Anterior Quadratus Lumborum Block at the Lateral Supra-arcuate Ligament for Analgesia After Open Liver Surgery

Bilateral single-injection 20 ml 0.56% ropivacaine. Intravenous analgesia was started postoperatively and consisted of 1ug/ml sufentanil，2 ml/h with a 5-minute lockout period, a limited 12 ml/h dose.

A thoracic epidural at the level of T7-10. Epidural infusion was started postoperatively and consisted of sufentanil (0.6ug/mL) and ropivacaine（0.2%） at 3ml/h.