Portopulmonary hypertension is an increase in blood pressure in the pulmonary circulation due to portal hypertension. This, in turn, is usually the result of cirrhosis of the liver.
What is portopulmonary hypertension?
In portopulmonary hypertension, hypertension of the pulmonary artery occurs as a result of portal hypertension. Pulmonary hypertension refers to increased vascular resistance in the arterial blood vessels of the lungs. This increased vascular resistance results in elevated blood pressure. Pulmonary hypertension occurs as a complication of portal hypertension. In portal hypertension, the blood pressure in the portal vein (vena portae) is elevated to more than 12 mmHg. Normally, there is a pressure of 3 to 6 mmHg in the portal vein. The portal vein is the blood vessel that brings deoxygenated and nutrient-rich blood from the unpaired abdominal organs to the liver.
Causes
The causes of portopulmonary hypertension are similar to the causes of portal hypertension. The condition most commonly arises within the liver. The most common cause is cirrhosis of the liver, with 0.25 to 2 percent of all patients with cirrhosis developing portopulmonary hypertension. Liver cirrhosis is the end stage of many liver diseases. Typically, cirrhosis develops over several years or even decades. Almost all chronic liver diseases end in cirrhosis sooner or later. In Europe, viral hepatitis and alcohol abuse are among the most common causes. In cirrhosis, the liver tissue that perishes due to liver disease is replaced by connective tissue. This process is called fibrosis. More than half of the liver’s functional tissue may be affected by the remodeling. As a result, blood flow to the liver is restricted. Blood backs up in the area of the portal vein in front of the liver. This results in high blood pressure within the liver (portal hypertension). It is not yet clear why portal hypertension also leads to an increase in blood pressure in the lungs. It is possible that increased blood flow in the lungs causes irritation of the inner lining of the vessels. Microthrombi in the small pulmonary arteries are also discussed as a causative factor. These microthrombi may occur due to liver-induced hypercoagulability. Portopulmonary hypertension may also occur as a complication of liver transplantation.
Symptoms, complaints, and signs
Pulmonary hypertension places a great deal of stress on the right heart, which must constantly pump against the increased pressure. This pressure load is thought to be compensated for by an increase in the size of the heart muscle (right heart hypertrophy). Hypertrophy of the heart due to pulmonary hypertension is also known as cor pulmonale. Patients with portopulmonary hypertension present with both pulmonary and hepatic symptoms. They are severely limited in their physical performance and suffer from shortness of breath, cough, circulatory disturbances up to fainting, angina pectoris, fatigue, peripheral edema, a blue discoloration of the skin or Raynaud’s syndrome. Raynaud’s syndrome is characterized by vascular spasms associated with reduced blood flow to the toes or fingers. Along with pulmonary hypertension, valvular insufficiency of the right heart valve usually occurs. If left untreated, cor pulmonale leads to right heart failure. Signs of right heart failure include congested jugular veins and edema, abdominal dropsy, and splenic swelling. Increased nocturnal urination, cold extremities and tachycardia may also be signs. Eventually, complete cardiac failure results in death. The symptoms of pulmonary hypertension are accompanied by the symptoms of portal hypertension. In pulmonary hypertension, bypass circulation forms. As a result, the veins on the anterior abdominal wall appear very prominent. The visible veins radiating from the umbilicus in a star shape are called caput medusae. Another bypass circulation runs through the esophagus. This is where the so-called esophageal varices form. These can easily perforate due to ingested food. Because of the severe bleeding, such a perforation is life-threatening.
Diagnosis and course of the disease
Diagnosis begins with a detailed medical history and a thorough physical examination. The first step in the laboratory is then to determine the liver values in the blood. These include GOT, GPT, GLDH and y-GT.Furthermore, the vitamin K-dependent coagulation factors (I, II, IV and VII) as well as protein S, protein C and antithrombin III are determined. Increased or decreased values indicate a functional impairment of the liver. To better assess the condition of the lungs and liver, an X-ray examination of the chest and abdomen is performed. Right heart catheterization with measurement of pulmonary arterial pressure can confirm the diagnosis of portopulmonary hypertension. ECG and echocardiography provide information about the extent of cardiac stress. Differentially, hepatorenal syndrome must be excluded. In this case, however, arterial oxygen deficiency is more likely to be the primary concern.
