Prevalence of the persistent median artery: an ultrasound study

The carpal tunnel is a gateway by which the median nerve and nine extrinsic hand muscles tendons pass to reach the hand. A persistent median artery that failed to regress during the second month of gestation can be found in a subset of the general population. Previous cadaveric, ultrasound and MRI studies have reported variable incidence of persistent median artery ranging from 2.2%-27.1%. The aim of this study is to investigate the prevalence of the persistent median artery in vivo through the use of ultrasound. METHODS. One hundred and twenty four wrists from sixty two individuals with no previous wrist injury were examined by using a Sonosite Micromaxx ultrasound machine. The wrists were examined using an L38e/10-5MHz transducer, from proximal to distal at the level of the carpal tunnel, at a depth of 3.8 cm using Doppler ultrasound. The diameter of the artery was measured at a depth of 1.9 cm. Allen's Test was performed on subjects with persistent median artery to determine vascular contribution to the hand. SUMMARY. The persistent median artery was found unilaterally in three individuals (4.84% of individuals 2.42% of wrists), with a mean diameter of 1.3 ± 0.5 mm. The artery does not appear to provide significant blood circulation to the hand during Allen's Test. CONCLUSIONS. The findings obtained from this study demonstrate a prevalence rate in line with similar studies reported in published literature. Ultrasound is a quick and effective method of not only to conduct anatomical descriptive studies, but also as a tool to screen patients prior to surgery. Surgeons operating in the wrist region should be aware of the possibility of the presence of the persistent median artery to prevent iatrogenic injury.