Endometrial Ablation

Here’s your RoshReview Question of the Week!

A 41-year-old G3P2103 woman is scheduled to undergo nonresectoscopic endometrial ablation for a history of heavy menstrual bleeding. She previously tried combined oral contraceptives but was not satisfied with medical management. An endometrial biopsy was completed and benign. Which of the following do you inform her is the most common complication when counseling her about the risks of the procedure?

• Abdominal pain

• Endometritis

• Hematometra

• Urinary tract injury

Check to see if your answer is correct at the links above!

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Read along with ACOG PB 81

What is an Endometrial Ablation? 

• History and Rationale 

  • Minimally invasive surgical procedure designed to treat heavy uterine bleeding in select women who DO NOT WANT FUTURE FERTILITY 

  • Developed originally in 1937 

    • 1967 - cryoendometrial ablation where you “supercooled” the endometrial lining

    • Becomes more prevalent in the 1980s when hysteroscopy became more widely available 

• How is it done today? - many ways! 

  • Laser and resectoscopic endometrial ablation 

    • Done under hysteroscopic visualization 

    • Uses a resectoscope with 4 current techniques 

      • Endometrial desiccation with electrosurgical rollerball or rollerbarrel - basically heats the tissue up to 60-90 degrees and destroys the endometrium 

      • Resection with monopolar or bipolar loop electrode - will also resect endometrium to level of myometrium (basically same way that we take care of fibroids from within)  

      • Radiofrequency vaporization - high energy to rapidly heat the intracellular water to 100 degrees C → vaporization of tissue, but no tissue is removed 

      • Laser vaporization - same as above 

  • Nonresectoscopic techniques (in the US) - can be nice because these can sometimes be less uncomfortable and can be performed in the office 

    • Bipolar radiofrequency (Novasure) - 3-dimensional bipolar mesh probe that delivers radiofrequency current until specific tissue impedance is reached 

    • Cryotherapy (Her Option, Cerene) - probe inserted into the uterus and cooled via liquid nitrogen or differential gas exchange 

    • Circulating hot water (Hydro ThermAblator or HTA-ablation) - only one of the non-resectoscopic techniques that uses hysteroscopy.

      • Sheath is inserted into the uterus → heated saline is administered for 10 minutes, and fluid should be at 90 degrees C

    • Combined thermal and bipolar frequency (Minerva) 

      • Heat applied to endometrium via silicone membrane with circulating ionized argon gas (advertised as “plasma”) 

    • Vapor ablation (Mara) - no longer FDA approved 

  • After the endometrium is burned, it can scar down, leading to difficulty entering the uterine cavity again 

  • Anesthesia 

    • Most trials describing non-resectoscopic ablation devices have used local anesthesia and parenteral conscious sedation

    • Can use cervical and paracervical block if desired to do procedures in the office - however need to select if patient is a good candidate for in office procedure (ie. low risk for complications) 

Candidacy for Endometrial Ablation  

• Who is the right candidate? 

  • Treatment is indicated for heavy bleeding in premenopausal women with no desire for future fertility 

    • An important caveat: this should be for those with heavy OVULATORY menstrual bleeding 

    • Should not be first line to treat for abnormal uterine bleeding due to anovulation 

      • This is because you should figure out the cause of that abnormal bleeding otherwise and treat the cause (ie. if due to PCOS, treat for PCOS) 

      • That is not to say that a patient with PCOS cannot have an ablation - however, you need to make sure that you are treating the causes of the PCOS.

  • Usually, these are patients who have tried other medical therapies and have failed or who should not have medical therapies

  • It is importance to counsel that patients should accept normalization of menstruation, not complete amenorrhea 

    • Not a treatment for those who do not want to have menstruation 

    • Variability across studies in amount of menstrual bleeding after ablation

    • In a meta-analysis, both non-resectoscopic and resectoscopic ablation resulted in similar rates of amenorrhea at 1 year (37% vs 38%) 

Preoperative Evaluation

• Evaluate the structure and histology of the endometrial cavity 

• Reasons:

  • Rule out cancer - either via hysteroscopy or endometrial biopsy in the office

    • Don’t want the reason for heavy bleeding to be cancer and complete endometrial ablation which can scar the endometrium and make later evaluation very difficult  

    • Those with hyperplasia (EIN) or cancer should not undergo ablation 

  •  Evaluate the shape of the uterine cavity 

    • Can be done either via sounding + transvaginal ultrasound, sonohysterogram, hysteroscopy, or combination 

    • Evaluate internal architecture (ie. is there a bicornuate uterus? Are there fibroids?)

