Endometrial Ablation 

Updated: Apr 16, 2021
Author: Stephanie Deter Pickett, MD; Chief Editor: Michel E Rivlin, MD 

Overview

Background

Endometrial ablation is an outpatient procedure that removes or destroys the endometrial layers. The opposing walls of the myometrium collapse onto each other, and the damaged tissue contracts and develops into a scar.[1] Any endometrium remaining after the ablation is trapped beneath the scar, preventing further bleeding. Estimation of the number of endometrial ablations performed each year is difficult, because many are performed in the office setting.

Endometrial ablation is performed to reduce menstrual bleeding, such as menorrhagia. Menorrhagia is menstrual bleeding that is heavy in amount or duration and that occurs at regular intervals. Loss of more than 80 mL of blood per menstrual cycle is considered abnormal. Menorrhagia affects approximately 10-30% of premenopausal women and up to 50% of perimenopausal women. Abnormal bleeding is a common reason for outpatient gynecologic visits and is one of the most common causes for surgery among women.

In the past, hysterectomy was the most common surgical treatment for menorrhagia; 10% of hysterectomies are performed for menstrual disorders. Although endometrial ablation is not a pure substitute for hysterectomy, it offers patients a fast, outpatient procedure, with little to no postoperative downtime; It also affords a reasonable surgical option for those patients who have failed, declined, or are ineligible for medical therapy, and who also desire to avoid hysterectomy.[2, 3, 4, 5]

The etiology of menorrhagia may not always be known, but endometrial hyperplasia or carcinoma must be excluded as the cause of bleeding before proceeding to the endometrial ablation.

Although the first medical literature reports of endometrial destructive procedures are older than 100 years, widespread adoption of this modality did not occur until the advent of hysteroscopically guided techniques.[2, 6, 7, 8, 9, 10] Until the mid-1990s, hysteroscopically guided ablation (resectoscopic endometrial ablation [REA]) using laser, fulguration, or vaporization techniques was the most common approach.[11, 12, 13, 14]

Since then, global endometrial ablation (GEA) devices, developed to treat all areas of the endometrial cavity simultaneously or with minimal manipulation of the device, have simplified the application of endometrial ablation and extended the location of the procedure to the office setting. These devices require less operator time and training to achieve excellent results. To date, 5 GEA devices have been approved by the US Food and Drug Administration (FDA) for minimally invasive treatment of idiopathic menorrhagia (see Equipment).

GEA techniques have improved the ease with which gynecologic surgeons can effectively treat abnormal uterine bleeding of benign origin. Improvements in these devices have come quickly, including the ability to treat submucosal fibroids and irregularly shaped endometrial cavities. The high overall success and patient satisfaction rates reported with GEA techniques make them a viable option for conservative surgical management.

Indications

Endometrial ablation is indicated for the treatment of menorrhagia in premenopausal or perimenopausal women with normal endometrial cavities. It may also be indicated for the treatment of postmenopausal bleeding of benign origin. Premenopausal patients should be advised that whereas endometrial ablation generally decreases menstrual bleeding, a small percentage of patients will experience no change.

Patients with anovulatory bleeding and bleeding secondary to fibroids are potential candidates for the procedure, but they should be aware that endometrial ablation does not specifically address ovulatory dysfunction and, by itself, does not remove fibroids. Thus, these patients may be at higher risk of unsatisfactory results and may be better served by other treatments, either medical or surgical.

The GEA devices currently available are approved for the treatment of abnormal uterine bleeding and intramural or submucosal fibroids smaller than 2 cm. Only the microwave endometrial ablation device (see Equipment) is approved for use in the presence of submucosal fibroids of up to 3 cm.

Some of the previous contraindications to endometrial ablations, including irregular cavity shape and larger-than-average cavity size, have been addressed by some of the global endometrial ablation devices. The microwave endometrial ablation device is FDA-approved for uteri measuring up to 14 cm, and the hydrothermal ablation device (see Equipment) is FDA-approved for irregularly shaped cavities.

The basic preoperative criteria for any patient opting for endometrial ablation are, at a minimum, the following:

  • Abnormal uterine bleeding of benign etiology (as evidenced by preoperative endometrial sampling and histologically benign findings)

  • No desire for future fertility

  • Desire to retain the uterus or to avoid hysterectomy

Although failure of medical therapy is not a prerequisite for the procedure, it is an important consideration.

Contraindications

Absolute contraindications for endometrial ablation include the following:

  • Pregnancy or a desire for future pregnancy

  • Active urogenital or pelvic infection (eg, cystitis, vaginitis, cervicitis, endometritis, salpingitis, pelvic inflammatory disease [PID], or tubo-ovarian abscess [TOA])

  • Suspected or documented premalignant or malignant conditions of the endometrium or uterus

Additional contraindications may include the following:

  • Recent uterine infection

  • A cavity that exceeds the device’s functional length and uterine diameter

  • Hydrosalpinx

  • History of classical cesarean section

  • History of a transmural myomectomy

  • Uterine anomalies

Infections should be treated preoperatively. When possible, repeat testing to document resolution should be completed preoperatively. In situations where posttreatment testing is not standard (eg, PID or TOA), clinical criteria should be used to document resolution of the infection.

Premalignant abnormalities of the endometrium should be treated with high-dose progestins or surgery, depending on the abnormality. Malignant conditions of the endometrium are treated by means of hysterectomy, with or without adjuvant radiation or chemotherapy. Endometrial ablation should not be performed in patients who have or are suspected of having either of these disease processes.

Therapy with the levonorgestrel-releasing intrauterine system (LNG-IUS) should be given particular consideration in patients with comorbid conditions predisposing to a higher risk of endometrial hyperplasia or carcinoma (eg, obesity, diabetes, family history, or anovulation). Endometrial carcinoma has been reported in patients who previously underwent endometrial ablation[15, 16, 17, 18, 19, 20, 21] ; thus, definitive surgical therapy with hysterectomy should be considered in high-risk patients, unless they are poor surgical candidates.

The bipolar energy ablation device (see Equipment) and the microwave ablation device should not be used in patients with previous classical cesarean delivery or transmural myomectomy out of concern for possible transmural thermal injury to the abdominal and pelvic organs. In addition, preoperative ultrasonographic evaluation must verify that transmural thickness is at least 1 cm in all areas of the uterus before microwave ablation is done, and intraoperative hysteroscopy is recommended to ensure uterine wall integrity.[22, 23]

Finally, reablation with a GEA device should be avoided because of the theoretical increased likelihood of transmural energy transmission. Repeat GEA is not approved by the FDA.

Outcomes

Satisfaction rate with endometrial ablation is high. Compared with hysterectomy, endometrial ablation leads to fewer hospital stays and complications. In addition, it is more cost-effective than a hysterectomy, even when the need for repeat procedures or subsequent hysterectomy is factored in. Increased operator skill level and technique lead to decreased operating time and complications, particularly with REA techniques.

GEA has been shown to be at least as effective as REA. One of the challenges in the comparison of GEA techniques is the relative lack of direct comparison data for the various GEA devices. However, many of these devices have been tested against the previously standard resectoscopic methods.

One study compared bipolar radiofrequency (RF) endometrial ablation with hydrothermablation for the treatment of menorrhagia at 5-year follow-up. Results showed that bipolar RF ablation was more effective and led to fewer surgical reinterventions.[24]

A retrospective study by Wyatt et al indicated that about half of women with preoperative heavy menstrual bleeding will experience pain resolution following RF endometrial ablation. In the study, 100 women reported preoperative dysmenorrhea, with postprocedure symptom resolution achieved in 48 of them (48%). The study also found that while postablation resolution of dysmenorrhea was characterized by a decrease in bleeding volume, it was not associated with a reduction in bleeding frequency.[25]

In a study by El-Nashar et al, the rate of failure (defined as bleeding or pain after endometrial ablation that required hysterectomy or reablation) for GEA was 16-30% at 5 years.[26] Failure was most likely to occur in women younger than 45 years and in women with parity of 5 or more, prior tubal ligation, and a history of dysmenorrhea. After endometrial ablation, 11-36% of women had a repeat ablation or other uterine-sparing procedure.

A review and meta-analysis assessed failure rates for second-generation endometrial ablation. Of the 10 parameters assessed (age, myomas, history of tubal ligation, body mass index, parity, preexisting dysmenorrhea, caesarean delivery, bleeding pattern, uterus position, and uterus length), dysmenorrhea at baseline was the strongest predictor of ablation failure.[27]

Hysterectomy is superior to ablation in attained amenorrhea. After ablation, the rate of women who eventually go on to have a hysterectomy has been reported as 20-30%. In the study by El-Nashar et al, predictors of amenorrhea included age greater than 45 years, uterine length less than 9 cm, endometrial thickness less than 4 mm, and use of radiofrequency ablation.[26]

Outcome measures for GEA have included bleeding assessment surveys, overall satisfaction assessment surveys, eumenorrhea rates, and amenorrhea rates. For ease of comparison, amenorrhea outcomes are reviewed here. It is noteworthy that for all of the global techniques, assessment of combined amenorrhea, hypomenorrhea, and eumenorrhea rates reveals very high success rates and overall satisfaction rates, typically approaching or exceeding 90%.

Although 1 randomized trial showed that endometrial ablation with cryotherapy was less likely than rollerball endometrial ablation to induce amenorrhea at 1 year, initial studies using a freeze time longer than 10 minutes (current FDA protocol) have resulted in amenorrhea rates higher than 60%.[28] Larger studies are under way to confirm these data.

Randomized trials comparing thermal balloon ablation with rollerball ablation showed that amenorrhea was less likely with the former at 12 and 36 months; however, there were no differences in amenorrhea rates at 5 years.[28]

A comparison of hydrothermal ablation with rollerball ablation showed that the initial amenorrhea rates were similar for the 2 techniques and that the rates remained relatively similar at the 3-year mark.[29]

Long-term follow-up studies of bipolar energy ablation showed an initial amenorrhea rate of 51% and a 65% rate at the 3-year mark.[30] Comparisons of this technique with thermal balloon ablation have been performed, with higher amenorrhea rates reported for the former.[31] In addition, bipolar energy ablation is associated with lower intraoperative and postoperative pain than thermal balloon ablation is.[32]

With microwave ablation, follow-up studies have revealed a 38% amenorrhea rate at 3 years. At 1 year, 2 years, or 5 years, amenorrhea rates were not significantly different from those seen with endometrial resection.[28]

The use of the levonorgestrel-releasing intrauterine contraceptive system has been found to be as effective as GEA for treating menorrhagia in women with normal uterine cavities.[33]

 

Periprocedural Care

Patient Education and Consent

Informed consent must be obtained. Patients should be counseled that endometrial ablation is not considered a form of sterilization and that subsequent pregnancies, though atypical, have been reported and are associated with a wide range of complications, including spontaneous abortion, abnormal placentation, preterm labor, preterm delivery, uterine rupture, and antepartum hemorrhage.[34, 35, 36, 37]

Preprocedural Planning

Obtain a careful history, and perform a physical examination. Remove any indwelling intrauterine device (IUD) that may be present (this can be done at the same time as the procedure).

Preoperative endometrial preparation

Endometrial ablation is most effective when the endometrium is resected to the level of the basalis, which is approximately 4-6 mm deep.[38] Endometrial thinning before ablation has been shown to improve both the operating conditions and the initial postoperative outcome. The bipolar ablation device is the only global endometrial ablation (GEA) device that has been shown to work with equal effectiveness with or without pretreatment.

Danazol, medroxyprogesterone, and gonadotropin-releasing hormone (GnRH) agonists have been used to pretreat the endometrium and obtain atrophy. Best results are seen after 6 weeks of drug therapy.[38] GnRH analogues produce more consistent endometrial thinning. Notably, pretreatment with GnRH agonists or danazol before resectoscopic endometrial ablation (REA) results in higher amenorrhea rates at 12 months, shorter procedures, greater reported ease of surgery, and lower postoperative dysmenorrhea rates.[39]

Dilation and curettage can be performed immediately before ablation to thin the endometrial lining by mechanical means. This is particularly recommended with the thermal balloon device.

Finally, timing the procedure to the follicular phase of the menstrual cycle can be used in place of the aforementioned methods.

Preoperative cervical preparation

Preoperative cervical preparation regimens include both intraoperative cervical dilation and the use of preoperative oral or vaginal regimens aimed at cervical softening or dilation. These outpatient regimens typically involve the use of misoprostol either the evening before the procedure, the morning of the procedure, or both. Because of the minimally invasive nature of endometrial ablation procedures, aggressive dilation regimens are generally not required.

Antibiotic prophylaxis

At present, no randomized controlled data support routine use of prophylactic antibiotics for REA and GEA procedures. Furthermore, observational data reveal an extremely low risk of infection. Accordingly, the American Congress of Obstetricians and Gynecologists (ACOG) does not recommend the routine use of prophylactic antibiotics for endometrial ablation.[40] However, the use of preoperative antibiotics, especially in the office setting, is not uncommon.

Sterilization at time of ablation

Because endometrial ablation is not itself a method of permanent sterilization, patients sometimes elect to undergo concomitant elective tubal sterilization when undergoing endometrial ablation. The sterilization procedure may be performed laparoscopically either before or after the ablation. In addition, some GEA techniques have been successfully performed in conjunction with hysteroscopically guided intratubal placement of microinserts (Essure; Conceptus, Inc, Mountain View, CA) for sterilization.

Because these microinserts may transmit heat through the tubes, the operator should strongly consider delaying their placement until after completion of the ablation. It is worth noting that Conceptus has issued a warning against concomitant performance of ablation and Essure placement, on the grounds that postoperative development of uterine synechiae may compromise subsequent tubal occlusion testing (hysterosalpingography).[41]

In view of the lack of long-term data involving these concomitant hysteroscopic procedures, caution is advised in the implementation of such techniques.

Office-based ablation

All of the GEA devices described in this article may be used in the outpatient office setting. Many regimens for analgesia are available in this setting, including pain medications ranging from preoperative nonsteroidal anti-inflammatory drugs (NSAIDs) to oral or intramuscular narcotics and adjunct medications ranging from oral anxiolytics to intravenous (IV) sedatives. Anesthesia may range from local anesthesia to monitored anesthesia care by an anesthesiologist.

Even in settings outside the operating room, physicians must maintain the appropriate emergency and operative equipment and protocols for handling rare complications such as anaphylaxis or allergic reactions, significant vagal reactions, hemorrhage, uterine perforation, and pelvic organ injury.

Preprocedural Evaluation

Laboratory testing

Urine human chorionic gonadotropin (hCG) testing can detect hCG levels as low as 20 mIU/mL (International Reference Preparation). The test becomes positive approximately 1 week after conception. Perform the test preoperatively on the day of surgery.

Endometrial ablation should not be performed in the presence of active pelvic infection; accordingly, gonorrhea and chlamydia testing is necessary.

Ultrasonography and hysteroscopy

Either pelvic ultrasonography or hysteroscopy is recommended to evaluate the uterine anatomy and measure uterine length before or at the time of the ablation. Ultrasonography may be used to assess for and measure intracavitary or submucosal myomas (see the images below).

Volume contrast imaging showing sagittal view of t Volume contrast imaging showing sagittal view of the uterus and endometrium (left) and coronal view of the endometrium with an endometrial polyp in the fundal region (arrow). Images courtesy of Noah Lazebnik, MD.
The orthogonal views (sagittal, axial and coronal) The orthogonal views (sagittal, axial and coronal), as well as the rendered 3D image of the endometrium, taken by vaginal 3-D ultrasound transducer. Images courtesy of Noah Lazebnik, MD.

Hysteroscopy is more commonly used before endometrial ablation to assess the length of the uterine cavity and to evaluate the internal architecture of the uterus. It can also visualize polyps, abnormally shaped cavities, and leiomyomas. The presence of these may be limitations to certain ablation techniques.

Endometrial biopsy

Endometrial biopsy is used to exclude endometrial hyperplasia and malignancy. For premenopausal patients in particular, endometrial biopsy can easily be accomplished in the office setting in most cases, and the results can be reviewed before ablation is scheduled. However, in patients unable to tolerate office biopsy or in clinical scenarios not amenable to sampling in the office, dilation and curettage with possible hysteroscopy is warranted to rule out premalignant and malignant conditions of the endometrium.

