[Pharmacological preparation of the endometrium in surgical hysteroscopy].

Danazol, GnRH analogues (GnRH-A), progestins and gestrinone have been indicated for medical pre-treatment of surgical hysteroscopy, although only danazol and GnRH-A had some clinical evaluation. Pre-hysteroscopic pharmacological preparation is, in general, intended to reduce endometrial thickness, intraoperative bleeding and the need for endouterine distension with fluid media. In addition, in case of endometrial ablation, medical pre-treatment should facilitate the complete removal of endometrium, thus allowing better long-term results. The mechanism of action of progestins, danazol and gestrinone is partly indirect, through inhibition of ovulation and mild reduction in the synthesis of gonadotropins, and partly direct, through, first, decidualization of the endometrium, and then complete inactivation. On the other hand, GnRH-A have only an indirect, central mechanism of action of inhibition, through pituitary desensitization, of the synthesis of gonadotropins, thus inducing a profound hypoestrogenism. GnRH analogues appear to be more effective and rapid than danazol at the endometrial level and better tolerated. However, the effectiveness of pre-treatment versus no treatment needs to be clearly demonstrated in well-designed controlled studies. No significant difference, so far, has been found between danazol and GnRH analogues in terms of both surgical safety and long-term results.