Colposcopy & Associated Ablative Procedures
This booklet is intended as a practical guide to patient care for registrars, medical officers, interns and medical students attached to the gynaecology units at the University of the Witwatersrand Academic Hospitals. Anyone can use it.
A single high grade cervical smear result is an indication for colposcopy & probably ‘See & Treat’ (see below). A recurrent low grade smear (at least two) should be colposcoped. Colposcopically proven low grade (CIN 1) may be treated by LLETZ (large loop excision of the transformation zone) OR observed, with good follow up. In patients older than 35 years, colposcopically & biopsy proven CIN 1 can be tested for HPV. Such women with HPV subtypes 16 & 18, may be offered LLETZ, laser conization, or cold knife conization, with HPV negative women observed with annual cytology &/or colposcopy.
HIV makes the risk of progression from low grade to high grade dysplasia greater, & recurrence after treatment. Improving CD4 counts on antiretroviral drugs may lessen this trend. Conservative management of colposcopically proven low grade disease avoids endless treatment, but follow up is essential.
COLPOSCOPY
- History: referral cervical smear, previous abnormal smears & treatment, LMP, parity & past medical history
- Exclude pregnancy if there is any possibility
- Explain colposcopy
- Place the patient in lithotomy
- Bimanual examination to assess uterine size & axis
- Speculum: examine the cervix with the naked eye, then by colposcope at low power, then high power. Coarse focus is by moving the colposcope nearer & further from the patient on its arm. Fine focus is attained by turning a wheel on the side of the scope
- Wipe excessive mucus if present off the cervix with cotton wool mounted on a sponge holder
- Soak the cervix with 2% Acetic acid on a drenched cotton wool ball on a sponge holder
- Aceto-white epithelium (a brilliant white patch with a sharp border) suggests dysplasia, as opposed to the grey-white with indistinct border of squamous metaplasia (non-pathological). The aceto-white areas may have a pavement like pattern (‘mosaic’), or fine evenly spaced red dots (‘punctation’). With experience, low grade abnormalities can be distinguished from high grade which tends to have larger mosaic squares for example. The presence of ‘corkscrew’ vessels or abruptly branching vessels suggests frank invasion. These are best seen with a green filter.
- ‘Adequate‘ colposcopy is defined as complete visualization of the squamo-columnar junction & the upper limit of aceto-white areas. Inadequate colposcopy was before an indication for cone biopsy, but LLETZ is now considered appropriate. If colposcopy is inadequate, excision (LLETZ, laser Cone, knife Cone) is preferable to ablative procedures (cryotherapy or laser vaporization) – for the latter there is no histology
- If the referral smear is low grade, perform punch biopsies (at least 2 & up to 4). If the referral smear is high grade, perform a LLETZ. Even if the colposcopy does not clearly show high grade, a difference between colposcopy & cytology results is an indication for LLETZ
- To assess the cervix by colposcopy & immediately perfom a LLETZ is called ‘See & Treat.’
LLETZ (Large Loop Excision of the transformation Zone) - how to do it
- A diathermy plate is needed – LLETZ uses monopolar diathermy
- A special speculum is used with an exhaust pipe inside the upper blade.
- A condom over the speculum or the thumb of a rubber glove, cut the end off with scissors, may hold back floppy vaginal walls
- Stain the cervix with 2% acetic acid to see the lesion
- Inject, with a dental syringe, 1% lignocaine at the junction of the cervix with the vaginal fornices at 12, 3, 6, & 9 o’clock
- After a minute, with the diathermy machine set to blended cut (with coagulation), pass the loop from left to right, or from above down to a depth deepest at the cervical canal of 1 cm.
- If the pass is too fast there is excessive bleeding, too slow & the loop may halt & it may be difficult to push further
- Ball diathermy is used across the entire crater, starting at the top. Specific bleeding points can be stemmed with a cotton bud. Roll the bud away & use ball diathermy
- Antiseptic creams & antibiotics are optional
- Follow up plans must be properly explained