Myomectomy of Submucous Leiomyomas

Leiomyomas are benign, monoclonal, smooth muscle tumors of the myometrium that, when in contact with the endometrium, are thought to contribute to infertility, abnormal uterine bleeding (AUB) and recurrent pregnancy loss (RPL). While there is general agreement that FIGO Type 0, 1 and 2 lesions contribute to these symptoms, the role of Type 3 tumors is unclear. Hysteroscopic myomectomy was first reported by Neuwirth and Amin in 1976 (1) and can be only performed when the leiomyomas are accessible transcervically and with an appropriate margin of myometrium between the tumor and the serosa (the outer free margin, or OFM) – a determination that requires careful preoperative evaluation with appropriate imaging techniques. Not all submucous myomas can be removed by the hysteroscopic approach and for FIGO Type 2-5 lesions, for example, attempting myomectomy would likely result in uterine perforation and possible visceral damage. Long-term outcomes of hysteroscopic myomectomy, at least for AUB, appear to be related to the complete resection of the submucous fibroid or fibroids.

When planning a hysteroscopic myomectomy there are several issues to consider including specific preparation of the cervix, endometrium, the leiomyoma and general medical preparation of the patient. 

Potential alternatives to GnRH-a include ulipristal acetate, a progesterone receptor modulator, and aromatase inhibitors (AI) although there are limited available data regarding their efficacy. Ulipristal acetate is administered orally, can rapidly stop bleeding and reduce the size of fibroids and, unlike GnRH-a, does not reduce the levels of circulating estradiol. AIs are also orally administered, but do reduce estradiol levels resulting in the symptoms of hypoestrogenemia. The AI letrozole has been compared to a GnRH-a, demonstrating similar volumetric reduction with fewer side effects (13).

Prior to performing hysteroscopic myomectomy the patient’s general medical state should assessed and then optimized. Anemia should be corrected with a combination of medical therapy to stop the bleeding and repletion of iron with appropriate oral therapy, or, if not tolerated or otherwise unsuccessful, with intravenous compounds (14, 15). Although GnRH-a are the most predictable agents for this purpose, formulations containing danazol, progestins, estrogens plus progestins or ulipristal acetate may also be used for this purpose. If the patient has other conditions or comorbidities such as coagulopathies, hypertension, diabetes, and cardiac or respiratory disorders, she should be evaluated by appropriate clinicians and treated as appropriate to optimize her medical condition.

The specific technique used for performing hysteroscopic submucous myomectomy depends on the resources available to the surgeon as well as surgical training and skill. When operating on women with infertility or RPL, including those who wish to preserve fertility, the surgical procedure should be designed and executed in a way that optimizes endometrial and myometrial integrity. This includes minimization of the use of RF electrical energy and otherwise operating in a fashion that preserves myometrial integrity..

In general, the techniques appropriate for small Type 0 leiomyomas are related to the diameter of the tumor and the dilation of the cervix. For example, after entering the endometrial cavity with an operative hysteroscope, the stalk can be transected either with hysteroscopic scissors or an RF instrument such as a monopolar or bipolar needle. If the leiomyoma diameter is less than the dilated diameter of the cervix, the detached fibroid can be grasped and extracted using a hysteroscopic tenaculum passed through the 5 or 7 Fr instrument channel. For larger lesions, the hysteroscope can be removed and the cervix dilated to a diameter adequate for extraction. For this approach, and after replacement of the hysteroscopic assembly, it is usually necessary to crimp the cervix with another tenaculum to seal the cervix, thereby preventing loss of distending media and loss of dissension of the endometrial cavity. When such an approach is not feasible, in utero morcellation or partial vaporization the lesion can be performed prior to transection using either with a needle or a vaporizing electrode. The morcellated or partially vaporized fragments can then be removed using the tenaculum or another appropriate grasping instrument. Blind removal should be discouraged as perforation becomes a substantial risk.  Other approaches to these small lesions that employ a resectoscope or hysteroscopic morcellator are described subsequently. 

