A Highly Rare Complication: Right Obturator Artery Pseudoaneurysm in a Crohn's Disease Patient Due to Multiple Perianal Abscesses and Drainages.

Background: Obturator artery pseudoaneurysm is a rare entity, typically caused by trauma or iatrogenic injury during pelvic procedures. It is associated with symptoms such as pain, swelling if the aneurysm is large, and anemia.

Objective: To report the first documented case of obturator artery pseudoaneurysm as a complication of perianal involvement in a patient with Crohn's disease, detailing the diagnostic approach and therapeutic interventions to highlight the importance of considering vascular complications in patients with complex perianal diseases.

Case presentation: A 39-year-old male with long-standing Crohn's disease affecting the perianal region, and a history of multiple surgical drainages for perianal abscesses, presented to the emergency room with minimal bloody discharge from a perianal fistula. He was vitally stable and thus, perianal MRI was booked on routine bases, revealing a large cystic lesion near the perineum, showing intense enhancement post IV contrast administration. Subsequent imaging confirmed the diagnosis of an obturator artery pseudoaneurysm. The patient underwent successful management via percutaneous trans-arterial embolization, recognized as a safe and effective treatment for such cases.

Conclusion: This case is the first in the literature reporting an obturator artery pseudoaneurysm in a patient with Crohn's disease. It underscores the necessity of vigilance for vascular complications in patients with extensive perianal Crohn's disease, offering significant educational value for improving outcomes in similar clinical scenarios.