 which seals the lumen of the sleeve 4 proximally against the environment for gases. The sleeve 4 is fixed to the tubular adaptation element 1 with an adequate diameter in order to be able to accommodate the corresponding dilatation trocars and then tapers conically to form a tubular channel with a smaller diameter which tightly encloses the Veress needle. The wall of the sleeve 4 is folded along the longitudinal axis to reduce the diameter and can be unfolded with little resistance. A plastic film is preferably used for the material of the sleeve. The folding with kinks in the longitudinal axis stabilizes the sleeve before and during the unfolding process. The sleeve is preferably inserted into the abdomen using an optical Veress needle under visual control. After insufflation of CO2 gas via the Veress needle or the gap between the sleeve and the Veress cannula, the Veress needle is removed and then replaced by

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a dilatation trocar consisting of a blunt trocar mandrel 5 and a trocar sleeve 6.

Figure 1 shows a side view of the unfolded sleeve with adaptation element 1 and sleeve 4.

Figure 2 shows a top view of the sleeve 4 with adaptation element 1 from the proximal side.
Figure 3 shows a side view of the partially unfolded sleeve 4 and the adaptation element 1. The dilatation trocar, which consists of the trocar sleeve 6 and the trocar mandrel 7, is inserted.

Figure 4a shows a possible folding of the sleeve wall in cross section.

Figure 4b shows the wall cross-section 4a in magnification.

Shaped elements 7, which run transversely to the longitudinal axis of the sleeve, serve to fix the sleeve in the tissue in the longitudinal axis when unfolded.
Figure 5 shows a side view of the fully unfolded sleeve 4 with adaptation element 1. The dilatation trocar consisting of the trocar sleeve 6 and the trocar mandrel 5 is fully inserted.

Figure 6 shows a cross-section through the trocar sleeve 6 of the dilatation trocar and the unfolded sleeve 4.

Figure 7 shows a longitudinal section through the adaptation element 1 and the sleeve 4. In the adaptation element 1, a sealing membrane 2 and a sealing valve 3 can be seen.

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List of reference symbols :

1 = Adaptation element

2 = Sealing membrane

3 = Sealing valve

4 = Sleeve

5 = trocar spike 6 = trocar sleeve

7 ~ Form elements

Claims (7)

1. Tubular sleeve with variable inner diameter serving as an instrument channel for minimally invasive surgery, characterized in that the sleeve 4 is fastened at the proximal end in a hollow adaptation element 1 and tapers in diameter distally by folding the wall in the longitudinal axis and tapers proximally in this diameter, whereby the sleeve can be unfolded to a larger diameter with the aid of a dilatation trocar. 2. Instrument sleeve according to claim 1, characterized in that sealing elements are integrated in the adaptation element 1, which seal the lumen of the sleeve against the proximal opening of the adaptation element. 3. Instrument sleeve according to claim 1, characterized in that the distal end of the sleeve has only the diameter of the Veress needle over a short distance of a few millimeters and has no folding of the wall and may even be conically shaped in order to obtain a transition to the outer surface of the Veress needle with as little caliber jump as possible, and thus to avoid step formation in the penetration pressure curve that would hinder the surgical procedure. This distal end has a predetermined breaking point in the longitudinal direction, which tears open when stretched. 4. Instrument sleeve according to claim 1, 2 or 3, characterized in that a supply channel with a valve for CO2 gas is attached to the adaptation element, which allows the supply of CO2 gas into the adaptation element, or the sleeve distal to the sealing elements. 5. Instrument sleeve characterized by a two-part construction, whereby a C-shaped, unfolded sleeve which tightly encloses the Veress needle and ends distally in an adaptation element with a larger diameter is first introduced with the Veress needle. After the primary puncture, the Veress needle is removed and an instrument sleeve according to claim 1, 2, 3 or 4, which can be folded in the longitudinal axis to save space, is inserted into the C-sleeve and then expanded, whereby the C-sleeve merely folds open and is removed at the end of the operation together with the instrument sleeve, if necessary by interlocking the two adaptation elements. 6. Instrument sleeve according to one or more of the above claims, characterized in that the wall of the sleeve is folded in the longitudinal direction to reduce the diameter and in an advantageous embodiment with a defined folding of the sleeve, the sleeve sections that do not form the outer surface of the jacket have, for example, shaped elements in the transverse direction that locally increase the outer diameter, which only reach the outer surface of the jacket after unfolding and fix the sleeve in the tissue in the longitudinal direction. After removal of the trocar sleeve, the instrument sleeve is folded up again by the pressure of the surrounding tissue and the shaped elements are then no longer on the outer surface of the jacket. The instrument sleeve can then be easily removed again in the folded state. 7. Sleeve according to one or more of the above claims, characterized in that the adaptation element can be reversibly adapted to a corresponding Veress needle.