For Type 0 fibroids, sequential strips of tissue are resected and removed until the entire fibroid is morcellated or until it reaches removed with a hysteroscopic tenaculum. The resected “chips” of tissue are removed as appropriate to maintain visualization of operative field by trapping chips between the inactivated loop and the distal tip of the resectoscope then pulling them through the outer sheath which should be left in place in the endometrial cavity. When a leiomyoma is a superficial Type 1 lesion it can be managed in a fashion similar to Type 0 leiomyomas. However, deeper Type 1 fibroids require the approach appropriate for more superficial Type 2 lesions.

 There are a number of techniques available for deeper Type 1 lesions. One is to start the resection where the leiomyoma is adjacent to the normal uninvolved endometrium. The resectoscope and base of the loop electrode are oriented toward the center of the fibroid to ensure that the deepest resection is within the tumor’s more central portion (Figure 4). The loop is extended, activated and then retracted through the tissue in a fashion that forms a trough that is oriented parallel to the plane of the adjacent normal endometrial surface. This trough demarcates and distinguishes the margin of the intracavitary from the intramural portion of the fibroid. Then, the resection progresses in a serial fashion resulting in removal of this lateral intracavitary quarter of the leiomyoma. The contralateral quarter of the intracavitary portion is then resected in a similar fashion working from the lateral to central aspect of the lesion. This process leaves intact the remaining intramural component of the leiomyoma which will typically begin to extrude into the endometrial cavity. This extrusion may be facilitated by time, sharp or blunt dissection or the use of a uterotonic such as prostaglandin F2α (18, 19). Blunt dissection can be accomplished with hysteroscopic scissors or with the robust “cold Collins knife”, a dissecting instrument available to attach to an RF resectoscope(3). 

Figure 4. Depiction of Loop Resection of Deep Type 1 Leiomyoma.

Leiomyoma extrusion also offers a method for identification of the pesudocapsule, the nearly avascular zone of compressed loose areolar tissue surrounding the leiomyoma at its interface with the myometrium. If this zone is carefully and adequately dissected (Figure 5) the lesion can be removed in a fashion that minimizes myometrial damage. Resection of the residual portion of the leiomyoma comprises some combination of continued resection of the lesion with dissection within the pesudocapsule. Tissue bridges are transected with brief activations of the ESU until the leiomyoma has been completely removed. In large case series using a similar technique there also was a low risk of postprocedural adhesions (3, 20).

RF Vaporization

A major advantage of the RF bulk vaporization technique is the absence of the tissue chips that require periodic interruption of the procedure so that they can be removed from the surgical field. Regardless, the surgeon should provide the pathologist with representative sample tissue for histopathological evaluation.

For fundally located tumors, this incision can allow the aperture of the device to be positioned at the equator of the leiomyoma, an orientation generally necessary for successful removal. The morcellating probe can also be used as a blunt dissection device once the pesudocapsule is identified and entered. High leiomyoma density, and, in particular, calcification, can be a challenge for electromechanical systems, a feature that may be visible sonographically. In such instances RF based techniques may be more efficient and ultimately successful.

Most patients require little post-operative care aside from simple analgesia, particularly if their procedure is performed under local anesthesia. Most can return to baseline activities immediately with limitations based upon whether and if they have been provided general anesthesia or systemic anesthetic or psychoactive formulations. 

Longer term care, in part, depends upon the needs of the patient and, in particular, the indication for the procedure. For example, second-look hysteroscopy may be considered when complete fibroid resection was not possible and particularly if the patient is infertile or desires future fertility and is at enhanced risk for the development of post-operative adhesions. The value of second-look hysteroscopy following complete resection of, for example, a deep Type 1 leiomyoma, is unclear as the incidence of adhesions in this circumstance has not been well evaluated.