Chapter 5 – Hysteroscopy Techniques and Treatment Settings

Abstract

This chapter covers the process of performing hysteroscopy, paying close attention to optimising patient comfort and maximising the effectiveness of the procedure. Tips are provided for successfully inserting the device and visualising the entire uterine cavity. The possible settings for performing a hysteroscopic investigation are outlined, with suggestions as to which setting may suit an individual patient. Oral anticoagulants have changed in recent years and the effect they may have on patients attending hysteroscopy clinics is discussed, with advice about how to avoid and manage excessive vaginal bleeding.

Chapter 5 Hysteroscopy Techniques and Treatment Settings

Jonathan M. Chester and T. Justin Clark

5.1 Introduction

5.2 Insertion of the Hysteroscope

The choice of approach depends upon the diameter of the hysteroscope and the likelihood of a narrowed or stenosed cervical canal.

5.2.1 Vaginoscopy

Recent evidence supports a ‘no-touch’ vaginoscopy as the default approach [1–3]. This technique is ideally suited to the outpatient clinic as it minimises patient discomfort because the vagina is not distended by the insertion of antiseptic swabs or a vaginal speculum, and cervical forceps such as the vulsellum and tenaculum are not needed. The approach is also quicker, at least as successful (feasible), and not associated with higher rates of infection than conventional approaches using vaginal instrumentation.

After purging the hysteroscope with the distension fluid, usually saline, the tip of the hysteroscope is introduced into the vaginal introitus, and as the irrigation fluid distends the vagina the hysteroscope is guided along the vaginal axis until the external cervical os is identified. In the authors’ experience, additional manoeuvres such as employing a Trendelenburg tilt or manually ‘sealing’ the vaginal outflow by closing the labia are not required. As most uteri are anteverted, the intravaginal cervix will be seen superiorly (coming from the ‘ceiling’ above) so that the external cervical os will be identified in the inferior aspect of the upper vagina. The tip of the hysteroscope is placed at the entrance to the external cervical os; this may require the operator’s hands to move upwards as they hold the camera head attached to the hysteroscope, thereby directing the distal end of the hysteroscope posteriorly. In nulliparous women with long intravaginal cervices the angulation required can be quite substantial. Once the distal lens of the hysteroscope is aligned with the external cervical os, it is usual for the hysteroscope to be directed anteriorly along the cervical canal, in keeping with the uterine anteflexion; this often requires the operator’s hands to move downwards. In this way, passage through the cervical canal is negotiated and the uterine cavity is accessed (Video 5.1).

If the cervix is not easily identified, then the hysteroscope should be advanced until the posterior aspect of the vaginal vault is reached, and then slowly withdrawn until the external cervical os comes into view within the distended vagina. It is usually seen superiorly (anteflexed uteri) but may emanate from an inferior aspect (coming from the ‘floor’ – retroflexed uteri). Another technique is to identify a mucus trail and follow it to the cervical os. If the external cervical os remains difficult to see then this may be because (i) the external cervical os is small with a non-prominent squamo-columnar junction (nullipara), (ii) the intravaginal cervix is long, necessitating more extreme angulation of the hysteroscope (nullipara), (iii) with uterovaginal prolapse, the cervix appears lower within the vagina than expected or (iv) there may be congenital uterine or cervical anomalies, such as a vaginal septum with small duplicate cervices, or acquired anomalies from distortion by fibroids or intra-abdominal adhesions involving the uterus that cause the cervix to be eccentrically placed within the upper vagina .

Vaginoscopy works in most cases, unless there is cervical stenosis, when cervical dilatation after application of local cervical anaesthesia will be required. A large randomised controlled trial showed that vaginoscopy resulted in less pain and more procedural success than conventional approaches using vaginal specula and cervical forceps [2].

5.2.2 Vaginal Instrumentation

Introduction of a vaginal speculum, counter-traction and dilatation of the cervix are necessary when vaginoscopy fails because of cervical stenosis or when using a hysteroscope with an outer sheath greater than 5.5 mm in diameter, such as resectoscopes and some hysteroscopic tissue removal systems. When dilating the cervix, a tenaculum should be placed on the anterior cervical lip at 12 o’clock, and gentle counter-traction applied to straighten the cervical canal and help overcome any resistance to the hysteroscope as it enters the cervical canal. Local anaesthetic is not always required if only a small amount of the relatively insensitive ectocervical tissue is grasped very gently and the patient is pre-warned of an impending sharp sensation. However, local anaesthetic will be necessary in an outpatient setting if tenaculum application is necessary to assist formal dilatation of the cervix (see Chapter 6). In such situations a single-toothed tenaculum is less traumatic, and placement in a horizontal plane on the anterior lip of the cervix will avoid interfering with access to the cervical canal. Furthermore, with women who are awake, a Cusco speculum is advised rather than a Sims type speculum, because downward traction on the vagina with the latter instrument can be painful and very uncomfortable. Note also the option of a smaller Cusco speculum, as discussed in Chapter 3. However, whenever possible, blind dilatation of the cervical canal should be avoided because this risks pain, bleeding and uterine trauma.

