Ovarian Remnant Syndrome

[Lindle]

Ovarian remnant syndrome is a relatively rare condition if taking the female population as a whole and occurs when remnants of ovarian tissue are left behind after the ovaries are removed (oophorectomy). But the primary risk factor is oophorectomy in those with endo, specifically severe endo, where the ovary might be firmly stuck down with adhesions/fibrosis and the delineation between healthy and diseased tissue is obscured. So in terms of rarity it will be significantly more common in those with severe endo involving endometriomas and is worth being aware of. There can be many causes of pain after a hysterectomy/BSO but suspicion should be raised if cyclical symptoms continue which might indicate that there is still some functioning ovarian tissue remaining.

We know that endometriomas are very often associated with rectovaginal endo, a scenario where the uterus and rectum are adhered to each other causing an obliterated pouch of Douglas (cul de sac) in the most severe stage. This predominantly, but not exclusively, affects the left side and the left ovary will typically be bound up in the deep fibrosis. It is therefore really important when considering surgery that this is done only by advanced excision surgeons who will be conscious of the dangers of incomplete oophorectomy.

We often hear that a gynaecologist has recommended a hysterectomy as 'treatment' for endo. There are times when this is appropriate for those with endo such as where there is also adenomyosis and/or severe bleeding/pain with periods. It is always recommended that the ovaries are retained if possible but if they, or one, are severely diseased then it can be appropriate to remove them.

In cases of severe endo it may be that the ovaries are so bound up with deep disease that a 'pelvic clearance' is recommended where all the endo is excised along with the uterus and ovaries. In any event where a hysterectomy/BSO is being recommended for those with endo all known endo should be excised at the same time so pre-lap imaging would be appropriate to map the pelvis to ensure as definitive a treatment as possible.

There may be cases where there is severe disease that is asymptomatic but a woman is approaching menopause and has endometriomas, and in such a case it may be considered appropriate to remove just the ovary/ovaries in order to prevent risk of malignancy.

All of these scenarios bring with them the risk of ovarian remnant syndrome which is usually an extremely painful condition in which the retained ovarian tissue can implant anywhere and is notoriously hard to treat. It usually doesn't respond well to medical treatment and surgery can be challenging. Given that primarily any surgical treatment is to address pain it is so important to be aware of this condition in order to avoid it rather than trading one set of symptoms for another.

(There is a similar scenario when retained deep endo is present in the vault after a total hysterectomy and continues to progress, especially in those who had uterosacral ligament endo, but that is a separate discussion).

Ultimately it is so important to acknowledge that a hysterectomy and oophorectomy in those with endo, especially when severe, can be a very complex procedure and should never be undertaken by a general gynaecologist in isolation.