Endometrial Ablation

Number: 0091

Policy

1. Aetna considers endometrial ablation medically necessary for women who meet all of the following selection criteria:
   1. MenorrhagiaFootnotes^* unresponsive to (or with a contraindication to) either:
      1. Dilation and curettage; or
      2. Hormonal therapy or other pharmacotherapy;
      Footnotes^*Note: The degree of severity and persistence of the menorrhagia and the failure of prior treatment should be such that the member would otherwise be a candidate for a hysterectomy; these alternative less invasive approaches should have been attempted in the past year; or
      To stop residual menstrual bleeding after androgen treatment in a female to male transgender person who meet criteria for gonadectomy in CPB 0615 - Gender Affirming Surgery. Note: some plans exclude coverage of surgery for gender reassignment; please check benefit plan descriptions; and
   2. Endometrial sampling or D&C has been performed within the year prior to the procedure to exclude cancer, pre-cancer or hyperplasia, and the results of the histopathological report have been reviewed before the ablation procedure is scheduled (should be done in the past year); and
   3. Structural abnormalities (fibroids, polyps) that require surgery or represent a contraindication to an ablation procedure have been excluded (this is almost always done by ultrasound in the past year); and
   4. Pap smear and gynecologic examination have excluded significant cervical disease.  (Note: The Pap smear should be up to date so not necessarily within the past year).

   Aetna considers hysteroscopic sterilization experimental and investigational when performed at the same time as radiofrequency endometrial ablation, as ablation has been shown to decrease the sucess rate of sterilization.

   Aetna considers endometrial ablation experimental and investigational for all other indications (e.g., post-menopausal bleeding) because its effectiveness for other indications has not been established.

   Aetna considers the following endometrial ablation approaches to be established for treatment of women who meet the selection criteria set forth above:

   1. Chemical ablation with trichloroacetic acid
   2. Cryoablation (freezing) (Her Option Cryoablation Therapy)
   3. Electrosurgical ablation/electrocautery ablation (e.g., electric rollerball, resecting loop with electric current, triangular mesh with electrical current)
   4. Laser
   5. Microwave endometrial ablation (Microsulis Microwave Endometrial Ablation (MEA) System)
   6. Radiofrequency ablation (The NovaSure Procedure, and the Minerva Endometrial Ablation System)
   7. Thermoablation/hydrothermal ablation/balloon therapy ablation (e.g., heated saline (Genesys HydroThermAblator), thermal fluid-filled balloon (Gynecare Thermachoice)). 
2. Aetna considers photodynamic endometrial ablation experimental and investigational because there is insufficient scientific evidence to support its effectiveness.

See also CPB 0304 - Fibroid Treatment.

Background

Menorrhagia (excessive uterine bleeding) affects approximately 20 % of women of reproductive age.  It may be due to many causes, including hormonal disorders, fibroids, tumors, or other problems.  Pharmacotherapy and surgery are the mainstay treatments.  Most commonly, hormonal and non-hormonal medications are followed by dilatation and curettage, and ultimately, in many cases, hysterectomy.

Endometrial ablation techniques have evolved as an alternative to hysterectomy.  Ablation techniques (e.g., laser, resecting loop with electric current, electric rollerball, thermal fluid-filled balloon, radiofrequency, freezing, heated saline) remove some of the lining of the uterus in an attempt to control excessive bleeding.  After endometrial ablation, pregnancy is not likely to occur.

Current guidelines recommend an endometrial sampling procedure be done prior to the endometrial ablation. The American College of Obstetricians and Gynecologists (ACOG) Practice Bulletin on endometrial ablation (2007) states: “Endometrial sampling, typically with an outpatient technique, can be used to evaluate all women for hyperplasia or malignancy, and results should be reviewed before ablation is scheduled. Women with endometrial hyperplasia or uterine cancer should not undergo endometrial ablation.”

The early techniques of endometrial ablation, introduced in the 1980s and still used today involve the use of a hysteroscope with either a "rollerball" or wire loop through which electrical heat travels to remove (resection) the endometrial lining.  After the uterus is filled with fluid to enlarge it for better viewing, the surgeon moves the rollerball back and forth across the lining or uses the wire loop to shave off the tissue.  Potential risks of this ablation method include infection, perforation of the uterus, cervical laceration, and fluid overload.