Insertion of a vaginal speculum will also be required if a global endometrial biopsy is indicated, but the operator should be mindful of the increased discomfort associated with blind endometrial biopsy. When access has been difficult, it is worth considering hysteroscopically directed biopsies if only a tiny amount of tissue is needed, or inserting an extra long bespoke device for blind tissue aspiration down the barrel of the hysteroscopic sheath, such as the ‘H Pipelle’ [4].

5.2.3 Distension Media Delivery

Gaseous distension using CO₂ is all but extinct from contemporary hysteroscopic practice. Low-viscosity fluid distension media such as isotonic normal saline and non-isotonic sorbitol or glycine can be delivered in a variety of ways: by syringe, gravity feed, pressurised bag, or a fluid management system (automated pump) (see Chapter 3). Diagnostic outpatient procedures may only require syringe delivery but operative procedures need a continuous flow of fluid. For more complex operative hysteroscopy (e.g. myomectomy, transcervical resection of the endometrium, adhesiolysis), the use of a fluid management system is important. Accurately measuring fluid inflow and outflow is essential for safe practice, and maintaining a constant intrauterine pressure aids visualisation and is key to technical success.

Occasionally a problem may arise when bleeding inside the uterine cavity prevents a clear view of the endometrium. Raising the intrauterine pressure, by increasing the inflow of the distension medium and reducing the outflow, may stop the bleeding by compressing the blood vessels and creating a tamponade. Care must be taken in the outpatient setting because this manoeuvre will cause increased pain and the procedure may need to be stopped if it becomes intolerable.

5.2.4 Intracervical Advancement of the Hysteroscope

This is the most difficult part of the procedure. The operator should appreciate the angle of viewing (whether 0° or an offset distal lens, usually 30°) provided by the chosen hysteroscope, as this will dictate correct orientation (Video 5.2, Figures 5.1–5.3) [5]. The key principle is to avoid trauma to the fragile endocervical mucosa, as this stimulates pain, can lead to poor views from bleeding and predisposes to false passage formation and uterine perforation. The initial inspection of the most proximal portion of the cervical canal is vital. If the cervical canal cannot be definitively seen, it is crucial not to push on blindly, as this risks pain, creation of a false passage and uterine perforation. Systematic panoramic inspection of the proximal cervix, using small back-and-forth movements, will usually identify the cervical canal and the characteristic endocervical folds by allowing the distension medium to open the cervix, creating a ‘microcavity’. When not immediately apparent, the operator should consider whether the uterus is acutely anteflexed or retroflexed in relation to the cervical axis. Lifting and lowering the hands as the hysteroscope is gently held will angle the hysteroscope more anteriorly or posteriorly, and will usually lead to the identification of the cervical canal and redirection of the objective lens into the axis of the canal. The degree of distal lens angulation needs to be appreciated when manipulating the hysteroscope. These principles, described below, are illustrated in Video 5.2 and Figures 5.1–5.3.

Figure 5.1 Correct technique with the 0° forward-facing distal lens. When the 0° hysteroscope is aligned with the long axis of the cervical canal (dark circle), it is located centrally on the monitor. This alignment should be maintained while traversing the canal and internal os and is achieved by adhering to the principle of strict visual control. If the correct view is lost, the instrument should be withdrawn very slightly and the angle of approach finely adjusted to relocate it before advancing further. On entering the cavity, the distal lens is moved upward if the uterus is anteflexed, by moving the shaft of the endoscope downwards, and vice versa if the uterus is retroflexed.

The cervical canal appears as a dark circle, which should be identified before further advancement of the hysteroscope. This dark circle is produced by light absorption from the distant uterine fundus. When the long axis of the hysteroscope is aligned with the cervical canal, the dark circle will appear centrally with a 0° ‘end-on’ rigid or flexible hysteroscope (Figure 5.1). A 0° distal lens permits direct visualisation and is much easier for mastering orientation as the direction of view corresponds to the natural approach, thus avoiding tissue trauma. This is in contrast to a 30° forward-oblique hysteroscope, where the dark circle will appear eccentrically, that is at the 6 or 12 o’clock position, depending upon which way up the endoscope is held, when the hysteroscope is aligned with the axis of the cervical canal (Figure 5.2a and b).

