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Leiomyomata Uteri

Leiomyomata uteri, also known as fibroids or uterine myomas, are benign smooth muscle tumors of the uterus. Myomas are the most common pelvic tumor in women, occurring in approximately 20% of women of reproductive age fibroids. Approximately 30% of hysterectomy procedures are performed to treat myomas.

Etiology

An exciting advance in gynecology is the identification of a small number of genes that are mutated in uterine myomas, but not in normal myometrial cells. Preliminary data indicate that mutations in these genes may cause uterine myomas. Myomas were discovered to be monoclonal tumors.

Symptoms and Signs

Many myomas are asymptomatic. When symptoms do occur, they are most often associated with the number, size, and location of the tumors. Approximately one third of women with myomas report abnormal uterine bleeding. Most commonly the abnormal bleeding is menorrhagia, but intermenstrual bleeding does occur. One third of women with myomas report pelvic pain or pressure. Myomas that compress the bladder.

Some women with myomas present with a chief complaint of infertility, yet the relationship of myomas to subfertility is not well understood. Myomas that compress the fallopian tubes clearly can cause infertility.

Recurrent pregnancy loss can be caused by uterine factors such as myomata. Myomas that compromise endometrial function may be associated with recurrent miscarriage, but as with infertility, before performing a myomectomy.

The absolute diagnosis of uterine myomata is based on surgical removal of the tissue for pathologic analysis. Definitive surgical-pathologic diagnosis of uterine myomata is not indicated in every case of suspected uterine myomata, however. In many cases, the diagnosis of uterine myomata can be presumed based solely on physical findings. Pelvic ultrasonography can be used to confirm the diagnosis and to evaluate the possibility that an adnexal mass.

Treatment

Women with asymptomatic pelvic masses believed by the clinician to be myomas are eligible for expectant management by taking serial histories and performing physical assessments.

Yearly follow-up intervals may be elected if the tumors are documented to be stable or slow growing after 1-2 years of observation. Asymptomatic patients with uterine enlargement less than or equal to 12 weeks of gestational size and slow uterine growth (less than 6 weeks of gestational size in 1 year).

Expectant management is also reasonable for patients with larger, slow-growing asymptomatic leiomyomata. Expectant management should be reconsidered if symptoms change, if menstrual patterns change, or if the pelvic mass.

For symptomatic myomas, surgery is the preferred treatment option. Myomata are genetically mutated clonal tumors. Although they are responsive to hormones, it is unlikely that any hormonal intervention short of inducing menopause will produce a long-term therapeutic effect. With most hormonal treatments, the uterus returns to pre-treatment size, and symptoms recur within a few months of discontinuing hormonal therapy.

Hysterectomy

Approximately one third of all hysterectomy procedures are performed to treat myomata. The severity of the symptoms, the size of the myomata, and the reproductive plans of the woman all enter into the decision to perform a hysterectomy. The ACOG-published criteria for the use of hysterectomy for the treatment of fibroids.

Myomectomy

In the surgical treatment of uterine myomata, approximately 10 hysterectomy procedures are performed for each abdominal myomectomy procedure. The advantages of myomectomy are preservation of procreative capability and lack of negative psychologic effects due to removing the uterus. A disadvantage of myomectomy is that recurrence of myomata is common. In one recent study there was recurrence in 50% of women treated with myomectomy. Criteria for the use of myomectomy for the treatment of uterine leiomyomata.

One randomized study clearly demonstrated that, at the time of myomectomy, injection of the myomata with dilute vasopressin significantly reduced blood loss compared with saline injection (225 mL of blood loss versus 675 mL). Another randomized study showed no difference between vasopressin and cervical tourniquet techniques for reducing blood loss at the time of myomectomy.

A problem with myomectomy surgery is that postoperative adhesions occur frequently. In one study, the rate of adhesion formation at second-look laparoscopy was dependent on the site of the uterine incision. Among patients with a posterior uterine incision, 94% had adhesions at second-look laparoscopy. Among patients with an anterior uterine incision, 56% had adhesions at second-look laparoscopy. A single incision, placed in the anterior uterine wall, is the preferred surgical approach for myomectomy. Surgical adhesion barriers may be helpful to reduce the rate of adhesion formation postmyomectomy.