Risk of cervical stenosis after large loop excision or laser conization

Risk of Cervical Stenosis After Large Loop Excision or Laser Conization JEAN-JACQUES BALDAUF, MD, MICHEL DREYFUS, MD, JEAN RITTER, MD, PIERRE MEYER, MD, AND EMILE PHILIPPE, MD Objective:

To

assess

the

frequency

of cervical

stenosis

in

patients treated by laser conization or the loop electrosurgical excision procedure and to determine the preoperative and therapeutic factors associated with its occurrence. Methods: Two hundred fifty-five women treated by laser conization and 277 treated by loop electrosurgical excision procedure were followed regularly by postoperative colposcopy for mean periods of 38 and 16 months, respectively. Stenosis was defined as cervical narrowing that prevented insertion of a 2.5-mm Hegar dilator. Results: Thirty-eight cases of cervical stenosis, of which seven were complete, were diagnosed up to 28 months after treatment. The risk of postoperative cervical stenosis was higher for patients over 50 years of age (relative risk [RR1 3.07, 95% confidence interval 195% CII 1.30, 7.26; P = .031), for those with a totally endocervical lesion (RR 3.79, 95% CI 1.88, 7.62; P = .OOl), for those with an excision 20 mm high or greater (RR 2.96, 95% CI 1.63, 5.38; P = .005), and for those with laser conization (RR 2.35, 95% CI 1.24, 4.46; P = .009). Parity, menopause, previous treatment for cervical intraepithelial neoplasia, satisfactory colposcopy, size of the lesion, its histologic diagnosis, and the extent of excision did not increase the risk for cervical stenosis. Excision was not as high with loop electrosurgical excision as with laser conization (14.3 f 5.0 mm versus 20.2 -t 6.0 mm). The height of excision (RR 1.95, 95% CI 1.02, 3.76; P = .04) and a totally endocervical lesion (RR 5.07, 95% CI 1.96, 14.44; P = .OOl) were the only independent factors associated with postoperative stenosis identified by a multivariate analysis using logistic regression. Conclusion: The height of excision and a totally endocervital lesion were the main factors associated with cervical stenosis. The decreased risk associated with the loop electrosurgical excision procedure seems to be due to a shorter endocervical excision. (Obstet Gynecol 2996;88:933-8. Copyright 0 2996 by The American College of Obstetricians and Gynecologists.)

The treatment of cervical intraepithelial neoplasia (GIN) has become more conservative over the years. Approximately 15 years ago, laser conization was considered a good alternative to cold-knife conization because of its precision and the quality of hemostasis obtained, despite the absence of cervical suture.‘,2 More recently, the loop electrosurgical excision procedure has become a commonly used method because of its lower cost and technical ease.?-’ Because this method provides a specimen with which the completeness of treatment can be confirmed and initially overlooked microinvasive or invasive cancer can be detected, many physicians use it rather than an ablative procedure to treat low-grade CIN.h-y The literature on laser conization and the loop electrosurgical excision procedure consistently shows that success rates exceed 9OYL and that short-term morbidity remains 1ow2,315,h,10; however, little is known about long-term complications. One adverse effect, cervical stenosis, may cause menstrual disorders, have an impact on fertility, and complicate the patient’s postoperative follow-up. Stenosis was mentioned in several studies,2z”zh, 11I12 but the postoperative follow-up was often short. Furthermore, the absence of systematic colposcopy after treatment may obscure the exact frequency of stenosis. Risk factors for stenosis have received little attention. Our objective was to assess the frequency of cervical stenosis in patients treated by laser conization or the loop electrosurgical excision procedure and to determine preoperative or therapeutic factors associated with its occurrence.

