Contrary to what many still believe, hysteroscopic myomectomy can be one of the safest, mostly easily learned surgical procedures in gynecology. It is certainly underutilized and continues to be offered and performed by relatively few gynecologists.
With proper training and attention to the preoperative evaluation, surgical technique, and strict fluid management, we can offer patients a treatment for submucous fibroids that is superior in most cases both to other surgical options—such as hysterectomy, open myomectomy, and uterine artery embolization—and to nonsurgical treatments.
The resection of submucosal myomas transcervically is a less invasive approach than are other surgical procedures. We can achieve excellent outcomes in terms of both fertility and the resolution of abnormal uterine bleeding and other symptoms. And we can do so with rates of complications, recurrence, and repeat resection that are much lower than commonly expected.
The Preoperative Evaluation
A comprehensive preoperative evaluation is critical. We want the best possible assessment of the size and location of the fibroid or fibroids, as well as the depth and even the vascularity of each fibroid.
We want to know how deeply each fibroid penetrates into the myometrium and whether it is resectable with the hysteroscope. With such an assessment, we can make a sound decision about whether the fibroid can be treated hysteroscopically and whether we, individually, have the expertise to do it. In general, the risk of fluid absorption, bleeding, and uterine perforation increases as the percentage of fibroid extending into the myometrium increases.
Diagnostic hysteroscopy, sonohysterography, transvaginal ultrasonography, and—in some cases—MRI may be used for this evaluation.
Just Before Surgery
The creation of false passages at the time of cervical dilation, cervical tears, and uterine perforation all are common to hysteroscopy performed with a stenotic, or unripe, cervix. It is therefore important that we consider administering a cervical-ripening agent as a prelude to surgery.
Some institutions and physicians will administer a cervical-ripening agent to women deemed to be at high risk of having cervical stenosis, such as patients who are nulliparous or who have had a cone biopsy. In other institutions, every patient undergoes a preoperative cervical-softening procedure.
One protocol worth serious consideration is the routine oral administration of 200 mcg of misoprostol (Cytotec) 8–12 hours before surgery for all patients, with high-risk patients receiving an additional dose 2 days before surgery. The protocol will result in a cervix that is softer, significantly less likely to tear, and certainly more easily dilated. This can be achieved with few and infrequent side effects, sometimes including some cramping, fever, or vaginal bleeding. Some, but not all, pharmacies will dispense the drug in single or double tablets; it is worth knowing where to refer patients.
Hysteroscopes and Fluid Management
Gynecologic surgeons today have a choice of three different types of instruments for resecting myomas hysteroscopically, and their relative popularity probably varies by region. The longest-standing option is a monopolar hysteroscope, which uses monopolar radiofrequency current in a wire loop. The bipolar scope, which employs bipolar energy in a wire loop, was introduced about 10 years ago.
The Smith & Nephew rotating resectoscope is the newest addition, having been available for almost a year. It differs from classic resectoscopes in two ways: The system converts electrical energy into mechanical energy to remove the fibroid, and it immediately evacuates the fibroid segments.
The uterine-distention medium used will vary by modality. Operative hysteroscopy that is performed in a monopolar environment, for instance, requires a hypotonic electrolyte-free solution, such as 1.5% glycine, 3% sorbitol, and 5% mannitol. Bipolar operative hysteroscopy can be performed using an isotonic, electrolyte-containing solution like saline or Ringer's lactate solution. The rotating resectoscope requires normal saline.
In any case, regardless of the chosen modality, fluid management is critical for intraoperative safety. It demands meticulous attention and vigilance. The exact inflow and outflow of any fluid must be monitored to prevent the complications that can result from excess fluid absorption and subsequent hyponatremia (with an electrolyte-free solution) or fluid overload.
A good fluid management system, which is essential to all operative hysteroscopy, will rapidly and continuously measure fluid input and output, and will provide a real-time assessment of the fluid deficit. Each hospital should have a protocol for fluid management that specifies, among other things, a fluid deficit at which surgery using each modality should be stopped.
We should be operating, in other words, with a set maximum allowable limit of fluid absorption. If we discontinue surgery when the fluid volume reaches this predetermined level, we can avoid major fluid-related complications.