Posterior mdiastinum provides passage to all structures except

Posterior MediastinumBoundariesAnteriorly: (i) Pericardium, (ii) bifurcation of trachea, (iii) pulmonary vessels, and (iv) posterior pa of the upper surface of the diaphragm.Posteriorly: Lower eight thoracic veebrae and intervening discs.On each side: Mediastinal pleura.Contents1. Oesophagus2. Aeries: Descending thoracic aoa and its branches.3. Veins: (i) Azygos vein, (ii) hemiazygos vein, and (iii) accessory hemiazygos vein.4. Nerves: (i) Vagi, and (ii) splanchnic nerves, greater, lesser and least, arising from the lower eight thoracic ganglia of the sympathetic chain.5. Lymph nodes and lymphatics: (i) Posterior mediastinal lymph nodes lying alongside the aoa, and (ii) the thoracic ductRef: BD Chaurasia; Volume 1; 6th edition