What Is Peritoneal Effusion?
Small amounts of fluid can naturally be found in the abdominal cavity to lubricate the tissues and linings of organs within the abdominal cavity. On average, women in good overall health have more peritoneal fluid than healthy men, which can also fluctuate with the menstrual cycle. However, abnormal amounts of intraperitoneal fluid may develop as a sign of mesothelioma or other health conditions.
Peritoneal effusion, also referred to as ascites, is a condition that causes fluid to build up between the layers of the peritoneum within the abdominal cavity. It can develop from highly active cancers, like mesothelioma, that involve the peritoneal lining and produce excess fluid that accumulates in the abdominal cavity. Blocked lymph nodes, a sign of more advanced disease, may also trigger peritoneal effusion.
More than 85% of all ascites cases are the result of cirrhosis of the liver, though up to 10% are associated with a cancer diagnosis. They are most common in patients with peritoneal surface malignancies such as ovarian, uterine, breast, pancreatic, liver and lung cancers. The finding has also been identified in the majority of peritoneal mesothelioma cases. Patients with peritoneal mesothelioma, which develops after inhalation or ingestion of asbestos fibers, typically present with either abdominal pain and no peritoneal effusion or experience no abdominal pain, but have both peritoneal effusion and abdominal distension or swelling.
Diagnosing the Symptoms of Peritoneal Effusions
Peritoneal effusions are a sign of a larger illness themselves and can emerge for a number of reasons, each of which can bring about different associated symptoms. For instance, malignant peritoneal mesothelioma patients may experience effusions coupled with bowel obstruction, weight loss and fever. The severity of mesothelioma cancer symptoms may increase as more fluid collects within the peritoneal cavity.
Symptoms Associated with Peritoneal Effusion
- Ankle or leg swelling
- Chest pain
- Difficulty breathing
- Loss of appetite
- Pain or swelling of the abdomen
- Weight gain
After a patient presents with symptoms, an abdominal ultrasound is often used to diagnose the ascites. For mesothelioma patients, imaging tests like an X-ray or a CT scan (computed tomography) may also be used to confirm the presence of peritoneal effusion. When diagnosing peritoneal mesothelioma, a doctor can see several presentations on the CT scan. For patients who have developed ascites, researchers may refer to the appearance on the scan as the “wet type.” This presentation indicates excess abdominal fluid, swelling of the intestines and small nodules in the organs. Peritoneal mesothelioma patients with ascites may also present as the “mixed type” on their scan, meaning they have developed ascites and may have large tumors that are common with the “dry type” presentation seen on some CT scans.
In addition to imaging scans, a fluid wave test may be performed by a physician to identify the ascites if there is substantial fluid retention within the abdominal cavity. The test relies on placing pressure on the abdomen and tapping the area to monitor a ripple effect from one side of the abdomen to the other. Peritoneal effusion is present if the ripple from the tapping can be felt on the other side of the abdomen.
Diagnosing ascites is an important first step in pinpointing the underlying condition causing the fluid build up. Patients may first see a gastrointestinal specialist before the underlying cause is identified. Once ascites has been identified, a doctor will likely take a biopsy, or fluid sample. Through pathology tests, they can confirm whether the fluid is malignant or benign, although fluid analysis alone many times is not enough to establish a diagnosis of mesothelioma. For peritoneal mesothelioma patients, a biopsy of the peritoneum is ultimately needed to confirm the cancer’s presence.
Prognosis of Peritoneal Effusion
Overall, malignant peritoneal mesothelioma is the second most common form of the cancer, with life expectancy generally ranging from two to six years. An individual’s prognosis can differ based on their age, gender and overall health. Though the presence of peritoneal effusion may signal a later stage of disease and a worse prognosis, patients may still be able to seek treatment to alleviate symptoms and possibly extend survival time.
Depending on the condition causing a peritoneal effusion, patients may have a number of treatment options. For mesothelioma patients, a palliative treatment plan may be recommended to reduce the fluid buildup and relieve associated symptoms. Paracentesis is the most common approach. A paracentesis is a minimally invasive procedure that uses a needle and drainage tube to remove ascites. This procedure may be done on more than one occasion to provide symptom relief. In some cases, patients have also seen relief through another procedure called peritoneovenous shunt placement, which moves fluid out of the abdomen and back into the veins.
Additionally, treating symptoms palliatively through the use of indwelling catheters has shown promise for mesothelioma patients with ascites. These catheters are placed in the abdominal cavity with an external portion that can be drained as needed. One retrospective study analyzed results from 20 cancer patients experiencing peritoneal ascites. The researchers found that a peritoneal catheter was a useful and minimally invasive palliative option for the patients, with a success rate of at least 95.2%. Patients had a median survival time of 27 days following the placement of the catheter, making this an encouraging palliative option for patients with late-stage mesothelioma.
In addition to palliative treatments for relieving the fluid buildup in the abdomen, patients may also undergo active treatment options directed to the mesothelioma that can reduce ascites. Depending on a patient’s specific case, one of the most effective peritoneal mesothelioma treatment options is cytoreductive surgery to remove as much of the disease as possible combined with a heated chemotherapy wash called hyperthermic intraperitoneal chemotherapy or HIPEC. Research has shown this treatment can extend life expectancy to five years or longer for some patients, though it likely will not be a viable option for those with more advanced peritoneal mesothelioma.
Chemotherapy, another common peritoneal mesothelioma treatment, has also been shown to help relieve pressure from the ascites by reducing the production of peritoneal fluid. When the chemotherapy kills the cancer cells, they stop fluid production, which in turn reduces the pressure being felt by patients. Immunotherapy treatments have also shown promise in mesothelioma and can be used in cases where chemotherapy has already been tried. Patients may also elect to participate in clinical trials to take advantage of up-and-coming treatment options.
Any individual who has known asbestos exposure or experiences any mesothelioma symptoms should talk to a doctor right away. Early detection of the disease may prevent ascites from developing and help doctors determine the best treatment plan for extending survival.