Abstract:
A temporary clip for controlling blood flow comprises a balloon for exerting clipping or clip-releasing force when inflated. A tube is connected to the balloon to inject into or sucks fluid from the balloon to inflate or deflate the balloon. The fluid pressure in the balloon is remote-controlled.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to a temporary clip for controlling blood flow in an object artery. 
     In neurosurgery, clips are used for controlling bleeding of arteries. Some clips are left permanently or semi-permanently at their site of clipping, and others are removed as soon as their purpose are over. Clips removed after use are called temporary clips. 
     For example, when a premature rupture of cerebral aneurysm occurs before a clear vision of a site of operation is obtained, blood stanching by temporary clipping is necessary. In such temporary clipping, clipping pressure differs for different object arteries. And, in a bleeding of a large quantity during operation, quick clipping is necessary, but it is a rather difficult and troublesome work to confirm a bleeding site and apply temporary clipping to the confirmed site after a bleeding of a large quantity. Therefore, it is desired that a loosened clip is placed beforehand at an anticipated temporary clip site and that the clip is quickly tightened by remote control when bleeding begins. 
     Besides, since peripheral circulation is not to be disturbed for a long time, a temporary clip must be repeatedly tightened and loosened at a same site. 
     Heretofore, a same clip has been used for permanent and temporary clipping, and various types of temporary clips are to be prepared for various clipping pressure. And heretofore used temporary clips are not adapted either to be placed beforehand or to be repeatedly tightened and loosened by remote control. 
     SUMMARY OF THE INVENTION 
     Therefore, an object of this invention is to provide a remote-controlled temporary clip wherein clipping pressure can be changed by remote control. 
     Another object of this invention is to provide a temporary clip adapted to be placed beforehand at an anticipated clipping site in a loosened state and to be tightened promptly when clipping is required. 
     Still another object of this invention is to provide a temporary clip adapted to be repeatedly tightened and loosened at a same clipping site. 
     Still another object of this invention is to provide a remote-controlled temporary clip wherein clipping pressure is indicated on a pressure gauge. 
     And still another object of this invention is to provide an automatic-controlled temporary clip wherein clipping pressure is automatically controlled to a value preset in a pressure controller. 
     In order to achieve these objects, an inflatable balloon is used to control clipping pressure of temporary clipping. An inflator/deflator injects fluid into or sucks from the balloon through a flexible tube. 
     These and other objects, features and advantages of the present invention will become clear from the following description of the preferred embodiments in conjunction with the accompanying drawings in which the same numerals indicate the same or the corresponding parts. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIGS. 1A and 1B show an arrangement of a temporary clip of an embodiment of this invention wherein clipping pressure is automatically controlled. 
     FIGS. 2A and 2B show an arrangement of a temporary clip of another embodiment of this invention. 
     FIGS. 3A and 3B show an arrangement of a temporary clip of still another embodiment of this invention. 
     FIG. 4 shows a modification of FIG. 1, wherein a pressure controller is changed to a manually operated inflator/deflator. 
     FIG. 5 shows a modification of FIG. 2, wherein a pressure gauge is provided. 
     FIG. 6 shows a modification of FIG. 3, wherein a pressure gauge is provided. 
     FIG. 7 shows an example of temporary clipping. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to FIG. 7, there is shown an example of temporary clipping used in neurosurgery. An aneurysm is detected by diagnoses. Neck of the aneurysm is to be clipped by a permanent clip to stop further bleeding. When there is a premature rupture, the artery supplying bleeding blood is clipped by a temporary clip, and as soon as the necessity of the temporary clipping is over, the temporary clipping is released to allow blood flow in peripheral vessels. 
     Referring to FIG. 1, an embodiment of a temporary clip of this invention comprises a clip body 1, a balloon 3, a flexible tube 4, and a pressure controller 50. 
     The clip body 1 comprises a first member 11, a second member 12, a pin 18 for supporting these first and second members at a common supporting point, and a spring 2. The first member 11 and the second member 12 have shapes roughly symmetrical to each other, each composed of a curved portion and a handle portion. 
     The pin 13 serves as an axis of rotation of the first and the second members 11,12. The spring 2 exerts elastic force in a direction for closing both ends 111, 121 of the curved portions of the first and the second members 11, 12, forming a circular space between the two curved portions. 