Materials and Methods This retrospective study included 276 patients treated by laser conization between January 1985 and February 1992 and 286 women treated by the loop electrosurgical excision procedure between February 1992 and May 1995. Excluded were 17 patients lost to follow-up, 12

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whose treatment was too recent, and one who had a hysterectomy 3 weeks after incomplete excision of a microinvasive carcinoma. The 532 remaining patients were followed in our colposcopy unit for a mean of 38 months (range 3-124) after laser conization (n = 255) and 16 months (range 3-48) after the loop electrosurgical excision procedure (n = 277). Before the procedure, all women were examined by the same colposcopist, who performed directed punch biopsies with or without an endocervical curettage to confirm the diagnosis of CIN. The size of the lesion was estimated at colposcopy by dividing the cervix into eight sectors. Four quadrants were initially defined by two perpendicular lines crossing each other in the center of the cervical canal, after which a circular line was drawn through the mid-portion of each quadrant. Lesions included in one or two sectors were considered small, those covering three or four sectors were medium in size, and lesions found in more than four sectors were large. Until February 1992, a patient with high-grade CIN, or with low-grade CIN but unsatisfactory colposcopy, was treated by laser conization, whereas a woman who had low-grade CIN and satisfactory colposcopy was treated by vaporization. Since February 1992, all of these patients have been treated with loop electrosurgical excision. All procedures were performed by the same operator. In both methods, the cervix was first stained with Lugol’s iodine solution to identify the external limits of the lesion and to determine the extent of the excision. Laser conization was performed under general anesthesia. Ten to 20 mL of a vasoconstrictive solution (lidocaine with 2% epinephrine or diluted ornithine vasopressin, 1 ILJ/lO mL) was injected outside of the transformation zone. A CO2 laser (Sharplan 1040; Laser Industries, Tel Aviv, Israel) coupled with a colposcope was used at the maximal power of 40 W with a 0.6-mm spot size, delivering a power density of 5000-7000 W/cm’. After a circular section 0.5-l cm deep was made, the partly excised specimen was manipulated using two small metallic hooks to enable the laser beam to be directed obliquely toward the cervical canal, to obtain a cone the height of which depended on the endocervical extension of the lesion. Hemostasis was completed by coagulation of the residual bleeding points with a defocused laser beam. The loop electrosurgical excision procedure was performed under general or local anesthesia after infiltration of the cervix with lo-20 mL of a lidocaine solution with 2% epinephrine. According to the size of the lesion, a loop lo-25 mm wide and lo-20 mm high was used so as to excise the lesion in one piece as often as possible. An additional endocervical excision was performed with a smaller loop when the endocervical limit of the lesion

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Post-Excision Cervical Stenosis

was not visible at preoperative colposcopy. Newgeneration electrosurgical generators (Valleylab Force 2; Valleylab Inc., Boulder, CO; and Erbotom ACC 450; Erbe Elektromedizin Gmbh, Tubingen, Germany) were used at a power of 30-50 W. If necessary, hemostasis was completed by coagulation of the excision bed with a ball electrode. Specimens were immediately oriented and fixed in a formaldehyde solution, then cut in radial slices at a maximum thickness of 3 mm. All tissue blocks were identified in reference to their clock-face position and embedded. Their number varied from 12 and 20, according to the specimen size. Excision was considered incomplete when neoplastic tissue was found on the margins or in glands located at the edge of the section. The diameter of the base and the height of the specimens were measured by the pathologist on the fixed tissues. When a second endocervical cut was performed, the excision height was obtained by adding that of both specimens. Patients were asked to return for follow-up 3-6 months after treatment, at 12 months, and then annually for 4 additional years. Beyond that, the patients without cytologic or colposcopic anomaly were referred back to their general practitioner or gynecologist for an annual cytologic follow-up. At each visit, exocervical and endocervical smears were taken before colposcopy, and a directed biopsy was done in instances of colposcopic anomaly. An endocervical curettage was performed in any case of abnormal cytology, whether colposcopy was normal or unsatisfactory. The diagnosis of a residual lesion was established on the basis of the directed biopsy or the endocervical curettage. Stenosis was defined as cervical narrowing that prevented insertion of a 2.5-mm Hegar dilator. Stenosis was considered complete, if there was total occlusion of the cervical canal. Statistical analysis and calculations were performed using a commercially available software package (SOLO Statistical System; BMDP Statistical Software Inc., Los Angeles, CA). Comparisons between groups were made with the unpaired Student t test for variables with a normal distribution (age, height, and width of excision) and the 2 test for categorical variables. We used univariate and multivariate analyses to evaluate the association between clinical variables and postoperative cervical stenosis. For the univariate analysis, we calculated the relative risks (RRs) and 95% confidence intervals (CIs) and explored the data using the 2 test for categorical variables. For the multivariate analysis, stepwise logistic regression was used to identify variables having an independent effect on cervical stenosis. P < .05 was considered significant.

