Surgical landmarks for identification of the thoracodorsal pedicle during axillary dissection in carcinoma breast patients: a prospective observational study.

BACKGROUND

Axillary lymph node dissection (ALND) plays a pivotal role in breast cancer surgery, serving both staging and locoregional control. The thoracodorsal pedicle (TDP), comprising the thoracodorsal artery, vein, and nerve are critical structures encountered during ALND. Preserving the TDP is essential to minimize postoperative complications, such as impaired shoulder function and arm lymphedema, and to support successful reconstructive outcomes, particularly when utilizing the latissimus dorsi muscle for flap procedures. Accurate identification and careful preservation of the TDP especially by trainee surgeon during ALND are therefore crucial for optimizing both oncologic safety and postoperative quality of life for breast cancer patients.

METHODS

This observational study included 30 female breast cancer patients undergoing modified radical mastectomy (MRM) or breast-conserving surgery (BCS) with ALND. During surgery, anatomical distances from the thoracodorsal pedicle (TDP) to key landmarks, the Lateral Thoracic Vein (LTV), and the pectoralis minor muscle were measured using vernier calipers. The clock-face orientation of the axillary vein was also employed to describe the relative position of the lateral thoracic vein (LTV) and TDP.

RESULTS

In all 30 patients, the lateral thoracic vein (LTV) was consistently identified at the anteroinferior aspect of the axillary vein (9 o'clock position). In contrast, the thoracodorsal pedicle (TDP) was located posterior-laterally at the 6 o'clock position. The mean distance from the TDP-axillary vein junction to the pectoralis minor (C) was 27.2 ± 10.0 mm, and the distance from the TDP -axillary vein junction to the LTV-axillary vein junction (B) was 13.1 ± 12.5 mm. The derived distance from the LTV to the pectoralis minor (A = C - B) was 14.1 ± 16.0 mm. All measurements followed a normal distribution (Shapiro-Wilk p > 0.05), and their low skewness values indicated good symmetry.

CONCLUSION

Use of LTV and pectoralis minor muscle as anatomical landmarks and clock-face orientation reliably identifies the thoracodorsal pedicle during ALND, and offer a reliable and reproducible method to locate the thoracodorsal pedicle intraoperatively, thereby improving surgical precision and minimizing risk during axillary dissection.