Bren (2001) reviewed some of the new methods of endometrial ablation.  In 1997, the Food and Drug Administration (FDA) approved ThermaChoice, the first non-hysteroscopic ablation device to treat excessive uterine bleeding (menorrhagia) due to benign (non-cancerous) causes.  The ThermaChoice Uterine Balloon Therapy System (Gynecare, Somerville, NJ) consists of a balloon that is inserted through the neck of the cervix and into the uterus.  Through a catheter connected to a controller console, the balloon is inflated with fluid and heated to 188^°F (87^°C) for 8 mins to destroy the uterine lining.

In 2001, the FDA approved 3 more similar devices.  These devices are to be used only in women who have not yet reached menopause and whose child-bearing is completed.  The Hydro ThermAblator (BEI Medical Systems Inc, Teterboro, NJ) delivers heated saline solution into the uterus.  The heated saline solution is delivered using hysteroscopic guidance.  The heated solution destroys the uterine lining in about 10 mins.

The Her Option Uterine Cryoblation Therapy System (CryoGen Inc., San Diego, CA) uses a cryoprobe capable of producing temperatures down to minus 148^°F (minus 100^°C) at the tip.  This extreme cold is applied to the tissue for 10 mins to freeze and destroy the uterine lining.  Ultrasound is used to guide and monitor the procedure.

An assessment by the National Institute for Health and Clinical Excellence (NICE, 2006) found limited short-term evidence on the safety and effectiveness of endometrial cryotherapy for menorrhagia appears adequate to support the use of this procedure in carefully selected patients.  Specialist advisors to NICE stated that the evidence from randomized controlled clinical trials is limited, and that this procedure was one of a number of ablation techniques that uses different energy.  The specialist advisors to NICE stated that the procedure appears to be safe, but there are no data available on the incidence of major complications.  The theoretical adverse events include thermal injury to the cervix and vagina.  Anecdotal adverse events include persistent discharge and endometritis.

The NovaSure Impedance Controlled Endometrial Ablation System (Novacept, Palo Alto, CA) uses a metallic mesh triangular electrode that is expanded out of a slender tube into the uterus.  A gentle suction brings the tissue into close contact with the triangular electrode, which delivers electrical current to the endometrial tissue, causing its destruction in about 90 seconds.  With this method, there is no hysteroscope or ultrasound, so the physician cannot view the uterus during the procedure.

Photodynamic endometrial ablation involves injecting a photosensitive chemical into the uterine cavity through a hysterosalpingography catheter.  A probe inserted through the cervix uses a laser to activate the photosensitive chemical, which destroys the endometrium.  It can often be carried out under local anesthetic on a day-case basis.  An assessment conducted for the NICE (2003) concluded that current evidence on the safety and efficacy of photodynamic endometrial ablation does not appear adequate to support the use of this procedure outside formal research.  The NICE's conclusions were based on the "extremely limited" evidence of the safety and effectiveness of this procedure.

An assessment conducted by the National Institute for Clinical Excellence (NICE, 2003) concluded that microwave endometrial ablation is an established method.  In reaching this conclusion, NICE considered a Cochrane systematic review of endometrial destruction techniques.  The systematic review concluded that women undergoing thermal ablation techniques had a similar reduction in bleeding and were as satisfied as women having hysteroscopic resection of the endometrium.  The advantages of thermal ablation techniques were that general anesthesia was not required, and the procedures were quicker and easier to perform.  The systematic review did not come to any conclusions about the relative advantages and disadvantages of the different thermal endometrial destruction techniques.  The NICE assessment noted that other studies found that between 70 and 80 % of women having microwave endometrial ablation were satisfied, and that 95 % of women had returned to normal activities within 3 weeks of having the procedure.

Common side effects after endometrial ablation include nausea, vomiting, and a vaginal discharge that can last from days to weeks. Complications of ablation are rare, but may include blood loss requiring a transfusion, perforation of the uterus, or unintended damage to other internal organs.