Equipment

When no other abnormalities are present, preoperative imaging with transvaginal ultrasonography may be sufficient for achieving an accurate assessment of overall uterine size and shape. In cases of suspected uterine abnormalities, saline-infusion sonohysterography or office hysteroscopy may be used to characterize the uterine cavity and aid in proper selection of the ablation device.

Proper selection of a device for endometrial ablation should take into account the following factors:

  • Cavity size and shape

  • Previous uterine surgery

  • Location of procedure

  • Results of the preoperative evaluation

For many patients, medical therapy often controls abnormal uterine bleeding. However, failure of such therapy or inability to tolerate it is not an absolute prerequisite for endometrial ablation.[2] Patients with abnormal uterine bleeding secondary to systemic disease should be managed medically; the use of endometrial ablation in these patients requires further study.

Equipment for resectoscopic procedures

REA procedures include rollerball fulguration, laser fulguration, vaporization, and endomyometrial resection. All are performed under direct visualization and require a modified urologic resectoscope that uses radiofrequency (RF) alternating current (AC).[2] Resection via a loop electrode,[42] fulguration or desiccation via a barrel or ball-shaped electrode,[38] and vaporization via a pointed-tip electrode have been commonly performed through the resectoscope.[14, 43]

Equipment for global (nonresectoscopic) procedures

Devices that have been approved for use in GEA procedures include the following:

  • Thermal balloon ablation device (ThermaChoice; Ethicon, Somerville, NJ)

  • Hydrothermal ablation (HTA) device (Hydro ThermAblator and Genesys HTA; Boston Scientific, San Diego, CA)

  • Bipolar energy ablation device (NovaSure; Hologic, Bedford, MA)

  • Cryotherapy ablation device (Her Option; Cooper Surgical, Trumbull, CT)

  • Microwave endometrial ablation device (Hologic, Bedford, MA)

Thermal balloon ablation

With the ThermaChoice, a single-use silicon balloon-tipped catheter probe-handpiece measuring 4-5 mm is connected via a cable to a dedicated control unit. The heating element is contained within the balloon, and a separate port attached to the handpiece allows instillation of 5% dextrose in water (D5W) into the balloon. The control unit aborts the procedure if the temperature of the fluid in the balloon does not reach the appropriate level during the preheating phase.

Hydrothermal ablation

The Hydro ThermAblator includes a single-use 7.8-mm outer-diameter (OD) sheath that attaches to a variety of standard 3-mm OD hysteroscopes, which, in turn, provide intraoperative direct visualization of the procedure. Attached to the hysteroscope is a closed fluid circuit that uses normal saline; this is managed by the control unit. The control unit automatically aborts the procedure if more than 10 mL of fluid is lost, regardless of route.

Bipolar energy ablation

The NovaSure includes a single-use 7.2-mm OD probe-handpiece that is attached to a microprocessor-based control unit. A bipolar gold mesh electrode array is located on the end of the probe, wrapped around 2 extendable curved arms that deploy through retraction of the sheath. The probe is equipped with standardized deployment lengths (eg, depth of cavity), which the operator manually sets before inserting the probe on the basis of an initial sounding of the uterus.

In addition, the NovaSure insufflates carbon dioxide into the cavity, in fixed volume, to determine the integrity of the cavity. The current generation of the device does not allow activation of the ablation phase if the cavity does not pass this integrity test.

The NovaSure also employs a closed circuit to apply suction to the endometrial cavity for the evacuation of steam, debris, and blood during the ablation phase.

Cryoablation

Her Option includes a single-use 4.5-mm OD probe-handpiece that is attached via a cable to a control unit. The probe is inserted into the endometrial cavity, and 2-4 "freeze" locations are typically employed. The probe creates an elliptical ice ball measuring approximately 3.5 cm by 5 cm. The procedure is performed under abdominal ultrasonographic guidance; although this may require extra personnel, it gives the operator valuable visual feedback for proper treatment of the entire cavity.

Microwave endometrialablation

The microwave endometrial ablation device includes an 8-mm OD single-use probe as well as a reusable probe, either of which can be attached to a 9.2-GHz, 30-W control unit via a reusable cable. The probe is manually moved about the entire endometrium while the operator receives temperature monitoring data via the control unit. A marker located 4 cm from the tip of the probe helps the operator identify the cervicouterine junction and thus avoid inadvertent ablation of the cervix.

Patient Preparation

Anesthesia

Several different anesthetic regimens may be used for endometrial ablation; the choice should be individualized on the basis of the patient’s characteristics and condition and the location of the procedure. Possibilities for anesthesia include the following:

  • No anesthesia

  • Paracervical block, with or without sedation

  • Regional anesthesia

  • General anesthesia

Positioning

The patient can be placed in either the low or the high dorsal lithotomy position. Proper positioning techniques should be observed to minimize the risk of femoral or peroneal nerve injury; however, because these procedures are generally of short duration, they are already associated with a lower risk than longer procedures such as hysterectomy. Multipositional stirrups (eg, Yellowfin or Allen) generally support the legs better than traditional "candy cane" stirrups do, especially for patients with an increased body mass index.

 

Technique

Approach Considerations

Endometrial sampling before ablation can help rule out current malignancy. However, malignancy can be masked after an ablation. Accordingly, one should consider alternatives to ablation for patients who are at very high risk for endometrial cancer. There is no known increased risk for endometrial malignancy after endometrial ablation.

Postoperatively, patients who have had endometrial ablation are able to go home on the day of the procedure. Postoperative pain is typically controlled with ibuprofen. The recommended follow-up is 2 weeks after the procedure.

Concomitant microinsert placement

Essure devices are small microinserts containing a stainless steel inner coil with polyester fibers and a superelastic nitinol outer anchoring coil. This device is inserted hysteroscopically into the fallopian tubes for contraception.

