Fluorescence-guided surgery with indocyanine green to identify an idiopathic chyle leak-case report

Background: Chylothorax is the leakage of chyle into the pleural space and is associated with up to 50% morbidity. Although, the identification of traumatic chylothoraces is well described, non-traumatic chylothoraxes, mostly idiopathic, present therapeutic challenges as they are difficult to localize. We describe an attempt at localizing and treating an idiopathic chylothorax refractory to conservative and minimally invasive techniques. This was done using indocyanine green (ICG) and was a joint case between a thoracic surgeon and an interventional radiologist. Case Description: A 50-year-old female with a recent history of coronavirus disease (COVID)-19 presented with shortness of breath. She was found to have a right pleural effusion and was admitted to the hospital, where a chest tube was inserted and pleural fluid analysis confirmed the diagnosis of a chylothorax. Conservative management was attempted but with little success. Initial magnetic resonance lymphangiogram (MRL) revealed abnormal enhancing lymphatic masses in the right paraspinal thoracic space as well as lympho-venous junction obstruction with large neck collaterals. She then underwent percutaneous lymphovenous junction angioplasty followed by multiple rounds of glue embolization without clinical improvement. The decision was then made to proceed with a thoracotomy, identification of the site of thoracic duct (TD) leakage, and a mechanical pleurodesis assisted by intraoperative imaging. Ten mg of ICG was injected into the inguinal lymph nodes. Using a camera capable of detection of near-infrared (NIR) light, we were able to visualize the site from which the ICG was extravasating in the chest. Glue was then injected in that area to further help in reducing the leak. After keeping her nil per os (NPO) and requiring one more ligation, a repeat MRL showed a markedly decreased leak into the right pleural space. Two weeks later, she was seen in clinic and reported significant improvement in her symptoms. Conclusions: This is the case of a 50- year-old female who was found to have a significant right chylothorax. She underwent conservative management, followed by tube thoracostomy, and TD ligation but was refractory to treatment. Fluorescence-guided surgery was pivotal to localize the leakage site and help seal it intraoperatively.