Iliac Arteriovenous Fistula and Pseudoaneurysm Secondary to Gunshot Trauma.

Abdominal arteriovenous fistula [AVF] is a rare but serious complication of penetrating trauma, often associated with high morbidity and mortality. This report presents the case of a 24-year-old male who sustained multiple gunshot wounds, leading to the formation of an ilio-iliac AVF and a pseudoaneurysm. The patient arrived at the emergency department hemodynamically unstable, with bullet wounds to the forearm, thigh, and lumbosacral region. Initial non-arterial phase CT revealed a pseudoaneurysm anterior to the right external iliac vessels and a surrounding hematoma, raising suspicion for AVF. A second biphasic CTA confirmed an AVF connection between the right external iliac artery and external iliac vein, as well as the arterialization of the vein. Additionally, fat stranding and bowel wall thickening suggested potential hollow viscus injury. Due to the patient's unstable condition and possible intra-abdominal injuries, an open laparotomy was performed. A stent was placed in the right external iliac artery, the vein was primarily repaired, and serosal injuries to the duodenum and cecum were surgically addressed. The patient recovered gradually, although a persistent serous discharge was noted and managed in follow-up. This case highlights the importance of considering AVF in penetrating abdominal trauma and the critical role of biphasic CTA in diagnosis and surgical planning.