JPH025421B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an indwelling endoscopic biliary prosthesis that is inserted endoscopically from the duodenal papilla into the bile duct and placed therein.

If the end of the bile duct is narrowed and jaundice due to bile accumulation or deterioration of the general condition appears, endoscopic prosthesis may be performed, especially in high-risk patients who cannot tolerate surgery, such as the elderly. There is a treatment in which it is inserted into the bile duct through the duodenal papilla and left in place to secure a passage between the bile duct and duodenum and drain bile.

Conventionally, the above-mentioned prosthesis has been formed such that the distal end thereof is bent into a loop shape in its normal state. Then, the rear end of this prosthesis is placed against the tip of the long tube of the indwelling device, and a stylet is inserted across this tube and the above-mentioned prosthesis to restrict the normally looped shape of the prosthesis and straighten it. Once inserted into the bile duct endoscopically, the stylet was removed from the prosthesis and left in place.

By the way, the stylet is used to regulate the shape of the prosthesis in its normal state, so a stylet with a high degree of rigidity is used.On the other hand, since the bile duct runs upward from the opening to the oral side, the stylet is quite rigid. This operation is difficult, as it must be inserted into the bile duct while being bent using a hard stylet and an endoscope's forceps elevator, making this task difficult and causing long-term pain to the patient. In addition, because the bile duct is narrow and the prosthesis is made of materials such as urethane or Teflon, which have weak restoring properties, the prosthesis may not be able to reliably return to a looped shape within the bile duct just by bending the prosthesis. Even if I let it do so, it sometimes fell out.

The present invention has been made based on the above circumstances, and its purpose is to allow the stylet to be held straight without using a highly rigid stylet, so that the insertion operation can be easily and quickly performed. It is an object of the present invention to provide an indwelling biliary prosthesis for an endoscope whose distal end portion is reliably deformed into a loop shape and does not come out after insertion.

An embodiment of the present invention will be described below with reference to the drawings. In the figure, 1 is an indwelling device for the prosthesis 2. This indwelling device 1 consists of a tube 5 having a thickness that allows it to be inserted into a forceps channel 4 of an endoscope 3, which will be described later. The tube 5 is made of a flexible material such as polyamide, polyurethane, tetrafluoroethylene, or a copolymer of tetrafluoroethylene and hexafluoroethylene, and has a through hole 6 at its rear end. A cap 7 is attached and fixed. This mouthpiece 7 is provided with an injection port body 9 having an injection hole 8 that communicates with the inside of the tube 5, and an O-ring 10 is attached to the inner peripheral surface of the through-hole 6. The shaft portion 12 of the operating body 11 is inserted into the through hole 6 in a hermetic and movable manner. Also,
A screw hole 13 communicating with the through hole 6 is formed in the base 7, and a set screw 14 capable of fixing the operating body 11 is screwed into the screw hole 13. Further, the inlet body 9 is rotatably provided with a pot 16 in which a passage 15 is bored, and by rotating this pot 16, the injection hole 8 of the inlet body 9 can be opened and closed. It's becoming like that.

On the other hand, an elongated operating member 17 made of metal, relatively rigid synthetic resin, or the like is inserted into the tube 5 . The rear end of the operating member 17 is connected to the operating body 11, and the tip thereof is connected to a pair of stays 18, 18 made of an elastic body such as metal. These stays 18, 18 are normally biased in a direction in which their tips open, and locking members 19, 19 are attached to these tips, respectively. Furthermore, a ring-shaped disengagement member 20 having an inner diameter smaller than that of the tube 5 is fitted onto the inner circumferential surface of the distal end of the tube 5, and when the operating member 17 is pulled as described later, the disengagement member 20 This allows the pair of stays 18, 18 to be displaced in the closing direction against the force. Further, a protective tube 21 is provided at the distal end of the tube 5 with its rear end connected to the distal end, and the rear end of the prosthesis 2 is removably fitted to the distal end of the protective tube 21. This process 2 is made of silicone rubber,
It is formed into a flexible tube shape from synthetic resin such as polyethylene, tetrafluoroethylene, a copolymer of tetrafluoroethylene and hexafluoropropylene, polyamide, etc., and the peripheral wall has many through holes 22. ... is bored, and the above-mentioned pair of stays 1 are provided on the inner peripheral surface of the rear end.
A groove portion 23 in which the locking members 19, 19 attached to the protective tubes 8, 18 are engaged to maintain the connected state to the protection tube 21.
is formed. In addition, at least one part of the distal end of the prosthesis 2 is provided along the peripheral wall thereof in the axial direction.
A wire rod 24 made of a shape memory alloy such as a Ni-Ti alloy or a Cu-Al-Zn alloy is buried. The wire rod 24 has a loop-like crystal structure when it is a parent phase in a high-temperature phase, and when it is plastically deformed by applying an external force, it undergoes martensitic transformation and forms a martensitic phase. Furthermore, the temperature at which the reverse transformation from the martensitic phase to the parent phase ends is body temperature (36 to 37
It is made of a shape memory alloy that has a temperature of over 30°F (°C). The prosthesis 2 is connected to the protective tube 21 with the wire 24 straightened by external force.

