sclerotherapy
Concise Oxford English Dictionary © 2008 Oxford University Press:
sclerotherapy /ˌsklɪərə(ʊ)ˈθɛrəpi, ˌsklɛ-/
▶noun Medicine the treatment of varicose blood vessels by the injection of an irritant which causes inflammation, coagulation of blood, and narrowing of the blood vessel wall.
'sclerotherapy' also found in these Oxford entries:

