Anatomic study of the suboccipital artery of Salmon with surgical significance

The anatomy of the muscular branches of the vertebral arteries has clinical relevance during surgical procedures, suboccipital injections, and manual therapies. Each vertebral artery is divided into four segments. Segment V3, found in the suboccipital triangle, courses posteromedially around the lateral mass to lie in a groove on the posterior arch of the atlas, ultimately coursing beneath the posterior atlanto-occipital membrane to enter the skull. Although not always present, any muscular branch that emanates from this segment to supply the suboccipital muscles is called the suboccipital artery of Salmon. There is a paucity of literature on this artery despite its clinical relevancy. We found the suboccipital artery of Salmon in 10 (67%) of 15 embalmed adult cadavers. This frequency is considerably higher than that in previous reports. Two (20%) of the 10 cadavers demonstrated bilateral and symmetrical suboccipital arteries of Salmon (one artery on each side). Four (40%) of the 10 cadavers had an arrangement of two parallel suboccipital arteries of Salmon on one side, and one on the contralateral side. Three (30%) of the 10 cadavers displayed an asymmetrical unilateral arrangement (only one artery). One (10%) of the 10 cadavers displayed the unique arrangement of three arteries of Salmon on one side and one artery on the contralateral side. This study adds to a limited, but growing, body of knowledge by providing photographic evidence of the course and arrangement of these arteries and, therefore, can be of value to surgeons and other clinicians whose procedures focus on the suboccipital region.