Misoprostol prior to hysteroscopy in premenopausal and postmenopausal patients. A meta-analysis of randomized trials.

Introduction: Hysteroscopy is a common gynaecological procedure used to
either diagnose or treat several conditions in premenopausal and postmenopausal
women. Despite the fact that this procedure is widely used, dilatation
of the cervix is often required either for ambulatory hysteroscopy or for hysteroscopy
under general anaesthesia. Given that cervical dilatation may either
increase the procedure's complication rate or may substantially increase pain
in outpatient procedures, a method that could reduce the requirement of dilating
the cervix could be of high clinical importance. Misoprostol has been proposed
as an effective agent that could reduce the need for cervical dilatation in
women undergoing hysteroscopy, since it had been successfully used as an effective
agent for cervical ripening in labour induction among pregnant women.
Despite the fact that several randomized trials have been published up to date
regarding the effect of misoprostol on cervical width prior to hysteroscopy, no
definite conclusion can be drawn, mainly due to the small sample size of the
trials, the heterogeneity of the patients included and the conflicting results.
Taking into account the lack of solid guidance on whether misoprostol
should be administered prior to hysteroscopy in pre- and postmenopausal patients,
we set to perform a meta-analysis of randomized controlled trials (RCTs).
Methods: We performed a systematic review of the literature through January
2011 in order to identify potentially eligible randomized controlled trials
that randomized patients to receive either misoprostol or placebo prior to diagnostic
or operative hysteroscopy. Patients could be either premenopausal or
postmenopausal. We considered all RCTs regardless of the dose and the route
of administration of misoprostol. Trials that randomized patients to receive different
doses or different administration routes of misoprostol were excluded
from the analysis.We calculated the risk ratios (RR) and 95% CI separately for premenopausal
and postmenopausal patients for the main outcomes: need for further cervical
dilatation in order to perform the hysteroscopic procedure and cervical width
prior to hysteroscopy. Secondary outcomes included major complications such
as uterine perforation and cervical laceration, and risk ratios were calculated
cumulatively for pre- and postmenopausal patients. Analyses were performed
in Revman 5.0 statistical software using the fixed or random effects model. All
p values were two-tailed with a level of significance at 0.05.
Results: Overall 24 potentially eligible trials including 2261 patients were
retrieved. Among them three trials compared different doses and different
routes of misoprostol and were excluded from the analyses leading to cumulatively
21 eligible trials. The results were completely different among preand
post menopausal patients; among premenopausal women the RR for need
for further cervical dilatation was significantly reduced in patients receiving
misoprostol 0.77 (95%CI 0.62-0.96) p = 0.02, and misoprostol resulted
in significantly higher cervical width prior to hysteroscopy mean difference
2.08 (95% 0.82-3.34) p = 0.001. On the contrary postmenopausal patients did
not experience any clear benefit in terms of need for further cervical dilatation
RR 1.14 (95%CI 0.68-1.90) or cervical width prior to the hysteroscopic
procedure mean difference 0.49 (95%CI -0.24 - 1.22). Regarding the overall
complication rate misoprostol did not significantly reduce the incidence
of uterine perforation RR 0.63(95%Ci 0.28-1.43); however it significantly
reduced the incidence of cervical laceration RR 0.40 (95%CI 0.25-0.65),
p <0.001.
Conclusions: Misoprostol prior to hysteroscopy significantly reduces the
need for cervical dilatation and increases the cervical width prior hysteroscopy
only in premenopausal patients. Postmenopausal women do not appear to
experience substantial benefits from cervical priming with misoprostol prior
to hysteroscopy.