Premalignant cervical lesions usually occur in women of childbearing years. Until recently, the historical choices for treatment of these included cryosurgery, electrocoagulation, laser vaporization or conization, knife conization, and hysterectomy. The first three options are outpatient procedures and allow for the possibility of future pregnancies. However, because they are ablative therapies, no tissue is sent for pathologic inspection, raising the possibility of missing microinvasive or invasive cancer. Conization and hysterectomy produce tissue specimens with wide margins but usually require outpatient surgery or hospitalization with general anesthesia, and hysterectomy precludes future pregnancies. The loop electrosurgical excisional procedure (LEEP) allows outpatient treatment of cervical lesions, produces good pathology specimens, and has a low risk of interfering with childbearing.
LEEP makes use of low-voltage and relatively high-frequency electric current. In pure cutting mode, high-frequency current is produced in a smooth, uninterrupted sine wave. The cutting effect is not produced by heating the wire. As the loop is introduced to the tissue, an arc occurs near the point of contact, causing the cells to be rapidly heated and exploded into steam. The steam envelope allows continued arcing, extending the cut. This produces a clean cut with little coagulation
artifact. The transformation zone can be removed, with a good-quality specimen sent to the pathology department for examination.
Figure. No caption available.
In the coagulation mode, fulguration of tissue is produced with short bursts of high-peak-voltage current. This mode is often used with a ball electrode to achieve hemostasis. Most modern units can combine the amount of cutting and the coagulation currents in blend modes.With all three operational modes, the current is quickly dispersed to the grounding electrode. The large surface area of the return electrode prevents high charge density and prevents burns. An improperly applied return electrode can result in burns.
Efficacy and patient acceptance of LEEP compare favorably with other treatment methods for cervical intraepithelial neoplasia (CIN). Few studies directly compare treatment modalities with sufficient statistical power to draw conclusions. A prospective, randomized study by Mitchel et al. did not find any significant differences for cryotherapy, laser ablation, and LEEP. This study could only detect large differences, and it did show a trend toward better outcomes for CIN 3 with LEEP. General studies indicate LEEP is 91% to 98% effective in treating CIN. LEEP is also a well-tolerated procedure, with 85% of patients reporting no discomfort. Most patients who do report discomfort indicate that the degree of pain is mild.
Electrosurgical generators used for LEEP are identical to ones used in dermatologic, laparoscopic, and urologic surgery. The alternating current output ranges between 100 and 5,000 kHz. At frequencies greater than 100 kHz, cellular membrane depolarization does not occur, and there is no associated shock or muscular contraction.
The amount of current used depends on the generator and the loop size. The relative cutting power needed is proportional to the amount of wire that comes into contact with the cervix. As the surface area of the cut increases, the amount of power needed to make the cut also increases. Larger or deeper cuts and larger loops require higher current settings. Drier or more keratinized skin also requires higher current settings. Setting the current too high results in increased thermal damage and increased risk of unintentional burns.
Modern electrical generator features usually include isolated circuitry (i.e., unit automatically deactivates if any active electrode current is not returned through the patient electrode) and return electrode monitoring (i.e., warns if the return circuit is interrupted). Most generators allow switching between cutting and coagulation modes and can blend a cutting effect with a coagulation effect. These blend modes permit concomitant coagulation hemostasis and surgical excision of tissues. Blend modes represent a greater proportion of coagulation effect that further minimizes bleeding but often increases thermal damage to the excised tissue. If a thermal artifact is present, evaluation of the specimen margin to exclude margin involvement by tumor becomes difficult.
Most loops have an insulated shaft and crossbar to prevent accidental thermal injury. Common loop sizes range from 1 × 1 cm to 2.0 × 1.5 cm. The stainless steel or tungsten wire of the loop is approximately 0.2 mm thick. Ball electrodes ranging from 3 to 5 mm are used for fulguration. The probe is a monopolar output and requires the use of a grounding electrode. Return (patient) electrodes may be adhesive gel pads or a solid “antenna” and may be disposable or reusable.
Figure. No caption available.
A smoke evacuator is essential to remove the plume produced during the procedure. It filters airborne particles and coexisting microorganisms present in the plume. Several manufacturers have combined an electrosurgical unit with a smoke evacuator so that, when the generator is activated, the smoke evacuator also is automatically activated. Negative pressures from the smoke evacuator cause air to flow into the vagina, up the fixed tubing in the speculum, and through the evacuator tubing toward the equipment. This minimizes plume spillage into the treatment room. A series of microfilters helps remove the carbon, odor, and viral particles generated. Because human papillomavirus (HPV) has been isolated from similar laser plumes, clinicians usually wear micro-pore or submicron surgical masks.
Most electrosurgical generator manufacturers recommend using insulated vaginal speculums to prevent secondary patient burns from conduction through the speculum to nonanesthetized vaginal and vulvar areas. Treat insulated speculums as if they were not insulated; do not touch them with an activated electrode! Nonconductive lateral wall retractors may assist with visualization to counteract lateral vaginal wall redundancy and protect the vaginal walls.
Patient preparation starts when the patient is informed she has dysplastic cervical cells on colposcopically directed biopsy. Basic education should be provided about cervical disease, treatment options, and the LEEP procedure. The patient may be given instructions to premedicate with a nonsteroidal antiinflammatory drug the night before and the morning of the procedure if there are no contraindications. The optimal timing of the procedure is within 7 days of completion of the menstrual period to minimize the likelihood that the patient is pregnant. After cervical LEEP, there may be swelling sufficient to occlude the endocervical canal, and this can lead to hematocolpos, with the need to drain the uterus.
Patient consent is mandatory, because every management strategy carries with it some element of risk. Among states and geographic regions, there is considerable variation about issues such as who constitutes a minor and when parental
consent must be received by the physician before treating a minor. Many states do not require parental informed consent before providing treatment to a minor with a sexually transmitted disease. Conditions related to HPV infections, such as cervical dysplasia, fall within the latter guideline. The physician should record on the minor patient's chart any and all efforts to secure and receive informed consent.
Burns in the vaginal vault are usually caused by poor visualization or operator inexperience. There is also a risk of burns through alternate grounding sites or under the pad due to poor return electrode contact. Most of the latter two sources of burns have been eliminated with modern return electrode monitoring. When testing the loop before the procedure, avoid inadvertent contact with the patient.
When excising the transformation zone with the LEEP procedure, perioperative bleeding is rare, especially with the use of fulguration and Monsel's solution. Significant late bleeding has been reported in 0% to 14% of patients who had LEEP therapy. Most did not require hospitalization and were treated with vaginal packing or suturing. This compares well with bleeding rates for laser therapy and for cryotherapy. Infection has been reported in 0% to 8% of patients.
A less common complication found in larger studies was cervical stenosis (0.5% to 4% of cases). Rarely, cervical os obliteration was reported. These complications occurred mainly with multiple procedures and deep removal of extensive lesions. Two grams of intravaginal estrogen placed after LEEP conization in postmenopausal women protects against os stenosis and obliteration. The risk of incompetent cervix and sterility are included in informed consent by some practitioners for theoretical reasons, but there are no published clinical data to support this. LEEP conization has been found to have a higher complication rate than LEEP excision of the transformation zone.
Pregnancy rates after LEEP are comparable to those after laser therapy and better than rates after conization. There also appears to be no significant difference in complications during pregnancy between patients who have undergone LEEP and those who have had other destructive cervical therapies. Although the data are not extensive, no difference has been found between women who had LEEP and matched controls in regard to their ability to conceive and carry the pregnancy to term.
LEEP is approximately 95% effective for treatment of immunocompetent women. Most recurrences happen within 1 year of treatment. The procedure provides an adequate specimen for pathologic study. Confirming complete removal of the lesion by observing specimen margins essentially eliminates the risk of missing microinvasive cancers. Despite removal of tissue, the transformation zone heals with a normal appearance in most patients, allowing for normal, long-term cytologic and colposcopic follow-up.
