<prompt> Most commonly used approach for retrosternal goitre:-Transthoracic second intercostal spaceTrans-sternal through anterior mediastinumTranscervicalAxillary approach  <response>: Retrosternal goitre: - 50 thyroid tissue located below neck - A.K.A i. Sub-sternal Goitre ii. Mediastinal Goitre Retrosternal Goitre Primary Mediastinal Goitre - BLOOD SUPPLY From Neck region From mediastinum region - APPROACH Transcervical Thoracic Primary Mediastinal Goitre: Diameter of Goitre Thoracic inlet 