Fibroids or leiomyomas are non-malignant muscle tumors that grow in the uterine wall. They can be found in about one out of every five (1:5) women >30Y of age. Fibroids are far more prevalent in African Americans and women and less frequent in other ethnic groups (i.e. Caucasians and Asians).
Fibroids, enlarge and/or distort uterine configuration. They can produce symptoms such as heavy, painful and prolonged menstrual periods. Other symptoms include pain with intercourse, backache, severe abdominal pain when large fibroids run out of blood supply or when superficial fibroids on a stem (pedunculated) undergo twisting (torsion). Sometimes fibroids will protrude into the uterine cavity, cause severe cramping and bleeding and so irritate the uterine lining as to compromise embryo attachment (anatomical implantation dysfunction). Women with fibroids are also at greater risk of miscarriage, premature delivery, malposition of the baby (mandating cesarean delivery) and an increased risk of bleeding after birth (post-partum hemorrhage)
Diagnosis can be made by one or more of the following symptoms/presentations: Symptomatology, pelvic examination pelvic ultrasound, hysterosalpingogram (HSG), sonohysterogram (HSN), CT-scan or MRI.
Fibroids are classified as:
- Submucosal: Here the fibroid grows just under the lining of the uterine cavity (mucosa) or protrudes into the uterine cavity. They might mold into the underlying uterine muscle (sessile) or be on a stalk (pedunculated). Submucosal fibroids can change the shape of the uterine cavity, irritate the lining and prevent implantation, cause miscarriage. These lesions must be removed in their entirety prior to undertaking embryo transfer, usually hysteroscopically. (see below)
- Subserosal: – Here the tumors grow under the outer layer (serosa) of the uterus. These fibroids will not compromise implantation, but if they are large, causing severe pain, and especially if they are multiple, pedunculated and thus at risk of undergoing torsion (twisting) the3y should be removed, usually laparoscopically. (See below).
- Intramural: – when the fibroids develop within the muscular wall of the uterus. This is the commonest presentation. Unless they are large and multiple and do not encroach on the uterine cavity, they can be left alone Surgical removal is usually by laparoscopy or laparotomy/abdominal open incision (See below)
The uterus is composed of a thick layer of smooth muscle (myometrium) surrounding the endometrial lining into which the embryo implants and which serves to protect and nourish a growing pregnancy. These tumors are rarely malignant (see below). Fibroid tumors, even large ones, can occur without producing any symptoms at all.
For the most part, only those fibroids that impinge upon the uterine (endometrial) cavity (submucosal) affect fertility. Exceptions include large fibroids in the muscle wall of the uterus (intramural) that can block the openings of the fallopian tubes as they enter the uterus, and where multiple fibroids cause abnormal uterine contraction patterns.
In some cases multiple uterine fibroids may so deprive the uterine lining (endometrium) of blood flow, that the delivery of estrogen to the endometrium is curtailed to the point that the lining cannot thicken sufficient to support a pregnancy. This can result in early 1st trimester (prior to the 13th week of pregnancy) miscarriages. Large or multiple fibroids, by curtailing the ability of the uterus to stretch in order to accommodate the spatial needs of a rapidly growing pregnancy, may precipitate 2nd trimester (beyond the 13th week) miscarriages and/or trigger the onset of premature labor.
Sizable fibroid tumors are usually easily identified by simple vaginal examination. However, even the smallest fibroid can be identified by transvaginal ultrasound. Sometimes it is difficult to tell if the fibroid is impinging on the uterine cavity. In such cases, a hysteroscopy (where a telescope like instrument, inserted via the vagina into the uterine cavity) or a sonohysterogram where injected fluid, distends the uterine cavity allowing for examination of its inner configuration can help distinguish between intramural and submucosal fibroids. CT scan and MRI can also be used to distinguish between fibroid tumors and another condition that also involves affects the uterine muscular wall, known as adenomyosis. This condition is characterized by endometrial tissue growing deeply into the uterine wall.. Given the often-diffuse nature of adenomyosis, it can be very difficult to remove surgically. This contrasts with fibroid tumors, which are well defined and are usually easily removed.