A number of studies have compared the effectiveness of endometrial ablation techniques, several of which are described below.  One randomized study found superior outcomes with electrosurgical ablation with triangular mesh (NovaSure) over balloon thermal ablation (ThermaChoice) for menorrhagia at long-term follow-up.  Kleijn and colleagues (2008) evaluated amenorrhea rates, hysterectomy rate, and health-related quality of life (HRQol) associated with the bipolar impedance-controlled endometrial ablation technique (NovaSure) in comparison with balloon ablation technique (ThermaChoice) at 5-year after administration.  A total of 126 pre-menopausal women suffering from menorrhagia with a pictorial blood loss assessment count greater than or equal to 150 without intra-cavitary abnormalities were included in this study.  They were randomly allocated to bipolar radio-frequency ablation and balloon ablation in a 2:1 ratio.  The main outcome measures were amenorrhea rate, hysterectomies, and HRQol as reported at 5-year follow-up.  At 5 years of follow-up, the total response rate was 96 % in the bipolar group and 90 % in the balloon group.  Amenorrhea was reported in the bipolar group by 48 % of women and in the balloon arm by 32 % (relative risk 1.6 [0.93 to 2.6]).  There were 8 women in the bipolar group (9.8 %) and 5 in the balloon group (12.9 %) who had undergone a hysterectomy.  Furthermore, there was a significant equal improvement of HRQoL over time in both groups.  The authors concluded that at 5-year follow-up, bipolar thermal ablation was superior over balloon ablation in the treatment of menorrhagia.

A study found equivalant outcomes from balloon ablation and rollerball ablation for treatment of menorrhagia.  Loffer and Grainger (2002) collected long-term follow-up data from women who participated in a randomized trial comparing uterine balloon therapy (UBT) with rollerball ablation for treatment of menorrhagia.  Women treated with endometrial ablation for menorrhagia who were available for 5-year follow-up were included in the analysis.  Of 255 women treated under the original protocol, 147 were available to be interviewed 5 years after the procedure.  Of these, 25 patients reported hysterectomy, repeat ablation, or dilatation and curettage (D&C) between years 3 and 5, leaving 122 eligible for analysis (61 UBT, 61 rollerball).  Of these 122 patients, 58 (95 %) having UBT and 59 (97 %) having rollerball ablation reported normal or less bleeding.  Similarly, 93 % and 100 %, respectively, were satisfied with the procedure.  Among the total population of 255 women, 42 hysterectomies (21 UBT, 21 rollerball), 5 repeat ablations (3 UBT, 2 rollerball), and 1 D&C (rollerball) were reported by year 5.  Thirty-five hysterectomies (83 %) were performed because of bleeding and/or pelvic pain; 1/3 of them were associated with myomas.  Nearly 7 of 10 women were cured of menorrhagia without additional intervention 5 years after ablation.  The authors concluded that UBT continues to be an effective, simple treatment of menorrhagia, with clinical outcomes similar to those of rollerball ablation at 5-year follow-up.

A randomized trial found radiofrequency ablation superior to thermoablation for treament of menorrhagia.  In a double-blind, randomized controlled trial, Penninx and colleagues (2010) compared the effectiveness of 2 second-generation ablation techniques, bipolar RF impedance-controlled endometrial ablation and hydro-thermablation in the treatment of menorrhagia.  Women with menorrhagia were randomly allocated to bipolar RF ablation (bipolar group) and hydro-thermablation (hydro-therm group).  At follow-up, both women and observers remained unaware of the type of treatment that had been performed.  The primary outcome was amenorrhea; secondary outcome measures were patient satisfaction and reintervention.  A total of 160 women were included in the study, of which 82 were allocated to the bipolar group and 78 to the hydro-therm group.  No complications occurred in either of the treatment groups.  After 12 months, 87 % (65 of 75) of the patients in the bipolar group were completely satisfied with the result of the treatment compared with 68 % (48 of 71) in the hydro-therm group (relative risk 1.3, 95 % confidence interval [CI]: 1.03 to1.6).  The amenorrhea rates were 47 % (35 of 75) in the bipolar group and 24 % (17 of 71) in the hydro-therm group (relative risk 2.0, 95 % CI: 1.2 to 3.1).  The relative risks for a re-intervention in the bipolar group compared with the hydro-therm group was 0.29 (95 % CI: 0.12 to 0.67), whereas for hysterectomy, this was 0.49 (95 % CI: 0.15 to1.5).  The authors concluded that in the treatment of menorrhagia, bipolar RF endometrial ablation system is superior to hydro-thermablation.

