DE4115136A1 - Removing body from blood vessel - using surgical instrument which consists of flexible wire with three hooks formed at one end - Google Patents

Abstract

An instrument for removing a foreign body from a blood vessel or the passageway of an internal organ is made from metal or from elastically deformable plastics. The instrument consists of a wire (1) which had its end portion split into three arms (2). Each arm (2) has a hook (4) formed at its outer end. The end of each hook extends radially inwards but is joined to the arm (2) by a curved section which extends radially outwards. The instrument is inserted into a blood vessel with the aid of a catheter which presses the hooks together. USE/ADVANTAGE - For removing foreign bodies from blood vessels. The surgical instrument is more flexible than existing instruments used for this purpose.

Description

Technical field

The invention relates to gripping systems for non-invasive Removal of foreign bodies from organ channels.

State of the art

Lungs have become foreign objects for more than 100 years various gripping tools removed and since 1964 also in Interventional radiology. Such foreign objects Distances are repeatedly described in the literature. C.T. Dotter et al. writes in Am. J. Roentgenol. 111: 467-472 (March 1971) on 29 cases collected. Broncho was used Scope forceps, stone extraction baskets and slings. R.G. Fisher et al. reported in Am. J. Roentgenol. 130: 541-548 (March 1978) additionally on the use of myocardial biopsy forceps, of hook-shaped guide wires and Fogartycathe tern.

In addition to the rigidity of the bronchoscopy and biopsy forceps, the difficult to use with a winding organ pathway is large outer diameter of at least 6F (2mm) with straight and 8F is disadvantageous in the case of a winding course, which J.B. Selby et al. in Radiology 176: 535-538 (August 1990).

Loops and stone extraction baskets set a free end of the Foreign body ahead. The stiff end of hook-shaped guide wires carries a risk of perforation. A Fogarty catheter is only suitable for certain organ diameter and also has no griffin function.

With increasing use of interventional catheter procedures Complications such as broken guidewire also occur or dislocations in balloon or spiral embolizations whose Removal still has to be done surgically today because of Outside diameter of the gripping tools available today is too large for peripheral vessels.

Description of the invention

The object of the present invention is the constructive To improve the design of a gripping tool so that it greater flexibility a much smaller outside diameter knife than conventional systems, and quickly as an emergency push through to grasp and remove a foreign body an already lying catheter from 3F (1 mm) outer diameter can be advanced. This gripping system is also suitable for use through a cannula or the instrument channel an endoscope.

This task is solved by a gripping system for organ pathways, for example blood vessels consisting of a guide wire, characterized in that at the front end two to four Spread arms are attached, the head area hook is shaped. A curve on the outside diminishes the friction in the catheter. The height of the hook at the front end of the Gripping arm, together with the rounding, may not exceed 90% of the seen catheter inner diameter, thus guaranteed is that the hook when advancing in the catheter even with curvy Do not run the ends of the catheter wall on the opposite side can touch, or the unfolded gripping system when back pull on the catheter opening hooked and a new catheter sation must take place. Especially with a small catheter diameter the maximum possible hook height should be aimed for in order to reach the gripping function.

Three gripping arms are preferably attached. With two griffins poor cannot seize foreign objects lying in parallel and the griffin can be seen in the two-dimensional x-ray Do not track the operation securely, which is a requirement for quick foreign body removal is necessary.

An arrangement of four gripper arms is not so compact foldable and therefore requires a larger inner lumen during insertion catheter.  

The gripper arms with slightly different lengths, with a round, oval or rectangular cross-section with a maximum diameter of 1 mm and a length of 2 mm to 25 mm, preferably 5 mm to 12 mm, are with a spreading angle of 10 ° to 90 °, preferably 20 ° up to 50 °, at the front end of the guide wire by welding, Soldered, glued or wrapped. The diameter of the guide guidewire can be 0.07 mm to 1 mm with a solid cross-section wear. To improve flexibility and guidance in the catheter it is recommended not to use the diameter of the guide wire choose larger than 0.3 mm and with much larger catheters inside the guide wire with another wire to wrap spirally.

Suitable materials for guide wire and gripper arms are surgical steel wire with spring properties and spring wire made of noble or base metals, which are medically harmless precious metals such as tantalum, titanium, platinum, ceramic materials, Plastic or gold are coated.

