Variations in the Anterolateral Thigh Flap's Vascular Anatomy in African Americans

Variations in anterolateral thigh (ALT) arterial anatomy are well documented. Ethnicity is a known risk factor for vascular variation in several organ systems, but its impact on ALT anatomy has not been studied. Anecdotally, we observed frequent ALT arterial variation in African American (AA) patients. We thus hypothesized that AA patients have higher rates of anomalous branching.

A total of 277 computed tomography angiograms (513 lower extremities) captured between May 1, 2013 and May 31, 2015 at a tertiary academic medical center were retrospectively analyzed to determine ALT arterial branching. Patient records were examined to ascertain demographics. Data were analyzed using descriptive statistics and multinomial logistic regression.

Males comprised 84.5%. Ethnic distribution was 55.2% AA and 36.5% Caucasian. The descending branch of the lateral circumflex femoral artery (dLCFA) originated from non-LCFA arteries (deep femoral, common femoral, or superficial femoral arteries) in 18.9% of Caucasian versus 9.1% of AA (odds ratio [OR]: 2.28; 95% confidence interval [CI]: 1.33-3.93, p < 0.01). An oblique branch was identified in 41.1% of Caucasian versus 51.9% of AA (OR: 1.56; 95% CI: 1.08-2.24, p = 0.02). Ethnicity was the only driving factor of dLCFA and oblique branch of the LCFA (oLCFA) anatomy (Wald chi-square: 14 and 11, p = 0.03 and 0.02, respectively).

Ethnicity significantly affects ALT arterial anatomy. AA are more likely to have classical dLCFA branching with a fourth oLCFA branch. A flap with an unrecognized oLCFA-dominant supply places patients at a higher risk for flap failure and loss. We recommend preoperative imaging before undertaking an ALT flap reconstruction.