[Abdominal Oblique Muscle Hematoma after Ultrasound-guided Transverse Abdominis Plane Block].

A 41-year-old female patient with no remarkable medical history underwent a uterine myomectomy under general anesthesia. Ultrasound-guided lateral TAP block was performed using a 21-gauge blunt needle after surgery. Heparin calcium at 5,000 units was administered subcutaneously twice on postopera- tive day (POD)Y 1, and fondaparinux at 2.5 mg was administered subcutaneously once daily from POD 2 to POD 5. On POD 3, right-sided flank pain was noticed, which persisted until POD 7. Abdominal ultrasonogra- phy revealed an abdominal oblique muscle hematoma with a size of 43x19x31 mm. The patient had no anemia, and was discharged on POD 8. Right-sided flank pain disappeared, and the hematoma could not be identified by ultrasonography on POD 20.