Classifications

• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B17/00—Surgical instruments, devices or methods
  • A61B17/22—Implements for squeezing-off ulcers or the like on inner organs of the body; Implements for scraping-out cavities of body organs, e.g. bones; for invasive removal or destruction of calculus using mechanical vibrations; for removing obstructions in blood vessels, not otherwise provided for
  • A61B17/221—Gripping devices in the form of loops or baskets for gripping calculi or similar types of obstructions
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B17/00—Surgical instruments, devices or methods
  • A61B17/22—Implements for squeezing-off ulcers or the like on inner organs of the body; Implements for scraping-out cavities of body organs, e.g. bones; for invasive removal or destruction of calculus using mechanical vibrations; for removing obstructions in blood vessels, not otherwise provided for
  • A61B17/221—Gripping devices in the form of loops or baskets for gripping calculi or similar types of obstructions
  • A61B2017/2212—Gripping devices in the form of loops or baskets for gripping calculi or similar types of obstructions having a closed distal end, e.g. a loop
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
  • A61F2/00—Filters implantable into blood vessels; Prostheses, i.e. artificial substitutes or replacements for parts of the body; Appliances for connecting them with the body; Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents
  • A61F2/02—Prostheses implantable into the body
  • A61F2/30—Joints
  • A61F2002/30001—Additional features of subject-matter classified in A61F2/28, A61F2/30 and subgroups thereof
  • A61F2002/30003—Material related properties of the prosthesis or of a coating on the prosthesis
  • A61F2002/3006—Properties of materials and coating materials
  • A61F2002/30092—Properties of materials and coating materials using shape memory or superelastic materials, e.g. nitinol
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
  • A61F2210/00—Particular material properties of prostheses classified in groups A61F2/00 - A61F2/26 or A61F2/82 or A61F9/00 or A61F11/00 or subgroups thereof
  • A61F2210/0014—Particular material properties of prostheses classified in groups A61F2/00 - A61F2/26 or A61F2/82 or A61F9/00 or A61F11/00 or subgroups thereof using shape memory or superelastic materials, e.g. nitinol
  • A61F2210/0023—Particular material properties of prostheses classified in groups A61F2/00 - A61F2/26 or A61F2/82 or A61F9/00 or A61F11/00 or subgroups thereof using shape memory or superelastic materials, e.g. nitinol operated at different temperatures whilst inside or touching the human body, heated or cooled by external energy source or cold supply
  • A61F2210/0033—Particular material properties of prostheses classified in groups A61F2/00 - A61F2/26 or A61F2/82 or A61F9/00 or A61F11/00 or subgroups thereof using shape memory or superelastic materials, e.g. nitinol operated at different temperatures whilst inside or touching the human body, heated or cooled by external energy source or cold supply electrically, e.g. heated by resistor

Definitions

• the present invention relates to devices for extracting members from relatively inaccessible locations and more 5 particularly to medical devices which are alternative to surgical procedures and are used for the extirpation of concretions from hollow organs, predominantly calculi from the ureter.
• Equipment for extracting calculi from the ureter is widely applied and one known type comprises a catheter, a wire loop-shaped extractor oriented lengthwise to the catheter, and a tool for extending and drawing the loop in the catheter, see for example, 3Fr Ureteroscopic
• Such equipment has the disadvantages that the calculus may not be caught reliably, that during the traction the calculus can traumatise the ureter walls, and that 20 the equipment has limited capability.
• Equipment of another type for extracting calculi from the ureter is known from A.B.Rutner, I.S. Fucilla, An Improved Helical Stone Basket, The Journal of Urology, 25 116 (1976), p.784-785 and which comprises a catheter, a wire basked-shaped extractor and a facility for controlling the extractor which moves the extractor lengthwise to the catheter.
• This prior art equipment also has the disadvantages that it has limited capabil- 30 ity and that it can traumatise the ureter wall. Ex ⁇ traction by direct traction is difficult and is carried •_ out over a long period of time under the action of a constant load suspended from a mechanism for moving the 6 extractor.
• the present invention seeks to enhance the efficiency of the operation with simultaneous decrease of trauma and length of time.
• an extractor device comprising a catheter member characterised in that at one end of the catheter member there is provided one or more wire elements of a material having a thermomechanical shape memory characteristic, and means extending along the catheter member enabling the elements to be heated wherein the shape of the wire elements can be changed, in dependence upon temperature, between a first elongate configuration in which their overall cross- section is substantially the same as or less than that of the catheter member, and a second configuration for extraction.
