Clavipectoral fascia plane block spread: an anatomical study

The clavipectoral fascia plane block (CPB) is a novel anesthetic management strategy proposed by Valdes-Vilches for clavicle fractures. This study aimed to investigate the distribution of the injected solution around the clavicle and the surrounding tissues.

Twelve clavicle samples were acquired from six cadavers. CPB was conducted using a 20 mL solution comprising methylene blue and iodinated contrast agent to improve visibility of the injected substance's dispersion. Methylene blue spread was assessed through anatomical dissection across distinct planes (subcutaneous, superficial muscular, deep muscular, and periosteal layers of the clavicle) in five cadavers. For the purpose of comparing methylene blue distribution, CT scans were performed on three cadavers.

Methylene blue was detected in the medial, intermediate, and lateral supraclavicular nerves, as well as superficial muscles including the deltoid, trapezius, sternocleidomastoid, and pectoralis major. However, no staining was observed in the deep muscle plane, including the subclavius, pectoralis minor, and clavipectoral fascia (CPF). Anterosuperior periosteum exhibited staining in 54% of surface, while only 4% of the posteroinferior surface. CT images displayed contrast staining in anterosuperior periclavicular region, consistent with observations from sagittal sections and anatomical dissections.

The CPB effectively distributes the administered solution in the anterosuperior region of the clavicular periosteum, superficial muscular plane, and supraclavicular nerves. However, it does not affect the posteroinferior region of the clavicular periosteum or the deep muscular plane, including the CPF.