Persistent median artery (palmar type) and median nerve block in the forearm: observational study of prevalence.

Abstract

We sought to define the crude prevalence rate of the persistent median artery (PMA) (palmar type). Although there is no reported case in the anesthetic literature, a few sporadic case reports and series reported in anatomical and orthopedic journals describe an incidence of between 1.5% and 27.1%. We conducted a prospective observational study to define the crude prevalence of the PMA (palmar type) by scanning 100 forearms of 50 volunteers using a high-frequency ultrasound probe. We found 19 PMAs in 13 individuals, thus giving a prevalence of 19%. Other arterial variants were also identified within this population. Anatomical variations of the blood supply to the forearm and hand can be identified with available high-frequency ultrasound equipment. Arterial variants immediately adjacent to the median nerve may occur in approximately 1 in 5 limbs. Practitioners should actively seek their presence or absence.