Early Endovenous Laser Ablation with a 1940 nm Wavelength for Symptomatic Marginal Veins in Pediatric Klippel-Trenaunay Syndrome: A 4-Year Retrospective Cohort Study on Safety, Limb Hypertrophy, and Quality of Life.

BACKGROUND: Symptomatic marginal veins and progressive limb overgrowth are hallmark features of Klippel-Trenaunay syndrome (KTS) and other PIK3CA-related overgrowth spectrum (PROS) disorders. Data on endovenous laser ablation (EVLA) using modern wavelengths in pediatric populations with long-term follow-up remain limited. METHODS: A retrospective, single-arm cohort study was conducted at a tertiary university hospital. Forty-four pediatric KTS patients (mean age 12.5 years) with symptomatic marginal vein incompetence underwent EVLA using a 1940-nm wavelength (4-6 W, 50-70 J/cm). Technical success, adverse events, limb circumference, Vein-QOL scores, and reintervention rates were assessed over 4 years. RESULTS: Technical success was 100% (44/44). Post-procedural pain (90.9%) and mild skin complications (95.5%) resolved almost entirely within one month (p < 0.001). Mean Vein-QOL scores increased from 828.4 (SD 93.95) to 1562.1 (SD 162.40) at 4 years (p < 0.001). Leg and thigh circumferences decreased by 8.1 cm and 8.9 cm, respectively (p < 0.001). Late recanalization occurred in 4.5% of patients. No deep vein thrombosis or pulmonary embolism was recorded. CONCLUSIONS: In this retrospective analysis, early 1940-nm EVLA for symptomatic marginal veins in pediatric KTS appears safe and highly effective, with durable improvements in limb hypertrophy and quality of life sustained at 4 years.