Operative hysteroscopy is a relatively safe and effective procedure, but given its frequent occurrence, one must be aware of potential complications and minimize the risk to the patients [15]. Although the incidence of major complications such as uterine perforation is reported to be 1.42% in most hysteroscopic reviews [16], there is very little data in the literature on the incidence, diagnosis, and management of false passage that can be encountered during hysteroscopic surgery [8]. If unrecognized, false passage can lead to uterine perforation at the level of the cervix or the lower uterine segment. Almost 50% of hysteroscopic complications are related to difficulty with cervical entry [16]. False passage can be easily misdiagnosed as adhesions in the uterine cavity. This often leads to abandonment of the procedure. Even if correctly recognized, surgeons sometimes prefer abandonment of the procedure for a fear of uterine perforation [15] and/or for fear of complications of excessive fluid deficit and its subsequent consequences of fluid overload and electrolyte disturbances.
This case series should increase the awareness of the complication of false passage during operative hysteroscopy among hysteroscopic surgeons, as false passage appears to be under-reported in the literature. Our study illustrates the importance of immediate diagnosis of false passage. The step-by-step description of the approaches and the techniques used to overcome such complication are easy to adopt by practitioners. Using the approaches and the techniques described in this case series enabled us to successfully manage the false passage complication, and in turn, complete the intended operative hysteroscopic procedures in all the patients in the study. Kumar and Kumar 2006 describe a similar technique of withdrawal of the hysteroscope to identify both the false passage and internal cervical os and then reinsertion of the hysteroscope into the true internal cervical os [4]. The authors of this case series also propose, in theory, another method to overcome the false passage; this method would require the availability of a smaller operative hysteroscope, which can be advanced through the opening of the internal os without the need for any further maneuver or attempts at dilating the internal cervical os. If the intended operative procedure could not be completed with a smaller operative hysteroscope, or such a small operative hysteroscope is not available, the operator can use the division of the bridge of tissue technique using a hysteroscopic scissor to be able to advance a larger operative hysteroscope or resectoscope into the endometrial cavity.
Although this study describes two techniques for the management of false passage, other techniques can also be used depending on the situation and on a case-by-case basis. Zhu et al. describe a technique of gradual dissection to enlarge the opening to the internal cervical os, using 7 French double-action forceps under hysteroscopic visualization, until the endometrial cavity was recognized [2]. In addition, some investigators described a technique of how cervical stenosis and a false passage can be overcome by dilating cervical stenosis with a vessel dilator passed over a guide wire, after hysteroscopic hydro-dilation provides adequate distention and visualization of both the false passage and endocervical canal [6].
As with any other surgical procedures, it is imperative to indicate that during hysteroscopy every effort should be made to avoid complications such as a false passage. Such prevention should be started during history taking and pelvic examination. Previous history of cesarean section, advanced stages of endometriosis, or history of pelvic inflammatory disease should raise the index of suspicion of possible pelvic adhesions that may alter the angle between the cervical canal and the body of the uterus. Simple vigilance can be sufficient to reduce the likelihood of false passage. Routine bi-manual examination and correlation with prior TV 2D US should be done to determine whether the uterus is in a retroverted position or in an acute anteflexed anteverted position. The presence of uterine fibroids and their locations should be observed, as such tumors may alter the position of the uterus, and in turn, may increase the chance of false passage. In a cohort study, Kresowik et al. suggest that the use of transabdominal US guidance during difficult hysteroscopy can reduce the incidence of false passage and subsequent uterine perforation (1.9%) as compared to no ultrasound scan guidance (5.3%) [7]. In addition, Wortman et al. suggest that sonographic guidance during difficult cases of reoperative hysteroscopic surgery for the management of delayed complications after global endometrial ablation failures can reduce the incidence of uterine perforation [17]. Song et al. describe the typical ultrasound appearance of the false cavity as eccentric in position, in contrast to the endometrial echo which is centrally placed [8].
Garcia describes few tools and techniques that may help to overcome the difficulty that may be encountered during cervical dilatation or performing a hysteroscopy in patients with a problematic cervix or distorted anatomy [18]. Positioning the patient with their buttocks even with the lower break of the table can allow maximum manipulation of the uterine dilators and the hysteroscope. Replacing a weighted speculum with a Deaver retractor during cervical dilation may help in increasing the range of manipulation. Single toothed tenaculum should be used on the anterior or post lip of the cervix to straighten the cervico-uterine angle and facilitate easy negotiation of the cervical canal. If creation of a false passage is anticipated, as with difficult introduction of the uterine sound, or in the presence of cervical stenosis, or a problematic cervix, the use of a smaller diameter office operative hysteroscope to negotiate the internal os can be attempted. In addition, the use of sonographic guidance as suggested by Wortman et al. and Song et al. may also be helpful to overcome the difficulty to perform a hysteroscopy [8, 17]. Furthermore, the use of a small diameter rigid or flexible hysteroscope, if available, prior to dilation may avoid most cases of false passage.
Routine preoperative use of misoprostol prior to hysteroscopy has been advocated by some gynecologists to facilitate cervical dilatation and avoid cervical tear, false passage, and uterine perforation [19]. In a Cochrane review, Al-Fozan et al. analyze 19 randomized controlled trials (RCT) [1870 participants] and report on the preoperative use of misoprostol to reduce the rate of complications, including false passage during hysteroscopy [19]. In this review, the authors conclude that misoprostol was superior to placebo in facilitating cervical dilatation with fewer women requiring mechanical dilatation [19]. These authors also report that the use of misoprostol prior to hysteroscopy was associated with less likely intraoperative complications such as cervical lacerations and false passage [19].
However, in the experience of the authors of this study, the use of misoprostol can be associated with severe uterine cramps in some patients. In addition, the use of misoprostol has also been associated with vaginal bleeding, which can mask the view during hysteroscopy. Such findings have been reported by other investigators [19]. Therefore, the use of misoprostol by our group is limited to selected cases.