The pericardium is a thick sac that surrounds the heart
The pericardium is believed to have a general protective function on the heart, although animals can live normal lives without a pericardium.
There are several diseases that can affect the pericardium and cause major problems:
- Peritoneopericardial hernia - an abnormal connection between the abdominal cavity and the pericardial sac
- Pericardial effusion is a build-up of fluid between the pericardial sac and the heart. It is a common sequela to other disease processes, including cardiac tumors (especially hemangiosarcoma, as well as mesothelioma, and lymphoma), pericarditis, and, of course, idiopathic pericardial effusion.
- Pericardial effusion can be very dangerous, because the pericardial space is relatively limited. As fluid builds up under pressure, it can achieve cardiac tamponade, which is a sufficient pressure to compress the heart and its chambers. It can cause weakness, collapse, right-sided congestive heart failure, which can lead to abdominal and pleural (chest cavity) effusion, and eventually death.
- Idiopathic pericardial effusion is of unknown (or undiscovered) origin, although there seems to be some degree of vasculitis (inflammation of blood vessels) and lymphangitis (inflammation of lymph vessels) in the pericardium itself, which is leading to the fluid.
- Pericarditis of bacterial or fungal origin is most commonly a result of a penetrating migrating foreign object or from pneumonia.
- Pericardial effusion can be strongly suspected by globoid/round heart enlargement on chest radiographs (x-rays) and then confirmed via echocardiogram (ultrasound/sonogram of the heart) and/or Computed Tomography (CT/CATscan).
- The pressure can be temporarily relieved by draining the fluid from the sac (usually with ultrasound guidance). The fluid is then submitted to the laboratory to determine its cell counts and other properties, as well as for bacterial and fungal culture.
- Based on the nature of the fluid, a treatment plan may be instituted.
- In many cases, the fluid will recur, often within minutes to weeks.
- With recurrent fluid and/or the presence of a mass, a pericardiectomy is usually recommended
- Because hemangiosarcoma tends to metastasize (spread to distant sites) early, a patient should be evaluated for metastasis (generally chest radiographs and abdominal ultrasound) before considering surgery.
- If the tumor cannot be removed, a pericardiectomy can be performed to prevent the fluid from compressing the heart; the chest cavity is much larger and can tolerate as well as reabsorb more fluid.
- If the tumor can be removed along with the pericardiectomy, a much better prognosis may be achieved.
- Restrictive pericarditis is another disease in which the pericardium itself is impeding venous outflow; this can lead to chylothorax (leakage of chyle (lymph fluid) into the chest cavity), which in turn can cause severe damage and restrictive scarring of the lungs. Pericardiectomy is commonly performed along with other treatments for chylothorax.
- To avoid damage to the phrenic nerve, which is responsible for movement of the diaphragm, a sub-phrenic pericardiectomy is typically performed.
- Pericardiectomy can be performed via:
- Open thoracotomy to allow exploration of the chest and performing other procedures.
- Trans-diaphragmatically via an abdominal approach allows a thorough pericardectomy.
- More limited "pericardial windows" can be performed via thoracoscopic approach.
- The pericardium is then submitted for histopathology (biopsy review by a pathologist).
- Patients are commonly monitored in the hospital for 24-48 hours post-operatively, and their comfort is managed, after which they are often discharged without complication pending the biopsy report.
Ultimately, the prognosis depends on the underlying disease, but pericardiectomy frequently improves pets' comfort, function, and survival time; many pets can have their signs and problems resolved by pericardiectomy.
Please schedule an appointment with our board-certified surgeon, Dr. Jeff Christiansen at the clinic of your choice, to evaluate your pet and to discuss options to improve your pet's or patient's length and quality of life.
If you have additional questions, please feel free to e-mail Dr. Christiansen directly.