Breast Reconstruction Using the Axillary-Approach Endoscopic Extended Latissimus Dorsi (Ax-eeLD) Flap

<b>Background/Objectives</b>: Although the endoscopic extended latissimus dorsi (eeLD) flap avoids dorsal scarring, a lateral thoracic incision is still required. We developed an axillary-approach endoscopic extended latissimus dorsi (Ax-eeLD) flap enabling harvest through a single 40-mm axillary incision and two 5-mm ports. This study evaluated its safety and feasibility and compared outcomes with conventional eeLD. <b>Methods</b>: Patients who underwent Ax-eeLD flap (study group) were retrospectively analyzed and compared with the patients who underwent conventional eeLD flap (control group, <i>n</i> = 15). The flap was elevated endoscopically via a single 40-mm axillary incision and two 5-mm ports, harvesting the entire latissimus dorsi muscle with its surrounding adipose tissue. Outcomes included incision length, operative time, complications, secondary fat grafting, and BREAST-Q scores. <b>Results</b>: Fifteen patients (post-mastectomy, <i>n</i> = 13; congenital hypoplasia, <i>n</i> = 2) underwent Ax-eeLD flap. All procedures used only the planned incisions without intraoperative complications. The study group had significantly shorter incisions than the control group (39 ± 1 mm vs. 89 ± 9 mm, <i>p</i> < 0.01). Operative times were similar between the groups. Eight patients developed seromas, all of which were resolved by outpatient aspiration. The frequency of postoperative cases requiring fat grafting did not differ significantly between the study and control groups (4 vs. 8; <i>p</i> = 0.26). BREAST-Q scores improved postoperatively and were similar between groups. <b>Conclusions</b>: Ax-eeLD flap enables minimally invasive harvest of the latissimus dorsi without lateral thoracic scarring. This retrospective case series supports technical feasibility and safety; further prospective studies with objective volume assessment are required.