The endocervical canal Strategies for an easy access to the uterine cavity

INTRODUCTION

The rapid advance of technology and the miniaturization of hysteroscopes has allowed an easier and painless access to the uterine cavity. As a result, the number of interventions carried out in the office setting, and outside the operating room, is increasing in a rapid manner.

However, failed access to the uterine cavity, either due to cervical stenosis or pain, remains the leading cause of inability to perform in office hysteroscopy. This chapter will discuss different strategies to facilitate the access through the uterine cervical canal.

TECHNICAL ASPECTS

Although performing in-office hysteroscopy is a relatively easy procedure, there are several aspects that determine the success in its implementation. A clear communication between

the physician and the patient as well as a pleasant environment help to reduce patient’s anxiety. The use of small diameter instruments and the experience of the hysteroscopist performing the procedure, also determine the success.

Classic uterine entry technique.

The classic uterine entry technique consist in placing a vaginal speculum to gain visualization of the cervix, after cleaning it with an antiseptic solution, the cervix is ​​fixed with the application single tooth tenaculum on the anterior lip.

Once this phase is completed, the tip of the hysteroscope is introduced in the external os allowing the entrance normal saline solution and starting to move through the cervical canal toward the internal os. This entry technique is currently used very rarely and could be considered to be obsolete.

The Bettocchi technique (vaginoscopy).

The uterine approach by vaginoscopy first described in 1995 by Bettocchi and Selvaggi (1) avoids both the use of the speculum and tenaculum to grab the uterine cervix, an obvious way to reduce the discomfort experienced by the patient. This technique consist of direct introduction of the hysteroscope in the vagina, getting the expantion of the vaginal walls by fluid distention with normal saline. This separation of the vaginal walls allows to locate the EO introducing the hysteroscope, and then continue through the cervical canal.

This is the most commonly entry technique used in cinical practice. A study published by Sagiv R. et al. showed that the approach by vaginoscopy was significantly less painful for the patient than the classic approach with speculum and paracervical block. (2)

Scrolling through the cervical canal.

Progress through the cervical canal should be done with a clear and comprehensive vision of the entire canal and following the angle that this presents. The orientation of the longitudinal crests “plica palmatae” guide us the way to the IO.

The technique varies according to the angle of the optics utilized (0º-12º-30º) the main aspect of this technique is to advance the hysteroscope through the middle of the cervical canal, avoiding collision with the side walls. Perhaps the most difficult area encountered when using this technique is at the level of the IO where there is a fibromuscular area that narrows the final access to the uterine cavity.

SPECIAL MEASURES

There are certain measures that are used to reduce pain and anxiety of the patient. Pre-procedure patient preparation, cervical priming and the use of local anesthesia, are very often utilized when performing in office hysteroscopy. A study published by Naegle F. el al, revealed that pain experienced by the patient is the most common cause of failure to complete in office hysteroscopy.

Pre-procedure preparation (analgesia).

Most practicioners use some form of analgesia prior to performing hysteroscopy. A common practice is the use of a non-steroidal anti-inflammatory (indomethacin, diclofenac) one hour before performing the procedure. A review

published by of Ahmad et al (4) on management of pain during in office hysteroscopy revealed a significant reduction in discofort experienced by the patient with the use of analgesia both during the procedure as well as 30 minutes after conclusion of the hysteroscopy. Often the analgesic is associated with an anxiolytic (midazolam) thereby also reducing anxiety before the procedure.

Cervical Priming

The first published reference on the use of prostaglandins for cervical priming before hysteroscopy dates back to 1985 (5). Currently, the routine use of prostaglandis is under discussion; it seems logical to use it only in cases where difficulty whit the insertion of the hysteroscope is anticipated.

The use of prostaglandins before hysteroscopy facilitates cervical dilation, lower the possibility of complications such as cervical laceration, decreases consistency and resistance of the cervix and reduces pain during the performance of hysteroscopy. (6) Misoprostol, a synthetic analogue of prostaglandin E1 (PGE1) is the most commonly used prostaglandin for cervical preparation due to its effectiveness, low cost and availability. These benefits are clear in premenopausal patients while they are not proven in postmenopausal or in patients receiving GnRH analogues. Although, in a recent study, Oppegaard et al observed that after 14 days of pretreatment with vaginal estradiol, the administration of misoprostol has a significant effect on cervical ripening prior to hysteroscopy in postmenopausal patients. (7).

Most published studies use the vaginal route, but increasingly more articles support the oral or sublingual route and even intracervical administration (8). The most commonly used dose for cervical priming is 200 to 400 mcg orally or vaginally and between 3 to 12 hours before performing the procedure. A recently published study comparing oral misoprostol with vaginal administration, has not found significant differences in cervical dilation between the two routes of administration.

Anesthesia.

Different anesthetic that can be applied on the cervix to decrease pain during hysteroscopy are the paracervical block, intracervical inyection and topical anesthesia. The paracervical block anesthesia is the only one that has proven to be effective in decreasing pain perception, while topical anesthesia has no significant effect on pain.

Paracervical block anesthesia

The technique for paracervical block administration of anesthesia involves the injection of 10 to 20 ml

of anesthetic at the cervicovaginal junction at 4 and 8 o’clock, this will block pain transmission through the uterosacral ligaments. Several studies have shown that paracervical block anesthesia produces an improvement in pain perception with cervical manipulation during hysteroscopy, however, it does not seem to reduce pain associated with the manipulation of the corpus / uterine fundus, or fallopian tubes. The anesthetic most frequently used is 1% lidocaine with epinephrine for added vasoconstriction properties which decreases the absorption of the lidocaine and increases the duration of the anesthetic effect for up to 2 to 6 hours. Infiltration is usually done at the level of the uterosacral ligaments, between 3 and 10 mm deep and about 5 to 10 ml of the anesthetic is injected.

Cervical anesthesia

It consists of the injection of the anesthetic directly into the cervical tissue. Usually infiltration takes place in the quarters, inyecting a total of 5 ml each puncture to a depth of 10 mm. As in the paracervical anesthesia, 1% lidocaine with epinephrine is the most commonly used anesthetic. There is conflicting evidence regarding the efficacy of this route of administration, generating doubts about the decrease of pain perceived by the patient.

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