No data suggest that these procedures cannot be done at the same time as an endometrial ablation. There has been concern that uterine synechiae would interfere with the ability to perform and interpret the hysterosalpingogram that is normally performed 3 months postoperatively, but data have shown that uterine synechiae did not interfere with the ability to document proper location of the Essure device or the ability to grade the degree of tubal occlusion.[44]

Because the Essure microinserts are made of nickel-titanium, there is the potential for energy conduction when bipolar energy ablation is used. When endometrial ablation is being done concomitantly with hysteroscopic tubal occlusion, performing the ablation before placing microinsert placement should prevent such complications.[44]

Essure has also been shown to be safe for use in conjunction with thermal balloon ablation for accomplishing endometrial ablation and permanent sterilization.[45] The ThermaChoice is approved by the US Food and Drug Administration (FDA) for this indication, but the NovaSure has not been and thus would be an off-label choice.[46]

Concomitant use of Adiana catheter

The Adiana catheter (Hologic, Bedford, MA) is a catheter inserted hysteroscopically into the fallopian tubes for contraception. The catheter delivers a low level of radiofrequency (RF) energy and then releases a silicon matrix that allows scar tissue to form, blocking the fallopian tubes. There is no metal in the device to interfere with energy conduction during endometrial ablation. At present, only limited data are available time regarding the safety of using the Adiana catheter concomitantly with endometrial ablation.

Mirena versus endometrial ablation

The levonorgestrel-releasing intrauterine device (IUD) marketed as Mirena (Bayer HealthCare Pharmaceuticals, Wayne, NJ) is effective for reducing heavy menstrual bleeding. Multiple studies have compared the effects of this IUD with those of endometrial ablation, with varying results. A meta-analysis found Mirena and endometrial ablation to be comparable in terms of menstrual blood loss and overall quality of life.[33, 47]

Resectoscopic Endometrial Ablation

Resectoscopic endometrial ablation (REA) procedures include rollerball (roller barrel) desiccation, laser vaporization, and wire-loop resection. All of these procedures are performed through the resectoscope under direct visualization with laser energy or with monopolar or bipolar RF energy sources. In general, REA procedures are less costly than global endometrial ablation (GEA) procedures.

For standard monopolar electrosurgical techniques, distention media typically consist of low-viscosity, electrolyte-free solutions (eg, 1.5% glycine, 3% sorbitol, 5% mannitol, or combined sorbitol-mannitol). The potential for systemic intravasation of these solutions and subsequent adverse sequelae necessitates use of a strict fluid measurement and management system, preferably automated, to monitor differences between fluid instilled and fluid returned. To further reduce intravasation risk, the lowest effective intracavitary pressure should be used.

Newer bipolar devices are also available; however, the small gauge of the device (typically < 5 mm) results in increased operating times. Electrolyte-free distention media are not required, allowing the operator to use normal saline instead. Consequently, there is not the same risk of fluid intravasation, and this advantage may outweigh the risks of increased operating time for an experienced operator.

Rollerball (roller barrel) desiccation

The distention medium is introduced, the power is set to 50-150 W on the generator, and monopolar energy is used to desiccate the endometrium. The rollerball is initially placed at the fundus, then moved to the anterior and lateral walls, and finally moved to the posterior wall. The goal is to destroy the visible endometrium to a depth of 1-2 mm; this prevents regeneration because the basal and spiral arterioles do not survive the exposure. The procedure is approximately 30 minutes in duration.

Laser vaporization

A neodymium:yttrium-aluminum-garnet (Nd:YAG) laser is placed through the instrument channel of the hysteroscope. The laser fibers touch and then photocoagulate the endometrial tissue. Because of the high cost of the equipment and the considerable training required, this procedure is not commonly used.

Wire-loop resection

A wire loop is used with the operative hysteroscope to manually resect the endometrium to a depth of 5-6 mm. The loop is connected to either a monopolar or a bipolar electric current.

Global Endometrial Ablation

Each GEA technique requires thorough knowledge of the equipment, the procedure, and intraoperative response of the uterus and endometrium (see the Table below). The newer tools for GEA require less operator time and training to achieve excellent results than the earlier devices did.

Table. Global Endometrial Ablation Techniques (Open Table in a new window)

Method

Sounded Uterine Length

Cervical Dilation

Time

Pretreatment

 

Min

Max

(cm)

(min)

 

Thermal balloon

4

10

5

8

Suction curettage

Cryotherapy

n/a

10

5

14

Yes

Hydrothermablation

4

10.5

8

10

Yes

Microwave

6

14

8

3.5

Yes

Bipolar energy

6

10

8.5

1.5

No

Almost all GEA devices are designed with fail-safe mechanisms to detect procedural abnormalities (eg, uterine cavity defects, fluid loss, and pressure loss). Some are also designed to automatically detect procedure completion, as in the case of the NovaSure, which measures tissue impedance to determine depth of ablation in an attempt to ensure proper treatment.

Thermal balloon ablation

In its first iteration, ThermaChoice consisted of a latex balloon. This was replaced with a silicone balloon in ThermaChoice II. The third generation of the device, ThermaChoice III, uses a stronger and more flexible Silastic balloon, thereby improving coverage throughout the cavity and, potentially, over small submucosal myomas smaller than 2 cm.

Thermal balloon ablation is performed via a cannula. Advance the balloon-tipped probe into the cavity and inflate it with 5% dextrose in water (D5W) to a pressure of 160-180 mm Hg, up to a total of 30 mL of fluid (see the image below).

