リンパ管造影およびCTが有用であった胸部大動脈術後乳び胸

Usefulness of Lipiodol Lymphangiography and Computed Tomography in Surgical Management of Chylothorax After Thoracic Aortic Surgery

心大血管術後の乳び胸はまれな合併症であるが，保存的治療に抵抗し治療に難渋することがある．外科的治療の際には，漏出部位の同定が困難なことも少なくない．われわれは，ethyl ester of iodinated poppy-seed oil fatty acid（以下，リピオドール）リンパ管造影像とCTにより漏出部位と胸管走行を評価し，異なる外科的治療戦略により治癒しえた大動脈術後乳び胸の2例を経験したため報告する．

Chylothorax is an uncommon but clinically relevant complication following thoracic aortic surgery. Although conservative management is usually the initial approach, persistent high-output chylous effusion may require surgical intervention, for which accurate identification of the leakage site is important. We describe two cases of refractory postoperative chylothorax following aortic surgery, in which surgical management was guided by intranodal lipiodol lymphangiography combined with computed tomography （CT）. The first patient developed chylothorax after descending aortic replacement via left thoracotomy for chronic Stanford type B aortic dissection. Despite fasting, total parenteral nutrition, and octreotide administration, chylous drainage persisted. Lymphatic imaging suggested a localized leak adjacent to the distal anastomosis of the descending aortic graft, and direct local ligation was performed. The second patient developed chylothorax after total aortic arch replacement for a distal arch aneurysm. Imaging demonstrated chyle leakage from the dorsal aspect of the arch graft, where local repair was considered difficult；therefore, thoracoscopic thoracic duct ligation via a right-sided approach was selected. In both cases, chylothorax resolved promptly after reoperation without recurrence. Lipiodol lymphangiography combined with CT provides valuable anatomical information for identifying the leakage site and thoracic duct course, thereby facilitating selection of an appropriate, case-specific surgical strategy in refractory postoperative chylothorax.