Obstefrics 6 Gynecology

Table

1.

Clinical, Colposcopic, and Histologic Characteristics Laser conization (M = 255)

Characteristic Age (y) Mean t standard deviation z50 Nulliparous Postmenopausal Previous treatment for CIN Unsatisfactory colposcopy Lesion size and location Totally endocervical lesion Small lesion Medium lesion Large lesion Histology Normal Low-grade CIN High-grade CIN Microinvasion NS = not significant;

CIN

33.2 15 77 14 25 76

Loop excision (II = 277)

t 8.0 (5.9%) (30.2%) (5.5%) (Y.S%) (29.8%)

32.9 10 104 10 38 71

t 8.6 (3.6%‘) (37.5%) (3.6%) (13.7%) (25.6%)

14 (5.5%)

21 96 67 93

(7.6%) (34.6%:) (24.2%) (33.6%)

18 46 208 5

(6.5%) (16.6%) (75.1%) (1.8%)

50 (19.64) 76 (2Y.SS) 115 (45.1%)

P NS NS NS NS NS NS ,001

coo1 10 (3%) 11 (4.3%) 225 (88.3%) Y (3.5%) = cervical

intraepithelial

neoplasia

Results The clinical, colposcopic, and histologic characteristics of the patients treated by laser conization or the loop electrosurgical excision procedure are summarized in Table 1. The age range of the patients was 18-70 years in the laser group and 18-72 years in the loop electrosurgical excision procedure group. Five women in the laser group and seven in the loop electrosurgical excision procedure group had had previous excision of CIN. No significant difference was observed in their clinical characteristics, but lower rates of small-size lesions and of low-grade CIN were noted in the laser group. The basediameter of the specimenswas comparable for laser conization and the loop electrosurgical excision procedure (Table 2), but specimen height was signifiTable

2. Characteristics

Characteristic Height (mm) Range Mean ? SD 220 mm Diameter at base (mm) Range Mean + SD 220 mm Non-involved endocervical SD = standard

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88, NO.

deviation;

6, DECEMBER

of Specimens Laser conization (12 = 255)

Loop excision (II = 277)

P

5-35 20.2 -r 6.0 156 (61.2%)

5-25 14.3 2 5.0 52 (18.8%)

<.OOl c.001

10-35 20.3 t 4.5 169 (66.3%) 244 (95.7%)

10-35 20.1 2 4.5 183 (66.1%) 260 (93.9%)

NS NS NS

NS = not significant.