ThermaChoice uterine balloon device. ThermaChoice uterine balloon device.

Activate the device (this requires a minimum pressure of 150 mm Hg). It automatically passes through a 2-minute warm-up phase, then an 8-minute ablation phase, and finally a 2-minute cooldown phase. During the ablation phase, the fluid is maintained at 87°C. Tissue is destroyed to a depth of 3.3-5 mm.

The system automatically shuts down under the following conditions:

  • Rapid decrease in pressure

  • Pressure >210 mm Hg

  • Pressure < 45 mm Hg, temperature >95°C

  • Temperature < 75°C for > 15 seconds

The procedure is performed blindly, and total procedure time is approximately 30 minutes.

It is important to keep in mind that the ThermaChoice requires a pressure of 160-180 mm Hg for proper application of the balloon to the endometrial cavity. During the initial filling of the balloon, the operator may notice a rapid increase in uterine pressure as a result of a uterine contraction, which is typically self-limited. After completion of the initial filling of the balloon, the uterus may relax, resulting in a slight loss of pressure. This can be addressed by continued slow filling if the pressure has stabilized to a less-than-optimal level.

Occasionally, a uterine contraction may be encountered during the ablation phase, resulting in intracavitary pressures exceeding the predetermined device limit and possible automatic cessation of the procedure. This can be remedied by releasing a small amount of fluid from the balloon intraoperatively to maintain the appropriate pressure.

Alternatively, uterine relaxation may be encountered during the ablation phase. However, additional fluid injection is not recommended, because the introduction of cool fluid would compromise endometrial cavitary temperature. It is reasonable to continue the procedure; the device will continue ablation as long as the pressure remains above 45 mm Hg (though it should ideally be at least 100 mm Hg to ensure minimally adequate pressure within the cavity).

Cryoablation

In endometrial cryoablation with Her Option, a cryoprobe is placed into the uterus and cooled with pressurized carbon dioxide to create temperatures of –100° to –120°C.

Advance the cryoprobe into the endometrial cavity (see the image below), typically starting with the tip of the probe at one cornu. Activate the device. This cools the probe to –90°C, which results in the formation of an elliptical ice ball that measures approximately 3.5-5 cm. Each of these freeze cycles is followed by a thaw cycle. The process takes 4-6 minutes and is repeated at the contralateral cornu. It may be repeated in the lower uterine segment.

HerOption cryoablation device. HerOption cryoablation device.

As a rule, 2 to 3 ice balls are adequate for complete treatment, but the number of ice balls can be increased, depending on the total size of the endometrial cavity. A temperature of –20°C is required for permanent destruction, and this is achieved at 3-5 mm from the edge of the ice ball, where the temperature increases to a nondestructive 0°C.

Monitor the procedure via transabdominal ultrasonography. Monitor the edge of the ice ball to ensure that it does not traverse the uterine serosa. Total procedure time is up to 20 minutes.

Of the GEA devices described in this article, Her Option confers the deepest tissue penetration (up to 9-12 mm) with probably the least discomfort; freezing techniques generally result in less pain than heat-employing techniques. A significant advantage of this device includes the ability to observe tissue destruction ultrasonographically, though such observation can be compromised in obese patients. Performing the procedure with a full bladder can help with visualization, as can intrauterine saline instillation.

Placement of the initial freeze at the fundus prevents the operator from having to attempt to move the probe through an ice ball. Increasing the cornual freeze times may be necessary to achieve the proper depth of tissue destruction. Like hydrothermablation, endometrial cryoablation is not limited by the size of the uterus.

Hydrothermal ablation

Hydrothermal ablation is the only second-generation ablation technique that uses hysteroscopy during treatment. The device is a closed-loop system in which heated saline circulates freely in the uterine cavity and is monitored hysteroscopically. A sheath is placed over a standard 3 mm hysteroscope to provide fluid recirculation. A computerized system controls the cycles, which consist of a priming cycle and a treatment cycle.

Advance the hysteroscope with sheath into the lower uterine segment (see the image below), and instill room-temperature saline into the cavity using gravity to create a low distending pressure (ie, well below 70 mm Hg, which is the approximate opening pressure of the fallopian tubes). During the priming cycle, the fluid is circulated in the uterine cavity for 2 minutes.

Hydrothermal endometrial ablation (HTA) device. Hydrothermal endometrial ablation (HTA) device.

Once activated, the device preheats the circulating fluid to 80-90°C, which takes approximately 3 minutes. Again, the pressure should be maintained at 40-50 mm Hg to prevent fluid exiting through the fallopian tubes. A 10-minute treatment phase follows, during which the system shuts down if a deficit larger than 10 mL or a gain larger than 20 mL is measured. This phase is followed by a 1-minute cooldown phase, during which the fluid is at 45°C.

The entire procedure is performed under direct hysteroscopic visualization; it is the only GEA device that allows such visualization during the ablation phase. Total operating time is approximately 20 minutes. One advantage of hydrothermal ablation is that it is effective in irregularly shaped uterine cavities, because the water will contact all surfaces. At present, this device is the only one approved by the US Food and Drug Administration (FDA) for ablation of abnormally shaped endometrial cavities.

The procedural success of hydrothermal ablation is partially dependent on achieving a proper watertight seal at the level of the cervix. The manufacturer produces an extra ridged sheath attachment that is designed to ensure a proper seal. Another method of ensuring a proper seal is to apply a single-toothed tenaculum at the 3 o’clock or 9 o’clock position (or both) for further cervical compression. If automatic shutoff of the device should occur (for the reasons cited above), repeating the procedure is generally not recommended.

