粘膜下肌瘤宫腔镜电切术（图文演示）

HYSTEROSCOPIC   RESECTION   OF   SUBMUCOUS   LEIOMYOMAS
Authors
R de Tayrac, A Gervaise, H Fernandez
Abstract
The description of the hysteroscopic resection of submucous leiomyomas covers all aspects of the surgical procedure used for the management of submucous leiomyomas.
Operating room set up, position of patient and equipment, instruments used are thoroughly described. The technical key steps of the surgical procedure are presented in a step by step way: adjustment of system, operative steps.
Consequently, this operating technique is well standardized for the management of this condition.

中文版：粘膜下肌瘤宫腔镜电切术（中文图文演示）

1. Introduction
Operative hysteroscopy has modified the surgical management of benign uterine neoplasms. It is now performed to treat lesions that used to require a hysterectomy, including uterine fibroids (leiomyomas), polyps, malformations and adhesions (Fernandez, 1998).
Uterine leiomyomas are the most common benign tumors in women of childbearing age. Their incidence is estimated to be 20%, half of which is symptomatic (Rongières, 1999). Submucous leiomyomas can be treated by operative hysteroscopy (Hallez, 1995; Neuwirth, 1983). The trans-cervical endouterine resection technique is indicated for symptomatic leiomyomas (menometrorrhagia, postmenopausal metrorrhagia, infertility). It is a conservative and minimally invasive treatment. Its long-term (>5 years) success rate for bleeding disorders ranges from 68% to 94% (Cravello, 1999).

2. Classification
• Histology

Leiomyomas (also referred to as fibroids) are poorly vascularized tumors composed of smooth muscle fibers surrounded by collagen fibers. They are firm and can become calcified. These benign tumors must be distinguished from leiomyosarcomas.

1. Round ligament
2. Uterine tube
3. Fundus of uterus
4. Proper ovarian ligament
5. Uterine cavity
6. Endometrium
7. Myometrium
8. Mesometrium of broad ligament
9. Uterine artery
10. Ureter
11. Cervical canal
12. Uterosacral ligament
13. External uterine opening
14. Vagina

• Leiomyomas



Depending on the position of the largest transverse diameter of the leiomyoma in relation to the myometrium, 3 types of leiomyomas can be distinguished:
1. Subserous leiomyomas, located at the surface of the uterus on the peritoneal side;
2. Intramural leiomyomas, embedded in the myometrial wall;
3. Submucous leiomyomas, protruding into the uterine cavity.
Only submucous leiomyomas can be treated by operative hysteroscopy.

• Submucous leiomyomas

Three grades of submucous leiomyomas can be identified, according to the degree of intramural development:
1. Grade 0: development limited to the uterine cavity (pedunculated or with limited implant base);
2. Grade 1: partial intramural development (endocavity component >50%);
3. Grade 2: predominantly intramural development (endocavity <50%).

3. Indications
Indications
- symptomatic leiomyoma: menometrorrhagia, postmenopausal metrorrhagia, dysmenorrhea, infertility, history of early miscarriage;
- submucosal localization (grades 0 and 1; grade 2 if thickness of the myometrium outside of the leiomyoma is >5 mm);
- size <50 mm;
- a single leiomyoma or bifocal localization if small in size.

Contraindications
- contraindications to anesthesia;
- genital infections;
- pregnancy;
- multiple leiomyomas (indication for open polymyomectomy).

4. Preop period
&#8226; Ultrasonography

Pelvic ultrasonography via the abdominal and endovaginal route delineates the size and grade of the submucous leiomyoma(s). For grade 2 submucous leiomyomas, ultrasonography is used to measure the distance between the external margin of the leiomyoma and the serous membrane of the uterus to assess the risk of intraoperative perforation of the uterus. The ultrasound is also used to search for associated subserous or intramural myomas.
It is also possible to perform a saline contrast hysterosonography, involving the injection of saline into the uterine cavity during continuous scanning.

&#8226; Diagnostic hysteroscopy

If the ultrasonographic results are not precise enough, a diagnostic hysteroscopy can confirm the submucosal nature of the fibroid(s). This specifies the quantity, size, type and localization of the tumors.

Informing the patient
When a hysteroscopic leiomyoma resection is planned, the patient must be informed of the following:
- risks of complications: uterine perforation, endometritis and metabolic dyscrasias caused by glycine absorption;
- possible need for a complete resection during a second procedure (40-50 mm leiomyomas and grade 2 leiomyomas);
- possibility of failure of the procedure, with the need for a secondary hysterectomy.

