Anatomically, the thyroid gland has an inner true capsule which is thin and adheres closely to the thyroidal tissue [Fancy et al., 2010]. External to this is a false capsule formed by the middle layer of the deep cervical fascia, which splits anterolaterally to ensheathe the thyroid gland, thus forming the thyroid sheath [Bliss et al., 2000]. In this fashion, the potential space called the capsule-sheath space is formed. It contains also loose connective tissue, blood vessels, nerves and parathyroid gland. Anesthetic deposited in this space would block the surface of thyroid gland and permeate directly into the parenchyma producing effective local anesthesia for thyroid surgical procedures. It is supposed also to involve autonomic nerve block of the thyroid gland [Fliers et al., 2010]. Additionally, a subcutaneous injection along the sternocleidomastoid muscle (SCM) would also enhance effective local anesthesia for the initial skin incision and further contribute to a more ideal working environment for the surgeon. Therefore, anesthetic technique termed ultrasound-guided capsule-sheath space block (CSSB) combined with anterior cervical cutaneous nerves block (CCNB) for thyroidectomy is done [Wang et al., 2015] .