Aural Hematoma
General information
Other common/scientific names: auricular hematoma, hematoma of the ear
An aural hematoma is an accumulation of blood between the cartilage of the pinna (or ear flap) and the skin of the pinna. The pinna will appear "puffed-up", like a fluid-filled pillow.
Causes
Violent shaking of the head or scratching or pawing at the ear causes small blood vessels to burst. The blood from these vessels then collects between the cartilage of the pinna and the skin of the pinna. Aural hematomas are almost always secondary to an underlying condition causing the ear to be inflamed and itchy. Common underlying conditions are ear mites, ear infections, foreign bodies and allergies.
Cardinal symptom
Fluid-filled swelling of the ear flap
Symptoms
An aural hematoma appears as a fluid-filled pocket of the pinna. At first the fluid-filled area may be soft and occupy only a small portion of the pinna. As time goes on, the hematoma may become larger and firmer and may involve the entire pinna. Eventually blood clots and fibrous material will form within the hematoma and, if left untreated, the pinna will scar, thicken and shrivel.
Diagnosis
An aural hematoma is diagnosed on physical examination by the clinical signs. Although not usually necessary, a needle may be used to aspirate some of the blood-tinged fluid from the swollen pinna to confirm the diagnosis.
Treatment
Aural hematomas may be treated by aspiration of the hematoma followed by injection of a steroid, drain placement, or surgery.
In the aspiration method, the hematoma is drained using a needle and syringe, and then a steroid is injected back into the space between the cartilage and skin of the pinna. This method is only appropriate in hematomas with a very fluid consistency (usually only acute cases), and even then has a somewhat higher recurrence rate than drain placement or surgery. However, because it is the least invasive of the treatment options and does not usually require sedation, it may be an appropriate treatment option for some cats.
Drain placement requires sedation. Small incisions are made at the top and bottom of the hematoma and the fluid is expressed. Any fibrous material that may have built up within the hematoma over time is removed using small hemostats inserted through the incisions. A drain is placed into the dead space and exits through the two incisions. It is then sutured into place. The drain may be left in for 2-4 weeks.
Surgery also requires sedation. An incision is made along the length of the hematoma and fluid, blood clots and fibrous material are removed. The cartilage and skin are then sutured together in order to close down the space where blood had collected. Sometimes small plastic “buttons” that can be inserted through the pinna will be used instead of suture material. The sutures or buttons are removed in 2-4 weeks. Other surgery methods are also used, including laser surgery, in which small round holes are made in the pinna using a surgical laser.
Any of the treatment options may also include the placement of a bandage on the ear and/or the use of an Elizabethan collar to prevent further self-trauma to the ear. Lastly, the underlying cause of the hematoma (ear infection, allergy, etc.) must be identified and treated or recurrence of the hematoma is likely.
Prognosis
Treatment will allow for a pinna with minimal scarring. However, if the underlying cause of the aural hematoma is not addressed or recurs, there may be recurrence of the hematoma.
If an aural hematoma is not treated, the ear pinna is likely to scar badly and a permanently thickened cauliflower-like ear will result. This scarred pinna may obscure the ear canal and make the ear more susceptible to ear infections.
Prevention
Have your cat examined if it is shaking its head or pawing at its ears so the underlying problem can be addressed before an aural hematoma develops.