New methods of endometrial ablation are being investigated.  In a prospective, randomized, controlled study, Kucuk and Okman (2005) assessed the effectiveness of trichloroacetic acid (TCA) instillation into uterine cavity for the treatment of patents with dysfunctional uterine bleeding (DUB).  A total of 90 women were randomized to receive only TCA or receive a single dose of gonadotropin-releasing hormone analog 1 month before the procedure.  All subjects underwent an evaluation that included cycle history, body mass index measurement, and trans-vaginal ultrasonography of pelvis, diagnostic hysteroscopy and endometrial biopsy.  At the end of 12 months, amenorrhea rates in group 1 and group 2 were 26.7 % versus 31.1 %, with pooled amenorrhea, hypomenorrhea, and eumenorrhea rates of 95.6 % versus 97.8 %, respectively.  There was no significant difference between the groups' vis-à-vis post-procedure results.  More than 90 % of women who had this procedure were satisfied with the results.  There were no observed negative effects or related complications with this treatment.  These investigators concluded that an instillation of TCA into uterine cavity produced acceptable results and provided conservative management of DUB.  This is in agreement with the findings of a randomized controlled trial by Kucukozkan et al (2004) who reported that endometrial ablation by TCA may readily be performed as an alternative method in the treatment of DUB.  These investigators also noted that suppression of endometrium with danazol or especially with goserelin acetate before chemical ablation with TCA resulted in significant success rate.

In a meta-analysis, Daniels et al (2012) examined the relative effectiveness of second generation ablation techniques in the treatment of heavy menstrual bleeding.  A total of 19 randomized controlled trials (RCTs; involving 3,287 women) were identified through electronic searches of the Cochrane Library, Medline, Embase and PsycINFO databases from inception to April 2011.  The reference lists of known relevant articles were searched for further articles.  Two reviewers independently selected articles without language restrictions.  Randomized controlled trials involving second generation endometrial destruction techniques for women with heavy menstrual bleeding unresponsive to medical treatment were selected for analysis.  Of the 3 most commonly used techniques, network meta-analysis showed that bipolar radiofrequency and microwave ablation resulted in higher rates of amenorrhea than thermal balloon ablation at around 12 months (odds ratio 2.51, 95 % CI: 1.53 to 4.12, p < 0.001; and 1.66, 1.01 to 2.71, p = 0.05, respectively), but there was no evidence of a convincing difference between the 3 techniques in the number of women dissatisfied with treatment or still experiencing heavy bleeding.  Compared with bipolar radio frequency and microwave devices, an increased number of women still experienced heavy bleeding after free fluid ablation (95 % CI: 2.19: 1.07 to 4.50, p = 0.03; and 95 5 CI: 2.91: 1.23 to 6.88, p = 0.02, respectively).  Compared with radiofrequency ablation, free fluid ablation was associated with reduced rates of amenorrhea (95 % CI: 0.36, 0.19 to 0.67, p = 0.004) and increased rates of dissatisfaction (95 % CI: 4.79, 1.07 to 21.5, p = 0.04).  Of the less commonly used devices, endometrial laser intra-uterine thermotherapy was associated with increased rates of amenorrhea compared with all the other devices, while cryoablation led to a reduced rate compared with bipolar radiofrequency and microwave.  The authors concluded that bipolar radiofrequency and microwave ablative devices are more effective than thermal balloon and free fluid ablation in the treatment of heavy menstrual bleeding with second generation endometrial ablation devices.

