An intraoperative endoscopic photograph showing the surgical anatomy of the posterior mediastinum during a thoracic procedure. The operative field highlights the sulcus azygoaortalis (labeled 'c'), a physiological groove located between the descending thoracic aorta and the azygos vein. The adventitia of the thoracic aorta (labeled 'a') is visible through the dissection site. The azygos vein (labeled 'b') is positioned adjacent to the aortic wall. The mediastinal pleura has been incised and reflected, with its edges (labeled 'd') clearly demarcated at the periphery of the dissection. A harmonic scalpel or ultrasonic dissector is visible in the lower right, positioned near the operative site. This image demonstrates the critical anatomical relationships required for mobilization of the esophagus and identification of the thoracic duct, which typically resides within the loose connective tissue of this sulcus. The orientation reflects a sagittal surgical plane used during lymphadenectomy or esophageal surgery.

This clinical photograph provides an intraoperative view of the posterior mediastinum during a surgical procedure, specifically highlighting the anatomical relationships surrounding the azygos venous system and the thoracic duct. The image demonstrates the thoracic duct (a) being carefully isolated and elevated by a surgical dissector, appearing as a thin, translucent, yellowish vessel. Anatomical landmarks include the azygos vein (b) and the arch of the azygos vein (c) positioned laterally. The esophagus (d) is visible deep to the reflected mediastinal pleura (f). Posteriorly, intercostal veins (e) are seen draining into the azygos system. Also visible are branches of the vagal nerve (g) providing innervation in the periesophageal region. This image is educational for thoracic surgery and surgical anatomy, illustrating the critical proximity of the thoracic duct to the azygos vein and esophagus, which is essential for preventing intraoperative lymphatic injury during esophagectomy or mediastinal lymphadenectomy.

This endoscopic clinical photograph displays a intraoperative thoracoscopic view (VATS) of the right posterior mediastinum. The image highlights critical anatomical landmarks and their spatial relationships to a localized pathology. Centrally, the azygos vein is visible as a prominent bluish, tubular vascular structure. Parallel and adjacent to it lies the esophagus, appearing as a paler, vertically oriented muscular tube. A pathological mass is identified in the inferior aspect of the field, situated in the space between the azygos vein and the esophagus. The mass appears as a rounded, well-circumscribed, and highly vascularized structure with a smooth surface, identified in clinical context as hyaline-vascular Castleman disease. To the right of the surgical field, the parenchyma of the right lung is visible, demonstrating typical anthracotic pigment. This image serves as an educational reference for thoracic surgery and mediastinal anatomy, illustrating the typical presentation and surgical orientation for resecting posterior mediastinal tumors while avoiding injury to the azygos vein and esophagus.

This axial thoracic CT angiography image demonstrates the anatomy of the mediastinum at the level of the aortic arch. The primary focus is the right azygos vein, marked with white arrows, as it arches anteriorly to discharge into the posterior aspect of the superior vena cava (SVC). The SVC appears slightly compressed or displaced, which context suggests is due to an aneurysmal dilatation of the adjacent ascending aorta. Other visible anatomical structures include the large diameter of the ascending aorta, the descending aorta situated posteriorly to the left, the trachea at the midline, and the esophagus. The pulmonary trunk and portions of the lungs are also visible. The image highlights the drainage pathway of the azygos system and illustrates how adjacent vascular pathologies, such as an aortic aneurysm, can exert mass effect on the low-pressure venous structures of the mediastinum. This content is valuable for students and radiologists studying thoracic vascular anatomy and the clinical presentation of aortic aneurysms.