Chylothorax is one of the complications after oesophagectomy, but remains a rare complication. The frequency of chylothorax is reported to be between 1.1–2.7% after oesophageal resection [5, 6].
Chylothorax treatment after oesophagectomy is troublesome itself, and with an aberrant thoracic duct, the treatment becomes more difficult. In 1953, Adachi reported classification of thoracic duct variations with 9 types of normal anatomy . In our case, there were right and left thoracic ducts; the right one was clipped in the operation of oesophageal cancer, but the left one remained. Thus, we classified this case to the type III Adachi thoracic duct classification.
Regarding whether to resect the thoracic ducts or preserve them in oesophageal resection, there have been few reports on the efficacy of thoracic duct resection , and a consensus of resection of thoracic duct has yet to be reached. In our hospital, we usually clip and dissect the thoracic duct at the level above the diaphragm for oesophageal cancer; however, postoperative chylothorax still remains a rare complication.
Conservative therapy is initially suggested. The treatment consists of thoracic cavity drainage, nutritional support, pleurodesis, and measures to diminish chyle flow. If conservative treatment is not successful, in the following cases, surgical treatment is chosen: chyle leak continuing, nutritional status deteriorating and the possibility of infection increasing. In adult cases, Selle et al.  reported the standard that in cases with over 1500 ml fluid flowing out over 5 days, conservative treatment over 2 weeks and nutritional status deterioration are adaptations of surgical treatment. We conducted lymphangiography and focal pleurodesis because conservative therapy continued over 2 weeks. In previous studies, conservative treatment (excluding thoracic duct embolization) had a success rate of 53.8% in the postoperative chylothorax [3, 10,11,12,13,14,15], with or without thoracic duct resection.
We watched and investigated the operation video carefully after the appearance of chylothorax; the thoracic duct was clipped and dissected conventionally at that time. Thus, we would consider that there was an aberrant thoracic duct, which is not usually the case. In the case of minimal invasive oesophageal resection, it is very useful to re-examine the operation video precisely after incidence of complications.
The thoracic duct is the largest lymphatic vessel in the human body . Because of its proximity to other organs, such as the oesophagus, the thoracic duct is at risk during surgery. Routine ligation of the thoracic duct is advocated to prevent chyle leakage [17, 18]. However, thoracic chyle leakage still occurs, even when the thoracic duct is clipped . There are many variations in thoracic duct anatomy. In our case, MRI showed thoracic duct variation. Above the diaphragm, the normal thoracic duct runs along the right side of the thoracic vertebrae and the dorsal side of oesophagus, and between the thoracic aorta and azygos vein. Around the 6th to 4th thoracic vertebrae, it passes behind the oesophagus through the thoracic vertebrae and enters into left posterior mediastinum. Finally, it goes through upper mediastinum to neck, and then, it goes down and enters into the left vein angle . In the lymphangiography, Cha and Sirijintakarn  reported that the frequency of variation is 26.8% (65 cases of 243 cases), and Asada et al.  reported a frequency of variation of 29% (60 cases of 207 cases). When chylothorax occurs, lymphangiography is needed because of the possibility of variation, detecting the thoracic duct run and leaking point [23, 24].
In this case, we transported the narrow tube to the leakage point and have shown the effectiveness of focal pleurodesis through IVR, in combination with conventional octreotide administration and nutritional therapy, for the treatment of postoperative chylothorax following oesophagectomy. Our finding suggests that when used concurrently with conventional treatments, focal pleurodesis facilitates early chest tube removal and there is no need of surgical treatment with or without thoracic duct variation.