Resection of Submucous Myoma
Although uterine myomata may occur at any location within the uterus, the submucous variety accounts for most clinical symptoms. The usual clinical presentation for these lesions includes heavy and prolonged bleeding. The diagnosis is made most commonly by diagnostic hysteroscopy and less commonly by radiographic imaging procedures (Fig. 111–1A, B). The hysteroscopic appearance of a submucous myoma is consistently recognizable. A rounded mass lesion is seen (Fig. 111–2). Myomata are white or pink (Fig. 111–3). Their contour may be spherical or hemispherical, and they always project into the uterine cavity. Close-up scrutiny reveals numerous thin-walled, sinusoidal vessels branching upon the surface. Areas of ecchymosis or adherent blood clots are commonplace (Fig. 111–4). If a viscid medium is used to distend the uterus, the actual site(s) of hemorrhage may be viewed as the blood spews from the ruptured, surface, sinusoidal vessel (Fig. 111–5).
The treatment of choice for a submucous myoma is hysteroscopic destruction, preferably by resection. Alternative treatments include myolysis utilizing laser fiber or bipolar needles, or arterial embolization performed by invasive radiology. The obvious advantages of hysteroscopic resection are that it is less invasive than radiologic embolization, which entails arteriography; additionally, the physical removal of the myoma provides a specimen for the pathologist. Although leiomyosarcoma is not common, it is a risk and is associated with the presence of what may appear to be an otherwise benign myoma.
Candidates for hysteroscopic treatment should be prepared with the intramuscular administration of a gonadotropin-releasing hormone (GnRH) agonist (Lupron), 3.75 mg monthly for 3 months before the anticipated surgery. Lupron will reduce the size of the myoma, will reduce its vascularity, and will atrophy the surrounding endometrium. For large submucous myomata, the hysteroscopy should be accompanied by a simultaneous laparoscopy.
The patient is positioned as described in Chapter 106. The instruments of choice are the resectoscope fitted with a cutting-loop electrode, a fine electrosurgical needle, or a neodymium yttrium-aluminum-garnet (Nd-YAG) laser fiber (Fig. 111–6A, B). Most hysteroscopic surgeons will excise the myoma by shaving it with the resectoscope loop (see Fig. 111–6A). Therefore, a nonelectrolytic distending medium is required. Typically, the most appropriate medium in this case will be 5% mannitol. The medium is infused via tubing through the intake port of the operative sheath. Before the instrument is inserted, all the air is purged from the connecting tubing and the operating sheath. An endoscopic television camera is attached to the eyepiece of the optic, and the instrument is inserted transcervically into the uterine cavity under direct vision.
The myoma is located, and the cavity is flushed to remove blood and debris. The myoma is carefully mapped by circumnavigating around it with the hysteroscope. The pedicle of the myoma is identified. The relative width of the attachment is noted, as is its site of attachment. The uterine cornua and the tubal ostia are similarly located. The objective lens of the resectoscope is withdrawn away from the lesion to give the best panoramic view of the field (Fig. 111–7A). The cutting loop of the resectoscope is extended outward to the superior and posterior surfaces of the myoma, making contact with the lesion. The electrosurgical generator pedal activates the flow of electricity and cuts the myoma as the electrode is brought back toward the sheath of the resectoscope (Fig. 111–7B
