Ascites – Fluid in the Abdominal Cavity Due to Liver Cirrhosis and Other Causes

Ascites, or abdominal dropsy, refers to the pathological accumulation of free fluid in the abdominal cavity (peritoneum). It is not a disease in its own right. Ascites is a symptom that can occur in the context of various, mostly chronic, diseases.

Ascites occurs, among other things, in connection with certain liver, kidney, heart, and cancer-related conditions. However, it most commonly develops in patients with liver cirrhosis.

Ascites typically manifests as a noticeable bulge and swelling of the abdomen. This leads to significant weight gain and an increase in abdominal circumference. In addition, the abdomen feels tight and bloated in cases of severe ascites.

Since the swollen abdomen also presses on the stomach and lungs, this can

• malaise,
• loss of appetite, and
• shortness of breath

result.

Man with ascites © donikz | AdobeStock

In ascites, fluid leaks from the blood vessels into the abdominal cavity. In most cases, this is caused by impaired blood flow to the liver or reduced pumping capacity of the right side of the heart.

In chronic liver disease such as cirrhosis, ascites develops as follows: On the one hand, the liver produces less protein and albumin, which normally keep water within the blood vessels. At the same time, blood backs up in the portal vein, which carries venous blood from the abdominal organs to the liver (portal hypertension).

In addition, the kidneys retain sodium and water, meaning they excrete less sodium and water. As a result, there is more fluid than normal in the blood vessels of the abdominal organs, and pressure increases.

Furthermore, the walls of the blood vessels become more permeable to fluid due to increased vascular permeability. As a result, this fluid cannot be retained within the blood vessels. Consequently, the fluid is forced into the abdominal cavity, where it leads to ascites.

Other conditions can also cause ascites through similar mechanisms.

Ascites can be caused by various underlying conditions. The most common cause of ascites is liver cirrhosis. Other liver diseases that can lead to ascites include

• alcoholic hepatitis without cirrhosis,
• chronic hepatitis,
• liver metastases, and
• occlusion of the hepatic veins.

Other possible causes of ascites include

• heart conditions such as right-sided heart failure or pericarditis,
• kidney diseases such as renal failure,
• cancers such as peritoneal cancer or tumors in the abdominal cavity, as well as
• inflammations and infections such as pancreatitis, peritonitis, and tuberculosis.

In addition, ascites can also be caused by protein deficiency resulting from malnutrition.

Small amounts of fluid in the abdominal cavity usually cause only mild symptoms or none at all.

Ascites with large amounts of fluid in the abdominal cavity leads to abdominal swelling with a noticeable increase in weight and abdominal circumference.

When standing, the abdomen is thick and protruding; when lying down, it becomes somewhat flatter with flared flanks. In addition, the navel may be flattened or pushed outward.

Since the accumulation of fluid in the abdomen puts pressure on the stomach and lungs, ascites can also cause

• malaise,
• loss of appetite, and
• shortness of breath

. Furthermore, some patients with ascites develop edema in the ankles, meaning the ankles swell.

To diagnose ascites,

• a physical examination,
• ultrasound (sonography), and
• the so-called peritoneal puncture

are available.

The physical examination, in particular, plays an important role in the diagnosis of ascites. During this examination, the treating physician taps the abdomen and measures the abdominal circumference. When tapping (percussing) the abdomen, the fluid produces a dull sound. Additionally, when the side of the abdomen is tapped, a wave forms that can be felt on the opposite side.

In this way, ascites can be detected when there is 100 ml or more of fluid in the abdominal cavity.

A very quick and accurate method for diagnosing ascites is an ultrasound examination (sonography). With this method, even the smallest amounts of fluid—as little as 30 ml—in the abdominal cavity can be detected.

To determine the cause of ascites, a peritoneal tap may be performed. In this procedure, a fluid sample is extracted from the abdominal cavity using a needle inserted through the abdominal wall under local anesthesia. The sample is then examined in the laboratory for possible infectious agents, tumor cells, and protein content.

Liver cirrhosis is a common cause of ascites © SciePro | AdobeStock

The treatment of ascites involves addressing both the underlying cause and the symptoms. Both therapeutic approaches should be applied simultaneously.

The goal of causal therapy for ascites is to treat and, if possible, cure the underlying disease. Its success is a prerequisite for the long-term success of symptomatic therapy.

Symptomatic treatment of ascites aims to flush out or remove the fluid accumulation in the abdominal cavity from the body. Treatment of the underlying disease is initially secondary.

However, if the cause of ascites is not addressed, the fluid accumulation will recur over time. The fluid is typically drained from the abdominal cavity

• via peritoneal puncture (ascites puncture) and
• diuretic medications (so-called diuretics).

A peritoneal puncture (ascites puncture) is a minor routine procedure. It very rarely causes complications. The treating physician inserts a hollow needle or cannula through the patient’s abdominal wall. The excess fluid is then drained from the abdominal cavity through a small tube. In this way, up to 2 liters of fluid can be removed per procedure.

Diuretics can also gently flush fluid out of the body. This results in a weight loss of no more than 500 grams per day.

The active ingredients used in this treatment include spironolactone and furosemide. In addition, this diuretic therapy should be accompanied by

• a low-sodium diet,
• restricted fluid intake, and
• bed rest

. Any potential deficiency in protein and minerals should also be addressed.

The prognosis for ascites depends on whether the underlying cause can be successfully treated. If this is not the case, fluid will continue to accumulate in the patient’s abdominal cavity.

For example, the prognosis for ascites in people with liver cirrhosis is very poor. After one year, only about 40 percent of those affected are still alive; after two years, less than 30 percent.

What exactly is ascites?

Ascites refers to a pathological accumulation of fluid in the abdominal cavity. This fluid in the abdomen results from fluid leaking from the blood vessels into the abdominal cavity and is often a symptom of a serious condition such as liver cirrhosis.

What is the most common cause of ascites?

The most common cause of ascites is advanced liver cirrhosis. Portal hypertension and increased pressure in the portal vein cause blood and fluid to accumulate, which is usually what leads to ascites. Heart failure, tumors, and peritoneal carcinomatosis are also among the other causes of ascites.

How is ascites treated?

Treatment for ascites depends on its underlying cause. Diuretics are often used to reduce the amount of fluid. In cases of severe ascites, a paracentesis or ascites puncture is performed to remove fluid from the abdominal cavity. Additionally, the treatment of ascites is closely linked to the treatment of the underlying disease.

What is malignant ascites?

Malignant ascites occurs in cases of cancer or peritoneal carcinomatosis and is caused by tumor cells in the peritoneum. In malignant ascites, fluid accumulates in the abdominal cavity due to inflammation and altered vascular permeability. Treatment of malignant ascites usually involves paracentesis or drainage to relieve symptoms.

What complications can occur with ascites?

A serious complication is spontaneous bacterial peritonitis, a form of bacterial peritonitis that can occur in people with ascites. This infection of the abdominal cavity is acute and requires immediate medical treatment with antibiotics. If left untreated, ascites can lead to severe inflammation, organ failure, and advanced complications of liver cirrhosis.