Complications of osmotic dilators

Uterine cervical stenosis: from classification to advances in management. Overcoming the obstacles to access the uterine cavity

BACKGROUND

To date hysteroscopy is the gold standard technique for the evaluation and management of intrauterine pathologies. The cervical canal represents the access route to the uterine cavity. The presence of cervical stenosis often makes entry into the uterine cavity difficult and occasionally impossible. Cervical stenosis has a multifactorial etiology. It is the result of adhesion processes that can lead to the narrowing or total obliteration of the cervical canal.

PURPOSE

In this review, we summarize the scientific evidence about cervical stenosis, aiming to identify the best strategy to overcome this challenging condition.

METHODS

The literature review followed the scale for the quality assessment of narrative review articles (SANRA). All articles describing the hysteroscopic management of cervical stenosis were considered eligible. Only original papers that reported data on the topic were included.

RESULTS

Various strategies have been proposed to address cervical stenosis, including surgical and non-surgical methods. Medical treatments such as the preprocedural use of cervical-ripening agents or osmotic dilators have been explored. Surgical options include the use of cervical dilators and hysteroscopic treatments.

CONCLUSIONS

Cervical stenosis can present challenges in achieving successful intrauterine procedures. Operative hysteroscopy has been shown to have the highest success rate, particularly in cases of severe cervical stenosis, and is currently considered the gold standard for managing this condition. Despite the availability of miniaturized instruments that have made the management of cervical stenosis more feasible, it remains a complex task, even for experienced hysteroscopists.

Spontaneous Pregnancy After the Removal of Long-Term Retained Laminaria

We report the case of a woman with laminaria retention up to six years, followed by spontaneous pregnancy after the removal by hysteroscope of the intrauterine retained laminaria. A 26-year-old woman (G1P0) visited our hospital with complaints of prolonged menstrual bleeding, dyspareunia, and infertility. She had a history of dilatation and evacuation (D&E) at nine weeks of gestation six years earlier. A transvaginal ultrasound showed an artifact, and hysteroscopy revealed a long foreign body, which was suspected to be a laminaria retained after the prior abortion. In the hysteroscopic surgical procedure, the laminaria was cut, and the two halves were excised using resectoscope electrodes and hooked to the electrodes for removal. Thereafter, a year later, she conceived spontaneously and gave birth to a baby by cesarean delivery due to the arrest of labor progress. We are the first to present a pregnant case after the removal of a six-year retained laminaria.

Second-trimester Abortion

In 2019, the US Centers for Disease Control reported that 7% of abortions were performed after 13 weeks of pregnancy, a small proportion of all terminations. However, the need for second-trimester abortions will increase commensurate with restrictions to access nationwide. Second-trimester abortions are performed with medications or through a procedure. Health care practitioners serving persons at risk of pregnancy should understand how abortions are performed and how to deliver evidence-based postabortion care. The purpose of this article is to provide a foundation for caring for individuals before, during, and after second-trimester abortion.

Comparison of Efficacy of Vaginal Misoprostol versus a Synthetic Osmotic Dilator (Dilapan-S) for Cervical Preparation before Operative Hysteroscopy: A Randomized Controlled Study

Objectives

To compare the need for mechanical cervical dilatation following vaginal misoprostol or synthetic osmotic dilator (Dilapan-S) usage for cervical preparation before operative hysteroscopy.

Materials and Methods

Fifty-five premenopausal women scheduled for operative hysteroscopic procedures with a 26 Fr resectoscope were included in this randomized, controlled clinical trial. After randomization, either 400 μg of vaginal misoprostol or intracervical synthetic osmotic dilator (Dilapan-S) was inserted 12 h before operative hysteroscopy. The need for additional mechanical cervical dilatation before insertion of the resectoscope was compared between the two groups. Initial cervical diameter before mechanical dilatation, intraoperative complications (cervical tears, creation of a false passage), and ease of dilatation were also compared between the two groups.

Results

In the misoprostol group, 92% of women required additional mechanical cervical dilatation, whereas only 36% of women in the Dilapan-S group required additional dilatation (P < 0.05). The median initial cervical diameter achieved with Dilapan was 9 mm (Q1: 7 mm; Q3: 10 mm), and with misoprostol, it was 6 mm (Q1: 4.5 mm; Q3: 8 mm) (P < 0.05). There was no significant difference in other outcome parameters between the two groups.

Conclusion

Synthetic osmotic dilator (Dilapan-S) is more efficacious than vaginal misoprostol at ripening the cervix before operative hysteroscopy.

Post-abortion Complications: A Narrative Review for Emergency Clinicians

An abortion is a procedure defined by termination of pregnancy, most commonly performed in the first or second trimester. There are several means of classification, but the most important includes whether the abortion was maternally “safe” (performed in a safe, clean environment with experienced providers and no legal restrictions) or “unsafe” (performed with hazardous materials and techniques, by person without the needed skills, or in an environment where minimal medical standards are not met). Complication rates depend on the procedure type, gestational age, patient comorbidities, clinician experience, and most importantly, whether the abortion is safe or unsafe. Safe abortions have significantly lower complication rates compared to unsafe abortions. Complications include bleeding, retained products of conception, retained cervical dilator, uterine perforation, amniotic fluid embolism, misoprostol toxicity, and endometritis. Mortality rates for safe abortions are less than 0.2%, compared to unsafe abortion rates that range between 4.7-13.2%. History and physical examination are integral components in recognizing complications of safe and unsafe abortions, with management dependent upon the diagnosis. This narrative review provides a focused overview of post-abortion complications for emergency clinicians.

Expulsion of a fragmented laminaria one week after a same-day dilation and evacuation procedure

We describe a complication from same-day cervical preparation with simultaneous use of Aquacryl hydrogel osmotic dilator, laminaria and misoprostol vaginally for a same-day dilation and evacuation procedure at 19 weeks' gestation. The laminaria fragmented and embedded in the cervix at the time of procedure. Removal was unsuccessful in clinic and the patient was discharged on one week of antibiotics. The patient returned after the administration of misoprostol vaginally and the surgeon found the fragment in the vagina. We cannot conclude if the fragment was expelled with misoprostol use or prior to its administration.