Surgical Treatment: The mainstay for the treatment of fibroid tumors is surgical removal (myomectomy). Small, asymptomatic fibroids that do not impinge upon the endometrial cavity will usually not require treatment other than observation and vigilance. Large fibroids and submucosal fibroids should be removed prior to starting fertility treatments such as In Vitro Fertilization (IVF) in order to decrease the chance of implantation failure, miscarriage, pregnancy complications and premature labor. Intramural and subserosal fibroids are readily removable by laparoscopic resection or via an abdominal incision. The former allows for a more rapid convalescence and is ideal for the removal of small and accessible superficial fibroid tumors, while the latter approach is preferred for treating larger and less accessible fibroids.
Myomectomy can affect fertility in several ways. If the endometrial cavity is entered during the surgery, there is a possibility of post adhesions forming within the uterine cavity. This should always be checked by the performance of a hysteroscopy or through a sonohysterogram, prior to beginning fertility treatment. Because myomectomy can be bloody, there is a high likelihood of post-operative abdominal adhesion formation, which could bind down or encase the ovaries, preventing the release of the eggs, or block the ends of the fallopian tubes. For this reason, it is important that myomectomies be formed only by accomplished surgeons, who are familiar with techniques to limit blood loss and prevent adhesion formation.
Regardless of whether the laparoscopic or abdominal approach is employed, adequate closure of the uterine wall is essential in order to reduce the subsequent risk of uterine rupture during pregnancy or labor. This is one of the main arguments used against the use of laparoscopic removal of large, multiple or remotely situated fibroids. While laparoscopic myomectomy requires but a few days (at most) for post-operative convalescence, abdominal myomectomy usually requires 6-8 weeks of recovery time. When myomectomy necessitates or results in the uterine cavity being entered (purposefully or inadvertently), it should always be followed up with a “2nd look” hysteroscopy to rule out scar tissue formation, which occurs frequently in the presence of submucosal fibroids.
Uterine polyps (and in some cases, also submucosal fibroids), can usually be removed hysteroscopically (through the vagina). This eliminates the need for abdominal surgery and greatly reduces the recovery time. Hysteroscopic surgery is only useful if the majority of the fibroid protrudes into the endometrial cavity, ensuring that the tumor defect will not be too large. This surgery is often done under laparoscopic guidance, to reduce the risk of uterine perforation. After hysteroscopic surgery it is often advisable to prescribe cyclical hormonal therapy for a few months to encourage regeneration of the endometrial lining over the area of tumor defect and healing of the uterine muscle. A 2nd look hysteroscopy should be performed a few months later in all cases, to rule out scar tissue formation even if it means delaying or deferring the initiation of definitive fertility treatment.
Medical Treatment: The growth of fibroid tumors is estrogen-dependent. Thus when a woman enters menopause and stops making female hormones, fibroids tend to shrink in size on their own. Conditions that mimic menopause can also reduce the size of fibroid tumors. The most common of theses treatment is with a medication such as leuprolide acetate (Lupron), which shuts off the communication of the brain with the ovaries, preventing hormone production. However, this type of medication can only be taken for a limited period (usually 6 months) and once the medication is stopped the fibroids will usually regain their original size within a few months. The medication is therefore only a “temporary fix,” used mostly to decrease the size of large fibroids in order to make their ultimate surgical removal easier, or to help a woman bridge the gap until spontaneous menopause sets in. For the majority of women there is no major benefit from Lupron therapy prior to surgery.
Embolization of Fibroid Tumors: Myomectomy always carries the small (although infrequent) risk that severe, uncontrollable intra-operative bleeding could require the performance of a hysterectomy (complete removal of the uterus) as a life saving measure. Moreover, some women are poor candidates for surgery. This is where a new procedure known as embolization comes in. Embolization is a procedure in which small particles are injected into the arteries of the uterus under radiological guidance to shut off the blood supply to the fibroids, in the hope that they will “shrink” and perhaps, even disappear.
Embolization is relatively new to the field of gynecology and little is known about its potential effects on future fertility. We are concerned that in the process of shutting off the blood supply to the uterus, it will permanently so reduce endometrial blood flow, as to compromise embryo implantation. For this reason, I do not currently recommend this therapy for women who still wish to conceive and carry a baby in their uterus. At present, it seems best suited for symptomatic women who are finished with their childbearing or who are planning to use a gestational surrogate.
Malignant Change in Fibroid Tumors: Fibroids rarely undergo malignant change. The reported incidence is less than 1 in 2000 cases. Fibroids usually grow very slowly (over a number of years). However, when growth occurs rapidly over a month or two, especially in older women who have large fibroids, it should raise the suspicion of this very rare but extremely serious complication.