Ultrasound-guided cervical cervicis plane (CCeP) block: a cadaver study

Background Ultrasound-guided cervical cervicis plane (CCeP) block has been described to anesthetize the dorsal rami of the cervical spinal nerves for postoperative analgesia in posterior cervical spine surgery. However, the anatomical characteristics and the spread pattern of local anesthetic within the CCeP layer remain inadequately studied. This study utilizes fresh cadaveric models to evaluate the spread of CCeP injections at the C2 and C5 levels, aiming to assess staining of the targeted cervical dorsal rami and to identify any spread to adjacent structures. Methods Dye injection with 0.1% Methylene Blue was used to perform the CCeP block in 20 fresh frozen cadavers at either C2 or C5 level. The cadavers were dissected to evaluate the extent of dye spread within the CCeP layer. Results Injections with 10 mL dye at the C2 level resulted in staining of the C2 and C3 dorsal rami consistently. Injections with 10 mL dye at the C5 level resulted in staining of the C3 to C5 dorsal rami consistently, but not above the C2 level of the CCeP layer. No staining of the multifidus muscle, retrolaminar region, or ventral rami was observed with either C2 or C5 injections. Conclusions CCeP block can provide selective blockade of the cervical dorsal rami at multiple vertebral levels. The absence of staining in the multifidus muscle, retrolaminar region, or ventral rami demonstrates the potential for the CCeP block to avoid the risk of associated side effects.