BSGE/ESGE guideline on management of fluid distension media in operative hysteroscopy.

Abstract

Hysteroscopy enables visualisation of the uterine cavity and allows the diagnosis and surgical treatment of intrauterine pathology. To achieve this, the uterine cavity needs to be distended by a medium which could either be fluid or carbon dioxide [1]. Carbon dioxide is used for diagnostic hysteroscopy, as bleeding during operative procedures obscures visibility. For this reason, fluid media are used for operative procedures, as they allow continuous irrigation giving a clear picture and enable use of both mechanical and electrosurgical instruments. During operative hysteroscopy absorption of large volumes of distension solutions can occur leading to serious complications arising from significant fluid overload. Excessive fluid absorption is most likely with prolonged hysteroscopic procedures requiring continuous irrigation of fluid or where blood vessels within the myometrium are opened. Thus, particular care is required with resection of the endometrium (transcervical resection of the endometrium – TCRE) and hysteroscopic myomectomy – transcervical resection of fibroids – TCRF). Operative hysteroscopic procedures are usually carried out using resectoscopes which are larger diameter, continuous flow operating hysteroscopes. They incorporate a working element that moves an electrically activated wire loop. These devices were initially developed to use monopolar current, which require non-electrolyte distending media such as glycine and sorbitol. Such solutions are however hypotonic so that excessive absorption can cause a number of complications including hyponatremia, a variable degree of hypo-osmolality, and certain solution-specific problems that are described below. Isotonic electrolyte-containing solutions cannot be used with monopolar energy because this leads to activation of ions that disperse the electric current and reduce the power density. Hence the heat generated in tissues is insufficient to destroy or have a tissue effect [2]. Resectoscopes have now been developed to use bipolar electrical current with the advantage that they are compatible with electrolyte-containing distension solutions such as physiological normal saline and Ringer’s lactate. Use of these solutions reduces the risk of hyponatremia, but excessive absorption can, as with monopolar current, lead to expansion of the extracellular fluid volume with the potential to generate fluid overload, pulmonary oedema, hypertension and cardiac failure. Operative hysteroscopy can also be performed using small diameter, continuous flow hysteroscopes which incorporate a small, usually 5Fr or 7Fr, diameter working channel down which mechanical or electrosurgical instruments can be passed. Tissue removal systems refer to operative hysteroscopes that have been designed to simultaneously cut and aspirate tissue from within the uterine cavity. These systems usually incorporate their own fluid monitoring equipment but fluid overload can still occur. Smaller diameter operative hysteroscopes are less likely to cause fluid overload due to smaller diameter inflow channels and the generally less invasive nature of procedures that can be undertaken with such technology. However fluid overload may still occur and vigilance when using any operative hysteroscopic technology is mandatory.