Case report: Selective operative management of zone 3 carotid artery transection.

Introduction: Penetrating carotid artery injury is rare and particularly uncommon in zone 3 of the vessel. Due to anatomical challenges to open operative management in zone 3, there are minimal treatment recommendations for this highly morbid condition. The urgency associated with understanding proper management of this traumatic injury is further supported by the nearly 100 % rate of fatality in untreated penetrating carotid artery injuries.

Presentation Of Case: A 17-year-old male presented with a bullet wound to the right temple. He was intubated for airway protection given left-sided tracheal deviation secondary to a right neck hematoma. His Glasgow Coma Scale (GCS) was 11 on initial presentation, E3V2M6. The patient remained hemodynamically stable and underwent a CT angiogram of the head and neck. Imaging revealed a complete transection of the cervical (zone III) right internal carotid artery (RICA), a large pseudoaneurysm of the RICA distal to carotid bifurcation, and comminuted mandibular fracture. Collateral blood flow was preserved to the right hemisphere. Multi-disciplinary discussions deemed risks of operative intervention outweighed the benefits in the immediate peri-trauma period as the increased risk of hemispheric stroke, exsanguination, and death was thought to be prohibitive. Therefore, treatment of delayed intervascular stenting of the RICA was performed as opposed to emergent open RICA ligation or repair.

Discussion: Treatment decisions for zone 3 CAI rely on the patient's hemodynamic stability, with surgical ligation favored for immediate hemorrhage control in unstable cases, while stable patients may undergo observation or delayed endovascular intervention. Balancing the need for hemostasis to prevent further blood loss with the potential benefits of anticoagulation to maintain cerebral perfusion underscores the decision-making required in managing such cases.

Conclusion: The rarity and challenge of ICA injury at this anatomical location presents unique challenges. Our description of observation and delayed revascularization outlines the precarious, yet validated, treatment method for hemodynamically stable patients.