Portal hypertension is a condition where there is increased blood pressure within the portal vein, which carries blood from the intestines and spleen to the liver before it returns to general circulation. The liver plays a complex role in processing a wide range of nutrients and neutralizing toxins derived from the digestion process. Essentially, the liver acts as the body's "processing plant" and generates most of the building blocks from dietary intake, which are transferred to the liver through the portal vein.
At times, there can be a blockage in the blood flow through the portal vein. This can happen due to obstructions in the liver resulting from various processes, or due to blood clot formation within the portal vein itself. Thus, portal hypertension is not a diagnosis in itself but rather a consequence of another disorder that elevates the blood pressure within this vein.
The body tries to compensate for reduced blood flow by developing alternative pathways for the blood to flow. It creates new connections (collateral vessels) between the portal vein and other blood vessels in the body. However, some of these collateral sites can be at risk of bleeding, such as in the esophagus. Because of the increased pressure in the portal vein, the spleen may enlarge significantly, leading to a decrease in blood cell count, especially platelets, which increases the risk of bleeding.
In most cases of liver-related portal hypertension, there are no initial complaints, and the diagnosis may only arise during bleeding from these parallel connections, as explained above. An enlarged spleen can sometimes cause discomfort in children due to its larger size. Children with portal hypertension may also exhibit anemia or low platelet counts.
Suspicion of portal hypertension can be detected during a routine physical examination. The diagnosis can be confirmed using a specialized ultrasound called Doppler, which assesses blood flow within the portal vein. Additionally, Doppler ultrasound can assist in identifying abnormal blood vessels in the esophagus.
Whenever possible, the underlying cause of portal hypertension should be identified and treated. However, this is not always feasible, so management also involves lowering the pressure to prevent complications and bleeding.
Medications might be used to manage the pressure, along with repeated endoscopic examinations to diagnose enlarged blood vessels in the esophagus that are prone to bleeding (these vessels are called "varices"). If varices are detected, they can be treated by injecting a substance that induces their closure or by using specialized devices to tie them off. Beta-blocker medications, which can help lower portal blood pressure, are sometimes used.
In some cases, liver-related portal hypertension might only become apparent after a bleeding event from one of the varices. In such situations, treatment focuses on controlling bleeding and preventing complications.