Colposcopy and Treatment of Cervical Intraepithelial Neoplasia - RHO

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Chapter 13 Treatment of cervical intraepithelial neoplasia by loop electrosurgical excision procedure (LEEP) • Electrosurgical current applied to tissues can have one of three effects on the tissue, depending on the power setting and the waveform of the current used: desiccation, cutting, and fulguration. • Loop electrosurgical excision procedure (LEEP) is a relatively simple procedure that can be readily learnt. • The key advantage of LEEP over cryotherapy is that it removes rather than destroying the affected epithelium, allowing histological examination of the excised tissue. • A loop wider than the lesion(s) and the transformation zone to be removed should be used; otherwise, the lesion should be removed with multiple passes. • If the lesion involves the endocervical canal, a two-layer excisional method should be used. • Women will have a brown or black discharge for up to two weeks after LEEP. • Women should be advised not to use a vaginal douche, tampon, or have sexual intercourse for one month after LEEP. • Moderate to severe post-operative bleeding occurs in less than 2% of treated women and they should be seen promptly. • The failure rate with LEEP in women treated for the first time is around 10%. Electrosurgery is the use of radiofrequency electric current to cut tissue or achieve haemostasis. A loop electrosurgical excision procedure (LEEP) operator needs to keep in mind that electricity flows to ground along the path of the least electrical resistance. The electrical energy used in electrosurgery is transformed into heat and light energy. The heat from a high-voltage electrical arc between the operating electrode and tissue allows the practitioner to cut by vaporizing tissue (at 100ºC) or to coagulate by dehydrating tissue (above 100ºC). The cutting electrodes are loops of very fine (0.2 mm) stainless steel or tungsten wire to achieve different widths, depths, and configurations of cut (Figure 13.1). The higher temperatures involved in coagulation produce thermal effects greater than in electro- FIGURE 13.1: Ball electrode, macroneedle style electrode, loops 103
Chapter 13 (2) (1) FIGURE 13.2: Electrosurgical generator (1) and the smoke evacuator (2) surgical cutting. This is important in electrosurgery, since an adequate pathological examination requires that the coagulation effect be minimal in the excised surgical specimen. On the other hand, some coagulation effect is desirable, even while cutting, in order to minimize bleeding in the surgical field. Manufacturers of modern electrosurgical generators (Figure 13.2) are aware of the need to control bleeding. They offer electrosurgical cutting settings that lead to some coagulation by blending electrical currents, one with a cutting waveform and another with a coagulation waveform. This combination is called a blended cutting waveform, and is the type of waveform that will be referred to in this manual when electrosurgical cutting is discussed. When the coagulation setting is selected on the electrosurgical generator, the coagulation waveform has a higher peak-to-peak voltage (producing higher temperatures) than that used for a pure cutting waveform, and is meant only to heat the tissue above 100°C to achieve dehydration. There are three types of coagulation: desiccation, in which the active electrode touches the tissue; fulguration, in which the active electrode does not touch the tissue but ‘sprays’ multiple sparks between itself and the tissue; and puncture coagulation, in which an electrode, usually a needle, is inserted into the centre of a lesion. Coagulation using the fulguration setting and a 3- to 5- mm ball electrode is the type of coagulation that is normally referred to in this manual (one exception is be the use of a needle electrode to fulgurate a stubborn area of bleeding). The fulguration setting uses a higher peak-to-peak voltage waveform than the other coagulation settings, coagulating tissue with less current and, therefore, less potential harm to adjacent tissue. To obtain a proper effect, an electrosurgical generator requires that a patient-return electrode or dispersive plate be used to allow the electrical circuit to be completed and the optimal current to flow. The dispersive plate should always be placed as close to the surgical site as possible. This is in contrast to the desired effect at the active electrode, where the current density is purposely high to concentrate the electrical energy as it is transformed into heat. Unless good electrical contact is maintained at the dispersive electrode over a large area, there is a danger that the patient will suffer from an electrical burn at this site. To guard against this possibility, modern electrosurgical units have circuitry (commonly referred to as a return electrode monitoring system) that continuously monitors the adequacy of the ground plate (dispersive pad) connection to the patient. This type of circuitry not only alerts the operator of a problem, but also prevents operation until the circuit fault is corrected. It is highly recommended that any electrosurgical generator meet the basic standards described above to ensure that safe and