30 years' experience in the use of cutaneous lasers for the treatment of verrucous venous malformations in children: a retrospective cohort study at Great Ormond Street Hospital for children.

Verrucous venous malformation (VVM) is a rare vascular malformation with hyperkeratosis. Concomitant laser and surgery are first line treatments, but evidence establishing efficacy is limited. We assess the efficacy of laser alone for VVM. Retrospective analysis of patients receiving laser treatment for VVM between 1994-2023. Of 83 patients, 29 were excluded due to missing data, 7 due to concomitant surgical excision and 47 were evaluated. Pulse dye laser (PDL) and combined dual PDL-neodymium-doped yttrium aluminium garnet (PDL-Nd:YAG) lasers were used. Outcomes were difference in percentage surface area (SA) reduction and colour improvement after laser treatment. Two blinded healthcare professionals independently graded the VVMs. Tools used included a numerically graded colour chart, and a 10 × 10 surface area grid to assess pre/post photos printed to the same scale. Mean Joules delivered with PDL; 9.29 and PDL-Nd:YAG; 9.16. Spot size (mm) for PDL; 8.58 and PDL-Nd:YAG; 9.63. Mean number of treatments was 5.27 and 3.68 in red and purple lesions respectively. Mean SA reduction for red and purple lesions; PDL; 71.11% and 6.67%, and PDL-Nd:YAG; 54.30% and 32.35%. Mean colour improvement in red and purple; PDL; 53.13% and 8.59%, and PDL-Nd:YAG; 46.88% and 40.81%. Red responded better than purple (p = 0.0014 and p = 0.024), for SA and colour respectively. There was no statistical significance in better outcomes; age at first treatment or number of treatments. Laser alone is an effective non-invasive method for improvement of colour and SA. Red lesions responded better to laser. PDL-Nd:YAG laser is preferred in purple lesions.