1996

cantly greater in laser conizations than in the loop electrosurgical excision procedure. This difference remained significant when comparing patients having at least high-grade CIN (20.4 + 5.9 mm versus 14.5 ? 4.5 mm; P < .OOl),those with unsatisfactory colposcopy (19.7 + 6.3 mm versus 14.9 + 4.4 mm; P < .OOl), and those with a large lesion (21.0 C 5.8 mm versus 14.6 -C 4.5 mm; P < .OOl). We observed more incomplete excisions with the loop electrosurgical excision procedure than with laser conization, but the difference was not significant. Similarly, residual lesions were discovered at postoperative follow-up in six patients (2.4%) after laser conization and in 15 (5.4%) after the loop electrosurgical excision procedure. Again, this difference was not significant, and the height of the specimen was not significantly smaller in women who developed a residual lesion than in the others (16.0 + 6.5 mm versus 17.2 -C6.1 mm; P > .05). We found 26 cases of stenosis in the laser group (10.2%‘)and 12 (4.3%) in the loop electrosurgical excision group. In the first group, the frequency of postoperative stenosis was significantly lower in the first 100 patients treated (5.0%) than in those treated later (13.5%) (P = .02). In the second group, the frequency of postoperative stenosiswas not significantly different in the first 100 patients treated than in those treated later (4.0% versus 4.5%; P > .05). Thirty-six casesof stenosis (94.7%) were noted as early as the first postoperative visit, and the remaining two caseswere found at 28 and 18 months, respectively, after the cervix appeared to be normal at the first follow-up examination. The frequency of postoperative stenosis was not significantly lower in the 87 patients who were seenagain only once in our colposcopy unit (5.7%) than in the others (7.2%) (P > .05). Patients with postoperative stenosis were older than the others (36.3 2 9.8 years versus 32.8 I 8.5 years; P < .05). Among the 12 patients who had a second excision for residual CIN, only one (8.3%) had postoperative stenosis. This frequency was not significantly higher than that observed after a single excision (7.1%; P > .05). We noted seven complete and 31 incomplete stenoses.Two patients with complete stenosis and two with incomplete stenosis were postmenopausal. Among the 34 nonmenopausal women who developed stenosis,five had secondary amenorrhea, six had severe dysmenorrhea, and one had infertility related to scant cervical mucus. Among the women with stenosis, endocervical-cell retrieval was possible in 21 cases(55.3%); the squamocolumnar junction was visible at colposcopy in none. Tables 3 and 4 summarize the crude RRs of postoperative cervical stenosis after laser conization and the loop electrosurgical excision procedure. To evaluate the true net effect of each of the independent variables on

Baldauf

et al

Post-Excision Cervicnl Stenosis

935

Table

3. Univariate Occurrence

Characteristic Age 250 y Nulliparous Postmenopausal Previous treatment for CIN Unsatisfactory colposcopy Totally endocervical lesion Large lesion High-grade CIN or microinvasion Height of specimen ‘20 mm Exocervical diameter of specimen 220 mm

Analyses of Cervical Stenosis After Laser Conization Normal cervix (I? = 229)

Cervical stenosis (n = 26)

RR

11 72 10 22

(4.8%) (31.4%) (4.4%) (9.6%)

4 (15.4%) 5(19.2%) 4(15.4%) 3 (11.5%)

2.91 0.55 3.13 1.20

1.11-7.62 0.22-1.37 1.20-8.15 0.38-3.75

NS NS NS NS

68 (29.7%)

8 (30.8%)

1.05

0.48-2.30

NS

9 (3.9%)

5 (19.2%)

4.10

1.75-9.61

.005

107(46.7X) 228 (99.6%)

8 (30.8%) 23 (88.5%)

0.54 0.60

0.25-1.18 0.25-1.43

NS NS

139 (60.7%‘)

17 (65.4%)

1.20

0.56-2.58

NS

149 (65.1%)

20 (76.9%,)

1.70

0.72-3.99

NS

RR = relative risk; CI = confidence interval; CIN = cervical intraepithelial neoplasia.

95% CI

I’

NS = not significant;

postoperative stenosis, we performed a logistic regression analysis separately for laser conization and the loop electrosurgical excision procedure. A totally endocervical lesion was the only significant risk factor for postoperative stenosis after laser conization (RR 4.10, 95% CI 1.75, 9.61; P = .005), whereas an excision 20 mm high or greater (RR 4.33, 95% CI 1.57, 11.92; P = .014)

Table

4. Univariate Occurrence

Characteristic Age ~50 y Nulliparous Postmenopausal Previous treatment for CIN Unsatisfactory colposcopy Totally endocervical lesion Large lesion High-grade ClN or microinvasion Height of specimen C?O mm Exocervical diameter of specimen 220

Analyses of Cervical Stenosis After Loop Electrosurgical Excision Normal cervix (n = 265)

Cervical stenosis (II = 12)

9 99 10 34

(3.4%) (37.4%) (3.8%) (12.8%)

1 (8.3%) 5 (41.7%)