Mechanical dilation to remove incarcerated laminaria during a second trimester abortion

Cervical preparation with laminaria reduces complications with 2nd trimester dilation and evacuation. During a surgical abortion at 22 weeks, we could not remove laminaria manually or with ring forceps due to laminaria "dumbbelling" [1]. Without pushing laminaria into the uterus, we mechanically dilated the cervix and removed the incarcerated laminaria.

Leukocytosis during cervical preparation with osmotic dilators for dilation and evacuation

Objectives:

To describe leukocytosis trends during cervical preparation with osmotic dilators for second-trimester dilation and evacuation procedures, and to determine whether there is a difference in leukocytosis seen with laminaria versus Dilapan-S.

Methods:

We conducted a retrospective cohort study of 986 women presenting for dilation and evacuation from April 2008 through March 2009 at an outpatient clinic network. We included all procedures at ⩾14 weeks’ gestation where laminaria or Dilapan-S dilators were used for overnight dilation. All women had routine white blood cell testing during the study period.

Results:

There was a median increase of 2.4 × 10³/μL white blood cell count (95% confidence interval 2.2–2.7 × 10³/μL) from beginning of cervical preparation to the day of procedure (95% confidence interval and p value). Women receiving laminaria (n = 805) versus Dilapan-S (n = 181) had a greater increase in white blood cell count from baseline (median increase 2.7 versus 1.2 × 10³/μL, p < 0.001), including when adjusting for age, gestational age, parity, baseline white blood cell count, and number of dilators placed.

Conclusion:

There is increased leukocytosis during the course of cervical preparation with osmotic dilators, and this is increased with use of laminaria versus Dilapan-S. Rates of clinically recognized infection in second-trimester abortion are low regardless of dilator type used.

Management of Postabortion Complications for the Emergency Medicine Clinician

Although induced abortion is generally a safe outpatient procedure, many patients subsequently present to the emergency department, concerned about a postabortion complication. It is helpful for emergency physicians to understand the medications and procedures used in abortion care in the United States to effectively and efficiently triage and treat women presenting with potential complications from an abortion. Furthermore, because many states are experiencing increased abortion restrictions that limit access to care, emergency medicine physicians may encounter more patients presenting after self-managed abortions, which presents additional challenges. This article reviews the epidemiology and background of abortion care, including the range of symptoms and adverse effects that are within the scope of an uncomplicated procedure. This review also offers a comprehensive overview of management of abortion complications, including algorithms for more common complications and descriptions of less common but more severe adverse events. The article concludes with a recognition of the social stigma and legal regulations unique to abortion care.

Induction of labor in continuing pregnancies

This chapter aims to provide an evidence-based approach to cervical-ripening methods and induction of labor in high-, middle-, and low-income countries. We will review the epidemiology of induction and will also review pharmacological and mechanical methods of cervical-ripening as well as oxytocin for induction. Lastly, we will review current guidelines of when to determine an induction to be failed.

Society of Family Planning clinical recommendations: Cervical preparation for dilation and evacuation at 20-24 weeks' gestation

Although only 1.3% of abortions in the United States are between 20 and 24 weeks' gestation, these procedures are associated with elevated risks of morbidity and mortality. Adequate cervical preparation before dilation and evacuation (D&E) at 20-24 weeks' gestation reduces procedural risk. For this gestational range, at least one day of cervical preparation with osmotic dilators is recommended before D&E. The use of overnight osmotic dilators alone is sufficient for most D&Es at 20-24 weeks' gestation. Dilapan-S® dilators require a shorter time to achieve maximum dilation, may be more effective than laminaria and may increase the likelihood of success on the first D&E attempt. The use of adjunctive mifepristone administered one-day pre-operatively at the time of osmotic dilator placement, should be considered because evidence demonstrates that it makes D&E subjectively easier at 20-24 weeks without increasing side effects. While older studies suggest that two-days of serial osmotic dilators provide greater dilation than one day of dilators, adjunctive mifepristone may be comparable to a second day of dilators. Adjunctive misoprostol administered on the day of D&E does not appear to affect initial cervical dilation and procedure time and compared with mifepristone is associated with more side effects, such as pain and nausea. Using overnight mifepristone and same-day misoprostol without osmotic dilators at 20-24 weeks' gestation lengthens D&E procedure time and appears to increase immediate complications, at least among less experienced providers. Some evidence shows the feasibility of same-day cervical preparation before D&E at 20-24 weeks using Dilapan-S® with adjunctive misoprostol or serial repeat dosing of misoprostol, but same-day preparation should be limited to providers with significant experience with these regimens. The Society of Family Planning recommends preoperative cervical preparation before D&E at 20-24 weeks' gestation. Further studies are needed to clarify the best means of preparing the cervix in order to minimize abortion complications and improve outcomes in this gestational range.

Osmotic Dilator Intra-Abdominal Perforation: A Case Report

BACKGROUND

This report describes an unusual case of a retained hygroscopic osmotic dilator following second trimester dilation and evacuation.

CASE

A 24-year-old woman presented for elective pregnancy termination at 16 weeks gestational age. A cervical osmotic dilator could not be retrieved and fractured on attempted removal. Magnetic resonance imaging showed perforation through the cervix, possibly traversing the peritoneum. Hysteroscopy and laparoscopy were performed to remove the retained dilator. Significant inflammation and mesenteric adhesions surrounded the osmotic dilator, which was successfully removed.

CONCLUSION

This is the first reported case of an intra-abdominal osmotic dilator. Although this device is inert, close follow-up and timely retrieval, possibly with hysteroscopy or laparoscopy, are recommended to minimize the resulting inflammatory response.

