Transversus abdominis plane block guided by ultrasound
The linear array probe covered with ultrasonic protective sleeve was placed between the costal margin and the anterior superior iliac spine. Under ultrasound, three layers of muscle structures could be seen, namely, external oblique abdominal muscle, internal oblique abdominal muscle and transverse abdominal muscle. 15ml of 0.375% ropivacaine (AstraZeneca AB, Sweden, batch number: LBYR) was injected between external oblique abdominal muscle and transverse abdominal muscle by in-plane acupuncture.