Variations of the thoracodorsal axis: application for scapular tip free flap harvesting

Purpose: To illustrate variations of the vascular anatomy of the subscapular system highlighting practical implications on surgical access, patient positioning, and strategies to maximize the exposure of vascular pedicle. Methods: A retrospective review of patients undergoing reconstruction with a scapular tip free flap over a 2-year period at a tertiary referral center. Results: Forty patients were included. In 25 (62.5%) cases, the thoracodorsal artery (TD) ended bifurcating into latissimus dorsi (LD) and angular branch (AB), with the serratus artery branch arising from the LD pedicle; this vascular pattern was defined as “LD-dominant.” In 10 (25%) cases, the TD bifurcated into LD and AB, with the serratus artery branch arising from the latter vessel, defined as “AB-dominant.” Lastly, there was a trifurcation pattern in 5 (12.5%) patients. There was considerable variability in the distal branching pattern. Twenty-two (55%) patients had 2 LD branches; in 11 (27.5%) cases, there was only 1 LD branch, and 7 (17.5%) cases had 3. Thirty-seven patients (92.5%) had 1 AB; in the remaining three cases (7.5%), there were 2. The entry point of AB was located 4.86 cm (mean) ± 0.75 cm from the fibrous tip. The arm positioning and scapular retraction were the key maneuvers to facilitate pedicle exposure and dissection, with the shoulder abducted and scapula retracted away from the body. Conclusion: The subscapular vascular anatomy is highly variable. Knowledge of anatomic variability alongside surgical pearls to harvest STFF could facilitate the introduction of this flap into the toolkit of head and neck reconstructive teams.