Pleura and pericardium represent the actual anatomical border for thoracic and cardiovascular surgery, the two serous cavities’ pathology being often intricate and requiring attention from both lung and heart surgeons, as well as trauma and general surgery experts. The pleural fluid accumulation is the result of vascular pressure, structure and function imbalances, secondary to various conditions - benign or malignant, pleural effusions (PE) being associated with almost any type of cancer. Benignant conditions associated with pleural effusions include, but are not limited to, heart failure, cirrhosis, iatrogenic, infections or trauma. In half of the cases, pleural effusion is often the presenting symptom of various asymptomatic or paucisymptomatic metastatic cancers. Underlying cancers can range from primary lung, pleural (mesothelioma) or cardiac cancer (sarcoma) to any other metastatic cancer (colon, breast, cervical, ovarian, etc.). Concomitant occurrence of pericardial effusions complicates the evolution of the patients with pleural effusions and sometimes requires emergency surgery for decompression, especially when cardiac tamponade is imminent.

This issue aims to provide essential information on hot topics for the cardiothoracic surgeon such as etiology of pleural effusions, imaging of pleural effusions including the use of thoracic ultrasound, malignant pleuropericardial effusions, chylothorax diagnosis and management (medical and surgical), surgical treatment of pleuropericardial effusions/ therapeutic options for the pleuropericardial effusions. It covers the basic data on pleural anatomy and physiology followed by a short overview of PE etiology, imaging in clinical practice, with emphasis on chest ultrasound, which is widely available compared with CT scan, malignant pleuropericardial effusion- where do we stand- a short review of diagnostic and therapeutic options, chylothorax- diagnostic and management challenges, including both medical and surgical therapeutic options, post traumatic pleural effusions, COVID-19 induced pleural effusions, pleural empyema- current management, thoracic windows- pleural, pericardial, pericardiopleural, Eloesser- when, why and how, as well as the minimally invasive therapeutic options in PE.