thoracotomy vs incision

thoracotomy and incision both are nouns.

Word	Noun	Adjective	Verb	Adverb
thoracotomy	Yes	No	No	No
incision	Yes	No	No	No

As nouns, incision is a hypernym of thoracotomy; that is, incision is a word with a broader meaning than thoracotomy:

thoracotomy: surgical incision into the chest walls opening up the pleural cavity
incision: the cutting of or into body tissues or organs (especially by a surgeon as part of an operation)

Other hypernyms of thoracotomy include section, surgical incision.

thoracotomy (noun)	incision (noun)
surgical incision into the chest walls opening up the pleural cavity	the cutting of or into body tissues or organs (especially by a surgeon as part of an operation)
	a depression scratched or carved into a surface