Endocrine Society Guidelines (Hembree et al, 2009) indicated endometrial ablation in female to male transgender individuals with residual bleeding after testosterone treatment.  These guidelines stated that cessation of menses may occur within a few months with testosterone treatment alone, although high doses of testosterone may be required.  If uterine bleeding continues, addition of a progestational agent or endometrial ablation may be considered.

In a follow-up of a prospective, double-blind RCT, Sambrook et al (2014) compared long-term (5 years) outcomes following microwave endometrial ablation (MEA™) and thermal balloon ablation (TBall).  A total of 320 women eligible for and requesting endometrial ablation were included in this study.  Eligible women were randomized in a 1:1 ratio to undergo MEA or Tball.  Postal questionnaires were sent to participants at a minimum of 5 years post-operatively to determine satisfaction with outcome, menstrual status, bleeding scores and quality of life measurement.  Subsequent surgery was ascertained from the women and the hospital operative database.  The primary outcome measure was overall satisfaction with treatment.  Secondary outcomes included evaluation of menstrual loss, change in quality of life scores and subsequent surgery.  Of the women originally randomized 217/314 (69.1 %) returned questionnaires.  Non-responders were assumed to be treatment failures for data analysis.  The primary outcome of satisfaction was similar in both groups (58% for MEA™ versus 53% for TBall, difference 5%; 95% CI -6 to 16%). Amenorrhea rates were high following both techniques (51% versus 45%, difference 6%; 95% CI -5 to 17%). There was no significant difference in the hysterectomy rates between the 2 arms (9 % versus 7 %, difference 2 %; 95 % CI: -5 to 9 %).  The authors concluded that at 5 years post-treatment there were no significant clinical differences in patient satisfaction, menstrual status, quality of life scores or hysterectomy rates between MEA™ and Thermachoice 3, thermal balloon ablation.

Vitagliano et al (2014) evaluated post-operative pain after mini-invasive surgical treatment for dysfunctional uterine bleeding (DUB) with transcervical endometrial resection or thermal ablation balloon.  These researchers performed a longitudinal observational study, analyzing 47 women affected by DUB who underwent endometrial ablation.  The authors collected evaluation of pelvic pain at 1 and 4hours after intervention and the individual necessity of analgesics.  After 30 days, all patients underwent a gynecological visit to evaluate post-operative outcome.  Pelvic pain was higher 1 and 4 hours after procedure in thermal balloon ablation group, and patients in the same group required more analgesic rescue dose.  There were no complications such as uterine perforation, heavy blood loss or thermal injuries with both the procedures.  The authors concluded that thermal balloon ablation appeared a more painful procedure than endometrial resection, both in the immediate postsurgical time and 30 days after surgery.  Moreover, they stated that ad-hoc anesthesiologic and analgesic protocol should be adopted to ensure quick recovery and good acceptance of the procedure.

In a multi-center, prospective post-market study, Berman et al (2014) obtained information on practitioner experience in the use of the Genesys HydroThermAblator (HTA) System under normal clinical conditions through documentation of the system's acute safety features, in terms of burn rates, and its technical reliability.  Outcome measures were acute (within 21 days post-procedure) safety, serious adverse device effects, and technical malfunctions in a population of pre-menopausal women greater than or equal to 18 years of age.  A total of 992 women (mean age of 41.7 +/- 6.8 years; range of 22 to 65 years) were enrolled in 18 clinical sites throughout the United States.  The Genesys HTA System provided low burn rates in the intent-to-treat (n = 992 [0.4 %] [95 % CI: 0.1 to 1.0 %]) and evaluable (n = 931 [0.2 %] [95 % CI: 0.1 to 0.8 %]) subject populations.  Only 1 burn was clinically significant and was defined as a serious adverse device effect (1/992 [0.10 %] [95 % CI: 0.0 to 0.6 %]).  Fifty-three (5.1 %) technical malfunctions occurred in 44 procedures, and 27 (27/44 [61.4 %]) patients completed their procedures after 31 (31/ 53 [58.5 %]) technical problems were addressed and resolved.  The authors concluded that the Genesys HTA System delivers a safe and reliable treatment option for pre-menopausal women with heavy menstrual bleeding.

