Abstract:
An endoscope for resecting tissue inside body cavities, the principal feature of which is that the endoscopic tube contains a shaft carrying a grinding or milling head, which allows precise removal of scar tissue or other fairly firm tissue under endoscopic control without leaving irregular or thermally damaged wound sites.

Description:
BACKGROUND AND SUMMARY OF THE INVENTION 
     This invention is directed to an improved endoscope for removing scar tissue that is constricting hollow organs of the body. It was an object of the invention to provide a means for removing tissue under visual control with high precision and in a manner that is as unstressful to the patient as possible. 
     The endoscopes that have been used up to now to remove tissue under visual control have involved electrical surgery, a surgical knife, or a punching device. The devices have not been entirely successful in that electrical surgery will leave a more extensive zone of dead tissue due to heat development; a surgical knife is very difficult to use due to the very small operation site and because of the limited minipulability of the cutting element, and punching or nipping devices in the form of small forceps cause uncontrolled tearing of the tissue, which leads to irregular wound areas. 
     The present invention allows tissue resection by means of a grinding or milling process under endoscopic observation. The grinding or milling head connected to a rotating shaft is advanced toward the tissue to be removed under visual control, and the tissue is then slowly resected under constant observation, preferably by means of the cutting surfaces of small diamonds provided on the grinding head. The present method allows millimeter-precise operation without leaving an extended zone of dead tissue, as the grinding process takes place without any significant temperature. The device further provides the continuous flushing required for good endoscopic vision which also assures continuous cooling during the grinding operation. The resulting wound areas are smooth and can be exactly adapted to the normal shape of the organ. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention is shown in the drawings in which: 
     FIG. 1 is a longitudinal section through the end part of the endoscope with drive unit; 
     FIG. 2 is a horizontal section through the drive unit; 
     FIG. 3 is a longitudinal section through the tip of the endoscope. 
     FIG. 4 is a longitudinal section of a further embodiment of the invention. 
    
    
     DETAILED DESCRIPTION 
     The outer tube 3 of the endoscope 1 is preferably made of metal such as stainless steel or an alloy corresponding to the state of the art. As can best be seen in FIG. 3, tube 3 accommodates a tube 4 for the lens system and cold light guide and rotating shaft 5 with its bearing 6. The inlet connection 9 for flushing solutions allows the flushing solution to flow between the lens tube and the bearing of the rotating shaft through the endoscopic tube to the tip 2 of the endoscope and to flush the operation site clear. 
     The tubing 4 containing the lens system and the cold light guide as well as the bearing for the rotating shaft 6 is stabilized by one or more brackets 8 located within tube 3. The rotating shaft 5 carries the grinding head 7 which is provided with a screw connection for replacement purposes. A conventional locking ring 10 seals off the endoscopic tube and is connected with a sealing element 11 which is firmly fixed to the tube 4 containing the lens system with cold light guide, and which has one end of spring 17 fixed to its lower part. This spring 17 which is fastened at its other end to the drive unit, pushes the drive unit 23 away from the endoscopic tube. The drive unit can be displaced on the tube 4 containing the lens system and cold light guide as well as on a special guide rail 20 between the endoscopic tube with its locking element 11 and a limit stop plate firmly connected to the tube 4 for lens system and cold light guide against the pressure of the spring 17. These movements are controlled by the surgeon&#39;s hand holding the instrument by placing a finger into the ring 16 and gripping the handle. 
     When the bearing of the rotating shaft enters into the drive unit 23, the bearing will be fixed in its position by means of a conventional locking device 18 which may, for example, be in the form of a clamp attached to driving unit 23 and engaging tube 6. The conical wheel of the rotating shaft 21 meets the conical wheel of the flexible shaft 22 within chamber 34 contained within the drive unit 23. The flexible shaft 24 is fixed to the drive unit by means of a standard locking device 25. The standard locking device 13 fastens the lens system with cold light guide within its respective tube 4. Cold light is introduced through inlet 14, and the eyepiece of the lens system 15 forms the rear end of the endoscope. 
     Another embodiment of the invention is shown in FIG. 4. In this embodiment, the conical wheel 22 of the electric motor 31 which is supplied with electric current via a feeder cable 35. The drive unit 23 slides on tube 4 containing optical lens and cold light guide. The drive unit 23 is moved on guide rods 26 against the resistance of the spring 27. These movements are controlled by the surgeon placing his fingers into the rings 29 and 32. 
     List of Elements 
     1. Endoscope for tissue resection 
     2. Endoscope tip 
     3. Hollow outer tube of endoscope 
     4. Tube for lens system and cold light guide 
     5. Rotating shaft 
     6. Bearing of rotating shaft 
     7. Removable grinding head 
     8. Bracket for tube containing lens systems and cold light guide, and for rotating shaft bearing 
     9. Inlet connection for flushing solution 
     10. Locking ring for endoscopic tube 
     11. Locking plate firmly connected with tube containing lens system and cold light guide 
     12. Rear limit stop plate for movable drive unit, firmly connected with tube containing lens system and cold light guide 
     13. Locking system for tube containing lens system and cold light guide 
     14. Cold light connection 
     15. Eyepiece 
     16. Ring for surgeon&#39;s fingers 
     17. Spring 
     18. Locking system for rotating shaft bearing 
     19. Handle for surgeon&#39;s fingers 
     20. Guide rail for drive unit 
     21. Conical wheel of rotating shaft 
     22. Conical wheel of flexible shaft 
     23. Drive unit 
     24. Connection piece of flexible shaft 
     25. Locking system for flexible shaft on drive unit 
     26. Guide rods for drive unit 
     27. Spring for guide rods 
     28. Cold light cable 
     29. Ring for surgeon&#39;s fingers 
     30. Flushing duct 
     31. Electric motor 
     32. Ring for surgeon&#39;s thumb 
     33. Front lens of optical system 
     34. Chamber accommodating conical wheels 
     35. Electric current supply cable