title: Persistent median artery (palmar type) and median nerve block in the forearm: observational study of prevalence.
abstract: BACKGROUND
  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%.
  
  
  METHODS
  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.
  
  
  RESULTS
  We found 19 PMAs in 13 individuals, thus giving a prevalence of 19%. Other arterial variants were also identified within this population.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Department of Anaesthetics, Queen Elizabeth Hospital NHS Foundation Trust, Norfolk, UK.
authors.forename: James A
authors.initials: JA
authors.lastname: Stimpson
authors.forename: Ashwani
authors.initials: A
authors.lastname: Gupta
mesh_terms: D001158:Arteries / Q000002:abnormalities* / Q000000981:diagnostic imaging*; D005260:Female; D005542:Forearm / Q000098:blood supply* / Q000000981:diagnostic imaging* / Q000294:innervation; D006801:Humans; D008297:Male; D008475:Median Nerve / Q000000981:diagnostic imaging*; D009407:Nerve Block / Q000379:methods*; D015995:Prevalence; D018084:Ultrasonography, Interventional / Q000379:methods