Response to - Letter to the editor ‘Transparietal diffusion of polidocanol: Potential complication of sclerotherapy?’

I have read with great interest, the letter by Ramelet and Bossart in reference to our two-part publications titled ‘Skin necrosis following sclerotherapy. Part 1: Differential diagnosis based on classification of pathogenic mechanisms’ and ‘Skin necrosis following sclerotherapy. Part 2: Risk minimisation and management strategies’. We are grateful for the comments from Ramelet and Bossart and the opportunity to respond.

The focus of our original paper, ‘Skin necrosis following sclerotherapy. Part 1: Differential diagnosis based on classification of pathogenic mechanisms’, was to introduce the morphological classification in determining the implicated mechanism in sclerotherapy induced necrosis. To summarise, round necrosis indicates direct tissue damage which can occur via extravasation of the sclerosant in the peri-vascular tissue. In regard to the interesting point raised by Ramelet and Bossart regarding transparietal diffusion of polidocanol (POL), we recognise this is indeed another mechanism by which direct tissue damage can occur, in addition to the iatrogenic extravascular injection that was discussed in our paper. As correctly stated by Ramelet and Bossart in reference to Hansen ¹ and Schibler et al., ² extravascular of POL, whether via iatrogenic peri-vascular injection or transparietal diffusion would result in panniculitis of the implicated tissue, which would cutaneously manifest as round necrosis. The polidocanol studies referenced in the letter of Ramelet and Bossart largely study the tissue toxicity of POL in the liquid format. As discussed in the original manuscript, the risk of tissue damage from POL, especially in the foam format, is exceedingly low.

Stellate necrosis on the other hand results from direct intra-arterial injections, intravenous injections triggering the veno-arteriolar reflex vasospasm response (VAR-VAS) and injections near persistently open arterio-venous anastomoses or defective boundary valves. This is supported by the studies^3–5 referenced in the letter by Ramelet and Bossart reporting Nicolau’s dermatitis after intra-arterial injection of detergent sclerosants including POL and sodium tetradecyl sulphate (STS). Nicolau’s dermatitis, also known as, Nicolau’s syndrome, is a classic example of large stellate necrosis that occurs following intra-arterial injection, or arterial spasm. ³

We are very grateful to Dr Ramelet and Dr Bossart for engaging in our work through informative feedback on our work on Necrosis following Sclerotherapy.

With best wishes,

Dr Mina Kang and Prof. Kurosh Parsi