Endometrial ablation and hysteroscopic sterilization

An ACOG Committee Opinion on hysterosalpingography (HSG) after tubal sterilization advises against performing radiofrequency endometrial ablation on the same day as hysteroscopic sterilization because ablation significantly decreases success rate of sterilization when done on the same day. In addition, the prescribing information for the Essure implant recommends against performing the Essure procedure concomitantly with endometrial ablation. The prescribing information explains that ablation causes intrauterine synechiae which can compromise (i.e., prevent) the Essure confirmation test (modified HSG). The prescribing information states that women with inadequate confirmation tests cannot rely on Essure for contraception.

Hopkins, et al (2015) evaluated the accuracy of hysterosalpingography (HSG) in patients who underwent concomitant radiofrequency endometrial ablation and hysteroscopic sterilization. The investigators conducted a historical cohort study at a Midwestern academic medical center. A total of 186 women (94 with combined procedure and 92 with sterilization alone) were identified as having undergone intervention between January 1, 2003, and June 30, 2011. Two reviewers blinded to the surgical procedure interpreted the standard clinically indicated HSGs in each group. The primary outcome assessed was the inability to rely on the microinserts for contraception based on HSG interpretation using manufacturers’ guidelines (unsatisfactory HSG). Position of the devices and occlusion of tubes were assessed on all 3-month and, when available, all 6-month repeat HSGs. At the 3-month HSG, 5 of 76 (6.6%, 95% confidence interval [CI] 2.2–14.7%) in the sterilization-only group had unsatisfactory HSG compared with 13 of 71 (18.3%, 95% CI 10.1–29.3%) in the combined group (P = 0.03). After accounting for the seven patients who underwent repeat HSG at 6 months, 3 of 76 (3.95%, 95% CI 0.8–11.1%) in the sterilization-only group had unsatisfactory HSG compared with 13 of 71 (18.31%, 95% CI 10.1–29.3%) in the combined group (P = 0.005). The investigators concluded that, after completing all clinically indicated HSGs, patients who undergo concomitant radiofrequency endometrial ablation and hysteroscopic sterilization have an approximate fivefold increase (odds ratio 5.45, 95% CI 1.48–20.0) in the rate of unsatisfactory HSG for purposes of documenting tubal occlusion.

1. Electrical or electrocautery ablation, in which an electric current travels through a wire loop or rollerball is applied to the endometrial lining to cauterize the tissue;
2. Hydrothermal ablation, in which heated fluid is pumped into the uterus and destroys the endometrial lining via high temperatures;
3. Balloon therapy ablation, in which a balloon at the end of a catheter is inserted into the uterus and filled with fluid, which is then heated to the point that the endometrial tissues are eroded away;
4. Radiofrequency ablation in which a triangular mesh electrode is expanded to fill the uterine cavity, at which point the electrode delivers an electrical current and destroys the endometrial lining;
5. Cryoablation, in which a probe uses extremely low temperatures to freeze and destroy the endometrial tissues; and
6. Microwave ablation, in which microwave energy is delivered through a slender probe inserted into the uterus and destroys the endometrial lining. 

These investigators evaluated the feasibility, safety, and effectiveness of endometrial ablation performed with first- and second-generation techniques.  A literature search in PubMed from January 2000 to September 2015 was performed using the keywords endometrial ablation, menorrhagia, and heavy menstrual bleeding.  Results were restricted to systematic reviews, RCTs/controlled clinical trials, and observational studies written in English from January 2000 to September 2015.  There is no evidence that either broad category is more effective than the other in reducing heavy menstrual bleeding, and there is no evidence that rates of satisfaction differ significantly.  The authors concluded that the overall results of the presented studies suggested that endometrial ablation is an effective therapy for menorrhagia in women with bleeding disorders.

