Question

You are attending an operation to remove a thymic tumor from the superior mediastinum. The surgeon asks, "What important nerve lying on and partly curving posteriorly around the arch of the aorta should we be careful of as we remove this mass?" You quickly answer, "The--

A) left phrenic
B) left sympathetic trunk
C) left vagus
D) right phrenic
E) right sympathetic trunk

Answer 1

During thoracic surgery, specifically while removing a mass from the superior mediastinum, surgeons must take care to avoid damaging the left vagus nerve, which courses posterior to the arch of the aorta.

Step-by-step explanation:

The important nerve that the surgeon must be careful of while removing a thymic tumor from the superior mediastinum and that lies on and partly curving posteriorly around the arch of the aorta is the left vagus nerve (option C).

This is because the left vagus nerve is situated in close proximity to the arch of the aorta and is therefore at risk during procedures in this area, unlike the phrenic nerve, which innervates the diaphragm and lies more ventrally (towards the front) relative to the aorta.