Utility of planning MRI in percutaneous thoracic duct embolization for chylothorax

Intraoperative visualization of morphological patterns of the thoracic duct by subcutaneous inguinal injection of indocyanine green in esophagectomy for esophageal cancer

To prevent chylothorax after esophageal cancer surgery, it is important to recognize morphological patterns of the thoracic duct intraoperatively. The present study aimed to evaluate the safety and usefulness of near-infrared (NIR) fluorescence imaging with subcutaneous inguinal injection of indocyanine green (SII-ICG) to detect the thoracic duct during thoracoscopic esophagectomy for esophageal cancer. Patients (n = 16) who underwent thoracoscopic esophagectomy in the prone position with SII-ICG at Shinshu University Hospital between June 2020 and January 2022 were enrolled in the present study and retrospectively reviewed. Immediately prior to thoracoscopic esophagectomy, we injected 0.2-0.5 mg/kg ICG into the subcutaneous tissue in the bilateral inguinal region. The identification rate of the thoracic duct was 93.8% (n = 15), and the success rate of fluorescence using SII-ICG was 87.5% (n = 14). The visible thoracic ducts had four patterns: a typical pattern in 50% (n = 8), duplication pattern in 18.8% (n = 3), branching pattern in 12.5% (n = 2), and plexiform pattern in 12.5% (n = 2). In all cases, ICG fluorescence did not disappear and was visible during the thoracic surgery. No SII-ICG-related complications were observed. Intraoperative NIR fluorescence imaging of the thoracic duct using SII-ICG is a simple and safe method with very high detection sensitivity. This method can be a powerful tool for avoiding thoracic duct injuries during esophageal cancer surgery.

Imaging Findings of Thoracic Lymphatic Abnormalities

The lymphatic system plays an important role in balancing fluid compartments in the body. It is disrupted by various disease processes in the thorax, including injury to the thoracic lymphatic duct after surgery, as well as malignancy and heart failure. Because of the small size of lymphatic vessels, imaging of the lymphatics is relatively difficult, and effective imaging methods are still being optimized and developed. The standard of reference for lymphatic imaging has been conventional lymphangiography for several decades. Other modalities such as CT, noncontrast or contrast-enhanced MRI, and lymphoscintigraphy can also demonstrate lymphatic abnormalities and help in treatment planning. Imaging findings associated with lymphatic abnormalities can be seen in the pulmonary parenchyma, pleural space, and mediastinum. In the pulmonary parenchyma, common findings include interlobular septal thickening as well as reversal of lymphatic flow with intravasation of contrast material into pulmonary lymphatics. In the pleural space, findings include chylous pleural effusion and occasionally nonchylous pleural effusion. In the mediastinum, thoracic duct leak, plexiform thoracic duct, lymphatic malformations, and lymphangiectasis may occur. Management of chylothorax includes conservative or medical treatment, surgery, and interventional radiology procedures. The authors discuss thoracic lymphatic anatomy, imaging manifestations of lymphatic abnormalities in the various anatomic compartments, and interventional radiology treatment of chylothorax. Radiologists should be familiar with these imaging findings for diagnosis and to help guide appropriate management. ^©RSNA, 2022.

Delayed and Chronic Sequelae of Trauma and the Role of the Interventional Radiologist

In addition to acute injury requiring interventional radiologic treatments, patients with traumatic injuries can develop delayed or chronic complications. These injuries can involve nearly all solid organs in the abdomen. Coupled with significant improvements in visualizing these injuries with advanced imaging techniques such as minimally invasive procedures, nonoperative management of both acute traumatic injuries and their longer term sequelae has become the norm. This article reviews frequently seen complications of traumatic injury and their management by interventional radiologists.