The use of an osmotic dilator for induction of miscarriage in patients with the second trimester missed miscarriage

AIM

The aim of this study was to assess the outcomes of combined use of dilapan-S and pharmacological induction of miscarriage with mifepristone and misoprostol versus mifepristone and misoprostol only in patients with a second-trimester pregnancy loss.

MATERIALS AND METHODS

Our study included 74 patients with a second-trimester antenatal death who were randomized into two groups to receive pharmacological induction of miscarriage combined with intracervical insertion of dilapan-S (n = 37) or pharmacological induction of miscarriage only (n = 37). Efficacy endpoints included: blood loss volume, length of time between the procedure initiation and complete miscarriage, and the number of complications.

RESULTS

The use of dilapan-S together with mifepristone and misoprostol for induction of miscarriage in the second trimester in women with antenatal fetal death reduced the time from the start of the procedure to complete miscarriage by 1.98-fold. However, the use of dilapan-S did not significantly reduce the odds of such post-procedural complications as hematometra and retention of the products of conception in the uterus (p = .2501).

CONCLUSIONS

Combined management of antenatal pregnancy loss in the second trimester including intracervical insertion of dilapan-S and conventional induction with miscarriage may be considered a valuable clinical strategy. However, future studies should focus on ways to prevent postprocedural complications in this group of women.

Two cervical preparation regimens prior to surgical abortion at 10-14 weeks of gestation: A randomized clinical trial

BACKGROUND

The aim of the study was to determine whether same-day cervical preparation with an osmotic dilator and misoprostol was as effective and safe as overnight cervical preparation for surgical abortions at 10-14 weeks.

METHODS

Seventy women seeking surgical abortion at 10-14 weeks were allocated to receive one osmotic dilator 16-17 h or 6-7 h prior to an abortion. All women received misoprostol 400 μg orally 2 h before the abortion.

RESULTS

The abortion time of the same-day group was 7.42 ± 1.73 min, and that of the overnight group was 8.00 ± 2.19 min (p = 0.23). The blood loss volume of the same-day group was 20.6 ± 10.6 mL, and that of the overnight group was 16.3 ± 7.0 mL (p = 0.55). The degree of cervical dilation for the same-day group was inferior to the overnight group (p = 0.02).

CONCLUSIONS

Same-day cervical preparation with misoprostol and an osmotic dilator shortens the hospitalization days, suggesting same-day cervical preparation is safe, effective, and feasible for surgical abortion at 10-14 weeks of gestation.

Comparison of Effectiveness of Laminaria versus Vaginal Misoprostol for Cervical Preparation Before Operative Hysteroscopy in Women of Reproductive Age: A Prospective Randomized Trial

STUDY OBJECTIVE

To compare the effectiveness and safety of intracervical laminaria dilator versus intravaginal misoprostol administered before surgery to facilitate cervical dilation before operative hysteroscopy.

DESIGN

A prospective randomized study (Canadian Task Force classification 1).

SETTING

A university hospital.

PATIENTS

A total of 150 women were assigned at random to the following groups: laminaria dilation (n = 50), misoprostol dilation (n = 50), and mechanical dilation (n = 50).

INTERVENTIONS

Hysteroscopic surgery of intrauterine lesions.

MEASUREMENTS AND MAIN RESULTS

In this study, 150 women were assigned at random to receive cervical priming with an intracervical laminaria dilator, 200 μg of intravaginal misoprostol, or a mechanical dilator before operative hysteroscopy. Cervical response, surgical outcome, and complications of operative hysteroscopy were assessed. Visual analog scale (VAS) pain scores were recorded in the misoprostol and laminaria dilation groups. Demographic variables of the study groups were comparable (p = .278-.988). The duration of cervical pretreatment was similar with the intracervical laminaria dilator and intravaginal misoprostol (p = .803); however, intravaginal misoprostol was associated with more adverse effects (p = .031). Compared with the misoprostol dilation group, in which all patients required additional cervical dilation, notably fewer patients in the laminaria dilation group required additional cervical dilation after cervical preparation (p = .001). VAS pain scores were significantly higher in the laminaria dilation group, however (p = .001).

CONCLUSION

Cervical priming with an intracervical laminaria dilator before operative hysteroscopy reduces the need for cervical dilation and better facilitates hysteroscopic surgery compared with intravaginal misoprostol. Oral analgesic use may be required before the use of this device.

Other mechanical methods for pre-induction cervical ripening

Pre-induction cervical ripening is an important part of the labor induction process in women with an unfavorable cervix. This can be achieved either by pharmacologic or mechanical methods of cervical ripening. While the Foley catheter is the most commonly used mechanical method for labor induction, other mechanical methods are also available. This article reviews the safety profiles of osmotic dilators, extra-amniotic saline infusion, double-balloon catheters, and also compares their efficacy to that of other mechanical and pharmacologic cervical ripening methods. While mechanical methods have been shown to be safe and effective for cervical ripening, none of these alternatives has been shown to be superior to the Foley catheter.

Misoprostol 1 to 3 h preprocedure vs. overnight osmotic dilators prior to early second-trimester surgical abortion

OBJECTIVES

We sought to compare the effectiveness of at least 1 h of 400 mcg of buccal misoprostol to overnight osmotic dilators for early second-trimester surgical abortion cervical preparation.

DESIGN

We conducted a retrospective cohort study, reviewing 145 consecutive charts to compare procedure duration for women who received 400 mcg of buccal misoprostol at least 1 h preprocedure vs. overnight osmotic dilators before dilation and evacuation between 14 weeks, 0 days and 15 weeks, 6 days' gestation. Primary outcome was procedure duration and secondary outcomes included maximum mechanical dilator size, estimated blood loss and side effects.

