First, it must be confirmed that the woman meets the eligibility criteria in Table 13.1
If there is evidence of pelvic inflammatory disease (PID), cervicitis, vaginal trichomoniasis, bacterial vaginosis or anogenital ulcer, it is advisable to delay LEEP until that condition has been treated and resolved (see Chapter 11
, Table 11.1
). If there is marked atrophy due to estrogen deficiency in an older woman and staining of the outer margin of a lesion is indistinct, it is advisable to delay LEEP until after a course of topical estrogen treatment.
It is generally preferable to have the diagnosis of CIN firmly established before LEEP is performed. However, there may be exceptions to this general rule, for example, in the context of developing country settings, women may be offered treatment at their first colposcopy visit to maximize treatment coverage (otherwise patients lost to follow-up would not receive treatment for lesions). Expert colposcopists also may use this approach to maximize treatment coverage and to minimise the number of clinic visits in some clinical settings.
The instruments needed for LEEP should be placed on an instrument trolley or tray (Figure 13.3
If the woman is returning to the clinic on a second visit for treatment, colposcopic assessment should be carried out immediately before LEEP to confirm that the location and linear extent of the lesion are amenable to effective LEEP. The application of Lugol’s iodine solution is helpful to outline lesion margins before the start of treatment. An insulated vaginal speculum (Figure 13.3
) with an electrically insulating coating or a speculum covered with a latex condom (Figure 4.9
) should be used to avoid an electrical shock to the woman in the event that the activated electrode inadvertently touches the speculum (though this type of event usually does not cause any tissue damage because of the relatively large area of contact). Similarly, care must be taken to avoid causing pain by inadvertently touching the vaginal walls with the activated electrode. The later possibility may be avoided by using an insulated vaginal sidewall retractor in addition to an insulated vaginal speculum (Figure 13.3
) or by using a speculum covered by a condom (Figure 4.9
It is ideal if the vaginal speculum used has a smoke evacuator tube attached to the luminal surface of the anterior blade so that a source of suction can be attached. If this type of speculum is not available, a simple suction tube (preferably made of non-conductive and non-flammable material) may be used, and the open tip should be positioned as near as possible to the cervix. A smoke evacuation system with a high rate of flow and a means of filtering out the smoke particles and odour is mandatory.
Local anaesthesia is achieved 30 seconds after multiple injections of a total of 5ml or less of 1% xylocaine (or a similar agent) into the stromal tissue of the ectocervix. The injections are given in a ring pattern 1 -2 mm deep (at 3, 6, 9 and 12 o’clock positions) at the periphery of the lesion and transformation zone using a 5ml syringe and 25- to 27-gauge needle. It is common practice to reduce the amount of bleeding during the procedure by mixing a vasoconstrictor agent such as vasopressin (no more than one pressor unit) with the injected local anaesthetic agent. The use of xylocaine with 2% adrenaline instead of pitressin also is adequate for local anaesthesia, but may cause palpitations and leg tremors before surgery. However, this can be avoided if infiltration is subepithelial. If a two-layer excision (LEEP cone) is planned, local anaesthetic is injected into the anterior and posterior endocervical canal also.
The aim of the LEEP procedure is to remove the lesions and the transformation zone in their entirety and send the affected tissue to the histopathological laboratory for examination. The least amount of power that will effectively perform the electrosurgery should be used, so as to minimize the risk to the patient’s normal tissues and ensure that the excised specimen is in acceptable condition (with a minimum of thermal artifact) for pathological assessment. The power setting used depends on the size of the tissue electrode being used for cutting and whether fulguration is being performed - this information should be predetermined in each clinic and be available to the LEEP operator when choosing a power setting on the machine for cutting or fulguration. The commonly used power settings for the different loop electrodes are as follows: 1.0 ´ 1.0 cm 30 watts; 1.5 ´ 0.5 cm 35 watts; 2.0 ´ 0.8 cm 40 watts; 2.0 ´ 1.2 cm 50 watts. The power settings for 3 mm and 5 mm ball electrodes are 30 watts and 50 watts, respectively, in the coagulation mode. When possible, a lesion should be removed with one pass of the loop electrode, although this is not always feasible. Four basic operative scenarios are described below: