Aim. To present the first documented case of successful carotid endarterectomy in a patient with severe Factor XII deficiency and analyze the features of perioperative management.

Materials and methods. We report a case of a 70-year-old male with critical left internal carotid artery stenosis (90 %) and incidentally discovered severe Factor XII deficiency (activity 0.1 %, activated partial thromboplastin time (aPTT) 235.0 seconds) during preoperative screening. A comprehensive differential diagnosis of prolonged aPTT was performed, including measurement of intrinsic coagulation factor activities and immunological testing. Classical carotid endarterectomy under local anesthesia was performed using a standard perioperative thromboprophylaxis protocol.

Results. The surgery and postoperative period were uneventful with a blood loss of 150 ml. Standard thromboprophylaxis was administered using unfractionated heparin intraoperatively and low molecular weight heparin postoperatively. At 3-month follow-up, ultrasound confirmed satisfactory reconstruction with normal flow parameters.

Conclusions. Isolated factor XII deficiency is not a contraindication for carotid endarterectomy when proper preoperative diagnosis is established, and standard perioperative protocols are followed. A multidisciplinary approach involving a hematologist is essential for successful management of such patients.