RESULTS

Sixty-four women (44.1%) received buccal misoprostol (mean 1.6 h), and 81 women (55.9%) received overnight osmotic dilators. Groups did not differ regarding mean gestational age or gynecologic history. All procedures in both groups were completed. Procedure duration was not significantly different between the misoprostol and osmotic dilator groups (median 11.0 min vs. 10.0 min, p=.22), even after multivariable linear regression (p=.17). The mean total cervical preparation duration was 1.6 h for women in the misoprostol group compared to 20.3 h in the osmotic dilator group (p<.001). Secondary outcomes did not differ between groups.

CONCLUSIONS

We found that at least 1 h of preprocedure misoprostol decreased the duration of cervical preparation for early second-trimester procedures performed by an experienced surgeon.

IMPLICATIONS

In this small, retrospective review, at least 1 h of preprocedure buccal misoprostol decreased the duration from cervical preparation initiation to procedure completion in early second-trimester procedures performed by an experienced surgeon. These results should be considered as a pilot evaluation, and further prospective study is needed to further clarify whether this short interval could be applied in general practice.

Experimental comparison of properties of natural and synthetic osmotic dilators

PURPOSE

The in vitro study compares natural and synthetic osmotic dilators in selected parameters influencing their clinical efficacy.

METHODS

Diameters of Laminaria and synthetic dilators (Dilapan-S and Dilasoft) were measured in dry state, during free swelling in isotonic solution and during swelling against a force. Three aspects were evaluated-diameter increase, speed of action and consistency of action.

RESULTS

The maximum diameter increase of 3 and 4-mm Dilapan-S was 3.6 and 3.3 times, of Dilasoft 3.2 and 3.1 times, respectively. For Laminaria, it was 2.9 and 2.7 times. The difference between synthetic dilators and Laminaria was statistically significant (p < 0.01). Synthetic dilators also swelled faster. Under applied counter force, synthetic dilators increased their diameter more than Laminaria (+3.6 mm for Dilapan-S, +3.8 mm for Dilasoft, +1.2 mm for Laminaria; p < 0.01) and achieved faster expansion. Synthetic dilators also showed significantly higher consistency between samples in all experiments.

CONCLUSIONS

Synthetic dilators compared to Laminaria reached higher maximum diameters, acted faster, were more consistent and were able to expand against force three times more. The results support clinical observations that synthetic dilators are more suitable and preferable for same-day D&E procedure and that fewer synthetic dilators are needed to achieve the same effect.

Prevalence and risk factors of inadequate cervical dilation following laminaria insertion in second-trimester abortion--case control study

OBJECTIVE

The objective was to explore the prevalence of and risk factors for inadequate cervical dilation following insertion of a single set of laminaria in women scheduled for dilation & evacuation (D&E) at 14-24 weeks' gestation.

STUDY DESIGN

We retrospectively reviewed all cases of women who underwent pregnancy termination by D&E at 14-24 weeks' gestation between January 2003 and December 2013. All cases in which the surgical procedure was cancelled due to failure to achieve adequate cervical dilation after a single set of laminaria inadequate cervical dilation were included. The control group was women who underwent D&E following adequate cervical dilation after a single set of laminaria, and were matched according to gestational week in a ratio of 1:3.

RESULTS

The overall dilation failure rate was 3.2%, with 4.0% among the induced-abortion patients and 1.5% among the patients with fetal demise (p=.002). Patients who had inadequate cervical dilation had lower rates of gravidity (p=.002) and previous spontaneous vaginal delivery (p<.001), along with higher rates of primigravidity, nulliparity (p<.001), previous cesarean section/s (p=.041), previous abdominal surgeries (p=.001) and previous cervical procedures (p=.003), compared to controls. A multivariable logistic regression analysis revealed two risk factors for inadequate cervical dilation following laminaria insertion, namely, previous cesarean section (p=.002) and previous cervical procedure (p<.001), whereas increased gravidity was found to protect against inadequate cervical dilation (p=.002).

CONCLUSIONS

Previous cesarean section/s, cervical procedures and primigravidity were found to be risk factors for failure to achieve adequate cervical dilation after a single set of laminaria. Women who are scheduled for D&E, and in whom one of these risk factors exists, might benefit from additional interventions to achieve better cervical preparation.

Hypersensitivity to laminaria: a case report and review of literature

We report a case of laminaria hypersensitivity treated with diphenhydramine and corticosteroids. A literature review identified 10 previously reported cases, with 8 recognized as anaphylaxis, and good outcomes with corticosteroids and antihistamines despite limited epinephrine utilization. Laminaria hypersensitivity is likely IgE mediated with an increased anaphylaxis risk with prior exposure.

Cervical preparation for second-trimester surgical abortion prior to 20 weeks' gestation: SFP Guideline #2013-4

For a dilation and evacuation (D&E) procedure, the cervix must be dilated sufficiently to allow passage of operative instruments and products of conception without injuring the uterus or cervical canal. Preoperative preparation of the cervix reduces the risk of cervical laceration and uterine perforation. The cervix may be prepared with osmotic dilators, pharmacologic agents or both. Dilapan-S™ and laminaria are the two osmotic dilators currently available in the United States. Laminaria tents, made from dehydrated seaweed, require 12-24 h to achieve maximum dilation. Dilapan-S™, made of synthetic hydrogel, achieves significant dilation within 4 h and is thus preferable for same-day procedures. A single set of one to several dilators is usually adequate for D&E before 20 weeks' gestation. Misoprostol, a prostaglandin E1 analogue, is sometimes used instead of osmotic dilators. It is generally regarded as safe and effective; however, misoprostol achieves less dilation than overnight osmotic tents. The literature supports same-day cervical preparation with misoprostol or Dilapan-S™ up to 18 weeks' gestation. As the evidence regarding alternative regimens increases, highly experienced D&E providers may consider same-day regimens at later gestations utilizing serial doses of misoprostol or a combination of osmotic and pharmacologic agents. Misoprostol use as an adjunct to overnight osmotic dilation is not significantly beneficial before 19 weeks' gestation. Limited data demonstrate the safety of misoprostol before D&E in patients with a prior cesarean delivery. Mifepristone, a progesterone receptor antagonist, is also effective for cervical preparation prior to D&E, although data to support its use are limited. The Society of Family Planning recommends preoperative cervical preparation to decrease the risk of complications when performing a D&E. Since no single protocol has been found to be superior in all situations, clinical judgment is warranted when selecting a method of cervical preparation.

