Module
Diagnostic Indications for Hysteroscopy
Evaluation and treatment of endometrial cavity, tubal ostia, or endocervical canal is for abnormal uterine bleeding, endometrial thickening or polyps, fibroids, adhesion, Mullerian anomalies, retained intrauterine devices (IUDs), placental and fetal tissue, and endocervical lesions. Hysteroscopy avoids missing focal pathology with a blind endometrial biopsy. Hysteroscopy for evaluation of abnormal uterine bleeding (AUB) allows for evaluation with possible combination of treatment.
Other indications include:
- Abnormal hysterosalpingogram (HSG)
- Questionable ultrasound
- Infertility
- Pregnancy wastage
The most frequent use of hysteroscopy is to identify the causes of abnormal uterine bleeding. A dilation and curettage (D&C) is a blind procedure and not an appropriate way to establish the cause of abnormal bleeding.
Contraindications
- Absolute contraindications
- Pregnancy or suspicion of pregnancy
- Acute cervical or uterine infection
- Medical conditions precluding surgery
- Recent uterine perforation
- Known cervical or uterine cancer
- Known cancer or uterine infection
- Active herpes infections
- Relative contraindications
- Active bleeding which might obscure visualization
Uterine Access
- Preoperative preparation of the cervix
- Pharmacologic-misoprostol
- Mechanical-laminaria
- Slow, gentle insertion of dilators
- Avoid forceful entry
- Introduction and advancement of hysteroscope under direct vision
- Advance only during unobstructed panoramic view
The risk for uterine perforation can be reduced by accurate assessment of the cervico-uterine axes, gentle insertion of instruments, minimizing force, and introducing as well as advancing only under conditions of panoramic visual clarity.
How to Dilate the Cervix
- Must do bimanual exam first to assess uterine size, version and position
- Know outside diameter of hysteroscopic sheath – take all dilators larger than that diameter off the table
- Do not over-dilate: fluid will leak around scope and lose distention
See examples of dilators that follow.
Traumatic Complications of Hysteroscope Insertion
- Cervical stenosis can result in false passage with cervical dilation
- Under dilation of cervical canal can allow creation of a false passage when advancing the scope
- Inappropriate orientation of scope when using an angled lens. Visual field on monitor hysteroscope placement angle
Components of a Resectoscope
Hysteroscopic Sheath Continuous Flow
- Bipartite design: inner and outer sheaths
- Independent inflow and outflow channels for distension media
- Inflow through inner channel (always closest to eye piece)
- Outflow through outer sheath (farthest from the eyepiece)
- Able to proactively flush the uterine cavity
- Maintain a clear field of vision
The continuous flow operative hysteroscopic sheath was invented to overcome the inherent deficiencies of single channel sheaths.
The inner sheath carries distention medium to the uterine cavity, and a fitted outer sheath evacuates this medium by gravity or intermittent suction via a set of perforations along its distal margin. This allows for continuous flushing and rinsing of the uterine cavity, enabling a clear view of the operative field during all phases of an operative procedure.
Equipped with a 3 mm operating channel, the design allows instruments to be accurately placed anywhere within the uterine cavity. More contemporary assemblies are outfitted with intake and outflow ports that swivel and allow the medium to be instilled equally from either side while minimizing the risk of obstructing or dislodging the inflow tubing. Recently, the continuous flow design has been incorporated into simple diagnostic sheaths of larger dimension.
Basic Hysteroscopic Instrumentation
- Telescopic Optical Characteristics
- Field of view is summation of degree of field of view of distal lens
- Angle of lens to central axis of telescope
- Available fields of view
- Centered lens = 0º
- Offset (fore-oblique) expands field to 12º, 25º, or 30º, providing a significantly expanded field of view when the lens is rotated
- Larger angles of view proportionally sacrifice image illumination
- Angle of deflection is always opposite the light post
Orient Post, Then Rotate Target
- The angled lens allows you to view lateral structures without angling the scope
- All you have to do is rotate the scope, when post (P) is right and view (V) is left
Challenges of Operating through an Angled Scope
- The farther away the object is from your lens, the more difficult it is to manipulate an instrument to meet the object. camera view light cord
Summary
- Most scopes have four parts:
- Optics o Operating element
- Inner sheath-Fluid hook-up closest to eye piece
- Outer sheath
- Only dilate to outer diameter of scope sheath
- Know indications and contraindications for performing a basic diagnostic hysteroscope
Author
- Steven Swift, MD, Professor, Department of obstetrics and Gynecology Medical University of South Carolina
Developed in association with Advancing Minimally Invasive Gynecology Worldwide.
Version 3.0, reaffirmed January 2021