LEEP also offers the advantage of being a clinic procedure performed under local anesthesia. Treatment of even advanced lesions can be accomplished with the complete removal of the transformation zone or conization, with results comparable to knife conization. The cost of a LEEP unit is much less than laser equipment. In some cases, LEEP saves the hospital and anesthesia costs of conization. By improving diagnostic accuracy, LEEP may prevent the human and financial cost of missing microinvasive cancer.
Patient instructions should include prohibition of sexual intercourse, douching, and tampon use for 2 to 4 weeks. A discharge is expected for 2 to 3 weeks, but it may last up to 6 weeks. The patient should report any significant bleeding or malodorous vaginal discharge. A follow-up Papanicolaou (Pap) smear with or without colposcopy should be scheduled for 4 to 6 months later.
Patients are instructed to return in 1 month for results of the pathologic examination. A report indicating no dysplasia should be interpreted as showing that the sample had a clear margin, not that no dysplasia was present. Small internal lesions may be missed by pathology. Patients with no dysplasia in the resection margins may be followed for 2 years with Pap smears or colposcopy, or both, every 6 months. If all test results remain normal, routine yearly screening may be resumed, although the patient is permanently at high risk for developing cervical dysplasia. Any sign of recurrence requires repeat colposcopic examination.
Because the recurrence rate with positive margins is about 25%, immediate retreatment is usually not necessary. A positive endocervical curettage (ECC) result after a LEEP cone or LEEP procedure should have close follow-up, usually with colposcopy with directed biopsy and ECC, or referral for conization. It is important to check for recurrences deep in the os (i.e., skip lesions) and along the edge of the original LEEP cut. Patients with biopsy-proven recurrent lesions should be offered retreatment or hysterectomy. Women infected with human immunodeficiency virus (HIV) have high rates of recurrent and persistent CIN despite standard therapy, and low levels of CD4-positive T cells and margin involvement are risk factors for recurrence. The use of highly active antiretroviral therapy (HAART) is associated with a lower risk of recurrence, persistence, and progression of CIN.
SEE-AND-TREAT LOOP ELECTROSURGICAL EXCISIONAL PROCEDURE
See-and-treat LEEP refers to the practice of diagnosing and treating some patients in a single visit. This method is not widely performed in the United States and seems to be losing favor worldwide. It has been proposed for patients with evidence of high-grade dysplasia (not low-grade squamous intraepithelial lesions or HPV lesions) on Pap smear cytology with visible lesions and an adequate colposcopic examination or for highly unreliable patients not likely to follow-up. It should not be used when colposcopic findings are equivocal or suggest invasive cancer. The major concern with this approach is that an excision procedure may be performed unnecessarily. Traditional colposcopy followed by treatment was been found to be more cost-effective than see-and-treat LEEP.
Before performing a LEEP, colposcopically evaluate the cervix. Apply Lugol's solution to aid in distinguishing normal epithelium from lesions. A return electrode is attached to the patient, usually on the upper leg or under the buttocks. Anesthesia is performed using a 25- to 30-gauge needle and 1% or 2% lidocaine hydrochloride with 1:100,000 epinephrine. Infiltrate the lidocaine solution very superficially at the 12-, 3-, 6-, and 9-o'clock positions or into the center of each quadrant. About 5 mL total is usually adequate. Consider applying 20% benzocaine solution before injection and adding between 1:1 and 1:4 of a 8.3% sodium bicarbonate solution to the lidocaine to decrease the amount of pain with the injection.
(1) Infiltrate the lidocaine solution very superficially at the 12-, 3-, 6-, and 9-o'clock positions or into the center of each quadrant.
PITFALL: If using a side wall retractor, avoid pinching the vagina between the retractor and the speculum. Slowly open the retractor, making sure the side wall does not become entrapped.
Choose a loop that allows excision of the entire transformation zone (usually 12 to 20 mm wide and 7 to 10 mm deep) in one or two passes without major risk of contact with the vaginal side wall. Ring forceps held against the cervix may be a useful size referent. Set the current (usually 40 to 60 watts or 4 to 6 on higher-frequency units), and set the unit to a blended or pure cutting mode. The loop is attached to a pencil-like base that is controlled with a finger switch or foot switch.
