Treating a Peritoneopericardial Diaphragmatic Hernia in Pets
Peritoneopericardial diaphragmatic hernia (PPDH) is a congenital defect characterized by an abnormal opening between the peritoneal cavity and the pericardial sac. This condition is most commonly observed in cats and is often discovered incidentally during diagnostic evaluations for unrelated issues.
Understanding PPDH
PPDH develops during embryonic development due to the improper formation or fusion of the septum transversum. This leads to a diaphragmatic defect, permitting abdominal organs such as the liver, intestines, omentum, or spleen to migrate into the pericardial sac. This can result in a range of clinical signs depending on the organ involved and the severity.
Clinical Signs of PPDH
- Dyspnea or tachypnea
- Vomiting, anorexia, or weight loss
- Exercise intolerance and lethargy
- Gastrointestinal obstruction
- Shock or collapse in severe cases
Neurological symptoms such as head pressing or blindness may also occur, particularly with associated hepatic encephalopathy.
Diagnosing PPDH
Diagnosis of PPDH primarily relies on advanced imaging. Key tools include:
- Thoracic radiography – revealing an enlarged cardiac silhouette and misplaced abdominal organs
- Ultrasonography – for detailed visualization
- CT or MRI scans – in complex or ambiguous cases
- Contrast studies and echocardiography – for assessing concurrent cardiac anomalies
Bloodwork typically offers limited diagnostic value but may show subtle biochemical changes.
Treatment Options for PPDH
Treatment depends on the presentation and health status of the patient. Here are the main approaches:
Surgical Treatment
Surgery is the treatment of choice in animals showing clinical signs or with significant herniation. It includes:
- Repositioning herniated organs into the abdomen
- Debriding adhesions
- Closing the diaphragmatic defect using monofilament sutures
If the defect is large, a pericardial flap or graft may be necessary. A thoracostomy tube might also be placed if the pericardium is entered. Despite the need for anesthesia and precise surgical technique, the prognosis after surgery is generally good, with low mortality rates (8–14%).
Conservative Management
In asymptomatic or high-risk animals, conservative treatment may be suitable. This includes:
- Frequent veterinary monitoring
- Owner education on signs of progression
- Readiness to act if clinical signs emerge
This approach avoids surgical risk but requires vigilance due to the possibility of sudden complications like organ entrapment or cardiopulmonary failure.
Risk Factors and Long-Term Prognosis
PPDH has a hereditary component, especially in breeds like Persians, Himalayans, and Maine Coons. It can occur alongside other midline defects such as umbilical hernias or cardiac anomalies.
Outcomes for surgically treated animals are excellent if the animal is otherwise healthy. Long-term survival is often similar for conservatively managed pets, provided they remain asymptomatic. Still, regular follow-up checks are crucial to detect any changes.
Conclusion
PPDH is a manageable condition when diagnosed and monitored properly. Surgical intervention offers a definitive cure in most symptomatic animals, while conservative strategies can be effective in stable, asymptomatic pets. Regardless of the chosen treatment, ongoing observation is key to ensuring the long-term health and comfort of affected animals.