It is characteristic of the gripping system according to the invention that the straddled attached to the front end of a guidewire Gripping arms can be reversibly brought into such a compact form that it gets through an English catheter without getting caught can be advanced and at the other end in the organ again through their restoring forces in the material reduce gait shape. Such elastic spring behavior and the resulting restoring forces are based on the Properties of the selected materials and are the expert known. The spring action can, for example, by heating the material brought into the desired shape and subsequent rapid cooling (quenching) can be achieved.

With a larger available inner catheter diameter can also use a spiral wire sheath as a receiving sleeve serve for the gripping arms with the advantage that to execute the Gripping the catheter in the organ pathway no longer be must be moved.  

In this modification of the gripping system according to the invention the longest gripper arm at the front with a rounded protective cap provided by their eccentric attachment to the gripper arm also has a gripping function. In addition to the advantage of a ver This protective cap significantly reduces the larger gripping surface Danger of injuries to organs, since in the introductory phase the external shape corresponds to a conventional guidewire. To the better positioning in the middle of the insertion sleeve Protective cap also have a centering aid to prevent injuries to avoid in the event of incorrect positioning due to sharp edges.

The protective cap can also be applied to the individual in individual segments Gripping arms can be divided.

By a suitable choice of the compression spring and the hook cross-section the retraction force can be limited according to the invention. At About reach a maximum retraction force give the gripper arms Foreign objects are released independently. This will cause damage the organ pathway through a hooked foreign body largely ver avoided. The maximum retraction force is 0.5 N to 20 N before forces between 1.5 N and 3 N are applied

It shows that the structurally very simple fiction appropriate device the scope of foreign body extract tions under X-ray or ultrasound control Direction can be extended to very narrow peripheral vessels.

The invention is described below with reference to the Figil described in more detail.

Fig. 1 shows schematically a spread gripping system in a side view.

Fig. 2 shows schematically a longitudinal section through a catheter with a folded gripping system.

In the sequence a to d, Fig. 3 shows schematically the individual steps of removing a foreign body according to the invention from an organ pathway.

Fig. 4a shows schematically a longitudinal section through the modification of a gripping system according to the invention in the inserted state.

Fig. 4b schematically show a longitudinal section in the gripping phase.

Fig. 5 shows a schematic view from the front in the gripping phase.

Fig. 6a and 6b show an enlargement of the protective cap in a side view and in a plan view.

Fig. 7 shows a front view of a form variant of the protective cap.

Fig. 8 shows schematically the grasping of a foreign body in an organ pathway with the modification of a gripping system according to the invention.

The gripping system shown in Fig. 1 consists of a guide wire 1 , on the gripping arms 2 with a slightly different length are attached concentrically spread. The gripping arms 2 are each provided in their front area with a curve 3 to the outside and bent at right angles inwards to form a hook 4 .

In Fig. 2 the gripping system of Fig. 1 is shown folded in a catheter 5 . The gripping arms 2 with a slightly different length are attached to a guide wire 1 in a space-saving manner. The individual right-angled hooks 4 are arranged one behind the other so that they do not interfere with the unfolding. The curvature 3 is due to the spring effect of the gripping arm 2 always on the wall of the catheter 5 even with a curved catheter course.

Fig. 3 shows schematically the removal of a foreign body 7 , z. B. a displaced embolization spiral, from an organ pathway 6 , for example a bloodstream. The catheter 5 (which was previously used for the implantation of the embolization coil) is first brought as close as possible to the foreign body 7 . Then the gripping system ( Fig. 1) is inserted from the outside with the gripping arms 2 folded together into the catheter 5 and pushed forward ( Fig. 3a). After leaving the catheter 5 in the organ path 6, these gripping arms 2 unfold back into their original shape due to their resilient restoring force ( FIG. 1) and thus enclose part of the foreign body 7 ( FIG. 3b).

This foreign body 7, by further advancing the Kathe ters 5 over the guidewire 1 poor with the closing gripper 2 (Fig. 3c) held, as a result of forcibly Ver kleinerung of the radius of the circularly arranged gripping arms 2. The opposite hooks 4 act together as tweezers. Since the foreign body 7 usually does not fit through the inner lumen of the catheter 5 , it is removed from the organ path 6 together with the catheter 5 ( Fig. 3d), at the tip of which it is held with the gripping system ( Fig. 1). In this case, an optional locking device attached to the guide wire 1 outside the catheter 5 can prevent unintentional detachment of the foreign body 7 during the extraction process.

Fig. 4 shows a modification of the gripping system according to the invention.