Laminaria tent versus Misoprostol for cervical ripening before surgical process in missed abortion

OBJECTIVE

To compare the efficacy of Laminaria tents with Misoprostol for cervical ripening before surgical process in missed abortion.

METHOD

In a prospective study, 70 women with missed abortion were assigned to have either insertion of a 3 mm intracervical Laminaria tent (n = 35) or vaginal Misoprostol 400 μg (n = 35) on the day prior to suction dilation and curettage (D/C). The women were interviewed just prior to the D/C with regard to pain, vaginal bleeding, and cervical dilator preference.

RESULT

Cervical dilation was greater in the Laminaria group but not significantly different from that in the Misoprostol group. However, additional cervical dilation before D/C was required in more patients in the Misoprostol group (45.7 vs 14.3%, P = 0.001). Women who received Laminaria reported significantly more pain at the time of insertion (62.8% in Laminaria group vs 22.8% in Misoprostol group) compared with women who received Misoprostol. Conversely, Misoprostol was associated with more nausea, vomiting, diarrhea and vaginal bleeding.

CONCLUSIONS

Laminaria tents are more effective cervical dilators than vaginal Misoprostol when inserted the day prior to suction D and C. Vaginal Misoprostol insertion is more comfortable, although it is associated with an increased risk of vaginal bleeding.

Cervical preparation for second trimester dilation and evacuation

BACKGROUND

Abortion during the second trimester of pregnancy accounts for 10-15% of abortions performed worldwide. Dilation and evacuation (D&E) is the preferred method of second-trimester abortion in most parts of the developed world. Cervical preparation is recommended for dilation and curettage (D&C) after 12 weeks gestation and is standard practice for D&E beyond 14 weeks gestation. Prostaglandins, osmotic dilators, and Foley balloon catheters have been used and studied as cervical preparation prior to second-trimester D&E. However, no consensus exists as to which cervical preparation method is superior with regards to safety, procedure time, need for additional dilation, ability to perform the procedure, or patient and provider acceptability. Despite the fact that the advent of osmotic dilation has improved the safety of the D&E procedure during the second trimester, it is unclear whether a certain type of osmotic dilator is superior to another or whether osmotic dilation with adjuvant prostaglandin is superior to osmotic dilation alone or to prostaglandins alone.

OBJECTIVES

This review evaluates cervical preparation methods for second-trimester surgical abortion with respect to differences in procedure time, dilation achieved, need for additional dilation, complications, ability to complete the procedure, patient pain scores, and patient and provider acceptability and satisfaction.

SEARCH STRATEGY

We searched for trials of cervical preparation prior to second-trimester D&E.

SELECTION CRITERIA

We included all randomized controlled trials that compared osmotic, mechanical, antiprogesterone, prostaglandin, or other medical agents of cervical preparation for second-trimester surgical abortion from 14-24 weeks of gestation.

DATA COLLECTION AND ANALYSIS

Data were abstracted by two authors and data entry was verified by a third author. Mean difference and Peto Odds Ratio were calculated.

MAIN RESULTS

Osmotic dilators were found to be superior to prostaglandins with respect to cervical dilation throughout the second trimester and with respect to procedure time within the early second trimester. Addition of prostaglandins to osmotic dilators was not found to increase cervical dilation, except after 19 weeks gestation, however, no impact was seen on procedure time. Addition of Mifepristone to misoprostol was found to improve cervical dilation, yet increase procedure time and frequency of pre-procedural expulsions. Two-day cervical preparation was found to produce greater cervical preparation than one-day, but had no impact on procedure time. Serious complication rates or ability to complete the procedure did not differ significantly between any of the preparation methods reviewed.

AUTHORS' CONCLUSIONS

Cervical preparation with osmotic dilators and/or misoprostol before second-trimester D&E is safe and effective. Osmotic dilators appear to provide superior cervical dilation when compared to prostaglandins alone or when combined with prostaglandins, however this difference in cervical dilation does not appear to result in differences in procedure time or complication rates. There does not appear to be clear clinical benefit from two days of cervical preparation compared to one-day prior to second-trimester D&E below 19 weeks gestational duration. Mifepristone plus misoprostol was associated with high rates of pre-procedural expulsions and does not appear to be a useful method of cervical preparation before second-trimester dilation and evacuation. Same-day procedures appear to be a safe and reasonable option in the early second trimester, however, more research is needed to assess the effectiveness and safety of same-day procedures in the later second trimester.

A combination of misoprostol and estradiol for preoperative cervical ripening in postmenopausal women: a randomised controlled trial

OBJECTIVE

To compare the impact of 1000 microg of self-administered vaginal misoprostol versus self-administered vaginal placebo on preoperative cervical ripening after 2 weeks of pretreatment with estradiol vaginal tablets in postmenopausal women prior to day-care operative hysteroscopy.

DESIGN

Randomised, double-blind, placebo-controlled sequential trial.

SETTING

Norwegian university teaching hospital.

POPULATION

Sixty-seven postmenopausal women referred for day-care operative hysteroscopy.

METHODS

The women were randomised to receive either 1000 microg of self-administered vaginal misoprostol or self-administered vaginal placebo on the evening before day-care operative hysteroscopy. All women had administered a 25-microg vaginal estradiol tablet daily for 14 days prior to the operation.

MAIN OUTCOME MEASURES

PRIMARY OUTCOME

preoperative cervical dilatation at hysteroscopy.