• An advantage of the above device is that it enables members to be extracted from relatively inaccessible locations without damaging the surrounding material.
• the means extending along the catheter member may be electrical conductors connected between a controlled power supply and the wire elements.
• An advantage of this arrangement is its compactness since the shapes of the wire elements are changed by passing electric current through the wire elements themselves. Further ⁇ more, by controlling the length and/or diameter and/or composition of the wire elements, they may be arranged to deform or reconstruct at different rates of power supply and/or at different temperatures. This enables complex operations to be performed.
• the wire elements may define at least first and second loops which may be of different sizes. By appropriate selection of the electric resistance properties of the loops, one may be arranged to deform or reconstruct at a lower temperature than the other, which enables complex operations to be performed. In a modification, this feature may be achieved by providing independently controllable power supplies for the individual loops, but this is not quite as compact.
• the temperature of the wire elements is controlled between at least three temperatures, a first of which corresponds to the first configuration of the wire elements, and a second of which corresponds to the second configuration of the wire elements.
• the third temperature may be such as to maintain the material of the wire elements flexible so as not to damage the surrounding material.
• the member to be extracted may be such as to affect (thermally or otherwise) the member to be extracted, for example it may electrocoagulate a polyp for subsequent examination.
• thermomechanical storage memory effect comprising a titanium nickelide composition.
• the shape of the extractor device can be selected in dependence upon the situation of the operation performed. Deformation of such an extractor by decreasing its size when the extractor is introduced into the hollow organ decreases the patient's trauma.
• a pulsed power supply with variable pulse duration and pulse repetition rate provides the optimisation of the degree and rate of the extractor shape construction when catching the concretion thus increasing the operative capabilities of the equipment.
• Heating the extractor wires by this power supply during the concretion traction makes it possible to control their elastic modulus and, hence, the degree of hollow organ dilatation, thus making the hooking of the walls and the jamming of the concretion less probable. This decreases the trauma and lowers the probability of complications and the time of operation performed.
• connection of the wire extractor with the power supply as a coaxial cable with external and internal Teflon insulation provides the catheter with a minimal cross-section, which lowers the trauma of its introduction, and with lengthwise rigidity and lateral flexibility to smooth turns. Teflon provides a low friction coefficient for the catheter, and thermal protection for the surrounding tissues. All these facts decrease trauma, time of operation, and probability of complication.
• the use of an extractor in the form of a pear-shaped basket oriented with its widened portion toward the catheter permits the introduction of the concretion through a widened portion of the basket, more reliable holding of the concretion in the narrow portion of the basket and increases the degree of dilatation of the hollow organ during the concretion traction.
• thermo- and electro-insulating coating of the extractor wire elements together with the increase of electric safety and the decrease of thermal action on the surrounding tissues make it possible to achieve increased (with respect to the surrounding tissues) temperature of the extractor which increases the elastic modulus of its elements, decreases the deformation degree of the extractor during the traction and, hence, widens the operative capabilities, decreases trauma and time of operation.
• the insulating coating of the extractor wire elements makes them somewhat thicker thus decreasing the specific hollow organ pressure.
• Teflon as a material for coating the extractor wire elements is attributed to its thermoresistance, low coefficient of mechanical friction that leads to additional reduction of trauma ism.
• Figure 1 is a general block diagram of equipment in accordance with the present invention for extracting concretions from hollow organs
• Figure 2 is a block diagram of a pulsed power supply for use with embodiments of the present invention
• Figure 3 shows schematic views of a catheter and an extractor partially in longitudinal section, of a first embodiment of the present invention
• Figure 4 shows schematic views of an extractor in accordance with a second embodiment
• Figure 5 shows schematic views of a two-loop wire extractor in accordance with a third embodiment
• Figures 6 and 7, 8 are schematic views of single-loop extractors in accordance with further embodiments of the present invention.
• equipment 100 for extracting concretions from hollow organs comprises a wire extractor 101 made of a material with thermo-mechanical shape memory effect, a flexible catheter 102, and a controlled power supply 103 connected via its output 104 to the extractor 101.
• the material of the extractor 101 preferably comprises titanium and nickel, preferably in the form of titanium, nickel and a titanium nickelide compound.
