縦隔鏡を用いた食道癌根治手術を目指したThiel法固定献体での検討

Mediastinoscopic esophagectomy with a new crossover approach in Thiel-embalmed cadavers

◆要旨：【目的】食道癌根治術となる縦隔操作を食道裂孔および頸部から縦隔鏡下に行う手術手技を臨床応用するため，Thiel法固定献体を用いて106tbLリンパ節郭清手法を検討した．【手術手技】気縦隔下に，経裂孔的に左主気管支腹側縁を気管気管支角方向に剝離し，右頸部からも観察の下，左気管気管支角腹側縁に裂孔側よりリトラクターを挿入して内側下方に牽引し，右頸部からの大動脈弓下の視野を確保し106tbLリンパ節郭清を施行しえた．【結論】気縦隔法および左右頸部および経裂孔的な左気管気管支角の展開（クロスオーバーテクニック）によって106tbLリンパ節郭清が可能となり，根治的な縦隔郭清を伴う食道癌手術（mediastinoscopical esophagectomy with lymph node dissection：MELD）は臨床応用が可能と考えられた．

　［Purpose and methods］ We developed a method for performing complete mediastinoscopic esophagectomy as radical surgery via bilateral transcervical and transhiatal approach in six Thiel-embalmed human cadavers. ［Procedures］<Transhiatal approach> Hand-assisted laparoscopic surgery（HALS） is used for gastric conduit mobilization. The lower and middle mediastinal lymph nodes are dissected via the transhiatal approach. <Transcervical approach> The dorsal side of the left recurrent nerve is dissected up to the aortic arch and left recurrent nerve lymph nodes（106recL） are dissected under pneumomediastinum. Next, the right recurrent nerve lymph nodes（106recR） are dissected. The cartilage of the left main bronchus is dissected and pushed downward, thereby obtaining a good view between the aortic arch and left main bronchus via the transhiatal approach. The 106tbL lymph nodes are dissected until the aortic arch is reached. Simultaneously, the lymph nodes are dissected via a right cervical approach. This method is termed the “cross-over technique.” ［Discussion］ It is very difficult to dissect the 106tbL lymph nodes using the mediastinal method because the mediastinal area is narrow and contains very important structures. Therefore, to date, no authors have reported successful dissection of the 106tbL lymph nodes. We herein demonstrated that the upper mediastinal lymph nodes, including the 106tbL nodes, can be dissected using the bilateral transcervical and transhiatal approach under pneumomediastinum and named this method “mediastinoscopic esophagectomy with lymph node dissection”（MELD）. MELD is, therefore, considered to be a useful modality based on our experience with Thiel-embalmed human cadavers.