Conservative treatment, such as a low-fat medium-chain triglyceride diet, fasting, and TPN, are treatment options for chylothorax [1,2,3]. Takuwa et al. reported that 23 out of 37 patients with chylothorax after lung cancer surgery were successfully treated with a low-fat diet . However, the remaining 14 patients required pleurodesis or surgical intervention. In the present case, the patient was not successfully treated with fasting and TPN and ultimately underwent surgery.
Pleurodesis using multiple chemicals or autologous blood is one of the treatments for chylothorax [1,2,3]. Pleurodesis can control especially low levels of pleural effusion and was considered in our hospital because the pleural effusion was 500–1000 ml daily after fasting and TPN. However, pyothorax is a potential complication of pleurodesis, and since the patient had undergone aortic replacement with a prosthetic graft, pyothorax may have resulted in potentially fatal graft infection. In addition, adhesions in the thoracic cavity would have made subsequent TDL challenging. Therefore, pleurodesis was not performed.
Lymphatic embolization is another treatment option . It requires cannulation of the catheter from the cisterna chyli, and advancing it to reach the leakage site. The patient had no cisterna chyli, precluding catheter insertion, and ruling out lymphatic embolization.
For the reasons above, we performed TDL. Administering milk or olives stains the TD white and allows for identification of its course and the leakage site [3, 4]. We chose patent blue V, because we believed that a blue stain would be more visible. As a result, a blue-stained TD on the dorsal side of the aorta appeared although we could not identify the leakage site because of lung adhesions. If milk or olives cannot be used due to allergies, this method might be a viable alternative.
Barthelmes et al. reported that the side effects of patent blue V when identifying sentinel lymph nodes in breast cancer were allergic reactions (0.85%), skin tattooing (0.012%), and a bluish hue persisting for a few hours (0.037%) . In our case, blue pigmentation of the entire body persisted for 2 days after the second operation. However, we used 10% patent blue V compared to only 2.5% in Barthelmes et al.’s report. This significantly higher concentration may have caused the prolonged pigmentation.
Recently, ICG injection into lymph nodes or lymphatic vessels to identify the leakage site of chylous pleural effusion and the TD course has been reported [5, 6]. However, this method requires dedicated fluorescence imaging equipment, while one advantage of patent blue V is not requiring specific equipment.
We report a case of successful identification of the TD course using patent blue V. Our approach may be useful during TDL for chylothorax after thoracic surgery.