Preoperative medical treatment
Preoperative GnRH agonist therapy (Gonadotropin Releasing Hormone) may be prescribed for 2 to 3 months. The goal of this treatment is to reduce the volume of the leiomyomas by 30% to 40% prior to the procedure (Friedman et al., 1987; Lawrence et al., 1991). In this case, the procedure should be scheduled 6 to 10 weeks after the first analog injection. This treatment is particularly indicated in cases of severe anemia, as the GnRH analogues can treat the anemia by a suppression of any menometrorrhagia. In postmenopausal women with cervical stenosis, local or general estrogenotherapy can be prescribed for 2 to 3 weeks preceding the procedure to facilitate the dilatation of the cervix. Cervical priming, especially in nulliparous patients, can also be achieved by administering Misoprostol intravaginally 2 hours before the procedure.

5. Operating room
&#8226; Patient

- general anesthesia or local-regional anesthesia (epidural or spinal anesthesia);
- lithotomy position;
- perineal and cervicovaginal disinfection;
- prophylactic antibiotics when anesthesia is induced to prevent endometritis;
- urinary catheter (optional).

&#8226; Team

1        The surgeon is seated between the patient’s legs.
2        The assistant stands to the right of the surgeon.
3        The anesthesiologist is at the patient’s head.

&#8226; Equipment

Equipment placed to the surgeon’s left:
- endocamera and monitor;
- devices to control pressure and flow of distension media: a constant uterine distension must be maintained. The pressure is controlled continually by suction and irrigation pumps;
- standard or specifically adapted tubing for each type of pump;
- distension medium: glycocolle (1.5% glycine solution packaged in 3-liter plastic bags) is the medium most commonly used with monopolar cautery. With bipolar cautery, saline is used.
- light source: the same type of Xenon light source is used for diagnostic hysteroscopy, surgical hysteroscopy and laparoscopy.
- high-frequency electrosurgical generator:
1)        unipolar electrosurgery: high-frequency current is used (>300 000 Hz). Division of tissues is done with an unmodulated current that produces a rapid rise in temperature.
2)        bipolar electrosurgery: saline is used as the distension medium to decrease the risk of metabolic complications. The operating channel is narrower, which simplifies the dilation. “Spray” and “desiccation” modes exist. The maximum power used by the generators is 200 Watts.

6. Instruments

Usual equipment:
1. Hegar’s dilators (No. 1 to No. 10, diameter increasing from 0.5 to 1 mm);
2. Speculum with detachable valves;
3. Resection electrode (4 mm) ending with a 90° cutting loop (7 to 9 mm) for monopolar hysteroscopy, or a 90° 24 French cutting loop or a 5 French tip for bipolar hysteroscopy;
4. Rigid endoscope between 2.7 and 4 mm in diameter; the direction of view normally used in hysteroscopy is 12°.
5. Resectoscope: from 7 to 9 mm with two channels, one internal (irrigation) and one external (suction) for monopolar hysteroscopy, or from 5 to 9 mm with two channels and a double current operation channel for bipolar hysteroscopy. In all cases it has an operative handle: passive (electrode in) or active (electrode out);
6. Hysteroscope;
7. Irrigation and suction channels;
8. Two Pozzi graspers;
9. Hysterometer.

7. Adjustment of system
Monopolar system
The resection techniques described use monopolar current. The suction-irrigation pump must be preset to maintain an intrauterine pressure <=100 mm Hg, a 250 mL/s flow rate and a 0.2 bar suction pressure.
The procedure must not last longer than 45 minutes. The total volume of glycocolle used must be limited to 6 L. Precise monitoring of the distension liquid inflow and outflow must be done, and the procedure must be stopped immediately if there is a difference between the irrigation and suction flow rates (a 500 mL difference can be allowed). If there is too much of a difference, or if the procedure lasts too long, a chemistry panel must be performed immediately after the procedure to check for hyponatremia.

