顎関節の下関節腔鏡視法について 器具の開発およびｓｔｅｐ ｃａｎｎｕｌａｔｉｏｎ ｔｅｃｈｎｉｑｕｅの工夫

Abstract

Instruments were newly developed for a step cannulation technique to achieve an arthroscopy of the inferior articular cavity of the temporomandibular joint. In order to introduce a rigid needle arthroscope of 1.5 mm in diameter with its cannula into the cavity, three different kinds of instruments were designed; a guiding stylet of 200 mm in length and 0.95 mm in diameter, a guiding cannula of 140 mm in length and 1.25 mm in diameter, and an adjusting cannula of 82 mm in length and 1.5 mm in diameter. We also used an 18 gauge needle and a needle of 14 gauge i. v. catheter. The main purpose of lengthening the newly-devised instruments was for the convenience of serial changes among a stylet, cannulac and needles. We utilized the following new technique. First, palpate and certify the lateral pole of the mandibular head, insert a 23 gauge needle into the inferior articular cavity and pump saline into the cavity. After distention of the cavity, insert an 18 gauge needle into the cavity, and into this needle insert the guiding stylet and remove the needle. Over the guiding stylet, insert the guiding cannula into the cavity and remove the stylet. Over the guiding cannula, insert the needle of 14 gauge i. v. catheter into the cavity so as to cut the capsular tissue, and remove the needle. Over the guiding cannula again, insert the arthroscopic cannula, equipped with the adjusting cannula, into the cavity, and leaving the scopic cannula alone, remove the adjusting cannula with the guiding cannula. This step in serial order brings certain insertion of the arthroscope into the inferior cavity. After the insertion of an 18 gauge needle, easy and steady insertion of the cannula of arthroscope into the inferior cavity is accomplished by this method, and surgical damage is slight. Contrary to an accepted opinion of using blunt trocar to avoid injuring the surrounding tissue, the sharpness of the edge of 18 gauge needle and needle of 14 gauge i. v. catheter makes it easy to cut the strong tissue of the capsule with weak and controllable power, and does not give unnecessary damage to the tissue of the joint.