Reports on cases of factor Ⅴ (FⅤ) deficiency complicated by platelet function disorders in patients undergoing cardiac surgery are rare, and the utilization of thromboelastography in such cases is limited. This case presents a unique case of FⅤ deficiency complicated by platelet function disorders, highlighting the significance of tailored transfusion strategies guided by thromboelastography (TEG).

A 64-year-old hemodialysis patient who was diagnosed with FⅤ deficiency 24 years prior presented for an on-pump coronary artery bypass graft. The decrease in FⅤ activity on preoperative examination was mild. Based on this finding, it was determined that preoperative fresh frozen plasma supplementation was not required. However, the case was complicated by platelet function disorders; therefore, a preoperative transfusion of platelet concentrate was performed to correct the decreased platelet function, enabling subsequent surgery. Intraoperative and postoperative transfusion strategies were guided by TEG.

This study highlights TEG-guided transfusion management as a viable option for patients with FⅤ deficiency complicated by platelet function disorders.