SECONDARY OUTCOMES

difference in dilatation at recruitment and before hysteroscopy, number of women who achieved a preoperative cervical dilatation of 5 mm or more, acceptability, complications and adverse effects.

RESULTS

The mean cervical dilatation was 5.7 mm (SD, 1.6 mm) in the misoprostol group and 4.7 mm (SD, 1.5 mm) in the placebo group, the mean difference in cervical dilatation being 1.0 mm (95% CI, 0.2-1.7 mm). Self-administered vaginal misoprostol of 1000 microg at home on the evening before day-care hysteroscopy is safe and highly acceptable, although a small proportion of women experienced lower abdominal pain.

CONCLUSIONS

One thousand micrograms of self-administered vaginal misoprostol, 12 hours prior to day-care hysteroscopy, after 14 days of pretreatment with vaginal estradiol, has a significant cervical ripening effect compared with placebo in postmenopausal women.

Laminaria tent vs misoprostol for cervical priming before hysteroscopy: Randomized study

STUDY OBJECTIVE

To compare the efficacy of laminaria tents and orally administered misoprostol in priming the cervix before operative hysteroscopy.

DESIGN

Randomized, controlled study (Canadian Task Force classification I).

SETTING

Tertiary medical center.

PATIENTS

One hundred twenty premenopausal women who underwent operative hysteroscopy between March 2005 and January 2007.

INTERVENTION

The women were randomized to receive a laminaria tent or misoprostol for cervical priming.

MEASUREMENTS AND MAIN RESULTS

The primary outcomes were postpriming cervical width insofar as size of Hegar dilators and need for cervical dilation. The secondary outcomes were adverse effects from the priming methods. Postpriming cervical width was greater in the laminaria group but not significantly different from that in the misoprostol group. However, cervical dilation before hysteroscopy was required in more patients in the misoprostol group. Nausea, vomiting, diarrhea, and bleeding were more common in the misoprostol group, and the incidences of chills and headache were similar between the 2 groups.

CONCLUSION

Laminaria tents are superior to oral misoprostol insofar as less need for cervical dilation and fewer adverse effects.

Cervical dilation in second-trimester abortion

Dilation and evacuation, the most common method performed for second-trimester abortion in the United States, requires sufficient cervical dilation to reduce the risk of complications such as cervical laceration or uterine perforation. The cervix may be prepared with osmotic dilators such as laminaria, Lamicel, or Dilapan-S, or with pharmacologic agents such as misoprostol. Dilapan-S and Lamicel achieve their maximum dilation faster than laminaria, making same-day procedures possible. Misoprostol has limited data supporting its use in this setting. Decisions regarding which method is best are clinician-dependent, and factors such as gestational age and time allowed for preparation should be considered.

Does self-administered vaginal misoprostol result in cervical ripening in postmenopausal women after 14 days of pre-treatment with estradiol? Trial protocol for a randomised, placebo-controlled sequential trial

OBJECTIVE

To compare the impact of 1000 micrograms of self-administered vaginal misoprostol versus self-administered vaginal placebo on preoperative cervical ripening after pre-treatment with estradiol vaginal tablets at home in postmenopausal women prior to day-care operative hysteroscopy.

DESIGN

Randomised double-blind placebo-controlled sequential trial. The boundaries for the sequential trial were calculated on the primary outcomes of a difference of cervical dilatation > or = 1 millimetre, with the assumption of a type 1 error of 0.05 and a power of 0.95.

SETTING

Norwegian university teaching hospital.

POPULATION

Postmenopausal women referred for day-care operative hysteroscopy.

METHODS

The women were randomised to either 1000 micrograms of self-administered vaginal misoprostol or self-administered vaginal placebo the evening before day-care operative hysteroscopy. All women had administered a 25-microgram vaginal estradiol tablet daily for 14 days prior to the operation.

MAIN OUTCOME MEASURES

Preoperative cervical dilatation (difference between misoprostol and placebo group, primary outcome), difference in dilatation before and after administration of misoprostol or placebo, number of women who achieve a preoperative cervical dilatation > or = 5 millimetres, acceptability, complications and side effects (secondary outcomes).

RESULTS

Intra-operative findings and distribution of cervical dilatation in the two treatment groups: values are given as median (range) or n (%). Difference in dilatation before and after administration of misoprostol and placebo: values are given as median (range) of intraindividual differences. Percentage of women who achieve a cervical dilatation of > or = 5 mm, percentage of women who were difficult to dilate. Acceptability in the two treatment groups: values are given as completely acceptable n (%), fairly acceptable n (%), fairly unacceptable n (%), completely unacceptable n (%). Pain in the two treatment groups: pain was measured with a visual analogue scale ranging from 0 (no pain) to 10 (unbearable pain): values are given as median (range). Occurrence of side effects in the two treatment groups. Values are given as n (%). Complications given as n (%).

FUNDING SOURCES

No pharmaceutical company was involved in this study. A research grant from the regional research board of Northern Norway has been awarded to finance Dr K.S.O.'s leave from Hammerfest hospital as well as travel expenses between Hammerfest and Oslo, and research courses. The research grant from Prof B.I.N. (Helse Øst) funded the purchase of estradiol tablets, the manufacturing costs of misoprostol and placebo capsules from the hospital pharmacy, as well as the costs incurred for preparing the randomisation schedule and distribution of containers containing capsules to hospital. Prof B.I.N.'s research grant also funded insurance for the study participants.

CONCLUSIONS

Estimated completion date 31 December 2008.

Comparison of self-administered vaginal misoprostol versus placebo for cervical ripening prior to operative hysteroscopy using a sequential trial design

OBJECTIVE

To compare the impact of 1000 micrograms of self-administered vaginal misoprostol versus self-administered vaginal placebo at home on preoperative cervical ripening in both premenopausal and postmenopausal women before operative hysteroscopy.

