BACKGROUND Laryngomalacia is the most common cause of stridor in neonates and infants, and supraglottoplasty is the mainstay of surgical treatment. Although low-temperature plasma radiofrequency ablation (LTP-RFA) using coblation technology has been used for treating laryngomalacia, it is still lack of high-quality clinical evidence. Therefore, we conduct this prospective randomized study to clearly define the role of LTP-RFA for the
treatment of laryngomalacia in neonates and infants. METHODS Between Jan 2017 and Dec 2019, a total of 89 children with laryngomalacia were included for analysis. All patients were initially stratified according to the severity of laryngomalacia. Patients with severe laryngomalacia were randomly assigned to receive LTP-RFA or traditionally surgical supraglottoplasty, while patients with moderate laryngomalacia were assigned to LTP-RFA or observation. The primary end point was the efficacy and toxicities of LTP-RFA by assessing the changes of clinical score and visual analogue scale (VAS) symptom score. The total score was the combination of clinical score with VAS score. RESULTS Of the 89 children, 40 children presented with severe laryngomalacia, and the remaining 49 children were diagnosed as moderate laryngomalacia. The median age was 68 days (range, 19 to 337 days). For children with severe laryngomalacia, our results showed that LTP-RFA treatment significantly reduced the operative time (5.55±1.66 vs. 18.7±5.31 min, P<0.001), length of hospital stay (6.71±1.15 vs. 7.95±1.55 days, P=0.008) and the amount of intraoperative hemorrhage (1.71±1.79 vs. 4.90±1.82, P<0.001) when compared to traditionally surgical supraglottoplasty, while the treatment efficacy was comparable between LTP-RFA and traditionally surgical supraglottoplasty in terms of changed total score (P=0.322), changed clinical score (P=0.135) and changed VAS symptom score (P=0.559). Additionally, for children with moderate laryngomalacia, LTP-RFA treatment significantly improved the symptom evaluated by total score (P<0.001), clinical score (P<0.001) and VAS symptom score (P<0.001) in comparison with the observation group. Post-operative pneumonia was observed in 10 patients. No surgical related death was reported. CONCLUSIONS The present study indicated that LTP-RFA was an effective treatment option for both severe and moderate laryngomalacia in neonates and infants with a low intraoperative complication. Long-term outcomes of LTP-RFA for laryngomalacia would be reported in further studies.