Editing Thymus (section)

===Surgical removal===
[[Thymectomy]] is the surgical removal of the thymus.<ref name="Grays2016" /> The usual reason for removal is to gain access to the heart for surgery to correct [[congenital heart defects]] in the neonatal period.<ref name=":1">{{cite journal | vauthors = Eysteinsdottir JH, Freysdottir J, Haraldsson A, Stefansdottir J, Skaftadottir I, Helgason H, Ogmundsdottir HM | title = The influence of partial or total thymectomy during open heart surgery in infants on the immune function later in life | journal = Clinical and Experimental Immunology | volume = 136 | issue = 2 | pages = 349–55 | date = May 2004 | pmid = 15086401 | pmc = 1809033 | doi = 10.1111/j.1365-2249.2004.02437.x }}</ref> Other indications for thymectomy include the removal of thymomas and the treatment of myasthenia gravis.<ref name="Grays2016" /> In neonates the relative size of the thymus obstructs surgical access to the heart and its surrounding vessels.<ref name=":1" /> 

Removal of the thymus in infancy results in often fatal immunodeficiency, because functional T cells have not developed.<ref name="Grays2016" /><ref>{{Cite journal |last1=Prelog |first1=Martina |last2=Wilk |first2=Cordula |last3=Keller |first3=Michael |last4=Karall |first4=Thomas |last5=Orth |first5=Dorothea |last6=Geiger |first6=Ralf |last7=Walder |first7=Gernot |last8=Laufer |first8=Guenther |last9=Cottogni |first9=Marco |last10=Zimmerhackl Lothar |first10=Bernd |last11=Stein |first11=Joerg |last12=Grubeck-Loebenstein |first12=Beatrix |last13=Wuerzner |first13=Reinhard |date=2008-01-30 |title=Diminished response to tick-borne encephalitis vaccination in thymectomized children |url=https://www.sciencedirect.com/science/article/pii/S0264410X07013412 |journal=Vaccine |volume=26 |issue=5 |pages=595–600 |doi=10.1016/j.vaccine.2007.11.074 |pmid=18178293 |issn=0264-410X}}</ref> In older children and adults, which have a functioning lymphatic system with mature T cells also situated in other lymphoid organs, the effect is reduced, but includes failure to mount immune responses against new antigens,<ref name="Grays2016" /> an increase in cancers, and an increase in all-cause mortality.<ref>{{Cite journal |last1=Kooshesh |first1=Kameron A. |last2=Foy |first2=Brody H. |last3=Sykes |first3=David B. |last4=Gustafsson |first4=Karin |last5=Scadden |first5=David T. |date=2023-08-03 |title=Health Consequences of Thymus Removal in Adults |journal=New England Journal of Medicine |language=en |volume=389 |issue=5 |pages=406–417 |doi=10.1056/NEJMoa2302892 |pmid=37530823 |s2cid=260377788 |issn=0028-4793|pmc=10557034 }}</ref>