Hemi-lateral pleural effusion can occur in all situations
Case 307
【Progress】
Pleural effusion by thoracentesis revealed triglycerides 2308 (30-117) mg/dL, indicative of chylothorax.
【Discussion】
The pleural space is reported normally filled with 5 to 10 mL of serous fluid, which is secreted mainly from the parietal pleura and absorbed through the lymphatics in the parietal pleura (1, 2). The imbalance between the secretion and absorption causes macroscopic accumulation of pleural effusion. In the real clinical situation, congestive heart failure, pneumonia and malignancy are the most common cause of pleural effusions (1-3). Bilateral pleural effusion occurs in various situations. Hemi-lateral effusion occurs often associated with pulmonary lesions of pneumonia, lung cancer and trauma. However, hemi-lateral effusion in the situation without pulmonary lesion or trauma is found in limited diseases. Pleural tuberculosis, inflammation from extra-pulmonary lesion (cholecystitis, pancreatitis), pleural mesothelioma and chylothorax are listed.
The causes of chylothorax vary and categorized largely into traumatic and non-traumatic (4-6). Traumatic is sub-categorized into iatrogenic and non-iatrogenic (gun shot, et al.). As the clinical reality, chylothorax meets most often as a complication of thoracic surgery especially for esophageal cancer. As non-traumatic, idiopathic, disease (tuberculosis, sarcoidosis, filariasis, lymphangio-leiomyomatosis), and malignancy are listed. Malignancy is the most common cause of the non-traumatic, lymphoma is found in 70% of cases (4-7).
The typical pathway with the incidence of 65% of thoracic duct in human is as follows: Thoracic duct rises from cistern chyli at Th12-L1 level and goes upward on the right side of the thoracic vertebrae (4-7). It turns left at Th5 level, moves across the midline, goes upward medially behind the esophagus and finally enters the left subclavian vein at C7 level. Then, the leakage or damage of thoracic duct at the lower level of Th5 induces right chylothorax, while the thoracic duct damage at the higher level of Th5 induces left chylothorax (4). In the clinical reality, the right chylothorax is more common rather than the left chylothorax. However, in our case, the left pulmonary chylothorax emerged, indicative of damages of thoracic duct at the higher level of Th5.
Although conservative treatment is recommended at first, surgical thoracic duct ligation and thoracic duct embolization using micro-coil + glue (n-butyl cyanoacrylate, NBCA) via puncture of the caudal end of cisterna chyli and catheterization to the thoracic duct, can be applicable (8-10). Before surgical approach or intervention embolization, lymphangiography via pedal approach was previously used and at present, fat suppression heavily T2WI is reported to be useful to detect thoracic duct. In the present case, fat suppression heavily T2WI depicted the leakage of thoracic duct to left pleural space at the higher level of Th5. The conservative treatment was effective in the present case. In Case 133 of Hannan Municipal Hospital, Cell-free and concentrated ascites refusion therapy (CART) worked. Mean CT values of chylothorax in the present case and Case 133 were 10.2 – 13.7 and 8.43 – 8.53, indicative of non-specific.
【Summary】
We presented an eighty-one-year-old female with persistent cough and left pleural effusion. Pleural thoracentesis revealed chylothorax whose cause was fistula between thoracic duct to pleural effusion on fat suppression heavily T2WI. The chylothorax improved as time progress. It is borne in mind that the thoracic duct begins from cisterna chyli at L1-Th12 and goes upward at the right side of thoracic vertebrae, crosses the midline at Th5 level, goes upward medially behind the esophagus and finally outflows to the proximal end of the left subclavian vein. It indicates that the leak of thoracic duct at the lower level of Th5 induces right chylothorax, while the thoracic duct damage at the higher level of Th5 induces left chylothorax. Chylothorax is caused by traumatic or non-traumatic; surgical intervention for esophageal cancer is most common as traumatic: malignancy, most common in non-traumatic. Managements for chylothorax are conservative, CART, thoracic duct embolization might play a main role of treatment instead of surgical ligation after lymphangiography via femoral node approach.
【References】
1.Chung J, et al. Pleural effusion and empyema thoracis. In: Bope E T, Rakel R E, Kellerman R D, editors. Conn's Current Therapy 2010. 1st ed. Philadelphia: Saunders/ Elsevier; 2010. pp. 263–265.
2.Bouros D, et al. Parapneumonic effusion and empyema: best therapeutic approach. Monaldi Arch Chest Dis. 2001;56(2):144–148.
3.Schiza S, et al. Clinical presentation and management of empyema, lung abscess and pleural effusion. Curr Opin Pulm Med. 2006;12(3):205–211.
4.McGrath EE, et al. Chylothorax: Aetiology, diagnosis and therapeutic options. Respiratory Medicine: 2010; 104: 1-8
5.Nair SK, et al. Etiology and management of chylothorax in adults. Eur J Cardiothorac Surg. 2007; 32: 362-369
6.Bolger, C et al. Chylothorax after oesophagectomy. Br J Surg;1991: 78: 587-588
7.Ngan H, et al. The role of lymphography in chylothorax following thoracic surgery. Br J Radiol, 1988; 61: 1032-1036
8.Boffa,DJt al. A critical evaluation of a percutaneous diagnostic and treatment strategy for chylothorax after thoracic surgery.Eur J Cardiothorac Surg. 2008; 33: 435-439
9.Litherland, B, et al. Percutaneous radiological management of high-output chylothorax with CT-guided needle disruption. J Med Imaging Radiat Oncol. 2008; 52: 164-167
10.Matsumoto, et al. The effectiveness of lymphangiography as a treatment method for various chyle leakages. Br J Radiol. 2009; 82: 286-290
2023.8.22