Cone Biopsy: Perfecting the Procedure

Surgical Techniques Cone biopsy: perfecting the procedure

When colposcopy and cervical biopsy are inadequate in evaluating cervical dysplasia, cone biopsy of the cervix often will be both diagnostic and therapeutic.

BY MARC R. TOGLIA, MD

one biopsy of the cervix has been nant and requires aggressive treatment via used for more than a century to rule cone biopsy.1 Additional indications for the Cout the presence of invasive carcinoma procedure are listed in Table 1. in women with squamous intraepithelial From a diagnostic standpoint, cone biop-

lesions (SIL). And while less inva- Marc R. Toglia, MD sy should be performed when the sive techniques such as col- endocervical curettage is positive poscopy and loop electrosurgical for dysplasia because it is difficult excision procedures (LEEP) have to grade the severity of dysplasia reduced the need for diagnostic on the basis of the scant tissue conization dramatically, cervical fragments obtained by curettage. cone biopsy becomes necessary From a therapeutic standpoint, when these techniques prove lesions that involve the endocer- inadequate. vical canal are less likely to be adequately treated by destructive Indications techniques such as cryotherapy. When routine screening reveals Thus, for most women, cone abnormal cervical cytology such biopsy of the cervix is both diag- as atypical squamous cells Remove a single nostic and therapeutic. of undetermined significance specimen that (ASCUS), low-grade squamous Preparing for cone biopsy intraepithelial lesions (LGSIL), and includes the entire Cone biopsy involves the sur- high-grade squamous intraepithe- gical excision of a wedge-shaped lial lesions (HGSIL), colposcopy transformation portion of the ecto- and endo- and directed biopsy often are zone. cervix, including the removal of indicated. They help the physi- the entire squamocolumnar junc- cian rule out the presence of inva- ••• tion (SC junction) of the cervix, sive carcinoma and determine the grade and generally agreed to be the site of origin of distribution of the intraepithelial lesion. squamous cell carcinoma of the cervix. The Currently, only HGSIL is considered premalig- procedure may be performed using a scalpel, electroexcision (LEEP or fine-needle

Dr. Toglia is chief, subdivision of gynecology, at electrode), or CO2 laser. The choice Riddle Memorial Hospital in Media, Pa, and assis- between performing “cold-knife” versus tant clinical professor, department of OBG, at “hot-knife” conization is largely one of per- Thomas Jefferson Medical School in Philadelphia. sonal preference and depends on surgical continued on page 17

14 OBG MANAGEMENT • JANUARY 2002 Surgical Techniques lutain dpe ihpriso rmCucilLvnsoe ofa .Cria oiain nMn J Stovall eds. InIllustrations Mann WJ, conization. Cervical TG, adapted with from permission Hoffman Churchill M. Livingstone. Figure 1 Figure 2

Begin the cone biopsy by placing lateral sutures at the Use a #11 surgical blade to make the circular incision, angling cervicovaginal junction to decrease bleeding. the tip of the blade toward the endocervical canal. Gynecologic Surgery Figure 3 Figure 4 e ok Y ChurchillLivingstone; 1996:270-271. NY: New York, .

Grasp the specimen, including the entire transformation zone Complete the cone excision by cutting across endocervix. Apply and distal endocervical canal, with an Allis clamp. light cautery to the edges of the cervical bed.

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experience, the size/severity of the lesion, • Endocervical gland involvement. SIL fre- and the desires of the patient. In most cases, quently involves the endocervical glands, I prefer to use electrocautery because of its often to a depth of 5 mm or less. Several technical simplicity and the ability to operate investigators have suggested that excision of with only a local anesthetic. It is particularly endocervical glands to a depth of 7 to 10 appropriate for patients with an obvious mm produces acceptable cure rates.3 ectocervical lesion and in young, nulliparous Based on these 2 principles, the endocer- women in whom I am trying to minimize the vical portion of the cone should be 20 mm amount of healthy cervical tissue removed. wide (10 mm on either side of the canal) The use of colposcopy, either preopera- and no more than 2 cm deep. tively or intraoperatively, allows precise evaluation of the amount of cervical tissue Technique needed to be removed and reduces the inci- Traditionally, the first step in performing a dence of positive margins. The geometry, cone biopsy is to place sutures lateral to the i.e., width and depth, of the cone specimen cervix to decrease bleeding (Figure 1). will vary from patient to patient, depending While many surgeons believe that these on the size and location of the dysplastic sutures have a beneficial effect on hemosta- lesion, as well as the location of the SC junc- sis, others have not found them to be nec- tion. Specifically, the width of the cone essary.4 And although cone biopsy typically (ectocervical portion) is determined by the is performed under regional or general anes- size of the transformation zone and size and thesia, I have found that IV sedation and location of any ectocervical lesions. The injection of a local anesthetic are adequate depth of the cone (endocervical portion) is for most cone biopsies. determined by the location of the SC junc- Begin the procedure by placing either a tion, the presence or absence of endocervi- posterior weighted speculum (for a cold- cal disease, or the suspicion of a glandular knife cone) or an insulated speculum (for lesion. When a discrete intraepithelial lesion electrocautery) into the vagina. Then inject a has not been identified, it is critical to rule premixed solution of 2% xylocaine and epi- out a significant endocervical lesion. nephrine in a concentration of 1:200,000 into Therefore, the amount of tissue I plan to the cervical stroma at 12 o’clock outside the remove is based on the following 2 factors: intended margin of the cone biopsy. Then • Location of the SC junction. The more grasp this tissue with a single-tooth tenacu- endocervical the SC junction is, the more lum. Inject 5 to 10 cc of the solution para- likely the presence of a lesion higher in the cervically at 3 o’clock and again at 9 o’clock. canal. However, squamous intraepithelial I typically use a total of 20 to 30 cc to main- lesions rarely extend higher than 2 cm into tain hemostasis. Alternatively, the anesthetic the canal.2 can be infiltrated into the subepithelial stroma circumferentially around 1 Indications for cervical conization the ectocervix.