• a preferred composition by weight is 53.5 to 56.89 titanium, 7.0 to 10% of a titanium nickelide compound of the form TiN 3 , i ⁇ Ni- ⁇ ,Ti 2 Ni, with the balance comprising nickel.
• the controlled power supply 103 comprises a pulsed power supply with variable pulse duration and pulse repetition rate. It comprises a processor 105 connected to a control terminal 106, an oscillator 107, a display 108, and a current pulse shaper 109. The output of pulse shaper 109 constitutes the output 104 of the power supply 103.
• connection of the wire extractor 101 to the power supply 103 is made as a coaxial line formed of an internal conductor 10, its insulating coating 11, an external tubular conductor 12, and its insulating coating 13 which can be made of Teflon.
• the elements 10-13 form the catheter 102 (Fig. l) of the proposed equipment.
• the wire extractor 301 is constructed as a pear-shaped basket oriented with its widened part towards the catheter 302.
• Each wire 14 of the extractor is made of the material with thermo- mechanical shape memory effect and is provided with an insulating coating 15, e.g. made of Teflon.
• Figure 4 shows an extractor 401 made as a basket formed of six (i.e. an even number) wires which are connected electrically (e-»g. by soldering) at distal end 16 to each end to a guide wire 22.
• Half, i.e. three, of the wires are connected at their ends adjacent catheter 402 to the internal conductor 10.
• the ends of the other half of the wires are connected to the external tubular conductor 12 of the coaxial line forming the catheter 402.
• half of the wires 14 of the extractor are connected to each power supply terminals 103.
• This provides equal heating of all of the catching basket wire elements, complete radial symmetry of shape reconstruction and additional increase of the element elastic modulus, i.e. ensures that the dilatation of a hollow organ is uniform in all radial directions.
• the extractors 301, 401 shown in Figs. 3a and 4a are deformed by helical torsion in the longitudinal direction to the catheter 302, 402 and their shapes are then as shown in Figs. 3b and 4b, respectively.
• Figure 5a depicts an extractor 501 intended for catching a concretion which is almost inaccessible due to its complete overlapping of the gap in the hollow organ.
• the extractor 501 is made in the form of two wire loops 17 and 18 with different lengths.
• the longer wire loop 17 is additionally curved as an arc orthogonally to the plane of the principal loop bend, and the shorter one 18 is oriented as a connector for the end points of the additional arc bend of the loop 17.
• the divided ends of each of the loops 17 and 18 are connected with the individual conductors 10 and 12 through a coaxial line forming the catheter.
• Figure 5b shows two-loop extractor 501 in which its elements are deformed into the positions which are occupied by the wire loops 17 and 18 during introduction into the hollow organ. In this configuration, the narrow loop 17 can be moved past the concretion before adopting its Fig. 5a configuration.
• the extractor may reconstruct its shape by parts as follows: first, the small (short) loop 18 does, since its resistance is lower and current is higher, then the elongated (large) loop 17 reconstructs its shape since its electrical resistance is higher.
• Figure 6a depicts another extractor 601 intended for extracting or transporting calculi in a hollow organ which are almost inaccessible for catching due to complete overlapping of its gap. It has the form of a single wire loop 19 oriented laterally to the catheter 2.
• Figure 6b depicts the extractor loop 19 position aligned with the catheter 2 intended for the extractor introduction into the hollow organ.
• Loop 20 has no heat- or electrical- insulating coating and is specifically intended for extracting polyps and other formations under thermal action.
• the wire loop 20 is aligned longitudinally with the catheter 701 (Fig.7b).
• Wire loop 20 has no heat- or electrical-insulating coating and has a distal part 21 oriented transversely to the catheter 802.
• Fig. 8b shows the shape of loop 20 during its introduction into a hollow organ.
• the location, dimensions and shape of the object to be extracted from the hollow organ are determined from preliminary diagnostic examination. Taking these factors into account, as well as the accessibility for catching, an appropriate extractor is selected.
• a wire or wires of appropriate length and diameter is/are selected and, after heating to about 150°C, bent into the shape required for the operation.
• the extractor l may be heated by current from the pulsed power supply 103 through the coaxial cable forming the catheter 102.
• the pulsed power supply operates in the following mode.
• the pulses at 50 Hz from the oscillator 107 are supplied to the processor 105.
• the operator sets an appropriate repetition rate and pulse duration.
• Processor 105 output controls shaper 109 which generates current pulses of the required duration and pulse repetition rate.