Bipolar energy ablation

The NovaSure system consists of a disposable handpiece and a computerized electrosurgical generator. First, sound the uterine cavity, paying particular attention to the length of the cervix (from external os to internal os) and the total length of the uterus. Calculate the cavity length by subtraction, and enter this number into the controller. A slide lock on the handpiece allows the operator to preset the mesh deployment depth (ie, cavity length). The maximum cavity length possible is 6.5 cm.

Using the measured depth of the uterine cavity, advance the device to the uterine fundus, retract it 1 cm, and deploy the bipolar mesh (a metallic, gold-plated grid) by squeezing the main handle of the handpiece until the handle locks into the open position (see the image below).

NovaSure bipolar radio frequency device. NovaSure bipolar radio frequency device.

Manipulate the handpiece as necessary until the most distal portion of the mesh is at its widest possible measurement within the cavity (as measured by the rotary dial at the back end of the handpiece). Manipulations that may be used to achieve full deployment of the radiofrequency (RF) array may include gentle back-and-forth movements of the operator’s end of the device in any of the following directions: from one side to the other, from anterior to posterior, from clockwise to counterclockwise, and, with caution, in and out.

Submucosal myomas, even if smaller than 2 cm, can significantly impair the deployment of the array. Consequently, it is the author’s practice first to partially or fully resect these myomas hysteroscopically.

Enter the cavity width into the controller. Advance the cervical collar to the external os, and lock it in place to create a seal. Use the controller to perform a cavity assessment by initially insufflating a small amount of carbon dioxide into the cavity, ensuring that pressure can be maintained for 4 seconds (to rule out uterine perforation). The current version of this device includes a safety feature that prevents the overriding of the cavity assessment function, thus precluding ablation if the uterus does not pass the cavity assessment.

Apply suction to the cavity, drawing it into contact with the mesh. This allows the removal of blood, charred endometrium, and vapor at the same time.[48] These 3 factors can increase impedance and potentially reduce the depth of energy penetration.

During the ablation phase, the generator applies up to 180 W of bipolar power (automatically calculated by the controller on the basis of the previously entered parameters). This phase generally lasts 1-2 minutes. The device ablates to a resistance of 50 ohms or a total of 2 minutes, whichever comes first. This results in desiccation to a depth of 4-5 mm.

The procedure is performed blindly, and total operating time is approximately 10-15 minutes. An advantage of bipolar energy ablation is that it has equal efficacy whether pretreatment of the endometrium is undertaken or not, which makes it ideal for patients who are unable or unwilling to undergo preoperative hormonal treatment.

Microwave ablation

In microwave endometrial ablation, microwave energy (30 W at a frequency of 9.2 GHz) is applied to the endometrium with a transcervical probe that moves through the endometrial cavity. The microwave endometrial ablation device is the only GEA device approved by the FDA for use in the presence of submucosal leiomyomas up to 3 cm and cavity lengths up to 12 cm.

Advance the probe to the fundus, typically starting at one cornu. Activate the system, creating a temperature of 75-85°C that penetrates to a depth of 6 mm. Move the probe from side to side while slowly treating the entire cavity from fundus to the lower uterine segment (see the image below). Safety mechanisms prevent ablation if the probe has not yet been placed into the uterus, if the probe is advanced further than the original sounding, or if an abnormal rise in temperature (possibly due to perforation) is detected. Total treatment time is 2-5 minutes.

Microsulis Endometrial Ablation (MEA) microwave de Microsulis Endometrial Ablation (MEA) microwave device.

With this procedure, it is recommended that the patient not undergo mechanical dilation and curettage beforehand. However, ultrasonography (to document a transmural thickness of at least 1 cm) and hysteroscopy are recommended before the procedure.

Unique to the microwave endometrial ablation device is the thermocoupler, which gives the operator ongoing feedback regarding the temperature at the point of ablation. This is particularly useful in targeted treatment of submucosal myomas, the thorough ablation of which is monitored through both tactile and thermal feedback.

Complications

The risk of individual complications from endometrial ablation varies according to the technique used. All forms of ablation carry the risks discussed below.[49]

Generally, patients can expect to experience postoperative cramping, minor-to-moderate vaginal bleeding, vaginal discharge, nausea, or a combination of these symptoms. Cramping is typically short-lived, lasting from a few hours to a few days, and is generally controlled with oral analgesics. Most bleeding tapers quickly and transitions to a clear, watery discharge lasting up to 2 weeks. Any foul odor or discoloration of the discharge should prompt evaluation for possible infection.

More specifically, possible complications of endometrial ablation include the following:

  • Injury to cervix and vagina

  • Uterine injury

  • Postablation tubal syndrome

  • Pregnancy

  • Bleeding

  • Cervical stenosis

  • Infection

  • Hematometra, likely secondary to occlusion of the endocervical canal at the cervicouterine junction

Injury to cervix and vagina

Injury to the cervix or vagina occurs most often during insertion of the ablation device. Injury to the cervix can be decreased by using mechanical dilators or misoprostol to soften the cervix before the procedure. Injury to the vagina most often occurs with the use of monopolar devices and can be avoided with the use of bipolar resectoscopes and careful technique.

Uterine injury

The primary concern is for uterine perforation, which may result in injury to surrounding structures and vasculature. The incidence of uterine injury is reported to be 3-25 per 1000.[3] If perforation occurs with an activated electrode, an exploratory laparoscopy or laparotomy is recommended to evaluate the abdominal cavity.