effective electrosurgery can be performed. It is assumed that only a system that meets or exceeds such requirements will be used in any of the electrosurgical procedures described in this manual. Electrosurgery must not be performed in the presence of flammable gases, flammable anaesthetics, flammable liquids (e.g., alcohol-containing skinpreparation solutions or tinctures), flammable objects, oxidizing agents, or an oxygen-enriched atmosphere. The operator is, of course, at risk of receiving a burn from the active electrode if it is accidentally touched while activated. Practising LEEP and demonstrating competence before use on patients It is mandatory that every colposcopist has practised and demonstrated the ability to perform LEEP adequately by simulating the excision of cervical lesions on meat (beef, pork etc.) or fruits on which mock lesions have been painted to scale. Typewriter correction fluid or trichloroacetic acid work well for painting mock lesions. LEEP should always be practised using the colposcope, as is done in actual practice. If possible, colposcopists should have experience and demonstrated competence with cryotherapy before learning LEEP. 104
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Colposcopy and Treatment of Cervica
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INTERNATIONAL AGENCY FOR RESEARCH O
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Published by the International Agen
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Contents 11 Management that provide
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Acknowledgements The authors gratef
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Preface Health care providers have
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Chapter 1 An introduction to the an
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An introduction to the anatomy of t
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Chapter 2 An introduction to cervic
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An introduction to cervical intraep
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Chapter 3 An introduction to invasi
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An introduction to invasive cancer
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Chapter 4 Table 4.1: Indications fo
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Chapter 4 FIGURE 4.2: Colposcope wi
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Chapter 4 FIGURE 4.6: Endocervical
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Chapter 4 Table 4.2: Preneoplastic
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Chapter 5 between the two ocular le
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Chapter 5 Obtain specimens for labo
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Chapter 5 FIGURE 5.2: Biopsy techni
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Chapter 5 tissue tends to mimic inv
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Chapter 6 invasive carcinoma. Even
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Chapter 6 ages (Figures 1.7d, 1.7e,
Page 61 and 62: Chapter 6 FIGURE 6.7: The colour ch
Page 63 and 64: Chapter 6 Crypt openings Immature s
Page 65 and 66: Chapter 6 a FIGURE 6.17: An area of
Page 67 and 68: Chapter 7 The colposcopic diagnosis
Page 69 and 70: Chapter 7 appears as individual sma
Page 71 and 72: Chapter 7 acid stain is correlated
Page 73 and 74: Chapter 7 FIGURE 7.15: Moderately d
Page 75 and 76: Chapter 7 FIGURE 7.23: A dense acet
Page 77 and 78: Chapter 7 FIGURE 7.30: Mustard yell
Page 79 and 80: Chapter 7 We recommend that the stu
Page 81 and 82: Chapter 8 highlights this responsib
Page 83 and 84: Chapter 8 Appearance before applica
Page 85 and 86: Chapter 8 diagnosis of AIS and aden
Page 87 and 88: Chapter 8 a ↑ FIGURE 8.10: Adenoc
Page 89 and 90: Chapter 9 Inflammatory lesions of t
Page 91 and 92: Inflammatory lesions of the uterine
Page 93 and 94: Inflammatory lesions of the uterine
Page 95 and 96: Chapter 10 Table 10.1: Common sourc
Page 97 and 98: Chapter 10 Table 10.2 (cont.): A su
Page 99 and 100: Chapter 11 FIGURE 11.1: Flow chart
Page 101 and 102: Chapter 11 treatment policies for p
Page 103 and 104: Chapter 11 Vaginal delivery can be
Page 105 and 106: Chapter 12 involvement increases wi
Page 107 and 108: Chapter 12 Table 12.1: Eligibility
Page 109 and 110: Chapter 12 a b c d e f FIGURE 12.6:
Page 111: Chapter 12 during the follow-up in
Page 115 and 116: Chapter 13 (1) (2) (3) (4) (5) (8)
Page 117 and 118: Chapter 13 Once the specimen has be
Page 119 and 120: Chapter 13 in the endocervical cana
Page 121 and 122: Chapter 14 Decontamination, cleanin
Page 123 and 124: Decontamination, cleaning, high-lev
Page 125 and 126: References Herrero, R. (1997) Preva
Page 127 and 128: Further reading Suggestions on furt
Page 129 and 130: Appendix Leukoplakia Condylom
Page 131 and 132: Appendix regardless of your pregnan
Page 133 and 134: Appendix Monsel’s paste Ingredien
Page 135 and 136: Appendix 5 The modified Reid colpos
Page 137 and 138: Index Acetowhitening . . . . . . .
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Colposcopy and Treatment of Cervical Intraepithelial Neoplasia - RHO

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