Anatomical View of Thoracodorsal Artery Variants Using Computed Tomography Angiography

Background: The latissimus dorsi (LD) muscle has a dominant pedicle with one thoracodorsal artery and receives sufficient blood by segmental circulation through several perforators. Thus, it is widely used in various reconstructive surgeries. We are reporting on the patterns of the thoracodorsal artery analyzed by chest computed tomography (CT) angiography. Methods: We analyzed the preoperative chest CT angiography results of 350 patients scheduled to undergo LD flap breast reconstruction following complete mastectomy for breast cancer between October 2011 and October 2020. Results: A total of 700 blood vessels were classified according to the Kyungpook National University Plastic Surgery-Thoracodorsal Artery (KNUPS-TDA) classification: 388 (185 right and 203 left), 126 (64 right and 62 left), 91 (49 right and 42 left), 57 (27 right and 30 left), and 38 (25 right and 13 left) vessels were classified as type I, type II, type III, type IV, and type V, respectively. Among 350 patients, 205 patients showed matching types for left and right vessels, whereas 145 patients showed mismatching types. For 205 patients with matching types, the distribution by type was 134, 30, 30, 7, and 4 patients with type I, type II, type III, type IV, and type V, respectively. For 145 patients with mismatching types, the distribution by different combinations was 48, 25, 28, 19, 2, 9, 7, 3, 1, and 3 patients with type I + type II, type I + type III, type I + type IV, type I + type V, type II + type III, type II + type IV, type II + type V, type III + type IV, type III + type V, and type IV + type V, respectively. Conclusion: While there is some diversity in the vascular anatomical structures of the LD flap, the dominant vessel can be found in a similar location in almost all cases and no flap had absence of a dominant vessel. Therefore, in surgical procedures using the thoracodorsal artery as the pedicle, preoperative radiological confirmation is not absolutely necessary; however, due to variants, performing the surgery with an understanding of this aspect should lead to good outcomes.