Efficacy Comparison and Prognostic Factor Analysis of Ultrasound‐Guided Microwave Ablation Alone Versus Combined with Lauromacrogol Sclerotherapy for Mixed Cystic‐Solid Thyroid Nodules

Objectives To compare the therapeutic efficacy of microwave ablation (MWA) alone versus MWA combined with lauromacrogol sclerotherapy for benign mixed cystic‐solid thyroid nodules. Methods A total of 132 pathologically confirmed benign mixed cystic‐solid thyroid nodules were treated with either MWA alone (MWA group) or MWA combined with lauromacrogol sclerotherapy (MWA + LS group). Patients were followed up at 1, 3, 6, and 12 months postoperatively. The volume reduction rate (VRR) was compared between the 2 groups. Univariate and multivariate logistic regression analyses were used to assess the impact of factors such as nodule classification (based on cystic‐solid morphology), cystic fluid characteristics, proportion of solid component, lauromacrogol dosage, and ablation duration on treatment efficacy. Results In this comparison of MWA without aspiration (MWA group) versus MWA with aspiration and lauromacrogol sclerotherapy (MWA + LS group), the MWA + LS group showed higher VRR at all follow‐up time points ( p < .05). However, because the MWA‐alone group did not undergo aspiration, this difference represents the combined effect of fluid aspiration and sclerotherapy; the specific contribution of lauromacrogol cannot be determined from this study. Multivariate logistic regression identified nodule morphologic subtype as an independent predictor of treatment efficacy; the wall‐nodule type achieved significantly higher VRR than the intranodular‐septation type and eccentric type ( p < .05). Although univariate analysis showed a negative correlation between ablation duration and postoperative VRR ( p < .05), this factor was not an independent predictor in the multivariate model ( p = .102), suggesting its apparent effect may be confounded by nodule complexity and other baseline characteristics. Conclusion In this study comparing MWA without pre‐ablation aspiration (MWA group) versus MWA with pre‐ablation aspiration and lauromacrogol sclerotherapy (MWA + LS group), the combined approach was associated with higher VRR at all follow‐up time points, particularly for the wall‐nodule type. However, because the MWA‐alone group did not undergo aspiration, the observed advantage should be interpreted as the combined effect of fluid aspiration (which removes the heat‐sink effect and facilitates energy delivery) and lauromacrogol sclerotherapy, rather than as a benefit of lauromacrogol per se. The specific contribution of lauromacrogol beyond aspiration cannot be determined from this study. Shorter ablation time was associated with better postoperative outcomes in univariate analysis; though this was not an independent predictor in multivariate analysis. Future randomized controlled trials with an aspiration‐plus‐MWA control arm are essential to isolate the specific efficacy of lauromacrogol.