Medical Diagnosis
Case 133
【Progress】Drainage tube was inserted and retained into the right plural space. The plural effusion was continuously drained by the indwelling catheter and its volume was 700 to 4265 ml/day. Picibanil (OK-432) was injected into pleural space in order to induce pleural adhesion but in vain. The fluid color was becoming clear from whitish. Cell-free and concentrated ascites refusion therapy (CART) was initiated. When CART is not effective, lipiodol injection from femoral lymph-nodes is scheduled.
【Discussion】
The length of the thoracic duct is approximately 35- 45 cm and the diameter, 2 – 7 mm. The thoracic duct which has valves and paper-thin wall, carries and collect lymph from lower limb and chyle from the digestive organ. The volume of 0.5 – 4 L/day of lymph & chyle flow in the thoracic tract. The volume and color depend on the ingested volume of food and dietary fat, respectively (1, 2). In our case, the volume of pleural effusion was 700 to 4265 ml/day and its color was whitish to clear.
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 (1, 2). 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 (1). In the clinical reality, the right chylothorax is more common rather than the left chylothorax. In our case, the right chylothorax was more predominant in volume than the left one (Figs 1, 2).
The causes of chylothorax vary and are categorized largely into traumatic and non-traumatic (1, 3). 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 (1, 3). In our case, he had partial gastrectomy for advanced gastric cancer. It is considered that the blockage of the thoracic duct is caused by tumor cell growth in the duct or lymph-node compression.
Although conservative treatment is recommended at first, surgical thoracic duct ligation and thoracic duct embolization can be applicable (3-7). Before surgical approach or intervention embolization, lymphangiography via pedal approach was previously used and at present, lymphangiography via femoral lymph-node approach is favorable because of time-consuming and effectiveness of embolization with lipiodol alone (4, 7). Surgical ligation of thoracic duct is recommended at the supra-diaphragm level (1, 5, 6). Embolization of thoracic duct is conducted after confirmation of the leak using micro-coil + glue (n-butyl cyanoacrylate, NBCA) via puncture of the caudal end of cisterna chyli and catheterization to the thoracic duct. In our case, the conservative treatment was choiced.
【Summary】
We present a seventy three-year-old male suffering from dyspnea. Chest radiograph and chest CT showed the right-sided massive plural effusion and the left-sided small pleural effusion. Puncture of the pleural effusion showed whitish fluids. The drainage fluid volume was up to more than 4000mL/day. It is borne in mind that the thoracic duct carries and collect lymph from lower limb and chyle from the digestive organ, and its volume is dependent on the ingested food volume. The thoracic duct begins from cisterna chyli at L1-Th12 and goes upward at the right side of thoracic vertebrae, crosses the midline, turns left at Th5, 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. Thoracic duct embolization might play a main role of treatment instead of surgical ligation after lymphangiography via femoral node approach.
【References】
1.McGrath EE, et al. Chylothorax: Aetiology, diagnosis and therapeutic options. Respiratory Medicine: 2010; 104: 1-8
2.Nair SK, et al. Etiology and management of chylothorax in adults. Eur J Cardiothorac Surg. 2007; 32: 362-369
3.Bolger, C et al.Chylothorax after oesophagectomy. Br J Surg;1991: 78: 587-588
4.Ngan H, et al. The role of lymphography in chylothorax following thoracic surgery. Br J Radiol, 1988; 61: 1032-1036
5.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
6.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
7.Matsumoto, et al. The effectiveness of lymphangiography as a treatment method for various chyle leakages. Br J Radiol. 2009; 82: 286-290
2018.12.11