Complications
Portopulmonary hypertension is already a serious complication of portal hypertension. Because this in turn is often triggered by cirrhosis of the liver, other complications can occur that accompany but are not triggered by portopulmonary hypertension. These include abdominal wall varices, esophageal varices, varicose veins in other areas of the body, fluid accumulation in the abdomen (ascites), splenomegaly, and hepatic encephalopathy. Furthermore, portopulmonary hypertension also occurs as a serious complication after liver transplantation. It is characterized by an enlargement of the right heart, which develops as a result of the constant right heart strain during portal hypertension (cor pulmonale). This can develop into valvular damage, which subsequently leads to so-called tricuspid regurgitation. Tricuspid regurgitation is a special form of heart failure. It is characterized by completely different courses. However, there is always a risk of total overload of the heart, which can lead to rapid worsening of heart failure. Severe tricuspid regurgitation is manifested by cardiac arrhythmias, leg edema, and neck vein and liver congestion. Thus, a vicious circle is created in that, among other things, portopulmonary hypertension caused by liver cirrhosis damages the liver even more via the development of tricuspid regurgitation, which can lead to liver failure. In rare cases, sudden deaths from secondary pulmonary emboli may also be favored. Cardiac arrhythmias can also lead to sudden cardiac death in severe cases.
When should you see a doctor?
Shortness of breath, liver pain, fatigue, and other typical signs of portopulmonary hypertension require medical evaluation. Individuals who have cirrhosis of the liver should inform the appropriate medical professional of the above symptoms. The physician can quickly determine whether portopulmonary hypertension is present by examining the liver and take the necessary measures. Early treatment can greatly improve the prospects for a speedy recovery. Therefore, the first signs of hypertension should be observed and presented to the physician no later than the next day if they have not resolved by then. Portopulmonary hypertension is treated by a specialist in liver disease. In most cases, inpatient treatment is necessary. If the symptoms occur after a liver transplant, there is an acute danger to life. The patient must immediately inform the responsible physician. Other risk groups are chronic liver patients and people suffering from other diseases of the internal organs. People with immunodeficiency or cancer of the liver or spleen are also among the risk groups and should see a specialist immediately if they experience any of the above symptoms.
Treatment and therapy
Treatment of portopulmonary hypertension is aimed at treating the underlying disease. Cirrhosis of the liver is irreversible. However, progression of the disease can be halted with abstinence regarding all liver-toxic substances. Patients should avoid alcohol in particular. A balanced diet, a reduction in protein intake and the substitution of nutrients can also alleviate symptoms. In severe cirrhosis, liver transplantation may be required. Causative therapy is supported by symptom-oriented drug therapy. For this purpose, vasodilator substances such as prostaglandin analogues, ET-1 receptor antagonists and calcium antagonists are administered. If necessary, the administration of ß-blockers may also be indicated.
Prevention
Portopulmonary hypertension cannot be directly prevented. It can only be prevented if the underlying disease is detected and treated as early as possible. In the best case, of course, the underlying disease itself should be prevented. Since the main risk factor for the development of cirrhosis is alcohol abuse, abstaining from alcohol can prevent cirrhosis in most cases.
Follow-up
Portopulmonary hypertension can be treated in the follow-up phase by deliberate abstinence. In this way, progression of the disease can be slowed, sometimes even halted altogether. Abstinence from alcohol ensures a better sense of well-being. A varied diet rich in vitamins is recommended for those affected. Among other things, a reduced protein intake helps to alleviate symptoms. Healthy substitutes with nutrients nevertheless provide the body with sufficient vital substances. As a supplement and to follow up on the actual therapy, doctors often recommend vasodilators. In this way, aftercare also serves as a preventive measure. However, the disease can only be prevented to a limited extent. The risk is considerably reduced by health-conscious behavior. The main cause of the symptoms can therefore be strongly influenced. At the same time, the intake of sufficient vitamins improves the body’s defenses, and the quality of life increases. Exercise is also helpful, but sufferers should not overestimate themselves and avoid overexertion. Stress caused by a lot of work or interpersonal crises can also have a negative influence. Therefore, it is important to reduce such factors through relaxation techniques and stay as relaxed as possible.
Here’s what you can do yourself
Sufferers of portopulmonary hypertension should completely refrain from consuming alcohol. Food intake should be checked for ingredients before consumption, especially in restaurants. Even small amounts of alcohol can lead to complications and an increase in symptoms. Addicts are advised to undergo withdrawal as soon as possible. This is the only way to slow down the progress of the disease. In addition to medical care, the immune system must be supported on its own responsibility. A diet rich in vitamins and a balanced diet are important. In dealing with the disease, the organism needs sufficient defenses. These can be mobilized by the supply of sufficient oxygen as well as exercise in addition to a healthy food supply. In all physical activities, the body’s own limits must be observed and overexertion avoided. Also harmful are situations in which the person is exposed to emotional stress. These contribute to an increase in blood pressure and worsen the general state of health. Interpersonal conflicts should therefore be resolved quickly if possible or should be avoided. A stable and secure social environment is important in coping with all the adversities of the disease. To reduce built-up stressors, targeted mental training and various relaxation techniques can help. These can be applied independently according to the patient’s needs.
