Sonographic Findings of a Traumatic Diaphragmatic Hernia in a Feline.
Patient was reported outside and owners believed that he was hit by a car a week prior to the visit. He was found non-weight bearing on his left hindlimb with a slowly progressive increased respiratory rate. He was still eating and drinking well. Radiographs showed a diaphragmatic hernia with multiple pelvic fractures.
The liver is normal in overall size, shape and echogenicity, however a portion of the right liver, gallbladder and potentially the quadrate lobe is displaced within the thoracic cavity ventrolateral to the heart. The margin of the diaphragm is disrupted. No hepatic focal lesions are appreciated. The gallbladder appears normal in size, shape and is clean.
Diagnosis and Sonographic Analysis:
Diaphragmatic herniation with displacement of the liver and gallbladder - DDx: trauma (suspected) vs congenital
The patient was transferred to a specialty referral hospital where the diaphragmatic hernia was surgically corrected. The patient made a rapid recovery from surgery and is currently thriving 3 months post-op.
A special thanks to the staff at the Animal Medical Center of Watkins Park and Mid-Atlantic Animal Specialty Hospital for this interesting case.
Brief Overview of Diaphragmatic Hernias
Diaphragmatic hernias are commonly recognized by small animal clinicians and may be congenital or occur secondary to trauma. Congenital pleuroperitoneal hernias are seldom diagnosed in small animals because many affected animals die at birth or shortly thereafter. Most diaphragmatic hernias in dogs and cats are caused by trauma, particularly motor vehicle accidents. The abrupt increase in intraabdominal pressure accompanying forceful blows to the abdominal wall causes the lungs to rapidly deflate (if the glottis is open), producing a large pleuroperitoneal pressure gradient. Alternately, the pressure gradient that occurs between the thorax and the abdomen may cause the diaphragm to tear. The tears occur at the weakest points of the diaphragm, generally the muscular portions. Location and size of the tear or tears depend on the position of the animal at the time of impact and the location of the viscera. Traumatic diaphragmatic hernias are often associated with significant respiratory embarrassment; however, chronic diaphragmatic hernias in asymptomatic animals are not uncommon. Diaphragmatic hernias may also occur in animals with connective tissue disorders.
Chronic diaphragmatic hernias may have a higher mortality than acute diaphragmatic hernias; however, the prognosis with both groups is good to excellent with surgery.
If pulmonary contusions are severe, surgical repair of diaphragmatic hernias should be delayed until the patient’s condition has been stabilized; however, herniorrhaphy should not be delayed unnecessarily.
Theresa W. Fossum, DVM, MS, PhD, DACVS
Glendale, AZ, USA
Special thanks to both Watkins Park and Mid-Atlantic Animal Specialty Hospital for allowing us to collaborate on this case.