Effectiveness of free vastus lateralis musculocutaneous flap transplantation plus ultrasound-mediated transdermal Qianjin Weijing decoction for chronic empyema: a prospective, preference-based observational study

Objective To evaluate the effectiveness of free vastus lateralis musculocutaneous flap (VLMCF) transplantation combined with ultrasound-mediated delivery of Qianjin Weijing decoction for chronic empyema. Methods In this single-center prospective observational study (July 2023–June 2025), 114 patients elected either VLMCF surgery alone (control, n = 57) or VLMCF plus ultrasound-assisted transdermal decoction at bilateral Feishu points for 2 weeks (combined, n = 57). The primary outcome was residual cavity volume measured via 3D-CT. Secondary outcomes included nutritional, inflammatory, and quality-of-life (SF-36) markers. Analyses used ANCOVA to adjust for baseline imbalances and multiple imputation for missing data. Results At 2 weeks, the combined-therapy group showed a significantly greater reduction in cavity volume compared to the control (20.52 \ ± 4.45 vs. 24.40 \ ± 6.35 mL; adjusted mean difference: −3.72 mL; 95% CI: −5.85 to −1.59; p = 0.005). By 3 months, cavity volumes were comparable. Regarding secondary outcomes, the combined group had significantly lower procalcitonin levels at 3 months (adjusted difference: −0.10; p = 0.0005). However, no robust differences were found in albumin, hemoglobin, CRP, WBC, or functional recovery (ADL/SF-36) at either time point after FDR correction. Conclusion Adding ultrasound-mediated Qianjin Weijing decoction to VLMCF transplantation may accelerate early cavity resolution and improve procalcitonin profiles in chronic empyema patients. While mid-term functional and nutritional outcomes were similar to surgery alone, the combined regimen is a safe potential adjunct. Randomized controlled trials are needed to confirm long-term benefits and causality.