    • Reason is that many of the devices have uterine cavity requirements.

      • For example, for Novasure, the cavity must sound between 6-10cm and have a cornua to cornua distance of at least 2.5cm. Also, those with polyps or fibroids > 2cm were excluded from the FDA approval studies 

• Pretreatment 

  • Not required, but most surgeons will usually use hormonal agents to pre-treat to thin the endometrium 

  • GnRH agonist can be used 30-60 days prior to procedure 

• Risk counseling

  • There are many adverse events that have been reported from ablation and can depend on the device used:

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• Some rare but possible complications: 

  • Distention media overload - just like in hysteroscopy.

    • Especially if you are doing resectoscope and you are using monopolar instruments, you have to use electrolyte-free fluid like 3% sorbitol or 5% mannitol - review our hysteroscopy episode with Dr. Dolinko to learn more! 

  • Uterine trauma - as with any procedure in the uterus, there is possibility of injury. Specifically, with ablation, injury is usually caused when there is hemorrhage or perforation.

    • Cervical lacerations and vaginal burns can also occur if hot fluid comes out through the cervix  

  • Postablation tubal ligation syndrome

    • Can occur in patients with history of tubal ligation 

    • Described as cyclic pelvic pain, likely due to residual and trapped endometrium in one or both cornua - tissue cannot exit through the cervix or through the cornua due to ablation causing scar tissue + tubal ligation causes scar tissue 

    • Incidence has been reported as high as 10%  

• Complications that are more significant 

  • Pregnancy 

    • Ablation is not designed to be a form of birth control. Patients should be counseled extensively that they should not get pregnant and use a form of reliable birth control afterward 

    • Pregnancy can still occur after ablation 

      • Those that continue pregnancy have higher rates of malpresentation, prematurity, placenta accreta, and perinatal mortality 

  • Endometrial malignancy 

    • Endometrial ablation does not seem to delay the diagnosis of malignancy 

    • However, due to scarring of the endometrium, it can make it more difficult for usual assessment of the endometrial tissue such as biopsy or hysteroscopy 

    • In one study of 303 patients who needed endometrial sampling after ablation, the failure rate for obtaining bleeding assessment was 40% 

Contraindications to Endometrial Ablation

• Uterine size/shape - as discussed before; all available non-resectoscopic endometrial ablation devices have limitations with respect to size of cavity and extent of anatomic distortion 

• Do not perform if:

  • Pregnant or recently pregnant or desires future pregnancy 

  • Presence of active or recent uterine infection 

  • Endometrial malignancy or EIN 

• Consider not performing if: 

  • Uterine anomalies - ie septum or unicornuate uterus 

  • Myometrial thinning after uterine surgery 

  • Postmenopausal women - very few studies on postmenopausal women, and those are usually small; the studies were done in those with persistent bleeding after using HRT 

Outcomes from endometrial ablation

• Overall outcomes 

  • Non-resectoscopic and resectoscopic ablation result in comparable rates of amenorrhea and patient satisfaction 

  • However, resectoscopic ablation is associated with more OR time, more frequent use of GA, increased risk of surgical complication (ie. fluid overload) 

  • Resectoscopic procedures are less costly

    • Resectoscopic procedures: $125-$150 

    • Non-resectoscopic: $850-$1300  

• Improvement in bleeding 

  • Patients may have irregular bleeding immediately following procedure 

  • Success rates should not be determined until 8-12 weeks after surgery 

  • Randomized trial of Her Option cryo vs. resectoscope (279 patients): comparable rates of menstrual reduction at 1 year (85 vs. 89%) 

  • Patient satisfaction overall is high for both types of ablation (91 vs 88%) at one year, and similarly at 2-5 years (93 vs 87%) 

• Surgical outcomes 

  • Subsequent surgery rates range from 17-25% for both types 

  • Hysterectomy rates are 14 vs 19% 

  • Higher risk of treatment failure in younger patients (<45 years old): 

    • Risk of subsequent hysterectomy or repeat ablation was 2x in patients <45 years old compared to patients >45 years old