Effect of vacuum bell therapy on subcutaneous fat of the chest wall in patients with pectus excavatum.

BACKGROUND

Vacuum bell therapy is increasingly used as a nonoperative treatment for pectus excavatum (PE). However, whether this intervention induces subcutaneous fat thickening and the mechanisms underlying such changes remain uncertain. This study aimed to quantify vacuum bell-associated adipose tissue changes and clarify their clinical implications.

METHODS

Patients with PE treated with vacuum bell therapy at our center between July 2022 and January 2024 underwent low-dose chest computed tomography at treatment initiation and after one year of therapy. Measured parameters included the Haller index (HI), correction index, anterior and lateral chest wall subcutaneous fat thickness, skeletal depression depth (SkD), and surface depression depth (SuD). The fat influence rate (FIR) was calculated to quantify device-related adipogenesis stimulation. Multiple regression analysis was performed to identify factors associated with changes in anterior chest wall fat thickness.

RESULTS

Forty-seven patients were included, with a median age of 7.0 years (range: 1-14). The mean HI decreased from 3.6 ± 0.7 to 3.2 ± 0.5, with improvement observed in 35 patients (74.5%). Anterior chest wall fat thickness increased in 45 patients (95.7%), rising from 4.0 ± 2.1 mm to 7.6 ± 3.3 mm. The mean FIR was 95% (IQR: 39%). Improvement in surface depression (4.0 ± 3.3 mm) exceeded skeletal improvement (1.4 ± 3.8 mm), and no predictors reached statistical significance in regression analysis.

CONCLUSIONS

Vacuum bell therapy is effective and induces substantial anterior chest wall fat thickening, indicating that cosmetic improvement results from a dual mechanism involving skeletal remodeling and adipose thickening.

LEVEL OF EVIDENCE: Level III.