• the average current of the power supply can be regulated in steps from 0.2 to 5 A at an output voltage from 3-6V.
• the display 108 enables the operator to control the chosen mode of operation as desired.
• a power supply current of 4A was used to heat the wire elements of the extractor.
• the power supply is disconnected and the extractor is cooled to a temperature below 10°C, e.g., by irrigating with chlorethyl.
• the extractor is cooled to a temperature below 10°C, e.g., by irrigating with chlorethyl.
• it is deformed by helical torsion longitudinally of the catheter to the position shown in Figs. 3b and 4b in which the cross-sectional area of the deformed wire extractor is approximately equal to that of the catheter 2.
• the extractor and the catheter are introduced into the channel of an endoscopic device, e.g. a cystoscope when extracting calculi from the ureter, which is introduced into a hollow organ.
• the cystoscope is a familiar and conventional device for transporting the extractor to the ureter and, hence, has conventional auxiliary means in the form of an eyepiece lens, a moving means, an illuminating lamp, and a mirror, all of which are located in the region of a distal end of the tube.
• the extractor is moved out from the tube and is led up to the gap between the calculus and the ureter wall. Then the catheter is further moved out to the position where the extractor is behind the calculus.
• the pulsed power supply is switched on at the chosen pulse repetition rate of about 20 Hz.
• Such a mode provides an average current of 1.6 A through the wire elements 14 of the extractor.
• the wires 14 of the extractor are heated for four seconds to 55°C. Since the temperature interval for the extractor material shape reconstruction is 40-55°c there occurs complete shape reconstruction of the extractor, i.e. it acquires the original pear-shaped basket form (Fig. 3a) and accomplishes the ureter dilatation.
• the average current through the wires of the extractor basket is then reduced by - a factor of 8-10 by lowering the current pulse repetition rate and the pulse duration. By doing this it is possible to maintain an increased temperature of the metallic components of the extractor basket, compared to the surrounding body tissues.
• the basket is then advanced to the calculus by a traction force, under the effect of which the wires 14 of the extractor are moved apart and the calculus reaches the extractor cavity.
• the pear-shaped basket of the extractor, with the orientation of its widened part towards the catheter, and the increased elastic modulus of the wires made of titanium nickelide provide high dilatation of the ureter in front of the calculus (in the direction of traction). This makes the subsequent traction of the calculus easier.
• the modes of heating and additional heating are easily optimised and fixed in the form of the assigned operating modes of the pulsed power supply introduced in its processor. After this there is no need for operator control over the power supply. Examples of use of the equipment will now be described.
• Example 1 Extraction of calculus from ureter.
• the calculus is in the lower third part of the ureter.
• the extractor used is a six- wire basket 401 (Fig. 4a).
• the extractor is cooled to approximately 10°C. using chlorethyl and is shaped as a twisted rope (Fig. 4b) .
• the cystoscope is introduced through the ureter into the urinary bladder.
• the extractor is introduced into the cystoscope channel.
• the exit of the guide wire 22 of the extractor at the distal end of the cystoscope is determined visually.
• the extractor is introduced into the ureter by controlling the direction of the extractor movement by turning the cystoscope channel and its elevator.
• the extractor is moved in the ureter, with simultaneous rotation, and is brought in behind the calculus.
• the power supply 103 with the selected average output current 2.2 A for four seconds is connected to the cable-catheter.
• the extractor is in a fully opened state (Fig 4a) and moves apart the ureter walls with the help of its wires forming the basket.
• the extractor is then smoothly withdrawn from the cystoscope and calculus traction starts.
• the calculus enters the extractor basket and freely rolls over it.
• the smooth Teflon coating of the extractor prevents trauma of the ureter mucous coat.
• the power supply is disconnected and the cystoscope is removed from the urethra.
• the subsequent traction of the calculus through the urethra is carried out using the extractor without the cystoscope.
• a mushroom-shaped polyp is in the urinary bladder.
• the cystoscope is introduced into the urinary bladder.
• the urinary bladder is filled with physiological salt solution at temperature not below
• the loop-shaped wire extractor 701 (Fig. 7a) is deformed lengthwise to the catheter in such a way that its thickness does not exceed the catheter thickness (Fig. 7b) and is introduced then through the cystoscope into the urinary bladder.
• the mode with an average output current of 1.6 A is selected since the entire operation is carried out under visual monitoring.
• the extractor Under visual monitoring through the eyepiece of the cystoscope, the extractor is guided up to the polyp limb in such a way that it is half-way along the extractor.
