Radiographic and computed tomographic features of caval foramen hernias of the liver in 7 dogs: mimicking lung nodules

Successful early diagnosis and surgical treatment of congenital caval foramen hernia in an 8-month-old mixed breed cat

An 8-month-old neutered female domestic mixed breed cat was presented to Dr. L. Kriaučeliūnas Small Animal Clinic due to coughing that persisted for 2 weeks. Lateral and dorsoventral chest radiographs revealed an unusual dome-shaped soft tissue opacity mass that had contact with the cranial part of the diaphragm. Together with heart and abdominal ultrasound findings, we decided that one of the differential diagnoses was a diaphragmatic hernia. During the diagnostic celiotomy, a vertical 4 cm in length diaphragmatic deficit was visualized. Left medial and lateral liver lobes were herniated, yet healthy-looking. Adhesions between the liver lobes and the pericardium sac were visualized and dissected. The pericardium was sutured with simple interrupted suture pattern. A herniorrhaphy was performed suturing the diaphragm with the continuous suture pattern. Successful surgical treatment resulted in fully resolved clinical symptoms.

Caval foramen hernia in a cat

Case summary

A 3-year-old neutered female domestic shorthair cat presented for a 2-week history of hyporexia, lethargy and weight loss. Aspartate aminotransferase, alanine aminotransferase and cholesterol were mildly elevated. Thoracic radiographs identified a lobulated soft tissue opacity in the caudal thorax to the right of midline, with the border effacing the caudal vena cava and broad-based towards the diaphragm. The broad base was suggestive of diaphragmatic hernia, with the other radiographic features and location suggestive of caval foramen hernia. Ultrasound confirmed diaphragmatic hernia with liver herniation. CT showed the herniation of multiple liver lobes and the gallbladder through a defect at the caval foramen. Herniorrhaphy was performed via ventral midline coeliotomy. Following this procedure, the cat's clinical signs resolved and its weight has been regained.

Relevance and novel information

To our knowledge, this is the first report of successful caval foramen herniorrhaphy in a cat. Caval foramen hernia is a type of congenital diaphragmatic hernia. The authors suggest that its embryopathology involves defective septum transversum development. The case was detected during the standard diagnostic investigation of non-specific clinical signs. Its radiographic findings may easily be mistaken for a pulmonary mass. Although not seen in our case, caval foramen hernia is commonly associated with caudal vena cava obstruction, which can potentially result in Budd-Chiari-like syndrome.

Caval foramen hernia in a dog: Preoperative diagnosis and surgical treatment

A 13-year-old, 5.6-kg castrated-male Maltese was presented for reverse sneezing. A dome-shaped round mass abutting diaphragm was incidentally found ventral to caudal vena cava, which had the same echogenicity and density as that of the liver during ultrasonography and computed tomography, showing isoattenuation with a contrast study. Vascular distribution was identified throughout the mass. A caval foramen hernia (CFH) was diagnosed tentatively, followed by a herniorrhaphy and splenectomy of the chronically congested spleen. The patient had been doing well for 5-month postoperative but died because of aspiration pneumonia. CFH is an extremely rare condition, requiring surgery due to compression of the vena cava. It should be considered as a differential diagnosis when intrathoracic, mass-like lesions are identified near the diaphragm.