DESIGN

Two separate but identical parallel, randomised, double-blind, placebo-controlled sequential trials, one in premenopausal women and one in postmenopausal women. The boundaries for the sequential trials were calculated on the primary outcomes of a difference of cervical dilatation > or = 1 mm, with the assumption of a type 1 error of 0.05 and a power of 0.95.

SETTING

Norwegian university teaching hospital.

SAMPLE

Eighty-six women referred to outpatient operative hysteroscopy.

METHODS

The women were randomised to either 1000 micrograms of self-administered vaginal misoprostol or self-administered vaginal placebo the evening before outpatient operative hysteroscopy.

MAIN OUTCOME MEASURES

Preoperative cervical dilatation (primary outcome), number of women who achieve a preoperative cervical dilatation > or = 5 mm, acceptability, complications and adverse effects (secondary outcomes).

RESULTS

In premenopausal women, the mean cervical dilatation was 6.4 mm (SD 2.4) in the misoprostol group and 4.8 mm (SD 2.0) in the placebo group, the mean difference in cervical dilatation being 1.6 mm (95% CI 0.5-2.7). Among the premenopausal women receiving misoprostol, 88% achieved a cervical dilatation of > or = 5 mm compared with 65% in the placebo group. Twelve percent of the women who received misoprostol were difficult to dilate compared with 32% who received placebo. Dilatation was also quicker in the misoprostol group. Misoprostol had no effect on cervical ripening in postmenopausal women compared with placebo, and 43% of the women were difficult to dilate. The trials were terminated after analysis of 21 postmenopausal women and 65 premenopausal women after reaching a conclusion on the primary outcome with only 28% of the number of women needed in a fixed sample size trial. Three of 45 women who received misoprostol experienced severe lower abdominal pain, and there was an increased occurrence of light preoperative bleeding in the misoprostol group. Most women did not experience misoprostol-related adverse effects. The majority (83% of premenopausal and 76% of postmenopausal women) found self-administered vaginal misoprostol at home to be acceptable. There were two serious complications in the premenopausal misoprostol group: uterine perforation with subsequent peritonitis and heavy postoperative bleeding requiring blood transfusion, but these were not judged to be misoprostol related. Complications were otherwise comparatively minor and distributed equally between the two dosage groups.

CONCLUSIONS

One thousand micrograms of self-administered vaginal misoprostol 12 hours prior to operative hysteroscopy has a significant cervical ripening effect compared with placebo in premenopausal but not in postmenopausal women. Self-administered vaginal misoprostol of 1000 micrograms at home the evening before operative hysteroscopy is safe and highly acceptable, although a small proportion of women experienced severe lower abdominal pain. There is a risk of lower abdominal pain and light preoperative bleeding with this regimen, which is very cheap and easy to use.

Overcoming the challenging cervix: techniques to access the uterine cavity

OBJECTIVE

To identify cervical stenosis and review medical, surgical, and radiological modalities to access the uterine cavity.

MATERIALS AND METHODS

Computerized searches of Medline and PubMed from 1996 to 2005 were conducted using the key words "cervix," "cervical ripening," and "cervical stenosis." References from identified publications were manually searched and cross-referenced to identify additional relevant articles. We review relevant techniques on how to access the uterine cavity when cervical stenosis is encountered.

RESULTS

Many gynecologic procedures require uncomplicated access through the cervix to access the uterine cavity, including hysteroscopy, dilation and curettage, sonohysterogram, hysterosalpingogram, endometrial biopsy, and embryo transfer for in vitro fertilization. These procedures can be quite complicated when a cervix is obstructed. Management techniques described include the medical use of misoprostol and laminaria, intraoperative ultrasound guidance, and operative creation of a new passage. Additionally, techniques for bypassing the obstructed cervix and preventing cervical stenosis have been described.

CONCLUSIONS

Cervical stenosis can result in iatrogenic complications. Preoperative identification, cervical ripening agents, osmotic dilators, and the use of ultrasound guidance are useful in overcoming cervical stenosis. It is also key to identify those at risk for cervical stenosis and implement preventative techniques as needed.

Cervical preparation for second-trimester surgical abortion prior to 20 weeks of gestation

Roughly 11% of induced abortions in the United States are performed after 14 weeks of gestation, most commonly by dilation and evacuation (D&E). For a D&E procedure, the cervix must be dilated sufficiently to allow passage of operative instruments and products of conception without injuring the uterus or cervical canal. Preoperative preparation of the cervix reduces the risk of cervical laceration and uterine perforation. The cervix may be prepared with osmotic dilators, prostaglandin analogues, or both. Osmotic dilators currently available in the United States include Dilapan-S, Lamicel, and laminaria. Laminaria tents are made from dehydrated seaweed and require 12-24 h to achieve greatest dilation. The synthetic products, Dilapan-S and Lamicel, achieve maximum effect within 6 h. Dilapan-S achieves greater dilation than the others and, thus, requires fewer dilators to be placed but may be more difficult to remove. For same day procedures, Dilapan-S and Lamicel are preferable to laminaria. A single set of one to several dilators is usually adequate for D&E before 20 weeks of gestation. Additional sets over 1-2 days may be needed in challenging cases. Misoprostol, a prostaglandin analogue, is sometimes used instead of osmotic dilators; however, the data to support such use are limited. Misoprostol is inferior to overnight dilation with laminaria for cervical priming prior to D&E. Misoprostol use as an adjunct to overnight osmotic dilation is only marginally beneficial for priming beyond 16 weeks and does not truly demonstrate any benefit before 19 weeks of gestation. Limited data demonstrate the safety of misoprostol prior to D&E in patients with a uterine scar. The Society of Family Planning recommends preoperative cervical preparation to decrease the risk of complications when performing a D&E prior to 20 weeks of gestation. The three currently available osmotic dilators (laminaria, Lamicel, and Dilapan-S) are safe and effective for this use. Since no single protocol has been found to be superior, clinical judgment is warranted when selecting a method of preoperative cervical preparation.

