Pasteurella Multiocida infection resulting in a descending thoracic aorta mycotic pseudoaneurysm

Area of Science:

• Cardiovascular Surgery
• Infectious Diseases
• Vascular Surgery

Background:

• Mycotic aneurysms of the aorta are rare but life-threatening infections.
• Bacterial infections, particularly from organisms like Pasteurella Multiocida, can lead to aortic pseudoaneurysm formation.
• Canine bites represent a potential, albeit uncommon, source of infection for aortic pathogens.

Observation:

• A 61-year-old male presented with a descending thoracic aorta mycotic pseudoaneurysm following a canine bite and subsequent Pasteurella Multiocida bacteremia.
• Initial antibiotic treatment for bacteremia did not resolve the underlying pseudoaneurysm.
• The patient developed persistent malaise, prompting further investigation that revealed the aortic pathology.

Findings:

• Surgical management involved a thoracotomy, cardiopulmonary bypass, and complete resection of the infected pseudoaneurysm.
• The aorta was reconstructed using a Gelweave graft.
• A staged approach included a secondary washout and coverage of the graft with an omental flap due to gross infection and purulence.

Implications:

• Complete resection of the mycotic pseudoaneurysm is crucial for successful treatment.
• Omental flap coverage provides a viable biologic coverage strategy for aortic grafts in infected fields.
• This case highlights a successful management approach for virulent aortic infections following animal bites.