Use of computer-assisted tomography for diagnosis and standing surgical reduction of progressive ethmoidal hematoma in a mare.

Overview

• This study reports the diagnosis and treatment of a rare, non-cancerous mass called progressive ethmoidal hematoma (PEH) in the nasal passage of an 11-year-old pregnant Thoroughbred mare.
• Advanced imaging techniques including computed tomography (CT) were used to locate and measure the mass, leading to successful surgical removal while the mare was standing.

Background on Progressive Ethmoidal Hematoma (PEH)

• PEH is a rare, nonneoplastic (non-cancerous) mass that forms within the sinonasal passages of horses.
• The condition can cause nasal discharge and noisy breathing due to obstruction caused by the mass.
• PEH is challenging to diagnose and manage without appropriate imaging and surgical skills.

Case Description

• Patient: An 11-year-old pregnant Thoroughbred mare with intermittent nasal discharge and stertorous (noisy) respiration.
• Initial examination included:
  • Radiography showing increased opacity in the sinus and nasal cavities, indicating the presence of a mass or abnormal tissue.
  • Endoscopy revealing a visible mass emerging from the left ethmoidal turbinate (a bony structure inside the nasal cavity).
• Computed Tomography (CT):
  • Used to precisely visualize the location, size, and origin of the mass within the sinonasal region.
  • CT imaging was key in confirming the diagnosis of PEH and planning the surgical approach.

Surgical Technique

• The mare underwent a standing surgical procedure, which means the surgery was performed while the animal was awake but sedated.
• A temporary tracheostomy was performed first to secure the airway and ensure safe breathing during surgery.
• A frontonasal flap surgery:
  • Involved creating a bone flap in the frontonasal area (between the forehead and nose) to access the mass more directly.
  • The mass was exposed through this flap and removed after careful double ligation to control bleeding.

Postoperative Outcome and Confirmation

• Histopathological examination of the removed mass confirmed the diagnosis of progressive ethmoidal hematoma.
• The mare recovered without any postoperative complications.
• Importantly, the mare was able to carry her pregnancy to term and gave birth successfully after the surgery.

Clinical Significance

• This case highlights the importance of combining several diagnostic methods – radiography, endoscopy, and especially CT imaging – to accurately diagnose and localize PEH.
• CT imaging proved especially valuable in mapping the extent and origin of the lesion, enabling effective surgical planning and execution.
• Performing the surgical removal while the mare was standing minimized stress and risk associated with general anesthesia, particularly valuable in a pregnant horse.
• The report demonstrates a successful treatment approach for a rare equine sinonasal condition, emphasizing advances in veterinary diagnostic imaging and surgical techniques.