Effect of Ultrasonic Dissection on Donor-Site Morbidity and Drainage in Latissimus Dorsi Free Flaps.

Abstract

Donor-site morbidity, particularly prolonged drainage and seroma formation, remains a persistent challenge in latissimus dorsi myocutaneous (LDMC) flap surgery. Although the Harmonic scalpel allows simultaneous cutting and coagulation and has demonstrated advantages in other surgical settings, its potential to mitigate drainage-related morbidity during full-muscle LDMC flap harvest has not been fully characterized. This study evaluated its impact on donor-site outcomes in free LDMC flap reconstruction. A retrospective review was performed of patients who underwent free LDMC flap reconstruction for lower extremity defects (from 2015 to 2025). Patients were grouped by dissection method: Harmonic versus conventional electrocautery. Outcomes included total drain volume, mean daily drainage, drainage duration, and seroma. Group comparisons and multivariable regression were used to assess predictors. Forty-nine patients were analyzed (Harmonic, n = 21; Conventional, n = 28). Flap elevation time was significantly shorter in the Harmonic group (74.8 ± 14.7 vs. 120.2 ± 32.8 min, p < 0.001). Seroma occurred in six patients (21.4%) in the Conventional group but in none in the Harmonic group (p = 0.075). Mean total drainage volume was lower with Harmonic dissection (437.3 ± 242.0 vs. 610.7 ± 379.7 mL, p = 0.020), whereas mean daily drainage was similar (57.2 ± 21.5 vs. 54.8 ± 29.1 mL/day, p = 0.167). Drainage duration was significantly shorter in the Harmonic group (7.5 ± 2.4 vs. 10.9 ± 3.4 days, p = 0.004). On multivariable analysis, flap size independently predicted total drainage volume (β = 0.77, 95% CI 0.23-1.30, p = 0.006), and Harmonic use independently reduced drainage duration by 3.3 days (β = -3.32, 95% CI -5.54 to -1.09, p = 0.004). Harmonic dissection in free LDMC flap harvest shortened elevation time, reduced drainage duration, and eliminated seroma. These findings support its role in minimizing donor-site morbidity and improving efficiency.