Fibroids

Overview

Uterine Leiomyomata   (singular, leiomyoma, also known as fibroids) are benign tumours  arising from smooth muscle cells of the uterus. They contain normal tissues  albeit in abnormal proportions. They are often surrounded by a thin layer of  compressed collagen tissue and muscle fibres, referred to as a pseudocapsule.

Classification

Fibroids are usually described according to their locations within the uterus. The location of any particular fibroid can vary from time to time, according to fibroid growth, stage of menstrual cycle and the means used to assess it. Interestingly fibroids that lie in different positions in the uterus have a different genetic make-up, so they probably reflect subtly different diseases.

Intramural Fibroids

Intramural fibroids lie within the wall of the uterus. They may enlarge sufficiently to distort the outside of the uterus or the cavity of the uterus and may indeed extend from one side to the other.

Sub mucosal Fibroids

Sub mucosal fibroids chiefly lie beneath the lining (endometrium) of the uterus. It is these that are chiefly responsible for disturbance in menstrual function, usually heavy periods. The extent of the protrusion into the endometrial cavity is described by the European Society of Hysteroscopy Classification system as follows:

1. A type 0 fibroid is completely intra-cavity
2. A type 1 fibroid has at least 50% of its volume in the cavity
3. A type 2 fibroid has at least 50% of its volume in the uterine wall

Type 0 and 1 can be removed by hysteroscopic resection, whereas those that lie within the muscle of the uterus can often only be removed in part by this method.

Sub serosal Fibroids

Sub serosal fibroids are those lying in the outer layers of the uterus. They may have a narrow base in which case they are described as pedunculated. Sometimes they can extend from the outer uterine surface to lie within the broad ligaments, which are the peritoneal coverings covering the fallopian tubes and blood vessels that enter the uterus. These can be difficult to remove.

Cervical Fibroids

Cervical fibroids are located in the cervix rather than the body of the uterus.

Fibroids and Fertility

Do all fibroids impact upon fertility?

The short answer is no.  Fibroids are estimated to account for, or contribute to around 1-2% of  infertility.  Fibroids that distort the  lining of the uterus (endometrium) affect fertility by means that are at  present, incompletely understood.  Possibilities  include:

• The endometrial vascularity over the fibroid may be altered, reducing fertility and
• There may be differences in the biochemical milieu  and contractility of the uterus at the site of the fibroid.

Importantly, the location of the fibroid and not it’s  absolute size is the key factor in whether or not it may affect fertility.  Even very small fibroids, when distorting the  endometrial cavity, may impact on fertility whereas large fibroids on the outside  of the uterus may not.  The issue of  fibroids within the uterine musculature (intramural) is more difficult.  At present, it is thought that intramural  fibroids, of 4cm or more do affect  fertility, but removing these fibroids may not necessarily restore spontaneous  fertility rates to normal.  Note that  this is different in the case of IVF.

I strongly suspect  that although removing these fibroids results in a fertility gain, some of that  gain is negated with resultant adhesions. Thus the onus is on the  gynecologist to remove the fibroid, returning the uterus in as perfect a  fashion as possible, restoring myometrial continuity, with little chance of  infection, hematoma or subsequent adhesion formation.  This requires a meticulous surgical technique  and I believe anti-adhesive measures to play a role. Please see Laparoscopic Removal of Fibroids for  further discussion.

Do all fibroids interfere with a pregnancy?

Once again, the answer is no. Everything depends on the  site and size of the fibroid.  Interestingly if in comparing groups of women with and without submucosal  fibroids, once they are pregnant the miscarriage rate is similar.

Around 50 to 60% of fibroids increase in size during  pregnancy.  Most of this growth occurs  during the first trimester, slowing in the second and third trimesters.   Large fibroids greater than 5cm are more likely to grow where as smaller  fibroids may remain stable.  Size  remains roughly stable after pregnancy, but about 10% will decrease in volume by  around 10%. It is important to realise that both the uterus and the fibroids  increase in size by processes of hyperplasia and hypertrophy i.e. more muscle  cells and greater size in muscle cells.   The tissue cannot completely disappear after pregnancy but may shrink  somewhat.  Many women with fibroids do  not have any complications during pregnancy related to the fibroid.  Complications may however occur, with pain  being the most common.  To summarise, the effects of fibroids on  pregnancy may include:

• Miscarriage
• Premature labor and delivery
• Abnormal fetal position requiring operative  delivery
• Placental abruption (the placenta peels away  from the lining of the uterus)
• Abnormal fetal growth
• Morbidly adherent placenta (placenta unable to  be expelled after the birth)

Laparoscopic Treatment Of Fibroids – (Laparoscopic Myomectomy)

Laparoscopic Myomectomy is a surgical procedure in which a fibre optic  instrument is inserted through the abdominal wall in order to remove uterine leiomyomata (fibroids).

Reasons For Laparoscopic Myomectomy

There are  many reasons for removing fibroids, which will vary from person to person in  their type, size and significance. In the vast majority of cases where removal  of fibroids is required, a laparoscopic route is appropriate. This can either  be achieved by conventional “straight stick” laparoscopy or by Da Vinci  (robotic) myomectomy. Data on post-operative recovery and effects of laparoscopic  myomectomy versus open or laparotomy myomectomy, varies due to the extremely  heterogeneous nature of the patients and surgeons skills in the studies.  However, the benefits of laparoscopy are well  proven with respect to decreased complication and improved recovery times.  There are also undoubted cosmetic advantages to operating with small  incisions.

It is usual for the laparoscopic myomectomies that I perform to be  discharged on the same day.

Are all fibroids able to be removed laparoscopically

The short answer here is ‘no’ but in the  vast majority of cases, this will be possible. It is not until the size of the  fibroid approaches the height of the umbilicus (belly button) that serious  issues may occur. However, with appropriate planning, pre-operative preparation  and surgical skills, almost all problems can be avoided. Difficult procedures  involve very large fibroids, patients of increased body mass index and cases  where multiple fibroids co-exist.  In  these cases it is difficult, by any means, to preserve a sufficient amount of  uterine muscle in order to affect a neat and sound repair of the uterus. Some  fibroids regardless of size and according to location are easily removed. For  example, fibroids at the front and centre of the uterus are generally easier to  remove by any means. Difficult cases may be those where the fibroids extend  into the coverings around the sides of the uterus (broad ligaments), especially  if the fibroid has multiple parts and surrounds or pushes under the ureters.

What we are able to do today is far in  excess of that which was commonly done even two years ago.  This has been made possible by improvements  in sutures (specifically unidirectional barbed sutures), suturing technique,  diathermy instruments, adhesion barriers, new haemostatic matrices,  understanding of injectable haemostatic agents and morcellators.  The latter are instruments that reduce  fibroids to small strips so that they can be removed via small incisions.