Massive lower gastrointestinal bleeding due to pseudoaneurysm of the femoral artery following buttock gunshot injury: A case report.

Introduction: Arterio-enteric fistula is one of the extremely rare complications of penetrating trauma.

Case Presentation: A 27-year-old male presented to the emergency department with a gunshot to the right buttock. Initial assessments revealed a left femoral shaft fracture, the right buttock as the bullet inlet and the medial portion of the left thigh as an outlet, with no other significant findings. He underwent external fixation for the left femoral fracture. On the seventh day of admission, the patient experienced two episodes of massive melena and hypovolemic shock. The patient underwent an upper endoscopy without any remarkable findings. Also, we performed an emergent laparotomy to find the source of upper gastrointestinal bleeding (GIB); however, no evidence of upper GIB was found. Then, the patient underwent CT angiography, which subsequently identified a deep femoral artery pseudoaneurysm. Also, we performed a colonoscopy to investigate the source of GIB, revealing an orifice on the rectal wall. The patient underwent open surgery for a pseudoaneurysm. During surgery, a tract from the pseudoaneurysm of the deep femoral artery to the rectum was discovered, leading to the ligation of the deep femoral artery branch. After recovery from the operation and completion of the orthopedic treatment, the patient was discharged in an appropriate condition.

Clinical Discussion: Traumatic arterio-enteric fistulas can present with fatal gastrointestinal bleeding, requiring crucial investigations and proper imaging evaluations.

Conclusion: In case of new-onset massive melena during hospitalization, upper GIB should always be considered. However, in penetrating trauma patients, repeating CT angiography should be considered.