KEY POINTS
- The goal of hysteroscopic myomectomy is complete removal of the fibroid without trauma to normal uterine tissue.
- Patients with Type 0 and Type I fibroids often require only 1 surgery; patients with Type II fibroids should be advised that 2 surgeries may be needed to remove the entire fibroid.
- Adjuvant preoperative hormonal therapy facilitates surgical scheduling, helps prevent further blood loss in patients already suffering from anemia, and reduces distention media intravasation.
- The monopolar loop electrode is the fibroid removal system that is used most often.
Hysteroscopic myomectomy should be offered to all patients with symptomatic submucous fibroids who desire to avoid hysterectomy. Although it is a highly effective, minimally invasive technique, it is underutilized.
Unfortunately, fewer than one third of US gynecologists perform this procedure. In a 1997 survey of members of the American Association of Gynecologic Laparoscopists—an organization committed to minimally invasive surgery—only half of the respondents reported that they perform this surgery.1
The reasons for learning to perform hysteroscopic myomectomy are compelling:
- A large cohort of patients could benefit, since most heavy vaginal bleeding from fibroids is due to the submucous location, and hysteroscopic resection is a much more benign approach than hysterectomy. Symptomatic fibroids account for 27% of all hysterectomies performed in the US (the largest single diagnostic category) and more than 100,000 are performed for fibroids that cause abnormal uterine bleeding.2
- Removing these lesions hysteroscopically greatly improves prognosis in women with recurrent pregnancy loss and infertility due to submucous fibroids.3 Up to 15% of patients presenting with infertility have otherwise asymptomatic uterine defects, including submucous fibroids. For example, a meta-analysis of patients undergoing in vitro fertilization determined that, compared with controls, the relative risk of pregnancy for women with submucous fibroids was 0.32 (95% confidence interval [CI], 0.13–0.70). When the submucous fibroids were resected, the relative risk of pregnancy rose to 1.72 (CI, 1.13–2.58).3
Preoperative evaluation of fibroids
Severity of menorrhagia (the most common symptom) is considered directly related to the volume of the myoma within the endometrial cavity. It is not uncommon to see large tortuous vessels covering the surface of the fibroids; although the exact mechanism of fibroid-related menorrhagia is undetermined, the fragility of these vessels is probably responsible, at least in part.
Additionally, fibroids involving the uterine mucosa or submucosa may interfere with the muscular contraction necessary for hemostasis.
Surgical options and pretreatment depend on fibroid type. Submucous fibroids are classified according to the percentage of the fibroid within the endometrial cavity:4
- Type 0: pedunculated; 100% within the cavity
- Type I: more than 50% within the cavity
- Type II: more than 50% within the myometrium
The type dictates surgical options, determines endometrial pretreatment, and shapes patient expectations. Type 0 and Type I submucosal fibroids are more successfully removed in a single surgery, whereas Type II submucous fibroids usually require 2 procedures for complete removal.5
My preference is office hysteroscopy to evaluate the endometrial cavity combined with vaginal ultrasound to assess intramural disease. The view with the office hysteroscope is the same view you will have during surgery.
Patients with Type II myomas should be informed of the potential need for 2 procedures, as this fact often influences their treatment decisions. In addition, whenever a patient with a Type II myoma is pretreated with a gonadotropin-releasing hormone (GnRH) agonist, the physician should reassess the fibroid preoperatively to ensure that it has not become completely intramural.
Office assessment: Hysteroscopy plus ultrasound. Preoperative assessment can be achieved with a hysterosalpingogram, vaginal ultrasound, hysterosonogram, or office hysteroscopy.
Method. My preference is office hysteroscopy to evaluate the endometrial cavity combined with vaginal ultrasound to assess intramural disease. The view with the office hysteroscope is the same view you will have during surgery. There will be no surprises. With a small flexible hysteroscope using saline for distention, the procedure is done with no tenaculum, no paracervical block, and can be completed with 60 to 100 cc of fluid in less than 1 minute.
Patients are often intrigued to view the myoma responsible for their heavy vaginal bleeding.
Several advantages of preoperative hormonal therapy
Preoperative hormonal therapy has several advantages:
- Since it is best to resect submucous myomas when the endometrium is thin, hormonal therapy facilitates surgical scheduling.
- Since preoperative therapy creates a state of amenorrhea, it enables patients suffering from menorrhagia and anemia to build up their blood counts, reducing the need for transfusion.
- Most importantly, preoperative therapy can reduce blood flow to the uterus, thereby reducing the rate of fluid intravasation.
Adjuvants used for these functions include oral contraceptives, progestogens, danazol, and GnRH agonists. However, a recent Cochrane review suggests that only GnRH agonists reduce fluid absorption during operative hysteroscopy.6