Radiological outcomes of ultrasound-guided bleomycin sclerotherapy for pediatric lower extremity lymphatic malformations: a retrospective cohort study

Abstract Background Site-specific evidence for bleomycin sclerotherapy in pediatric lower extremity lymphatic malformations is limited. We evaluated treatment response, recurrence, treatment burden, surgery, and adverse events in relation to lesion morphology and anatomical depth. Methods This retrospective cohort included 39 children treated with ultrasound-guided bleomycin sclerotherapy between January 2017 and December 2021. Two senior radiologists and the principal surgeon reviewed available images, including the most recent follow-up studies, and response assignments, resolving disagreements by discussion. Response assessment combined recorded lesion dimensions with documented resolution and subsequent recurrence. Treatment burden was the number of bleomycin sessions. Anatomical comparisons were exploratory. Results Mean age was 36.2 ± 35.1 months (range, 0 to 173). Pretreatment magnetic resonance imaging was performed in 19 patients. All underwent ultrasonography. Mixed lesions accounted for 69.2%. Median recorded dimensional reduction was 74.7%. Final response was complete resolution in 7 patients, excellent in 9, moderate in 10, poor in 4, no response in 6, and recurrence in 3. Overall, 26/39 (66.7%) had at least moderate response without subsequent recurrence. The three recurrences followed initial resolution and were managed with observation. Median treatment burden was 3 sessions (range, 1 to 8). Seventeen patients required more than 3 sessions. Median sessions were 2, 3, and 4 for superficial/subcutaneous, deep fascial/intramuscular, and multicompartment lesions, respectively, without a significant difference between depth groups ( p = 0.111). Seven patients underwent surgery. Two self-limited local reactions and no major adverse events were documented. Conclusions Bleomycin sclerotherapy was associated with dimensional reduction in many children, but residual disease, recurrence, and additional treatment remained relevant. The exploratory anatomical findings require cautious interpretation because imaging availability differed between depth groups.