Editing Esophagus (section)

===Varices===
{{Main|Esophageal varices}}
[[Esophageal varices]] are swollen twisted branches of the [[azygous vein]] in the lower third of the esophagus. These blood vessels [[anastomose]] (join up) with those of the [[portal vein]] when [[portal hypertension]] develops.<ref>{{cite book|last1=Albert|first1=Daniel|title=Dorland's illustrated medical dictionary|date=2012|publisher=Saunders/Elsevier|location=Philadelphia, PA|isbn=978-1-4160-6257-8|page=2025|edition=32nd}}</ref> These blood vessels are engorged more than normal, and in the worst cases may partially obstruct the esophagus. These blood vessels develop as part of a collateral circulation that occurs to drain blood from the [[abdomen]] as a result of [[portal hypertension]], usually as a result of [[liver disease]]s such as [[cirrhosis]].<ref name=DAVIDSONS2010/>{{rp|941–42}} This collateral circulation occurs because the lower part of the esophagus drains into the left gastric vein, which is a branch of the portal vein. Because of the extensive venous plexus that exists between this vein and other veins, if portal hypertension occurs, the direction of blood drainage in this vein may reverse, with blood draining from the portal venous system, through the plexus. Veins in the plexus may engorge and lead to varices.<ref name=KUO2006/><ref name=PATTI1997/>

Esophageal varices often do not have symptoms until they rupture. A ruptured varix is considered a medical emergency because varices can bleed a lot. A bleeding varix may cause a person [[haematemesis|to vomit blood]], or suffer [[shock (circulatory)|shock]]. To deal with a ruptured varix, a band may be placed around the bleeding blood vessel, or a small amount of a clotting agent may be injected near the bleed. A surgeon may also try to use a small inflatable balloon to apply pressure to stop the wound. [[IV fluids]] and [[blood product]]s may be given in order to prevent [[hypovolemia]] from excess blood loss.<ref name=DAVIDSONS2010 />