Bipolar system
Bipolar spray electrosurgery is a more recent system. Its innocuousness and efficacy seem to be equivalent to the monopolar devices that are usually used. The diameter of the operating channel is identical for the new 24 French cutting loops and is smaller for the bipolar system when 5 French bipolar tips are used, avoiding the need for dilation. The distension medium used is saline, which decreases the risk of metabolic complications, and allows the procedure to last longer. The resection technique with the 24 French electrode, the operative steps and adaptations to the types of fibroids are the same as for hystero-resection using a monopolar system. The 5 French bipolar system can be used for fibroids less than 20 mm in diameter. The technique of this system involves contact spraying of the base of the fibroid if it is pedunculated, or of the entire fibroid if it is sessile. Theoretically, bipolar systems are safer because they can be used with saline. In contrast to the monopolar system, which penetrates into the tissues and can be partly obscured at certain points, the bipolar system is constantly visible.

8. Operative steps
&#8226; Dilation of the cervix


Bimanual examination is carried out to evaluate the position of the uterus before dilation. This lowers the risk of perforation. A speculum with detachable valves is inserted and the cervix is grasped with 2 Pozzi or Museux-Palmer graspers placed in a 3 o’clock and 9 o’clock position to bring the uterus into an intermediary position. The procedure routinely begins with a diagnostic hysteroscopy if this was not done during the preoperative evaluation. The cervix is then dilated with Hegar’s dilators, using progressively larger dilators until a No. 10 dilator can be inserted.

&#8226; Inserting the resectoscope

The endocamera, the resectoscope and the electrode are assembled and connected to the Xenon light source, the hysteroscopic unit, the electrosurgical generator and the suction-irrigation tubing. Care must be taken to remove all air bubbles from the tubing. The resectoscope is then introduced under videoscopic guidance and the fibroid(s) are identified and analyzed for quantity, size, type and precise location. The hysteroscopic resection is performed using the cutting mode of the electrosurgery device.

&#8226; Resection of leiomyomas
&#8226; Pedunculated leiomyomas

For pedunculated leiomyomas (grade 0) smaller than 20 mm, the base of the leiomyoma is resected under visual guidance, at the level of the healthy endometrial surface. The leiomyoma must then be extracted using a loop (without current) or a blunt dissector.
For grade 0 leiomyomas larger than 20 mm, the gynecologist progressively resects the leiomyoma under visual guidance, from the free margin to the level of the healthy endometrial surface. The shavings resulting from the resection should be removed regularly during this step using either the loop (without current) or blunt dissector, to maintain proper endoscopic visibility.

&#8226; Grade 1 and 2 leiomyomas

For grade 1 and 2 leiomyomas, the gynecologist begins by resecting the intracavitary portion. After removing the shavings from the resection with the loop or blunt curette, it is essential to identify the limit between the intramural portion of the leiomyoma and the healthy myometrium (this bleeds more easily, is more pink in color and is less firm), so that that the end of the resection can be selective, and is not pursued beyond the leiomyoma. Several methods can facilitate the protrusion of the intramural portion of the leiomyoma in the cavity: massage of the leiomyoma with the loop, hydromassage by alternating the opening and closing of the suction pump and simultaneously injecting 10 IU of oxytocin (slow IV). The resection is then completed, keeping the edges in view at all times.

&#8226; Difficult cases
In certain, more difficult cases (leiomyoma >40 mm, poor visibility, technical problems, operative time >45 minutes or glycocolle deficit >500 mL), the gynecologist must leave the base of the leiomyoma in place and schedule a second procedure.
Special precautions must be taken when resecting a leiomyoma in the horn of the uterus because of the risk of perforation of the horn (thickness of the uterine wall = 3-5 mm) and the risk of injuring the ostium of the uterine tubes (which must remain under visual control) in women of childbearing age.
In case of localized bleeding, the resection loop may be used in “coagulation mode” to perform hemostasis, provided that it is done selectively, because diffusion of the coagulation can be deleterious for the endometrium.
In patients undergoing menopause who present with a polypous endometrium, it is useful to perform a hysteroscopic resection of the endometrium (endometrectomy) at the end of the procedure.

9. Postop management
Hysteroscopic leiomyoma resection is performed in an outpatient setting. IV analgesics are not indicated.
A follow-up diagnostic hysteroscopy 2 months after the procedure is necessary only if infertility was the indication for the leiomyoma resection. The purpose of this control is to check for postoperative adhesions (10% of cases). It is usually easy to remove these recent, fine adhesions during the diagnostic procedure with the pointed tip of the hysteroscope.
A follow-up diagnostic hysteroscopy is also performed if the gynecologist suspects the persistence of intracavitary fibromatous tissue after the resection of large fibroids, to determine if a new operative hysteroscopic procedure is indicated.