TABLE TABLE To perform a cold-knife • When the clinician is unable to perform a satisfactory col- cone, use a #11 surgical blade poscopy and cervical cytology demonstrates HGSIL to begin a circular incision • When SIL is present in the endocervical curettage sample starting at 12 o’clock on the • When squamous cell carcinoma in situ or microinvasive carci- face of the cervix, angling the noma is diagnosed or suspected by cytology, colposcopy, or tip of the blade toward the directed biopsy endocervical canal (Figure 2). • When cervical cytology suggests a higher-grade lesion than Use a uterine sound to mark a that found by colposcopic-directed biopsy depth of 2 cm within the endo- • When cytology, biopsy, or endocervical curettage suggest the cervical canal, typically the presence of an endocervical glandular lesion. most cephalad margin of the continued on page 21

JANUARY 2002 • OBG MANAGEMENT 17 Surgical Techniques

Key points with scissors to minimize any cautery effect at the endocervical margin. Achieve hemostasis by electrofulgurating the bleeding ves- ■ Cone biopsy typically includes the removal of the entire squamocolumnar sels using 30 to 40 watts of power in the junction of the cervix, generally agreed to coagulation mode. Monsel solution or paste be the site of origin of squamous cell car- then can be applied as needed. This tech-

cinoma. nique is similar to CO2 laser conization, only it is easier to learn and quicker to perform. ■ Inject a premixed solution of 2% xylocaine and epinephrine in a concentration Follow-up of 1:200,000 into the cervical stroma at 12 o’clock outside the intended margin. Postoperatively, patients should undergo cytologic screening every 4 months for 2 years ■ For a “cold-knife” cone, use a #11 surgical to identify persistent or recurrent disease. blade to begin a circular incision starting at 12 o’clock on the face of the cervix. Patients with positive cone biopsy margins face the highest risk of persistent or recurrent cervical intraepithelial neoplasia (CIN). cone. The goal is to remove a single speci- Although there is considerable variation, stud- men that includes the entire transformation ies generally have reported a 30% incidence of zone and distal endocervical canal (Figure positive margins. The incidence of recurrent 3). After removing the cone, perform an dysplasia when the margins are positive has endocervical curettage to collect an addition- been reported to be as high as 50%.6,7 al specimen. Apply light cautery to the edges In women with positive margins, col- of the cervical bed, as well as any bleeding poscopy and cervical and endocervical cytol- points (Figure 4). Place 1 interrupted suture ogy are an important part of the follow-up. I (I prefer 2-0 polyglactin) in each quadrant of perform an endocervical curettage, in addi- the face of the cervix, starting from outside tion to a Pap smear, at each interval visit dur- the margin of the cone and exiting near the ing the first year postoperatively and perform cervical os. Then insert the suture near the colposcopy at the 6- and 12- month visits. cervical os and exit outside the margin of the After 2 years of follow-up with normal results, cone. Tying these sutures everts the cervical cytologic screening should be performed os to a degree and keeps the transformation annually, per routine care. zone closer to the external surface of the cervix, making it easier to find when per- REFERENCES 1. Koutsky LA, Holmes KK, Critchlow CW, et. al. A cohort study of the forming future colposcopies. risk of cervical intraepithelial neoplasia grade 2 or 3 in relation to the Electroexcision with a fine-needle elec- papillomavirus. N Engl J Med. 1992;327:1272-1278. trode is performed with a blend-1 waveform 2. Burke L. Evolution of therapeutic approaches to cervical intraepithelial neoplasia. J Lower Genital Tract Disease. 1997;1:267-273. using 18 watts of power.5 Perform the exci- 3. Burke L, Covell L, Antonioli D. Carbon dioxide laser therapy of cervi- sion using the “cut” button on the bovie cal intraepithelial neoplasia: factors determining success rates. Lasers handpiece and then use the leading edge of Surg Med. 1980;1:113-122. 4. Gilbert L, Saunders NJ, Stringer R, Sharp F. Haemostasis and cold knife the electrical arc to incise the tissue. (It is biopsy: a prospective randomized trial comparing a suture versus non- best to use the arc, i.e., visible spark, to do suture technique. Obstet Gynecol. 1989;74:640-643. the cutting rather than the tip of the instru- 5. Ferenczy A. Electroconization of the cervix with a fine-needle electrode. Obstet Gynecol. 1994;84:152-159. ment, which may “stick” to surrounding tis- 6. AbdulKarim F, Nunez C. Cervical intraepithelial neoplasia after coniza- sues.) Make a full circle to a depth of about tion: a study of 522 consecutive cervical cones. Obstet Gynecol. 7 mm to outline the ectocervical cone mar- 1985;65:77-81. 7. Lubicz S, Ezekwche C, Allen A, Schiffer M. Significance of cone biop- gins. Then “pull down” the stroma on the sy margins in the management of patients with cervical neoplasia. J edge of the specimen with a skin hook to Reprod Med. 1984;29:178-184. continue the dissection parallel to the long axis of the endocervical canal to a depth of The author reports no financial relationship with any 1.5 to 2.0 cm. I excise the “base” of the cone companies whose products are mentioned in this article.

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