Next, the operation of the above configuration will be explained. First, pull the operating member 17 and insert the pair of stays 18, 1.
8 is closed by the disengagement member 20, the rear end of the prosthesis 2 whose distal end is made straight by external force is fitted into the protective tube 21. Next, by pushing in the operating member 17, the pair of stays 18, 18 are opened, and the locking member 1
9 and 19 are grooves 2 formed in the process 2.
3, and tighten the set screw 14 provided on the cap 7 at a position where the rear end surface of the prosthesis 2 and the distal end surface of the tube 5 are at a predetermined distance as shown in FIG. The operating member 17 is fixed therethrough.

On the other hand, the endoscope 3 is introduced into the duodenum 25 as shown in FIG. 4, and its tip is brought close to the papilla 26. Then, the prosthesis 2 connected to the indwelling device 1 through the forceps channel 4 is inserted into the duodenum 25.
Using the forceps lifting device 27 of the endoscope 3, bend the distal end of the prosthesis 2 and align it with the traveling direction of the bile duct 28, as shown in FIG. Insert into 28.
At this time, the forceps lifting device 27 of the prosthesis 2
The bending operation by simply bending the flexible tube-shaped prosthesis 2 can be easily performed. Next, loosen the set screw 14, pull the operating body 11, displace the stays 18, 18 in the closing direction as shown in FIG.
After removing tubes 9 and 19 from the groove 23,
Protective tube 2
Separate from 1.

In this way, the prosthesis 2 is connected to the bile duct 28.
When inserted into the wire, the prosthesis 2 is heated by body temperature, so the wire 24 made of shape memory alloy embedded in the tip gradually begins to form a loop due to the shape memory effect, completing the reverse transformation. Then, as shown in FIG. 6, the distal end portion deformed into a loop shape engages with the bile duct 28 and is indwelled therein. At this time,
Even if the resistance within the bile duct 28 is strong, the distal end of the prosthesis 2 is reliably deformed into a loop shape due to the shape memory effect of the wire 24. In this indwelling state, the prosthesis 2 has its rear end attached to the duodenum 25.
The bile duct 28 and duodenum 25 communicate with each other through this prosthesis 2, and the bile duct 28
The bile accumulated in the bile is discharged into the duodenum 25.
This indwelling state can be confirmed by observing the wire rod 24 through X-ray fluoroscopy.

Also, if the wire 24 starts to deform into a loop shape while inserting the prosthesis 2 into the bile duct 28, turn the knob 16 to open the injection hole 8 and inject the cooled contrast medium from there. Since the prosthesis 2 is cooled, deformation of the wire 24 is stopped and insertion into the bile duct 28 can be performed reliably.

As described above, this invention provides a shape memory alloy that deforms into a loop shape when heated at the tip of the prosthesis consisting of a flexible tube.
The distal end of the prosthesis inserted into the bile duct can be reliably deformed into a loop shape without any manipulation, and can be left in the bile duct. Therefore, the prosthesis can be placed easily and reliably without falling off. In addition, since there is no need to pass a highly rigid stylet through the prosthesis as in the past, bending operations using the endoscope's forceps lifting device when inserting the prosthesis into the bile duct can be easily performed. The insertion work can be ensured and speeded up.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention, in which Fig. 1 is a cross-sectional view showing the whole, Fig. 2 is a side view of the distal end of the prosthesis deformed into a loop shape, and Fig. 3 is a diagram showing the relationship between the prosthesis and the indwelling device. The cross-sectional view of the uncoupled state and FIGS. 4 to 6 are explanatory views of the inserted state of the prosthesis, respectively. 2... Prosthesis, 24... Wire (shape memory alloy).

Claims (1)

[Scope of Claims] 1. An indwelling biliary prosthesis for an endoscope, characterized in that a shape memory alloy that deforms into a loop shape when heated is provided at the distal end of the prosthesis consisting of a flexible tube. 2. The indwelling endoscopic biliary prosthesis according to claim 1, wherein the shape memory alloy deforms into a loop shape at temperatures above body temperature.