(2) Choose a loop that allows excision of the entire transformation zone (usually 12 to 20 mm wide and 7 to 10 mm deep) in one or two passes without major risk of contact with the vaginal side wall.
To excise tissue, the loop is held just above the surface of the cervix and 2 to 5 mm lateral to the lesion or edge of the transformation zone. Current is applied before the loop contacts the cervix. The loop is pushed into the tissue to a depth of about 7–8 mm, because maximal crypt involvement by CIN is approximately 4 mm, and you must account for the volume of injected anesthetic.
(3) To excise tissue, the loop is held just above the surface of the cervix and 2 to 5 mm lateral to the lesion, and current is applied before the loop contacts the cervix.
PITFALL: If current is applied after contact is made, significant thermal injury will occur, and the quality of the cut will be poor.
PITFALL: Activate the loop only when looking at it. This avoids inadvertant alternate-site burns.
Draw the loop slowly through the tissue until the loop is 2 to 5 mm past the edge of the transformation zone on the opposite side. Remove the loop perpendicularly. The average cutting time is approximately 5 to 10 seconds. Remove the specimen with the loop or ring forceps, and immediately place the specimen in formalin. ECC is recommended by many experts at this point, especially if one was not performed during the preceding colposcopy.
(4) Draw the loop slowly through the tissue until the loop is 2 to 5 mm past the edge of the transformation zone on the opposite side.
PITFALL: The excision should be done in a single, smooth motion with continuous current. Stopping the cutting current before the excision is completed causes extensive thermal injury and may damage the loop.
Superficial fulguration is usually applied to the entire crater (being careful to not fulgurate the cervical os) and to any spots of point hemorrhage. The normal edge of the defect (lateral margin) is always fulgurated. Apply Monsel's solution to the defect's base.
(5) Superficial fulguration is usually applied to the entire crater and to any spots of point hemorrhage.
LEEP conization, also known as the “cowboy hat” procedure, can be performed when an excision into the canal is required. The technique is often used when a lesion extends into the endocervical canal. The cervix is anesthetized as described earlier, except that an additional 0.5 to 2 mL of lidocaine is infiltrated at the 6- and 12-o'clock positions around the os to a depth of approximately 1 cm.
(6) In LEEP conization, the cervix is anesthetized as previously described, except that an additional 0.5 to 2 mL of lidocaine is infiltrated at the 6- and 12-o'clock positions around the os to a depth of approximately 1 cm.
The transformation zone is excised in the manner described previously. Then, the distal endocervical canal can be excised an additional 9 to 10 mm, usually with a 10 × 10 mm loop or square electrode.
(7) The transformation zone is excised in the manner described previously, and the distal endocervical canal can be excised an additional 9 to 10 mm.
PITFALL: Orientation of the specimen is necessary for the pathologist to be able to determine if the deep margin is involved with dysplasia.
PITFALL: Avoid extending the excision into or past the internal cervical os. The depth or the remaining canal may be assessed after ectocervical excision by placing an instrument or sound into the canal.
INSTRUMENT AND MATERIALS ORDERING
LEEP units and associated materials may be obtained from Circon/Cryomedics, Racine, WI (phone: 888-524-7266 or 414- 639-7205; http://www.acmicorp.com/acmi/user); Cooper Surgical, Shelton, CT (phone: 800-645-3760 or 203-929-6321;http://www.coopersurgical.com); Ellman International, Inc., Hewlett, NY (phone: 1-800-835 5355 or 516-569-1482;http://www.ellman.com); Leisegang Medical, Inc., Boca Raton, FL (phone: 800-448-4450 or 561-994-0202; http://www.leisegang.com); Olympus America, Inc., Melville, NY (phone: 800-548-555 or 631-844-5000; http://www.olympusamerica.com); Utah Medical Products, Inc., Midvale, UT (phone: 800-533-4984 or 801-566-1200; http://www.utahmed.com); Wallach Surgical Devices, Inc., Orange, CT (phone: 203-799-2000 or 800-243-2463; http://www.wallachsurgical.com); and Welch Allen, Skaneateles Falls, NY (phone: 800-535-6663 or 315-685-4100; http://www.welchallyn.com).
