What could be the cause of tissue necrosis? I've had no previous sclerotherapy reaction with sotradecol

Thank you for your question. I would recommend consulting with a Board Certified Plastic Surgeon or Dermatologist for best treatment plan. I hope this helps!

This is a consequence of sclerotherapy with any type of injectable.  It has very little to do with the solution and it can happen regardless of what is used and who is injecting.  There is no way to know what "exactly" caused it and the best option here is to follow wound healing instructions.  Best, Dr. Emer.

This can happen with any sclerosing solution and technique (foam or traditional). It is most likely with the use of hypertonic saline and less commonly seen today with STS or polidochanol or other 'detergent class' sclerosing solutions. Use a product like Maderma or Scar Serum to help heal the wound with minimal scarring. 

The most common cause of tissue necrosis after sclerotherapy is extravasation of the solution outside the vein being treated. This can happen with any kind of solution- sotradecol, polidocanol, saline- and rarely related to the way in which the solution was compounded, or prepared. One other possibility is using a solution that is too concentrated (too strong) for the size vein (eg using 3% sotradecol in a spider vein), or injecting the solution with too much force. The doctor was only preparing the solution in front of you by mixing it with saline (0.9%) or sterile water to dilute the solution.

Sclerotherapy with any solution can cause tissue necrosis and this is usually due to escape of the sclerosing solution into the skin and outside of the vein.  The stronger the concentration of the solution the greater the risk of a problem. Fortunately tissue necrosis and ulceration is not a common problem.