Fig. 4a shows a further embodiment of the gripping system schematically in a partially broken illustration in the insertion state with closed gripping arms 2 . These are held by the spring force of the compression spring 11 at the opposite end of the guide wire 1 in the insertion state in the guide sleeve 9 . The foremost gripper arm 2 is provided with a rounded protective cap 8 . The protective cap 8 also serves as a stop when the gripper arms 2 are pulled back into the guide sleeve 9 .

At the outer end of the guide wire 1 , a handle 12 is introduced at a certain angle to the gripper arm 2 with the protective cap 8 . The handle 12 and the verbun with the insertion sleeve 9 which counterhold 10 serve the compression spring 11 as an abutment. The outer ends of the counter-holder 10 can also be annular (not shown). The inner diameter of the rings are then so large that the user's fingers can be inserted through them.

The compression spring 11 can also consist of an expanded part of the wire sheathing of the insertion sleeve 9 , which also has spring properties.

Fig. 4b and 5 show the further embodiment of the gripping system schematically in a partially broken representation in the gripping phase with tensioned compression spring 11 and spread gripping arms 2 from the side and in the view from the front. By shortening the distance between the handle 12 and the counter-holder 10 , the insertion sleeve 9 is pushed back on the guide wire 1 and releases the gripping arms 2 again.

Fig. 6a and 6b show the eccentrically mounted on a gripper arm 2 protective cap 8, which may also have a centering aid 13, so that the protective cap is positioned exactly 8 during the retraction of the gripping arms 2 in the middle of the introducer sheath. 9

Fig. 7 shows a front view of a form variant of an open gripping system, in which the protective cap is divided into individual segments 14 on the individual gripping arms 2 . The individual segments 14 take on the hook function.

Fig. 8 shows schematically the grasping of a foreign body 8 in an organ path 6 with the further embodiment of a gripping system ( Fig. 4). In this case, the gripping system ( Fig. 4a) is inserted into the organ pathway 6 via an already lying catheter 5 and is advanced further peripherally like a conventional guide wire to the foreign body 7 . By bending the gripping system beforehand ( Fig. 4), even a complicated operation area can be taken into account. By squeezing the grip fes 12 and the counter-holder 10 , the gripping arms 2 are unfolded and the foreign body 7 is detected by removing the compression by the spring force of the compression spring 11 pushing the insertion sleeve 9 back over the gripping arms 2 , which inevitably close. Then the foreign body 7 is removed together with the gripping system ( Fig. 4) and the catheter 5 from the organ path 6 .

The particular advantage of the gripping design according to the invention systems for organ pathways is that with a small catheter  inside the diameter of a catheter lying in the organ pathway function of the insertion sleeve. This enables a halfie the minimum outside diameter of conventional gripping systems. This means that foreign bodies can also be removed much more quickly via catheters far peripheral organ pathways are extracted, which are still used today need to be surgically removed.

Limiting the possible retraction force on the foreign body Avoiding injuries poses just like the edge-free outer shape of the modified gripping system when inserted an urgently needed improvement from a security perspective the conventional technology.

Claims (6)

1. Gripping systems for organ pathways, which is formed from metal or elastic plastic, characterized in that at the front end of a guide wire ( 1 ) with a spreading angle of 10 ° to 90 ° gripping arms ( 2 ) are attached, the front end, in addition to an optional Rounding ( 3 ), bent at a right angle to a hook ( 4 ), the material properties and cross section, and / or the compression spring ( 10 ), is modified so that the maximum gripping force when the gripping system is closed ( Fig. 3d and Fig . is 8) 0.5 N to 20 N. 2. Gripping system according to claim 1, characterized in that the gripping arms ( 2 ) have a slightly different length, with a round, oval or rectangular cross section of 0.06 mm to 1 mm in diameter, and a length of 2 mm to 30 mm. 3. Gripping system according to claim 1 and 2, characterized in that the guide wire ( 1 ) has a length of 2 cm to 200 cm and a diameter of 0.07 mm to 1 mm, preferably from a diameter of 0.3 mm is wrapped with a wire spiral or surrounded by a plastic jacket. 4. Gripping system according to claim 1 to 3, characterized in that the guide wire ( 1 ) is surrounded with an insertion sleeve ( 9 ) which receives the gripping arms ( 2 ) compactly. 5. Gripping system according to claim 4, characterized in that a protective cap ( 8 ) is attached to the front gripping arm ( 2 ) at right angles and eccentrically, which can also have a centering aid ( 13 ). 6. Gripping system according to claim 4, characterized in that the protective cap ( 8 ) can also be divided into individual segments ( 14 ) on the gripping arms ( 2 ), which take over the hook function.