Figure 5.2 Correct techniques with the offset 30° forward-oblique distal lens. (a) The 30° hysteroscope with the bevel of the lens and light source lowermost is most commonly used; the viewing angle of the distal lens points upward. This orientation is useful for the more common anteverted/anteflexed uterus. When aligned with the long axis of the cervical canal the dark circle is located at the bottom (6 o’clock position) of the monitor. This alignment should be maintained while traversing the canal and internal os. If the internal os is narrow and the uterus anteverted, then the hysteroscope can be rotated and inverted at this point so that the bevel aids upward deflection of the instrument into the uterine cavity and the view changes to that shown in (b). (b) When a 30° hysteroscope is inverted so that the viewing angle points downward (with the bevel of the lens and light source uppermost), the cervical canal (dark circle) will be located at the top (12 o’clock position) of the monitor. This orientation can be useful in guiding the instrument into the cavity when a retroverted/retroflexed uterus is encountered. If the internal os is narrow and the uterus retroverted, then the hysteroscope can be rotated at this point so that the bevel aids downward deflection of the instrument into the uterine cavity and the view changes to that shown in (a).

A rule of thumb when using a 30° forward-oblique hysteroscope is that wherever the light lead is inserted, that is where the dark circle representing the cervical canal should be. Of course, when using a 0° lens, the position of the light lead is immaterial. It is incorrect when using a 30° hysteroscope to have the dark circle placed centrally (Figure 5.3a) because this results in the hysteroscope directed to the posterior cervical wall, and if the circle is placed below the lower edge of the 6 o’clock position (Figure 5.3b) the hysteroscope is directed into the anterior cervical wall. Tips for traversing the cervix in problematic situations are given in Box 5.1 .

Figure 5.3 Incorrect techniques with the offset 30° forward-oblique distal lens. (a) Posterior misalignment of the lens (central dark circle). The natural tendency is to adjust the hysteroscope so that the cervical canal appears centrally. However, this is incorrect with an offset lens, as the instrument is then no longer aligned with the axis of the cervical canal. Damage to the cervical mucosa, and even cervical wall, will occur, causing pain. (b) Anterior misalignment of an offset 30° forward-oblique distal lens. Here the hysteroscope is misaligned with the cervical canal such that it will impinge upon its anterior wall. The cervical canal (dark circle) is only partially visualised on the monitor, appearing eccentrically at the 6 o’clock position.

Box 5.1 Tips and Tricks to Traverse the Cervix in Specific Situations

Narrow Cervix

The internal cervical os is usually the narrowest portion of the cervical canal and this, combined with its more fibrous composition, can obstruct entry into the uterine cavity. This means traversing it is the most difficult (and most painful in the outpatient setting) part of advancing the hysteroscope into the uterine cavity. Smaller diameter hysteroscopes enhance feasibility and painless insertion, but where operative hysteroscopic procedures are required, larger diameter (>4.5 mm) hysteroscopes are needed; this is where partial obstruction and resistance to further advancement can occur. A slight pause at this point will allow time for the inflowing medium to further distend the uterine isthmus and assist painless entry into the cavity. Optimal alignment between the hysteroscope and axis of the cervical canal is of prime importance.

Most modern, rigid, continuous-flow, operative hysteroscopes are bevelled at the end to facilitate uterine access; once the 30° hysteroscope approximates the internal cervical os, which is generally elliptical with the apices presented horizontally, it can be rotated in a horizontal plane (to 90° or 270° externally so that the cervical canal appears at 3 o’clock or 9 o’clock, respectively), pushed gently forward and then returned to an anterior/posterior plane once the uterine cavity is entered (Figure 5.4).

Figure 5.4 Practical hysteroscopy: rotation of the hysteroscope to ease passage through a relatively narrow internal cervical os. Note the horizontal ellipse of the internal cervical os.

Stenosed ‘Pin-point’ External Cervical Os

An approach using direct hysteroscopic visualisation is best but other approaches are available if this fails. The recommended techniques to incise the external cervical os to allow advancement of the hysteroscope are (in order of preference):

vaginoscopy using 5 Fr hysteroscopic scissors, graspers or 5 Fr electrodes
vaginal speculum to visualise the cervix with scalpel point / hand-held pointed scissors / diathermy blade
vaginal speculum to visualise the cervix with blind cervical os finder / dilators / tapered urethral forceps.

5.2.5 Inspection of the Uterine Cavity

Advancement of the hysteroscope should cease at the level of the uterine isthmus once the internal cervical os has been traversed. This allows time for the cavity to distend and focal lesions to be identified. Dual chamber uteri and large submucous fibroids may be overlooked if the instrument is advanced rapidly into the uterine body. Visualisation of both tubal ostia confirms that the uterine cavity has been reached (Figure 5.5a).

Figure 5.5 Hysteroscopic views in the uterine cavity during a diagnostic procedure. (a) Panoramic view. (b) Anterior wall. (c) Right tubal ostium. (d) Left tubal ostium. (e) Uterine fundus. (f) Right lateral wall. (g) Left lateral wall, (h) Posterior wall. (i) Cervical canal. (j) Cervical os.