Althuisius SM, Schornagel IJ, Dekker GA, et al. Loop electrosurgical excision procedure of the cervix and time of delivery in subsequent pregnancy. Int J Gynaecol Obstet 2001;72:31–34.
Bigrigg A, Haffenden DK, Sheeham AL, et al. Efficacy and safety of large loop excision of the transformation zone. Lancet 1994;343:32–34.
Buxton EJ, Luesley DM, Shafi MI, et al. Colposcopy directed punch biopsy: a potentially misleading investigation. Br J Obstet Gynaecol1991;98:1273–1276.
Duggan BD, Felix JC, Muderspach LI, et al. Cold-knife conization versus conization by the loop electrosurgical excision procedure: a randomized, prospective study. Am J Obstet Gynecol 1999;180:276–282.
Felix JC, Muderspach LI, Duggan BD, et al. The significance of positive margins in loop electrosurgical cone biopsies. Obstet Gynecol1994;84:996–1000.
Ferris DG, Hainer BL, Pfenninger JL, et al. Electrosurgical loop excision of the cervical transformation zone: the experience of family physicians. J Fam Pract 1995;41:337–344.
Gonzalez DI Jr, Zahn CM, Retzloff MG, et al. Recurrence of dysplasia after loop electrosurgical excision procedures with long-term follow-up. Am J Obstet Gynecol 2001;184:315–321.
Holschneider CH, Ghosh K, Montz FJ. See-and-treat in the management of high-grade squamous intraepithelial lesions of the cervix: a resource utilization analysis. Obstet Gynecol 1999;94:377–385.
Kobak WH, Roman LD, Felix JC, et al. The role of endocervical curettage at cervical conization for high-grade dysplasia. Obstet Gynecol1995;85:197–201.
Mathevet P, Dargent D, Roy M, et al. A randomized prospective study comparing three techniques of conization: cold knife, LASER, and LEEP. Gynecol Oncol 1994;54:175–179.
Mayeaux EJ Jr, Harper MB. Loop electrosurgical excisional procedure. J Fam Pract 1993:36:214–219.
Mitchel MF, Tortolero-Luna G, Cook E, et al. A randomized clinical trial of cryotherapy, laser vaporization, loop electrosurgical excision for treatment of squamous intraepithelial lesions of the cervix. Obstet Gynecol 1998;92:737–744.
Murdoch JB, Morgan PR, Lopes A, et al. Histological incomplete excision of CIN after large loop excision of the transformation zone (LLETZ) merits careful follow up, not retreatment. Br J Obstet Gynaecol 1992;99:990–993.
Naumann RW, Bell MC, Alvarez RD, et al. LLETZ is an acceptable alternative to diagnostic cold-knife conization. Gynecol Oncol1994;55:224–228.
Paraskevaidis E, Lolis ED, Koliopoulos G, et al. Cervical intraepithelial neoplasia outcomes after large loop excision with clear margins.Obstet Gynecol 2000;95:828–831.
Prentice ME, Dinh TA, Smith ER, et al. The predictive value of endocervical curettage and loop conization margins for persistent cervical intraepithelial neoplasia. J Low Genital Tract Dis 2000;4:155.
Sawchuck WS, Webber PJ, Lowy DR, et al. Infectious papillomavirus in the vapor of warts treated with carbon dioxide laser or electrocoagulation: detection and protection. J Am Acad Dermatol 1989;21:41–49.
Spitzer M. Fertility and pregnancy outcome after treatment for cervical intraepithelial neoplasia. J Low Genital Tract Dis 1998;2:225–230.
Spitzer M. Vaginal estrogen administration to prevent cervical os obliteration following cervical conization in women with amenorrhea. J Low Genital Tract Dis 1997;1:53–56.
Williams FS, Roure RM, Till M, et al. Treatment of cervical carcinoma in situ in HIV positive women. Int J Gynaecol Obstet 2000;71:135–139.