Anatomico-radiologic study of the distribution of the suboccipital artery of Salmon.

The frequency of suboccipital injections to treat headaches has increased. The third segment of the vertebral artery is located in the suboccipital triangle and its main muscular branch, the suboccipital artery of Salmon (SAS), supplies blood to the suboccipital muscles. The purpose of this study was to radiographically investigate the morphology and territory of distribution of SAS. PATIENTS AND METHODS: Computed tomography angiographs of brains of 50 subjects (25 female, 25 men, mean age 70.2 years) were analyzed. RESULTS: SAS was present in 48% of subjects. The vessel was present bilaterally in 37.1%, and had a mean (SD) luminal diameter of 1.71 (0.34)mm and mean (SD) length of 36.42 (17.1)mm. SAS was found to have two morphologic patterns: (1) a single main trunk with collateral branches (52.6%) and (2) a short common trunk that divided into two branches (48.4%). The SAS supplied the obliquus capitis inferior, semispinalis capitis, and splenius capitis muscles. When the SAS was absent, the suboccipital muscles were supplied by a branch of the occipital artery. No anastomoses were found between the SAS and occipital artery. CONCLUSION: The suboccipital muscles are vascularized by the SAS and occipital artery. The detailed course of the SAS is important for clinicians and surgeons who perform procedures in the suboccipital region.