     The curved portions have grooves in their inner surfaces for containing the balloon 3. When the balloon 3 is deflated, only a small portion of the balloon 3 comes out from the grooves leaving an ample space between the two curved portions as shown in FIG. 1A. 
     With a manual force applied at both ends 112, 122 of the handle portions, the ends 111, 121 of the curved portions are opened, and the clip body 1 can be easily placed at an anticipated site of temporary clipping. With the balloon 3 deflated as shown in FIG. 1A, the circular space between the curved portions is wide enough for holding an object artery loosely in the space. 
     When the balloon 3 is inflated, the balloon 8 expands into the circular space since the expansion into an outward direction is obstructed by the curved portions. And, as shown by FIG. 1B, the inflated balloon 3 clips the object artery 60. 
     Clipping pressure of this temporary clip is automatic-controlled by the pressure controller 50. This clipping pressure is varied by varying pressure setting 51, and is indicated by a pressure gauge 52 provided in the pressure controller 50. 
     For removing clipping of this temporary clip, the balloon 3 is deflated to come to a state shown in FIG. 1A. This remote control of removing clipping eliminates manual operations which may be in the way of a field of sight of operation. 
     Either pneumatic pressure or hydraulic pressure will be used for inflating the balloon 3, and as for the pressure controller 50, any conventional pneumatic or hydraulic pressure controller can be used. 
     In an embodiment shown in FIGS. 2, each of the first member and the second member of the clip body 1 has a grasping jaw portion and a handle portion. A spring (not shown) exerts elastic force in a direction of pressing the two grasping jaw portions against each other. 
     A balloon container 8 contains a balloon 3. A side 123 of a handle of the clip body 1 is fixed to a side of the balloon container 8. Balloon container 8 acts as a link mechanism between balloon 3 and the clip body 1. 
     In placing this clip of FIGS. 2 at an anticipated clipping site, the balloon 3 is inflated by pressing fluid from a manually actuated syringe 5 connected at another end of the flexible tube 4. The syringe 5 works as an inflator/deflator of the balloon 3. The jaw portions are opened as shown in FIG. 2B. In the opened jaw portion, an object artery is loosely held. When the balloon 3 is deflated, the jaw portion is closed by the elastic force of spring, and the clipping pressure can be controlled by controlling the pressure in the balloon 3 which exerts a force opposing to that of the spring. 
     In an embodiment shown in FIGS. 3, the clip body 1 is similar to that shown in FIGS. 2, but the handles of the first and the second members have grooves for containing the balloon 3. When the balloon 3 is inflated, the grasping jaw portion is opened as shown by FIG. 3B. The temporary clip shown by FIGS. 3 works in a same way with that shown by FIGS. 2 
     In these embodiments shown in FIGS. 2 and FIGS. 3, the pressure controller 50 of FIG. 1A may be connected at another end of the flexible tube 4. But, these types of clip body 1 as shown in FIGS. 2 and FIGS. 3 are usually used for on-off control of clipping, and clipping pressure is determined by an elastic force of the spring 2. And for such on-off control of clipping, a manual control by a syringe is convenient. 
     FIG. 4 shows a modification of an embodiment shown in FIGS. 1. In an embodiment shown in FIG. 4, a manually controlled syringe 5 is used as an inflator/deflator of the balloon 3, and a pressure gauge 7 is connected to the flexible tube 4 by a gauge connector 6. In this embodiment, clipping pressure is manually controlled and is indicated by the pressure gauge 7. 
     FIG. 5 shows a modification of an embodiment shown in FIGS. 2. In an embodiment shown in FIG. 5, a pressure gauge 7 is connected to the flexible tube 4 by a gauge connector 6. In this embodiment, pressure in the balloon 3 is indicated by the pressure gauge 7. The clipping pressure is a difference pressure between the elastic force of a spring and the pressure in the balloon 3, and the pressure gauge 7 may be graduated by this difference. 
     And FIG. 6 shows a modification of an embodiment shown in FIGS. 3. In this embodiment, the pressure in the balloon 3 is indicated by a pressure gauge 7. 
     Although only preferred embodiments are described in this specification, it should be understood that various changes and modifications may be made without departing from the spirit of this invention.