Postablation tubal syndrome

Postablation tubal syndrome, which develops in 6-10% of patients, occurs in women who have previously undergone tubal ligation. Patients present with cyclic pelvic pain and amenorrhea, remote from the procedure. The average time for the development of this complication is within 2-3 years of the ablation procedure.[4] The pain is related to trapped menstrual blood from residual endometrium at cornua. Hysterectomy is often the most effective treatment.

Pregnancy

Although infertility can occur after endometrial ablation, the procedure should not be viewed as a sterilization procedure, and patients should be counseled to use an appropriate contraception method. Pregnancies after endometrial ablation are rare, but when they occur, they may be associated with high rates of malpresentation, prematurity, placenta accreta, and perinatal mortality.[3]

Bleeding

Bleeding is most commonly encountered with uterine or cervical laceration. Delayed bleeding can develop as a result of endometrial sloughing. Blood coagulation studies should be obtained in cases of late postoperative bleeding, especially if these studies were not obtained preoperatively.

Cervical stenosis

Cervical stenosis may occur if the internal cervical os is also ablated with the endometrium. This complication may be treated with cervical dilatation.

Infection

The infection rate with all endometrial ablation techniques is approximately 1%. Prophylactic antibiotics are not required.

Risks associated with REA procedures

Because REA procedures require the use of a distention medium, potential fluid overload is a concern. Accordingly, careful attention must be paid to the amount of fluid infused, regardless of the type of medium used. A positive infusion balance of 800 mL can result in fluid shifts, possibly leading to pulmonary or cerebral edema.

Electrolyte imbalance is another risk. In REA procedures, low-viscosity fluids (eg, normal saline, glycine, and mannitol) are primarily used as distention media. Vascular absorption of such media can cause acute hyponatremia and a hypo-osmolar state, which can lead to cerebral edema.

Risks associated with GEA procedures

Unlike REA techniques, which rely on the instillation of hypertonic solutions into the endometrial cavity, GEA techniques do not carry the risks of fluid overload and electrolyte disturbance. Although complications rates are low overall, the potential major complications are grounds for concern and warrant strict adherence to the safety measures recommended by each device manufacturer. Many of these devices include safety mechanisms that prevent operator override of automatic shutdown protocols.

Complications secondary to uterine perforation or extravasation of hot fluid, resulting in bowel injury, are the most common major complications reported.[28] Hydrothermal ablation has also been reported to cause major burns to the vagina, buttocks, and thighs, secondary to leakage of hot water through the cervix.[50]

 

Medication

Medication Summary

The goals of pharmacotherapy are to obtain atrophy of the endometrium, reduce morbidity, and prevent complications.

Gonadotropins

Class Summary

These agents stimulate the release of luteinizing hormone and follicle-stimulating hormone from the anterior pituitary. In large doses, they can cause down-regulation of receptors in the pituitary gland, which, in turn, decreases secretion of luteinizing hormone and follicle-stimulating hormone. These agents produce more consistent endometrial thinning. Pretreatment with GnRH agonists or danazol before resectoscopic endometrial ablation (REA) results in higher amenorrhea rates at 12 months, shorter procedures, greater reported ease of surgery, and lower postoperative dysmenorrhea rates.

Goserelin (Zoladex)

Goserelin suppresses ovarian and testicular steroidogenesis by decreasing luteinizing hormone (LH) and follicle-stimulating hormone (FSH) levels. This agent is administered monthly as a subcutaneous (SC) implant in the upper abdominal wall; it is otherwise similar to the drugs in this class.

Leuprolide (Lupron, Lupron Depot, Eligard)

Leuprolide suppresses ovarian and testicular steroidogenesis by decreasing luteinizing hormone (LH) and follicle-stimulating hormone (FSH) levels. This agent is available in a daily subcutaneous (SC) dosing regimen and the much more convenient monthly intramuscular (IM) depo formulation. A 3-month depo dosing formulation is also available, but experience with its use for endometriosis is limited.

Nafarelin (Synarel)

Nafarelin is an analogue of gonadotropin-releasing hormone (GnRH) that is approximately 200 times more potent than natural endogenous GnRH. With long-term administration, this agent suppresses gonadotrope responsiveness to endogenous GnRH, thereby reducing the secretion of luteinizing hormone (LH) and follicle-stimulating hormone (FSH), which, in turn, reduces ovarian and testicular steroid production.

Nafarelin is available as a nasal solution (2 mg/mL). Administration of this agent is delivered via a nasal spray, which requires twice daily (bid) dosing; it is otherwise similar to the other drugs in this category.

Gonadorelin

Gonadotropin-releasing hormone (GnRH) agonists have been used to pretreat the endometrium and obtain atrophy.

Androgens

Class Summary

Agents from this class may suppress pituitary secretion of follicle-stimulating hormone and luteinizing hormone.

Danazol

Danazol causes atrophy of normal and ectopic endometrial tissue by suppressing pituitary output of luteinizing hormone and follicle-stimulating hormone. Pretreatment with danazol or GnRH agonists before resectoscopic endometrial ablation (REA) results in higher amenorrhea rates at 12 months, shorter procedures, greater reported ease of surgery, and lower postoperative dysmenorrhea rates.

Progestins

Class Summary

These agents may induce endometrial thinning by inhibiting the secretion of pituitary gonadotropins.

Medroxyprogesterone (Depo-Provera, Provera)

Progestins stop endometrial cell proliferation, allowing organized sloughing of cells after withdrawal. These agents typically do not stop acute bleeding episodes, but they produce normal bleeding episodes following withdrawal.

Medroxyprogesterone is a common progestin available in both an oral (PO) and an intramuscular (IM) depo form. The efficacy and adverse effects of this drug are similar to those of norethindrone.