Thoracic plane

Dr Craig Hacking ◉ ◈ and Dr Henry Knipe ◉ ◈ et al.

The thoracic plane, also known as the transthoracic plane or the plane of Ludwig is an artificial horizontal plane used to divide the mediastinum into the superior mediastinum and the inferior mediastinum.

It is defined as a horizontal line that runs from the manubriosternal joint (sternal angle or angle of Louis) to the inferior endplate of T4 ¹. Above the thoracic plane is the superior mediastinum and below the thoracic plane is the inferior mediastinum.

A number of important structures are transected by the thoracic plane ¹:

bifurcation of the trachea, i.e. the carina
aortic arch (inner concavity)
pulmonary trunk bifurcation
azygos vein drains into the SV C, arching over the right main bronchus
left recurrent laryngeal nerve loops around the aortic arch
thoracic duct moves from right to left hand side posterior to the esophagus
ligamentum arteriosum
cardiac plexus (superficial and deep parts)
termination of the prevertebral fascia and pretracheal fascia

thoracic plane (mnemonic)

Quiz questions

{"accessible":false,"alternatives":[{"id":4708,"text":"azygous vein drains into the superior vena cava"},{"id":4706,"text":"bifurcation of the pulmonary trunk"},{"id":4705,"text":"left recurrent laryngeal nerve loops around the aortic arch"},{"id":4707,"text":"ligamentum arteriosum"},{"id":4709,"text":"thoracic duct crosses from left to right hand side"}],"archived":false,"correctAlternativeId":4709,"explanation":"\u003cp\u003e\u003ca href=\"/articles/thoracic-plane\"\u003eTransthoracic plane\u003c/a\u003e, also known as the thoracic plane or the plane of Ludwig, is a horizontal plane between the \u003ca href=\"/articles/manubriosternal-joint\"\u003esternal angle\u003c/a\u003e and the level of the T4-T5 vertebra, which divides the \u003ca href=\"/articles/mediastinum\"\u003emediastinum\u003c/a\u003e into superior and inferior mediastinum.\u003c/p\u003e\u003cp\u003eIt transects a number of important anatomical structures. These include:\u003c/p\u003e\u003cul\u003e\n\u003cli\u003eBifurcation of the \u003ca href=\"/articles/trachea\"\u003etrachea\u003c/a\u003e (into primary bronchi)\u003c/li\u003e\n\u003cli\u003e\u003ca href=\"/articles/aortic-arch\"\u003eAortic arch\u003c/a\u003e\u003c/li\u003e\n\u003cli\u003eBifurcation of the pulmonary trunk\u003c/li\u003e\n\u003cli\u003e\n\u003ca href=\"/articles/azygos-vein\"\u003eAzygous vein\u003c/a\u003e empties into the \u003ca href=\"/articles/superior-vena-cava\"\u003eSVC\u003c/a\u003e, as it arches over the right main bronchus\u003c/li\u003e\n\u003cli\u003eLeft \u003ca href=\"/articles/recurrent-laryngeal-nerve\"\u003erecurrent laryngeal nerve\u003c/a\u003e loops around the aortic arch\u003c/li\u003e\n\u003cli\u003e\u003ca href=\"/articles/ligamentum-arteriosum\"\u003eLigamentum arteriosum\u003c/a\u003e\u003c/li\u003e\n\u003cli\u003e\n\u003ca href=\"/articles/thoracic-duct\"\u003eThoracic duct\u003c/a\u003e (crosses from right to left hand side, rendering the option above false)\u003c/li\u003e\n\u003c/ul\u003e","id":935,"imageUrl":null,"nextQuestionPath":"/questions/935/next","relatedArticles":[{"id":22287,"title":"Thoracic plane (mnemonic)","link":"/articles/thoracic-plane-mnemonic?lang=us"}],"stem":"\u003cp\u003eWhich of the following does\u003cstrong\u003e NOT\u003c/strong\u003e occur at the transthoracic plane?\u003c/p\u003e","articleId":"thoracic-plane","nextQuestionId":933}