(Source of images: Mary E. Connor.)

The key objective is to ensure both global observation of the entire uterine cavity and close inspection of the endometrial surfaces and any structural lesions so they can be better characterised (see Chapter 4). This is achieved using a systematic approach [5]. One method is to start with an initial panoramic view of the cavity, obtained with the hysteroscope at the level of the uterine isthmus. Uterine landmarks (cornua, tubal ostia, fundus) should be identified to confirm cavity entry and correctly orientate the hysteroscope. This is especially important when the uterus is rotated, or distorted by congenital or acquired lesions, and when operative hysteroscopy is to be performed. A global inspection allows for a general structural assessment with attention drawn to any focal lesions, such as polyps, fibroids, adhesions or congenital uterine anomalies.

The next step is to closely inspect the endometrium by advancing the distal end of the instrument to within a few millimetres of the mucosal surface in keeping with the depth of field (fixed focus) provided by the particular hysteroscope (usually 1–3 mm). The hysteroscopic images relayed via the video camera and displayed on the video monitor will appear magnified, allowing close inspection. Begin with a detailed inspection of the endometrium overlying the fundus, and of both cornual recesses and tubal ostia (Figure 5.5b–d). The order of examination does not really matter as long as the entire endometrial surface and cervical canal is assessed. There is considerable variation in the depth of the cornua and the appearance of the ostia, which may or may not be recessed behind an incomplete circular membrane. The ostia appear slit-like if closed, and circular when opened by the flow of the distension medium, but on occasion they may not be seen if covered by adhesions. The remaining endometrial surfaces are inspected, usually beginning with the anterior, followed by both lateral and finally posterior surfaces (Figure 5.5e–h).

Slowly withdraw the hysteroscope, again obtaining a panoramic view of the uterine cavity. Although the cervical canal was visualised while introducing the hysteroscope, it is better inspected in detail on withdrawal, as the canal has been nicely expanded by inflowing distension medium (Figure 5.5i). Once the external cervical os is reached (Figure 5.5j), remove the instrument.

Learning to insert a 30° forward-oblique hysteroscope through the cervical canal takes some consideration and practice because initially it feels counter-intuitive. However, to visualise the entire endometrial surface with a 0° hysteroscope, especially the lateralised and recessed cornual parts of the uterine cavity, requires side-to-side, up-and-down and back-and-forth movements. These manoeuvres produce a degree of torque on the cervix, causing significant discomfort in an awake patient. In contrast, limited movements are required with a 30° hysteroscope; inspection is simply a matter of rotating the 30° forward-oblique lens on its axis, thus directing and enlarging the field of view to the relevant areas. The camera must remain fixed in position to maintain orientation and facilitate diagnostic evaluation. Familiarity with manipulating an angled lens and orienting within the uterus is fundamental to resectoscopy and the use of miniature electrodes or mechanical instruments within operative hysteroscopes.

Some 0° hysteroscopes can afford the operator a wider field of view. These are either small, semi-rigid hysteroscopes housed within a distally curved 10° outer sheath (Alphascope®, Ethicon) or flexible, steerable instruments, which can be rotated through 360° to enable fuller peripheral viewing and visualisation of less accessible areas. Flexible hysteroscopes have two main mechanical advantages that may help reduce trauma and discomfort. First, on insertion, the soft fibroscope conforms to the natural curve of the cervical canal, minimising the need for traction on the cervix to straighten it. Second, the distal 0° tip can be directed towards either cornu without torquing the midshaft of the endoscope against the fragile endocervical mucosa.

If a flexible hysteroscope is used, then the standard technique described differs slightly; the 0° fibroscope is advanced, as for a rigid endoscope without an angled lens. The uterine cavity is inspected by rotating the hysteroscope and bending the distal end up and down (100–160° in either direction) using the angulation control lever close to the eyepiece of the instrument. Chapter 3 describes the types of hysteroscopes in more detail. However, flexible hysteroscopes are less versatile than rigid hysteroscopes as they are not suitable for most types of operative hysteroscopy, and they need to be cold-disinfected because sterilisation processes damage them.

If the endometrium appears unusually thickened, this can be assessed either by pressure to produce a surface imprint or by gently producing a furrow in the endometrium with the tip of the instrument (Figure 5.6). If the patient is awake, she should be pre-warned, as such manoeuvres can cause some discomfort. In addition, fragmentation of tissue and bleeding may compromise vision, so this is best undertaken at the end of the procedure when the visual inspection has been completed. For tips and tricks to optimise hysteroscopic visualisation, see Table 5.1.

Figure 5.6 Using the hysteroscope to assess the thickness of the endometrium: a channel made in the posterior endometrium allows the depth of the endometrium to be seen.

(Source of image: Mary E. Connor.)