Discussion RR

95% CI

2.43 1.19 x

0.35-16.86 0.39 -3.65

NS NS

4 (33.3% 1 3.14

1.03-9.56

NS

66 (24.9%)

5 (41.7%)

2.07

0.69-6.21

NS

18 (6.8%)

3 (25.0%)

4.06

1.25-13.21

NS

90 (34.0%1) 202 (76.2%)

3 (25.0%) 11 (91.7%)

0.66 3.31

0.19-2.35 0.50-21.83

NS NS

46 (17.4%)

6 (50.04)

4.33

1.57-l 1.92

,014

173 (63.3%)

10 (83.3%)

.57

0.61-10.75

NS

Abbreviations as in Table 3. *Number of cases affected too low for estimation

936

Baldauf et al

was the only significant risk factor for postoperative stenosis after the loop electrosurgical excision procedure. To evaluate the contribution of the excision procedure to postoperative stenosis, we combined the laser conization and loop electrosurgical excision procedure groups for univariate and multivariate analyses. Patients who developed postoperative stenosishad significantly higher excisions (20.7 + 7.0 mm versus 16.8 2 6.0 mm; P < .OOl), but these excisions were not significantly more extensive in width (21.2 ? 3.2 mm versus 20.1 -C4.6 mm; P > .05). In the univariate analysis, the risk of postoperative stenosis was higher for patients over 50 years of age (RR 3.07, 95%’Cl 1.30, 7.26; P = .031), for those with a totally endocervical lesion (RR 3.79, 95% CI 1.88, 7.62; P = .OOl), for those with laser conization (RR 2.35,95% CI 1.24,4.46; P = .009), and for those with an excision 20 mm high or greater (RR 2.96, 95%’ CI 1.63, 5.38; P = ,005). Multivariate analysis of significant or nearly significant effects (P < .15) was based on multiple logistic regression analyses of six risk factors: patient age, menopausal status, totally endocervital lesion, excision procedure, height of the specimen, and exocervical diameter of the excision. Although the prevalence of cervical stenosis was higher in the laser group (10.2%) than in the loop electrosurgical excision group (4.3%), the excision procedure did not prove to be associated independently with postoperative cervical stenosis (RR 1.75, 95% CI 0.74, 4.13; P > .05). The height of the specimen (RR 1.95, 95% CI 1.02, 3.76; P = .04) and a totally endocervical lesion (RR 5.07, 95%’CI 1.96, 14.44; P = .OOl) were the only independent risk factors associatedwith postoperative cervical stenosis.

Posf-Excision

Ccruicol

of relative

Stenosis

P

risk,

The objective of conization is to remove the whole lesion so as to reach a final diagnosis and to ensure local treatment by limiting the excision to what is strictly necessary to preserve cervical function. To our knowledge, no study has yet assessedthe preoperative and therapeutic factors associated with the occurrence of postoperative cervical stenosis.In our study, the height of the excision and a totally endocervical lesion were the only independent factors associatedwith the risk of stenosis. In this retrospective study, we noted a lower prevalence of small-size lesions and of low-grade CIN in the laser group than in the loop electrosurgical excision group because,before February 1992,these lesionswere generally treated by vaporization rather than by conization. This difference may have contributed to a smaller height of the excision with the loop electrosurgical excision procedure than with laser conization. Never-

Obsfefvics

6 G~ynecolo~y

theless, even when the comparison between the groups concerned histologically severe lesions, with identical size or topography, loop electrosurgical excision procedure cones were not as high as those obtained with laser conization, as reported by other authors.7,13,‘4 The mean height of our loop electrosurgical excisions is similar to those reported in the literature (range 9-28 mm).5,7*13-15 Similarly, the height of our laser conizations is comparable to those reported by Kristensen et a1,12Mor-Yosef et al,‘” and Larsson et al’; it is greater than those reported by other authors whose rates of incomplete excision are much higher than ours (range 6.653%). 2,7,13,14,16 It is difficult to compare frequencies of postoperative stenosis because definitions vary greatly among studies. Nevertheless, our findings are consistent with the frequencies mentioned in the literature: O-25% after laser conization1Z2,‘2*14 and 1.3-5.2% after the loop electrosurgical excision procedure.“,hS”,‘1,‘7 These results vary with the severity of the treated lesions, the height of excision, and the mode of postoperative follow-up. In this series, the duration of postoperative follow-up was shorter in the loop electrosurgical excision procedure group. This difference probably had a small impact on the lower frequency of stenosis in this group, as 94.7% of patients with stenosis were diagnosed during the first postoperative visit. Along with other authors, we observed significantly more cases of postoperative stenosis when the height of the excision was 20 mm or more.12 In 1000 patients treated with the diathermy loop, Hallam et al’ reported an overall cervical stenosis rate of 3Y0, but it was 12.3% in the subgroup with a nonvisible squamocolumnar junction in whom the excision was performed under colposcopic control at a mean height of 22 mm, and it was 27.770 when the excision was performed without colposcopic control at a mean height of 28 mm. Patients who developed stenosis after the loop electrosurgical excision procedure were generally over 45 years old. ‘,‘J’J~ In our study, those with postoperative stenosis were generally older than the others, but age did not appear to be an independent factor associated with the risk of postoperative stenosis. We did not observe significantly more cases of postoperative stenosis in patients who had received previous treatment for CIN. Furthermore, only one stenosis was observed among the 12 patients who had second excisions because of a residual lesion. Thus, the risk of postoperative stenosis was not significantly different after a second excision than after a single one. Despite the use of a cytobrush, which is considered more efficient than Ayre’s spatula in post-conization patients,‘* we could not collect endocervical or metaplastic cells in 45% of the patients with stenosis. Fur-

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1YYh

thermore, in none of them was the squamocolumnar junction visible at colposcopy. The frequency of unsatisfactory colposcopies ranges from 6% to 24% in patients treated with the loop electrosurgical excision procedure4,6,‘4 and from 11% to 30% after laser conization.14,16 This frequency increases with the height of the cone18 and if the junction was not visible before excision6 In cases of abnormal postoperative cytology, reactional aspects with no pathologic significance are frequently observed; at colposcopy, these may be distinguished from the rare residual lesions, but only if the squamocolumnar junction is visible.3,9 Therefore, in patients in whom excision was considered incomplete or in those with abnormal postoperative cytology, stenosis renders follow-up difficult and may necessitate a new excision for fear of leaving a residual lesion that may progress into cancer. It is particularly difficult to determine the height of the excision when the upper limit of the lesion is not visible at colposcopy. The height of the endocervical lesion cannot be determined precisely with endocervical curettage. Microhysteroscopy has been proposed for this purpose,‘” but this technique has not yet been sufficiently validated, and we have no relevant experience. Like others,17 we make an additional endocervical excision when the upper limit of the lesion is not visible at colposcopy. The histologic examination of this second specimen makes it easier to confirm the completeness of the excision.13 We observed more incomplete excisions and residual lesions after the loop electrosurgical excision procedure than after laser conization, but the difference was not significant. Because the height of the specimens is smaller in residual lesions and is significantly smaller in loop electrosurgical excision procedures, it seems logical that a certain number of stenoses can be avoided with the loop electrosurgical excision procedure, but at the cost of a higher frequency of residual lesions. Nevertheless, we do not believe that a systematic increase in the excision height can be justified for the loop electrosurgical excision procedure, for the following reasons: 1) Our results seem to indicate that to do so would increase the risk of stenosis; 2) the impact of such an approach on the frequency of residual lesions has not yet been evaluated; and 3) at present, residual lesions are rare, detectable by cytocolposcopic followup, and curable with a second excision that, in our experience, does not carry a higher risk of stenosis.

References 1. Larsson G, Gullberg BO, Grundsell H. A comparison of complications of laser and cold knife conization. Obstet Gynecol 1983;62: 213-7.