Endometrial Ablation for Post-Menopause Bleeding

The ACOG Practice Bulletin on “Endometrial ablation” (2007; re-affirmed 2015) stated that “The use of endometrial ablation in post-menopausal women or in women with disorders of hemostasis has not been rigorously evaluated“.   Furthermore, an UpToDate review on “An overview of endometrial ablation” (Sharp, 2017) states that “We suggest not performing endometrial ablation in postmenopausal women.  Endometrial ablation has been described in this population, mostly in women with persistent bleeding while on postmenopausal hormone therapy.  Prospective series have reported no cases of endometrial cancer in women who underwent endometrial ablation after menopause; however, these studies included fewer than 50 women and most patients were followed for less than five years … United States professional organizations also do not support the use of endometrial ablation in postmenopausal women.  The American Society for Reproductive Medicine advised that endometrial ablation is not indicated for postmenopausal women and ACOG states that it has not been rigorously studied in this population”.

Use of Anesthetic Block for Endometrial Ablation Pain

Klebanoff and colleagues (2018) noted that second-generation endometrial ablation has been demonstrated safe for abnormal uterine bleeding treatment, in pre-menopausal women who have completed child-bearing, in short-stay surgical centers and in physicians' offices.  However, no standard regarding anesthesia exists, and practice varies depending on physician or patient preference and hospital policy and setting.  In a RCT, these researchers examined if local anesthetic, in combination with general anesthesia, affects post-operative pain and associated narcotic use following endometrial ablation.  This was a single-blind, single-center study that was conducted in an academic-affiliated community hospital.  A total of 84 pre-menopausal women, aged 30 to 55 years, who were undergoing out-patient endometrial ablation for benign disease were randomized to receive standardized para-cervical injection of 20 ml 0.25 % bupivacaine (treatment group) or 20 ml normal saline solution (control group) upon completion of ablation.  The study was designed to test a 40 % 1-hour mean visual analog scale (VAS) pain score difference with an average standard deviation (SD) of 75 % of both groups' mean VAS scores, using a 2-tailed test, a type I error of 5 %, and statistical power of 80 %.  A sample of 36 patients per study group was required.  Assuming a 15 % attrition rate, the study enrolled 42 patients per study arm randomized in blocks of 2 (84 total); 2-tailed cross-tabulations with Fisher exact significance values where appropriate and Student t-tests were used to compare patient characteristics.  Backward step-wise regressions were conducted to control for confounding.  Between April 2016 and February 2017, a total of 108 women scheduled for endometrial ablation were screened (refusals, n = 21; ineligible, n = 3) to determine whether there were meaningful differences in post-operative VAS pain scores and post-operative narcotic use.  Of the 84 randomized women, 2 age-ineligible women were excluded.  Intent-to-treat (ITT) analyses included 1 incorrect randomization (in which the provider consciously decided to provide analgesia regardless of the protocol, after which the provider was excluded from further study participation) and 3 women having no ablation because of operative difficulties; 3 subjects were lost to 2nd-day follow-up.  Treatment group patients (n = 41) experienced 1.3 points lower 1-hour post-operative VAS pain scores than the control group (n = 41, p = 0.02).  The difference diminished by 4 hours (p = 0.31) and was negligible by 8 hours (p = 0.62).  Treatment group patients used 3.6 less morphine equivalents of post-operative pain medication (p = 0.05).  Regression analyses controlled for confounding reduced the 1-hour post-operative treatment group pain score difference to 0.8 (CI: -0.6 to 0.1); but slightly increased the average post-operative morphine equivalents to 3.7 (CI: -6.8 to -0.7).  The authors concluded that this RCT found that local anesthetic with low risk for complications, used in conjunction with general anesthesia, decreased post-operative pain at 1 hour and significantly reduced post-operative narcotic use following endometrial ablation.  Moreover, they stated that further research is needed to examine if the study results are generalizable and whether post-procedure is the best time to administer the para-cervical block to decrease endometrial ablation pain.