Comparison of self-administered vaginal misoprostol versus placebo for cervical ripening prior to operative hysteroscopy using a sequential trial design*

OBJECTIVE

To compare the impact of 1000-microgram self-administered vaginal misoprostol versus self-administered vaginal placebo at home on preoperative cervical ripening in both premenopausal and postmenopausal women prior to outpatient resectoscopy.

DESIGN

Randomised, double-blind, placebo-controlled sequential trial.

SETTING

Norwegian university teaching hospital.

SAMPLE

Premenopausal and postmenopausal women referred to outpatient resectoscopy.

METHODS

The women were randomised to either 1000 micrograms of self-administered vaginal misoprostol or self-administered vaginal placebo the evening before outpatient resectoscopy.

MAIN OUTCOME MEASURES

Preoperative cervical dilatation, acceptability and complications.

RESULTS

(a) Intraoperative findings and distribution of cervical dilatation in the two treatment groups. Values are given as median (range) or n (%). (b) Acceptability in the two treatment groups. Values are given as completely acceptable, n (%); fairly acceptable, n (%); fairly unacceptable, n (%) and completely unacceptable, n (%). (c) Pain in the two treatment groups. Pain was measured with a visual analogue scale score, scale ranges from 0 (no pain) to 10 (unbearable pain). Values are given as median (range). (d) Occurrence of adverse effects in the two treatment groups. Values are given as n (%). (e) Complications, given as n (%).

Mechanical Methods of Cervical Ripening and Labor Induction

This article reviews the safety and efficacy of mechanical agents for cervical ripening. Hygroscopic dilators, balloon catheters, and devices designed for cervical ripening have all been shown to be safe and effective for cervical ripening. Mechanical agents are as efficacious as other agents for cervical ripening. However, there is no method that has been conclusively shown to improve mode of delivery or perinatal outcome. The advantages of preinduction cervical ripening with mechanical devices include low cost, low incidence of systemic side effects, and low risk of uterine hyperstimulation.

Use of Misoprostol Before Hysteroscopy: A Systematic Review

OBJECTIVE

To evaluate the effectiveness of administering misoprostol prior to hysteroscopy in achieving cervical dilatation and reducing complications including cervical laceration.

DATA SOURCES

Computerized searches of MEDLINE, PubMed and EMBASE were conducted using the key words "hysteroscopy" and "misoprostol." References from identified publications were manually searched and cross-referenced to identify additional relevant articles.

STUDY SELECTION

We included randomized clinical trials that compared women undergoing hysteroscopy who received misoprostol before the procedure with those who received placebo. Studies were excluded if there was no control group, if placebo was not used, if women were not randomized, or if only the abstract was available. Ten of 19 articles identified met the criteria for systematic review.

DATA EXTRACTION AND SYNTHESIS

The two co-authors separately abstracted data. Any differences in data abstraction were resolved through discussion, and a consensus was reached. QUORUM guidelines for meta-analyses and systematic reviews of randomized controlled trials were followed. In premenopausal women, misoprostol before hysteroscopy resulted in a reduced need for further cervical dilatation (relative risk [RR] = 0.61; 95% confidence interval [CI] = 0.51, 0.73), a lower rate of cervical laceration (RR 0.22; 95% CI 0.09, 0.56) and increased cervical dilatation (weighted mean difference 2.64; 95% CI 1.73, 3.54). In premenopausal women, misoprostol also resulted in a higher rate of side effects, including vaginal bleeding (RR 11.09; 95% CI 3.08, 40.00), cramping (RR 7.98; 95% CI 3.38, 18.84), and elevated temperature (RR 5.24; 95% CI 1.37, 20.09). For every four premenopausal women who received misoprostol prior to hysteroscopy, one woman avoided the need for further cervical dilatation. For every 12 premenopausal women receiving misoprostol, one cervical laceration was avoided.

CONCLUSION

In premenopausal women, misoprostol appears to be promising as a cervical ripening agent prior to hysteroscopy, although further research is needed to identify the ideal dose, route, and timing. Further research in postmenopausal women or those receiving GnRH agonists is also needed, to determine whether misoprostol is effective in cervical ripening in this population.

A randomized trial of laminaria tents versus vaginal misoprostol for cervical ripening in first trimester surgical abortion

OBJECTIVE

To compare the use of laminaria tents with misoprostol for cervical ripening prior to first trimester surgical abortion.

METHOD

In a prospective, open-label, randomized trial, 70 women were assigned to have either insertion of a 3 mm intracervical laminaria tent or vaginal misoprostol 200 microg on the day prior to suction dilatation and curettage (D and C). Cervical dilatation and operating time were measured at the time of D and C; the surgeon subjectively rated the ease of dilatation. The women were interviewed just prior to the D and C with regard to pain, vaginal bleeding, and dilator preference.

RESULTS

Laminaria produced significantly (P < 0.001) greater pre-abortion dilatation of the cervix (34.8 Pratt +/- 6.2) than did misoprostol (28.4 Pratt +/- 5.8). There was no demonstrable difference in ease of dilatation or operating time. Women randomized to use of laminaria reported significantly more pain on insertion than did those who received misoprostol (P < 0.001). Conversely, misoprostol was associated with more vaginal bleeding (P < 0.01). Pain following insertion was similar in each group. Two patients aborted completely after misoprostol alone. Overall, the stated patient preference for cervical dilator was more likely to be misoprostol (P < 0.01).

CONCLUSIONS

Laminaria tents are more effective cervical dilators than vaginal misoprostol when inserted the day prior to suction D and C. Vaginal misoprostol insertion is more comfortable, although it is associated with an increased risk of vaginal bleeding and may abort the pregnancy. Patient preference favours misoprostol. In patient-centred care, both laminaria and misoprostol are suitable options for cervical preparation prior to suction D and C.