上位胸椎疾患に対する前方除圧固定術―経胸鎖関節進入法を用いて

Anterior Decompression and Fusion of the Upper Thoracic Spine by a Trans-Sternoclavicular Approach

　抄録：上位胸椎部の胸髄症において経胸鎖関節進入による胸椎前方固定術を施行し良好な臨床成績を得た．疾患は胸椎カリエス3例，胸椎症性脊髄症1例であり，全例に両下肢の不全麻痺，知覚障害を認めた．手術は下位頚椎前方進入の皮切を延長し，鎖骨中枢端と胸骨柄の一部を一塊として摘出して病巣部の除圧操作を行い，摘出した鎖骨胸骨複合体を移植骨として使用し椎体間固定を行った．全例に骨癒合が得られ臨床症状も改善した．術後，本進入法による前胸部や鎖骨部の疼痛，右肩関節の可動域制限を認めていない．上位胸椎はその解剖学的構造から前方進入が困難な部位であり種々の進入法が検討されている．今回行った進入法は比較的小さい骨切除で良好な術野が得られ，展開時に切除した胸骨鎖骨複合体をそのまま移植骨として使用できるため有用であると考えられた．

　Anterior fusion of the thoracic spine via a trans-sternoclavicular approach was used to treat four patients with thoracic myelopathy of the upper thoracic spine, and favorable results were obtained clinically. Three of the patients had caries (tuberculous spondylitis) of the thoracic spine, and the other patient had myelopathy secondary to thoracic spondylosis. All four patients had paraparesis and sensory disturbances in the lower half of the body. The surgical procedures included extension of the incision by an anterior approach to the lower cervical vertebrae, en bloc excision of the medial end of the clavicle and part of the sternal manubrium, decompression of the lesions, and interbody fusion using the excised sternoclavicular complex as a bone graft. Bone union was achieved, and symptom resolution was obtained in all patients. There were no adverse postoperative events, i.e., no instances of precordial/clavicular pain or restriction of the range of motion of the left shoulder joint. A variety of surgical approaches to the upper thoracic spine, has been assessed because the anterior approach is difficult due to the anatomical structure. Our approach provided a good operative field with a relatively small ostectomy. This approach is considered especially advantageous, because the sternoclavicular complex excised for exposure can be immediately used as a bone graft.