How to overcome a resistant cervix for hysteroscopy and endometrial biopsy

How to prime the cervix for hysteroscopy

The use of vaginal misoprostol, a prostaglandin E₁ analogue, 9 to 12 hours before hysteroscopy may help increase preprocedural cervical dilation in premenopausal women, especially in nulliparas and women undergoing operative hysteroscopy. Misoprostol, used to prevent and treat NSAID-induced gastric ulcers, is gaining favor as a cervical ripening agent. We performed a meta-analysis to assess its effectiveness in dilating the cervix and reducing the need for mechanical dilation.⁵

We identified 10 studies that met inclusion criteria; five of them included premenopausal women, four included postmenopausal women or women receiving a gonadotropin-releasing hormone (GnRH) agonist, and one study included both groups.⁵ A variety of dosing protocols were used, with dosages ranging from 100 μg to 1,000 μg of intravaginal or oral misoprostol 4 to 24 hours preoperatively (most studies evaluated the vaginal route).

We found that misoprostol significantly reduced the need for further cervical dilation, and was associated with a lower rate of cervical laceration. However, this was true only for the premenopausal group: 42.6% of premenopausal women given misoprostol needed further dilation, compared with 71.7% in the control group, and 2% of premenopausal women given misoprostol suffered cervical laceration, compared with 11% in the control group. Among postmenopausal women and those receiving a GnRH agonist, misoprostol lacked clear benefit and was associated with side effects such as nausea, diarrhea, abdominal cramping, and fever.

For every premenopausal woman who received misoprostol before hysteroscopy, one woman avoided the need for further cervical dilation. For every 12 premenopausal women receiving misoprostol, one cervical laceration was avoided.

The ideal dosing regimen could not be determined because of variations in protocols. Nor was it clear whether misoprostol had any benefit among postmenopausal women or those receiving a GnRH agonist.

Most studies of misoprostol for cervical ripening have involved intravaginal administration, with dosages of 200 μg to 400 μg given 9 to 12 hours before hysteroscopy showing the greatest benefit.

Ultrasonography may help guide dilation

Transabdominal ultrasonography has been used to guide dilation in difficult dilation and curettage procedures, and is especially useful in women with a history of uterine perforation.²⁷ It may be helpful in cases involving difficult cervical dilation during hysteroscopy or endometrial biopsy.

Steady the cervix. A tenaculum is not always required, but its use on the anterior lip of the cervix may help steady the cervix and provide countertraction during insertion of the hysteroscope through the cervical canal, especially if the cervix is not in an axial position.⁷

CASE Resolved!

Because she is nulliparous and may benefit from cervical priming, the patient is given 400 μg of intravaginal misoprostol 12 hours before hysteroscopy, as well as an oral NSAID 1 hour before the procedure. A bimanual examination reveals a sharply anteverted uterus, so a topical cervical anesthetic spray is applied to the anterior cervix, and a tenaculum is placed to help straighten the uterine position. The hysteroscope passes easily through the cervical canal, making further dilation unnecessary. The procedure is completed without difficulty and is well tolerated by the patient.

Difficult entry can also hamper endometrial biopsy

Every ObGyn has used endometrial biopsy to assess abnormal uterine bleeding, postmenopausal bleeding, infertility, or recurrent pregnancy loss, or to monitor women on hormone replacement therapy^28,29 —so its advantages over dilation and curettage should come as no surprise. They include the ability to perform it in an office setting, usually with minimal cervical dilation, often without anesthesia, and at less expense.²⁸ Complications include cramping and pain,^29-32 vasovagal reaction,²⁹ bleeding,²⁹ and inability to pass the biopsy catheter through the cervix into the uterine cavity. Another rare complication is uterine perforation.²⁹

As with hysteroscopy, many of these complications are related to difficulty entering the uterine cavity through the cervix.

Prerequisites include thorough assessment of the uterus

As with hysteroscopy, an accurate and detailed history is necessary to identify risk factors for a difficult procedure. Assess uterine size and position with a bimanual examination. Although a tenaculum is often unnecessary, its placement on the anterior lip of the cervix may help steady the cervix and allow the catheter to pass through the cervical canal into the uterine cavity, especially if the uterus is not in the axial position.^28,29 Again, it is useful to sound the uterine cavity to ascertain its depth. This may be done with the biopsy catheter.

Cervical dilation may be necessary

Even when women with cervical stenosis were excluded in one study, it was difficult to pass the Pipelle endometrial biopsy through the cervix in 41.7% of women.³⁰