Anomalous Medial Branch of Radial Artery: A Rare Variant

Anatomical and biometric study of the radial artery on human cadavers dissected in the anatomy laboratory

OBJECTIVE

To study the anatomy and biometry of the radial artery and to report the implications of this study for daily practice in Cardiac Surgery.

METHOD

Radial arteries from 45 human cadavers (28 males and 17 females, average age 79.2 (92) fixed in 10% formalin were dissected. The proximal and distal internal calibers and lengths of these radial arteries were measured.

RESULTS

Our results showed the presence of a single radial artery variation in 2.3% of the entire sample (1.1% of the 90 dissected upper limbs). The distance between the epicondyle and the emergence of the radial artery was 32.4 (6.67) mm in men and 30.7 (9.00) mm in women, with an average of 31.8 (7.58) mm. For the right upper limb, the mean proximal internal caliber of the radial artery was 3.16 (0.56) mm and its mean distal internal caliber was 2.62 (0.66) mm. For the left upper limb, the mean proximal internal caliber of the radial artery was 3.17 (0.59) mm and its mean distal internal caliber was 2.64 (0.68) mm. The mean length of the left radial artery was 197.0 (17) mm. The mean length of the right radial artery was 201.0 (33) mm.

CONCLUSION

It is very important to be aware of the possible anatomical variation of the radial artery. Despite its rarity, this knowledge may ensure a better safety and reliability of the harvesting technique for use as a graft.

Prevalence of Accessory Branches and Other Anatomical Variations in the Radial Artery Encountered during Radial Forearm Flap Harvest: A Systematic Review and Meta-analysis

Background Harvest of the radial forearm flap (RFF) for reconstructive surgery is proceeded by the Allen test to assess for adequate contralateral perfusion of the hand, yet the Allen test may fail to detect anatomical variations in the radial artery such as aberrant branching. Therefore, the goal of this study was to systematically review the literature regarding anatomical abnormalities of the radial artery that can affect flap harvest and to perform a meta-analysis to estimate the prevalence of such abnormalities.

Methods A systematic review of the literature was conducted using five online databases to identify all instances of radial artery anatomical variations. Abstracts were reviewed and categorized into either (1) large cohort studies of anatomical variations identified by angiogram or (2) case reports specifically mentioning anomalous or accessory branches of the radial artery. Data from the large cohort studies were included in a random effect meta-analysis to estimate the prevalence of such variations.

Results Eighteen angiogram cohort studies containing a total of 18,115 patients were included in the meta-analysis. Accessory branches were the least common anatomical variant reported, with an estimated average prevalence of 0.5%. Prevalence estimates for more common anatomical variants, including radial artery loops (0.9%), stenosis (1.3%), hypoplasia (1.9%), tortuosity (4.3%), and abnormal origin (5.6%), were also calculated. Thirteen case reports detailing anomalous branches of the radial artery were identified, seven of which involved accessory branches encountered during RFF harvest with no incidence of flap loss.

Conclusion Radial artery accessory branches are exceedingly rare, but the prevalence of other anatomical variations that can affect harvest of the RFF warrants consideration. We recommend surgeons consider comprehensive screening prior to RFF harvest to avoid intraoperative discovery of anatomical variants and suggest a low threshold for repeat perfusion testing intraoperatively if radial artery accessory branches are encountered.

[Aberrant birth of a radial artery in the upper third of the forearm: A case report]

We report the case of a 68-year-old patient, operated on in our department of a quadruple coronary bypass grafting. The grafting strategy consisted initially on harvesting the left internal thoracic artery and the left radial artery. The harvest of this latter failed because of a rare anatomical variation of the radial artery, which rose from the confluence of two branches: a superficial and a deep radial artery at the proximal third of the forearm approximately 10cm below the elbow.