A New Classification System for Anatomic Variations in Axial Blood Supply of Pectoralis Major Muscle Flap: Do They...

Despite its reliability, the pectoralis major flap has a relatively higher incidence of marginal flap necrosis, which may stem from instability of blood flow through the choke vessel system. Anatomical variations in axial blood supply may further negatively impact flap outcomes. We classified axial blood supply into three patterns based on the lateral thoracic (LT) pedicle's non-dominance (Type I), co-dominance (Type II), and dominance (Type III). We also recorded any other anatomical variations in the pectoralis major myocutaneous flap (PMMC). From December 1, 2021, to November 30, 2024, we performed PMMC reconstruction on 130 patients. Postoperative complications were seen in 18.46% of patients. We encountered 4 patients with type III patterns. Ligation of LT pedicle to achieve adequate flap length in type III pattern was associated with total flap necrosis. Knowledge of anatomical variations in both axial blood patterns and muscle types, as well as preservation of the LT pedicle until confirmation of the vascular pattern, could lower the chances of technical errors during flap elevation. This might reduce the chances of flap necrosis and postoperative complications.

The online version contains supplementary material available at 10.1007/s13193-025-02455-w.