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Cervical

Stenosis

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2. Baggish MS, Barash F, Noel Y, Brooks M. Comparison of thermal injury zones in loop electrical and laser cervical excisional conization. Am J Obstet Gynecol 1992;166:545-8. 3. Bigrigg A, Haffenden DK, Sheehan AL, Codling BW, Read MD. Efficacy and safety of large-loop excision of the transformation zone. Lancet 1994;343:32-4. 4. Prendiville W, Cullimore J, Norman S. Large loop excision of the transformation zone (LLETZ). A new method of management for women with cervical intraepithelial neoplasia. Br J Obstet Gynaeco1 1989;96:1054-60. 5. Hallam NF, West J, Harper C, Edwards A, Hope S, Merriman H, et al. Large loop excision of the transformation zone (LLETZ) as an alternative to both local ablative and cone biopsy treatment: A series of 1000 patients. J Gynecol Surg 1993;9:77-82. 6. Spitzer M, Chernys AE, Seltzer VL. The use of large loop excision of the transformation zone in an inner-city population. Obstet Gynecol 1993;82:731-5. 7. Oyesanya OA, Amerasinghe CN, Manning EA. Outpatient excisional management of cervical intraepithelial neoplasia. A prospective, randomized comparison between loop diathermy excision and laser excisional conization. Am J Obstet Gynecol 1993; 168:485-8. 8. Wright TC Jr, Gagnon S, Richart RM, Ferenczy A. Treatment of cervical intraepithelial neoplasia using the loop electrosurgical excision procedure. Obstet Gynecol 1992;79:173-8. 9. Alvarez RD, Helm CW, Edwards RI’, Naumann RW, Partridge El?, Shingleton HM, et al. Prospective randomized trial of LLETZ versus laser ablation in patients with cervical intraepithelial neoplasia. Gynecol Oncol 1994;52:17>9. 10. Andersen ES, Pedersen 8, Nielsen K. Laser conization: The results of treatment of cervical intraepithelial neoplasia. Gynecol Oncol 1994;54:201-4. 11. Ferenczy A. Electroconization of the cervix with a fine-needle electrode. Obstet Gynecol 1994;84:152-9. 12. Kristensen GB, Jensen LK, Holund B. A randomized trial comparing two methods of cold knife conization with laser conization. Obstet Gynecol 1990;76:1009-13. 13. Krebs HB, Pastore L, Helmkamp BF. Loop electrosurgical excision procedures for cervical dysplasia: Experience in a community hospital. Am J Obstet Gynecol 1993;169:289-93.

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14. Mathevet P, Dargent D, Roy M, Beau G. A randomized prospective study comparing three techniques of conization: Cold knife, laser, and LEEP. Gynecol Oncol1994;54:175-9. 15. Mor-Yosef S, Lopes A, Pearson S, Monaghan JM. Loop diathermy cone biopsy. Obstet Gynecol 1990;75:884-6. CK, Turner MJ, Soutter WP, Griffiths M, Krausz T. 16. Partington Laser vaporization versus laser excision conization in the treatment of cervical intraepithelial neoplasia. Obstet Gynecol 1989;73: 775-9. 17. Keijser KG, Kenemans P, van der Zanden PH, Schijf CP, Vooijs GP, Rolland R. Diathermy loop excision in the management of cervical intraepithelial neoplasia: Diagnosis and treatment in one procedure. Am J Obstet Gynecol 1992;166:1281-7. 18. Whiteley PF, Olah KS. Treatment of cervical intraepithelial neoplasia: Experience with the low-voltage diathermy loop. Am J Obstet Gynecol 1990;162:1272-7. 19. Hamou J, Salat-Baroux J, Coupez F, de Brux J. Microhysteroscopy: A new approach to the diagnosis of cervical intraepithelial neoplasia. Obstet Gynecol 1984;63:567-74.

Address

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to:

Jean-jacques Baldauf, MD Service de Gynkologie-Obste’trique H6pital de Hautepierre Avenue Moliere F-67098 Strasbouvg Cedex France

Received

April

1

12, 1996.

Received in revised form July 27, 1996 Accepted

August

20, 1996.

Copyright 0 1996 by The American College of Obstetricians Gynecologists. Published by Elsevier Science Inc.

Obstetrics

and

0 Gynecology