The abdominal cavity is home to plenty of organs. Some of them, like the stomach and intestines, are part of the gastrointestinal tract. Other organs, like the liver, gallbladder and pancreas, help with digestion, even though they’re not part of the GI tract itself. And then there are also organs like the spleen, kidneys and ureters, which are part of other important, non gastrointestinal systems. So let’s take a look at the injuries and diseases that can affect these abdominal organs.
First off, we have portal hypertension, which basically means increased pressure in the portal venous system. This is most commonly caused by liver cirrhosis, but can also be caused by vascular obstruction. Some causes of vascular obstruction include portal vein thrombosis, Budd-Chiari syndrome which is thrombosis or compression of the hepatic veins, as well as the parasitic flatworm infection known as schistosomiasis.
Okay, now, when fibrosis in the liver from cirrhosis obstructs the portal vein, the pressure rises in the portal vein and into its tributaries. This large volume of congested blood flows out from the portal system into the systemic system at the sites of portosystemic anastomoses, also called portocaval anastomoses.
The first site of portosystemic anastomosis is at the lower esophagus. At this point, the high pressure in the portal system can reach the anastomosis between the left gastric veins and the esophageal veins in the lower esophagus, causing engorged varicose veins which may then go on to rupture and lead to upper gastrointestinal bleeding.