• the power supply is then connected.
• the heated extractor with its loop catches the polyp limb (Fig. 7a).
• the power supply current is then increased to 5A and by catheter traction polyp electrocoagulation is carried out.
• the polyp remains undistorted and can be used for subsequent analysis.
• the operation is performed in the same way, but the extractor has the form of a scraper 801 (Fig. 8a).
• the angle of inclination of the operating part 21 of the scraper can be varied depending on the polyp location.
• Patient K There is a pea in the bronchus.
• the extractor 501 is used (Fig. 5a).
• a bronchoscope is introduced through the mouth into the bronchus and under visual monitoring a distal end of the bronchoscope is guided up to the pea.
• the extractor is introduced into the bronchoscope channel and advanced through it until it leaves the bronchoscope distal end. And then, under visual monitoring, the extractor is guided up to the pea and the larger loop of the extractor is advanced behind the pea.
• a control signal is supplied from the terminal 106 providing a current supply of 0.8 A to the extractor.
• This causes the shorter loop 18 to start its heating and reconstruction of its prescribed shape,i.e. the extractor is bent perpendicularly to the longitudinal axis of the catheter and then it becomes ring-shaped.
• the small loop 18 of the extractor is reconstructed, it is advanced until it touches the pea. After the small loop reaches the pea, a signal from terminal 106 is supplied for increasing the current to 1.0 A and the heating and reconstruction of the large loop 17 commences.
• the extractor is introduced into the urinary bladder and under visual monitoring its distal end is led up to the ureter ostium. Then the extractor is moved in and, if necessary, turned round the catheter longitudinal axis, and then is brought in behind the calculus.
• a signal is supplied from the control terminal 106 and a current of 0.8 A is supplied to the extractor.
• the extractor is bent perpendicularly to the catheter axis and adopts a ring shape (Fig. 6a) .
• the increase of the extractor elastic modulus during the heating allows the ureter to be widened by means of the extractor; the smooth Teflon coating of the extractor keeps the ureter mucous coat undistorted. Then by gradual withdrawal of the extractor the extraction of the calculus from the ureter is performed.
• each loop 17, 18 may have its shape controlled independently from a respective power supply. For especially complicated operations, three or more loops could be employed.
• the wire elements 14 are heated by the passage of an electric current therethrough and this has the advantage of compactness.
• electric heating elements of material not displaying the memory effect may be employed in close thermal communication with the elements 14.
• non-electrical methods of heating may be employed, for example hot air could be blown through the catheter 102.
• the elements 14 could be passed along a thermally-insulating catheter 102, with cooling if necessary, and then heated by body temperature when they emerge from the end of the catheter.
• each wire element 14 may be of non-memory effect material. Where there is a plurality of elements, some of them may be entirely of such material.
• the present invention is not limited to medical devices, and the extractor device can be used to extract any type of article from a wide range of inaccessible locations such as inside a pipe or tube (for example the waste outlet of a domestic sink) or inside a chamber within a large piece of machinery which would be difficult to dismantle.
• a pipe or tube for example the waste outlet of a domestic sink
• a chamber within a large piece of machinery which would be difficult to dismantle.

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• Health & Medical Sciences (AREA)
• Surgery (AREA)
• Life Sciences & Earth Sciences (AREA)
• Heart & Thoracic Surgery (AREA)
• Molecular Biology (AREA)
• Vascular Medicine (AREA)
• Engineering & Computer Science (AREA)
• Biomedical Technology (AREA)
• Orthopedic Medicine & Surgery (AREA)
• Medical Informatics (AREA)
• Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
• Animal Behavior & Ethology (AREA)
• General Health & Medical Sciences (AREA)
• Public Health (AREA)
• Veterinary Medicine (AREA)
• Surgical Instruments (AREA)
• Media Introduction/Drainage Providing Device (AREA)

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• 1991
  • 1991-03-19 RU SU914920731A patent/RU2003291C1/ru active
  • 1991-12-12 CA CA002106578A patent/CA2106578A1/en not_active Abandoned
  • 1991-12-12 AU AU90549/91A patent/AU9054991A/en not_active Abandoned
  • 1991-12-12 WO PCT/GB1991/002216 patent/WO1992016153A1/en not_active Application Discontinuation
• 1992
  • 1992-10-10 EP EP92900548A patent/EP0576428A1/en not_active Withdrawn

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