The authors stated that this study had several drawbacks.  There is the potential for under-reporting 4- and 8-hour pain scores, as these scores were assessed by contacting study subject on post-operative day 1.  However, all patients were given 10 tablets of Tylenol with codeine upon discharge, and patients from both groups reported having 9 tablets remaining.  Two consenting age-ineligible women were erroneously enrolled and were thus excluded from the analyses.  There were 3 other implementation errors; therefore the regression analyses assessed the extent to which they influenced the results, and the ITT analysis indicated that previous surgery and randomization violation had no effect on the 1-hour pain scores (and thus were excluded as control variables from the backward stepwise ultimate model).  Although these conditions were associated with narcotic use for 2 individuals, they had no significant effect on the mean narcotic use difference; the 2 study groups showed the same narcotic equivalent use difference in the unadjusted (t-test) and adjusted (regression) analyses.  Although the study was sufficiently powered to test its hypothesis, it was conducted in a large but single community hospital.  Additional trials in distinct settings need to be conducted to examine if the results are generalizable.  Evidence exists to suggest that endometrial ablations are safe and effective out-patient procedures that can be performed under local anesthesia.   Physicians are already performing these procedures without general anesthesia; however, as out-patient surgical centers are increasingly popular, the evidence produced in this trial should help guide operating physicians who have control over the method of anesthesia for their patients, and help guide hospital policy regarding anesthesia for endometrial ablation.  Pain scores are subjective; patients with a history of chronic pain and/or those using maintenance narcotics were excluded to minimize confounding.  The trial could not control for ablation device used by the operating physician.  However, there is some evidence that the NovaSure is associated with less intra- and post-operative pain than the ThermaChoice, and that thermal balloon ablation and radiofrequency impedance-controlled endometrial ablation are associated with statistically similar intra- and post-operative pain. The trial also could not control for intra-operative pain management by the anesthesia provider, which could theoretically affect post-operative pain scores.  However, all procedures were performed at the same study institution managed by 1 large anesthesia group who generally use similar patient management pathways for out-patient procedures.  Randomization of study group patients minimized the chance that intra-operative pain management would have been different for the 2 study groups.  The primary provider’s knowledge of patients’ study group allocation could have influenced their intra-operative provision of pain-reducing narcotics.  However, it was the post-anesthesia care unit (PACU) nurses, who were unaware of patients study group allocation, who administered the post-operative narcotics based on patient self-reporting of pain.  Even if the un-blinded providers gave more intra-operative medication to the control group than to the treatment group, it did not obviate the fact that the control group patients reported significantly (p = 0.02) more pain and used more post-operative narcotics to quell the pain.

Sub-Myometrial Vasopressin Injection Before Microwave Ablation of Vascular-Rich Submucosal Myomas

Tsuda and Kanaoka (2019) noted that vascular-rich myomas are resistant to treatment involving trans-cervical microwave myolysis (TCMM).  To overcome cooling by blood perfusion, these researchers injected dilute vasopressin (VP) solution into the space between the myometrium and the surface of the vascular-rich myomas.  A total of 7 out-patients [mean age n ± SD of 44.9 ± 3.9 years] with a single symptomatic vascular-rich submucosal myoma measuring 4.2-9.2 cm (6.5 ± 2.5 cm) underwent TCMM and MEA.  Before microwave irradiation, dilute VP solution was injected into the space between the myometrium and the surface of the vascular-rich myoma.  These investigators examined the changes in the volumes of the vascular-rich myomas and blood hemoglobin (Hb) levels before and 3 and 6 months after treatment.  In addition, improvements in menorrhagia and satisfaction after the operation were assessed using VAS.  Sub-myometrial injection of dilute VP effectively reduced the abundant blood flow.  The vascular-rich myomas were necrotized and shrank significantly by 69.0 % at 3 months and 72.4 % at 6 months after the operation (p < 0.05).  Blood Hb levels significantly increased at 3 months (p < 0.01).  In addition, the VAS results indicated that menorrhagia improved subjectively and the patients were satisfied with the results of the operation.  The authors concluded that VP injection before TCMM led to extended necrosis of vascular-rich submucosal myomas.  These researchers stated that this approach may be an alternative to hysterectomy for menorrhagia caused by vascular-rich submucosal myomas in peri-menopausal women.  Moreover, they noted that although injecting a dilute VP solution before TCMM and MEA appeared promising for the treatment of vascular-rich submucosal myomas, several limitations remain – a longer observation period and larger number of patients is needed to verify the usefulness of this approach.

The above policy is based on the following references: