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Ultrasound evaluation of cervical shortening after loop excision of the transformation zone (LETZ)
GYNECOLOGY &OBSTETRICS International Journal of Gynecology& Obstetrics50 (1995)175-178
Article
Ultrasound evaluation of cervical shortening after loop excision of the transformation zone (LETZ) H.A. Ricciotti*, L. Burke, M. Kobelin, B. Slomovic, J. Ludmir Department of Obstetrics and Gynecology, Beth Israel Hospital, Harvard Medical School, Boston, MA, USA
Received14February 1995;revision received13April 1995;accepted21 April 1995
AbStrPCt Objectives: To assesscervical shortening after loop excision of the transformation zone (LETZ), and confirm the validity of ultrasound measurementof cervical length. Methoa!s: Subjects(n = 29) were patients at the colposcopy clinic of Beth Israel Hospital who underwent vaginal ultrasound measurementof cervical length before and after LETZ. The pathologic specimen was measured by ruler. Mean cervical length (A S.D.), mean percentage (f S.D.) of cervical length removed, and correlation (r) between ultrasound and pathology specimen measurement were determined. Results: Mean (f S.D.) cervical length measurements prior to LETZ were 3.2 f 0.9 cm and after LETZ were 2.6 f 0.9 cm, with a difference of 0.7 * 0.4 cm. The pathologic specimen (mean f S.D.) was 0.6 f 0.3 cm. The correlation between ultrasound and pathology measurementwas r = 0.9 (p = 0.0001). Mean ( f S.D.) cervical length was shortened by 22 * 12%. Conclusions: There is excellent correlation between ultrasound and ruler measurement of the cervix. There is significant cervical length shortening after LETZ, but further study is needed to seewhether this persists or leads to pregnancy complications.
Keywords: Cervix; Loop excision of the transformation zone (LETZ); Ultrasound; Obstetric complications
1. Introduction
Large loop excision of the transformation zone (LETZ) is rapidly emerging in the management of women with cervical intraepithelial neoplasia (GIN) becauseit is simple and inexpensive to use [ 11. Some are advocating using LETZ instead of traditional biopsies as both the initial diagnostic l
Correspondingauthor, Fax: +I 617 667501 I.
0 1995 International 00%7292B5M9.50 SSDI 0020-7292(95)02432-C
Federation of Gynecology
and therapeutic procedure - ‘looking and leaping’. This use however has been criticized as an overenthusiastic treatment of minor dysplastic lesions [2]. It is presently not known whether obstetric complications related to LETZ will be more or lessfrequent than after traditional laser ablation or conization. Cone biopsies have well-recognized obstetric morbidity including incompetent cervix, premature rupture of membranesand preterm deand Obstetrics
176
HA. Ricciotti et al. /International Journal of Gynecology & Obstetrics 50 (199s) 175-178
livery [3]. These problems however occur in only a very small number of patients who have undergone cone biopsy. It is not known why some patients have pregnancy complications after conization and others do not. However one factor, cone size, does appear to be related to pregnancy complications. The incidence of both spontaneous mid-trimester abortion and prematurity increases in direct proportion to cone size 141. Presently there is no way to prospectively identify those patients who will have pregnancy complications after conization. The size of the excision from LETZ is quite variable and depends upon the size of the lesion and the discretion of the operator. The average specimendepth ranges from approximately 0.3 to 2.0 cm, and sometimesmultiple passesare used in an attempt to remove more tissue. It is quite easy to remove the majority of the cervix if multiple passesare used. Since LETZ is a relatively new procedure, the long-term effect of this procedure on the cervix and pregnancy is unknown. Several investigators have reported that cervical length as measured by vaginal ultrasound is shorter in women who deliver preterm. The shorter the cervical length, the higher the risk of preterm delivery [5,6]. Vaginal ultrasound has been reported as a reproducible and valid method of evaluating the cervix in these patients [7]. The purpose of this study was to assessin an objective way the change in cervical length secondary to the LETZ procedure, and to further validate vaginal ultrasound evaluation of the cervix. The study cohort will be followed in the future to determine long-term cervical length measurements and pregnancy outcomes.
Fig.1. Transvaginal ultrasound scanin the sagittalplaneshowingmeasurement of cervical length before LETZto be3.7cm and after LETZ 3.4 cm.
2. Materials and methods The study was approved by the Committee on Clinical Investigations of Beth Israel Hospital. Patients being treated for biopsy-proven dysplasia by LETZ were invited to participate. None of the patients invited declined to participate. All patients had grade-II or grade-III CIN (high-grade squamous intraepithelial lesion, SIL). Patients with CIN I (low-grade SIL) were excluded and followed with colposcopy.
Ultrasound scanswere performed by two of the authors using a General Electric RT 3200 Advantage II with a vaginal probe of 6.5 MHz. Cervical length was measured in the sagittal plane by first visualizing the internal cervical OS,then manipulating the probe until the entire cervical canal was visualized. The external OS was identified by following the curve of the posterior lip of the portio vaginalis of the cervix to its intersection with the cervical canal. Cervical length was measuredin
H.A. Ricciotti et al. / Internationd Journal of Gynecology & Obstetrics 50 (1995) I75-I78
177
Table 1 Cervical measurements Before LETZ (cm)
After LETZ (cm)
Difference (cm)
Pathology (cm)
% Removed
3.2 2.8 3.5 4.8 3.0 2.5 2.6 3.7 2.7 3.1 3.7 2.7 3.9 2.7 2.9 3.3 3.4 4.1 3.5 2.6 2.6 5.2 2.8 2.4 3.5 2.1 2.3 2.7 5.0 3.2 f 0.9
2.5 2.1 3.0 3.4 2.8 1.9 1.8 3.0 2.0 2.3 3.3 2.5 3.1 2.1 2.6 2.5 2.7 3.7 3.2 2.2 1.3 4.5 1.0 2.1 2.9 1.6 1.6 2.1 4.2 2.6 zt 0.9
0.7 0.7 0.5 1.4 0.2 0.6 0.8 0.7 0.7 0.8 0.4 0.2 0.8 0.6 0.3 0.8 0.7 0.4 0.3 0.4 1.3 0.7 1.8 0.3 0.6 0.5 0.7 0.6 0.8 0.7 f 0.4
0.7 0.5 0.6 1.0 0.2 0.6 1.0 0.8 0.7 0.8 0.4 0.2 0.6 0.7 0.3 0.8 0.7 0.4 0.3 0.4 1.3 0.4 1.8 0.2 0.5 0.5 0.6 0.6 0.8 0.6 zt 0.3
22 25 14 29 7 24 31 19 26 26 11 7 21 22 10 24 21 10 9 15 50 13 64 13 17 24 30 22 18 22 f 12
centimeters as a straight line from the internal to the external OS(Fig. 1). Patients (n = 29) were examined just prior to LET2 by vaginal ultrasound to determine their cervical length. The ultrasound examination was repeated immediately (approximately 5 min) after LETZ, and the cervical length remeasured. The length of the pathologic specimen by ruler examination (prior to fixation) was recorded. The ultrasonographer was blinded to the result of the pathologic specimen measurement. Mean ( f S.D.) cervical length measurementsby ultrasound and mean (f SD.) ruler measurements of the pathologic specimenswere determined. Correlation between means was calculated as the correlation coefficient, r. The mean (f SD.)
percentage of cervical length removed was calculated.
3.Results Twenty-nine patients with high-grade SIL being treated by LETZ were examined between January 1994 and January 1995. Sonographic cervical length measurements, pathologic specimen measurementsand percentage of cervical length removed are reported in Table 1. Mean (f S.D.) cervical length measurements prior to LETZ were 3.2 * 0.9 cm, and 5 min after LETZ were 2.6 A 0.9 cm , with a mean difference of 0.7 f 0.4 cm. The mean measurement of the pathologic specimenwas 0.6 f 0.3 cm. There was
178
H.A. Riccioiti et al. /International
Journal of Gynecology & Obstetrics 50 (1995) 175-178
no cervical edema observed on the post-LETZ ultrasound. The correlation coefficient between the ultrasound measurementand the pathology specimen was t = 0.9 @ < 0.0001). Mean (f S.D.) cervical length was shortened by 22 f 12%. 4. Discussion The use of ultrasound to assessthe cervix is gaining popularity. Ultrasonography has been used to describe the cervix of patients at risk for cervical incompetence and premature delivery [8]. Norms for cervical length as measured by transvaginal sonography have been described and their accuracy validated [9]. Our data show that vaginal sonographic evaluation of the cervix offers an objective means of evaluating cervical changesfollowing surgical procedures.A significant percentageof cervical length (22%) is removed by LETZ. The amount of cervix removed is dependent on the operator and the size of the lesion, since extensive high-grade lesions may require a larger or deeper excision. Transvaginal sonography offers an excellent method of following thesepatients, who may be at risk for future pregnancy complications. Extrapolating from cervical cone data, one can postulate that LETZ may place some patients at similar risk for incompetent cervix as cervical conization. We suspectthat those patients who end up with a significantly shortened cervix due to cervical surgery may represent the subset of patients who go on to have pregnancy complications, but this remains to be proven. With the advent of vaginal sonography, those patients with shortened cervices from extensive surgery may be prospectively identified by transvaginal sonography and followed closely for pregnancy complications.
The indications for LETZ are not as clear as those for cervical conization, and in some cases LETZ may be overused. The consequencesof such overuseare unknown but potentially serious. Further studies are necessary to determine whether cervical length regenerates. In addition, future pregnancy outcomes need to be followed in order to determine whether a cervix shortened by LETZ places the patient at increased risk for adverse pregnancy outcome. References 111 Prendiville W. Large loop excision of the transformation
zone (LLETZ). A new method of managementfor women with cervical intraepithelial neoplasia. Br J Obstet Gynaecol 1989;96: 1054. 121 Kennedy S, Robinson J, Hallam N. LLETZ and infertility. Br J Obstet Gynaecol 1993; 100: 965. [31 Jones JM, Sweetnam P, Hibbard BM. The outcome of pregnancy after cone biopsy of the cervix: a case-control study. Br J Obstet Gynaecol 1979; 86: 913. 141 Kuoppala T, Saarikoski S. Pregnancy and delivery after cone biopsy of the cervix. Arch Gynecol 1986;237: 149. 151 Andersen JF, Nugenet CE, Wanty SD et al. Prediction of risk for preterm delivery by ultrasound measurement of cervical length. Am J Obstet Gynecol 1990; 163: 859. 161 Murakawa H, Utumi T, Hasegawa I, Tanaka K, Ruximori R. Evaluation of threatened preterm delivery by transvaginal ultrasonographic measurement of cervical length. Obstet Gynecol 1993; 82: 829. [71 JacksonGM, Ludmir J, Bader TJ. The accuracy of digital examination and ultrasound in the evaluation of cervical length. Obstet Gynecol 1992;79: 214. 181 Ludmir J. Sonographic detection of cervical incompetence. Clin Obstet Gynecol 1988; 31: 101. [91 JacksonGM, Ludmir J, Bader TJ. The accuracy of digital examination and ultrasound in the evaluation of cervical length. Obstet Gynecol 1992;79: 214.
Article
Ultrasound evaluation of cervical shortening after loop excision of the transformation zone (LETZ) H.A. Ricciotti*, L. Burke, M. Kobelin, B. Slomovic, J. Ludmir Department of Obstetrics and Gynecology, Beth Israel Hospital, Harvard Medical School, Boston, MA, USA
Received14February 1995;revision received13April 1995;accepted21 April 1995
AbStrPCt Objectives: To assesscervical shortening after loop excision of the transformation zone (LETZ), and confirm the validity of ultrasound measurementof cervical length. Methoa!s: Subjects(n = 29) were patients at the colposcopy clinic of Beth Israel Hospital who underwent vaginal ultrasound measurementof cervical length before and after LETZ. The pathologic specimen was measured by ruler. Mean cervical length (A S.D.), mean percentage (f S.D.) of cervical length removed, and correlation (r) between ultrasound and pathology specimen measurement were determined. Results: Mean (f S.D.) cervical length measurements prior to LETZ were 3.2 f 0.9 cm and after LETZ were 2.6 f 0.9 cm, with a difference of 0.7 * 0.4 cm. The pathologic specimen (mean f S.D.) was 0.6 f 0.3 cm. The correlation between ultrasound and pathology measurementwas r = 0.9 (p = 0.0001). Mean ( f S.D.) cervical length was shortened by 22 * 12%. Conclusions: There is excellent correlation between ultrasound and ruler measurement of the cervix. There is significant cervical length shortening after LETZ, but further study is needed to seewhether this persists or leads to pregnancy complications.
Keywords: Cervix; Loop excision of the transformation zone (LETZ); Ultrasound; Obstetric complications
1. Introduction
Large loop excision of the transformation zone (LETZ) is rapidly emerging in the management of women with cervical intraepithelial neoplasia (GIN) becauseit is simple and inexpensive to use [ 11. Some are advocating using LETZ instead of traditional biopsies as both the initial diagnostic l
Correspondingauthor, Fax: +I 617 667501 I.
0 1995 International 00%7292B5M9.50 SSDI 0020-7292(95)02432-C
Federation of Gynecology
and therapeutic procedure - ‘looking and leaping’. This use however has been criticized as an overenthusiastic treatment of minor dysplastic lesions [2]. It is presently not known whether obstetric complications related to LETZ will be more or lessfrequent than after traditional laser ablation or conization. Cone biopsies have well-recognized obstetric morbidity including incompetent cervix, premature rupture of membranesand preterm deand Obstetrics
176
HA. Ricciotti et al. /International Journal of Gynecology & Obstetrics 50 (199s) 175-178
livery [3]. These problems however occur in only a very small number of patients who have undergone cone biopsy. It is not known why some patients have pregnancy complications after conization and others do not. However one factor, cone size, does appear to be related to pregnancy complications. The incidence of both spontaneous mid-trimester abortion and prematurity increases in direct proportion to cone size 141. Presently there is no way to prospectively identify those patients who will have pregnancy complications after conization. The size of the excision from LETZ is quite variable and depends upon the size of the lesion and the discretion of the operator. The average specimendepth ranges from approximately 0.3 to 2.0 cm, and sometimesmultiple passesare used in an attempt to remove more tissue. It is quite easy to remove the majority of the cervix if multiple passesare used. Since LETZ is a relatively new procedure, the long-term effect of this procedure on the cervix and pregnancy is unknown. Several investigators have reported that cervical length as measured by vaginal ultrasound is shorter in women who deliver preterm. The shorter the cervical length, the higher the risk of preterm delivery [5,6]. Vaginal ultrasound has been reported as a reproducible and valid method of evaluating the cervix in these patients [7]. The purpose of this study was to assessin an objective way the change in cervical length secondary to the LETZ procedure, and to further validate vaginal ultrasound evaluation of the cervix. The study cohort will be followed in the future to determine long-term cervical length measurements and pregnancy outcomes.
Fig.1. Transvaginal ultrasound scanin the sagittalplaneshowingmeasurement of cervical length before LETZto be3.7cm and after LETZ 3.4 cm.
2. Materials and methods The study was approved by the Committee on Clinical Investigations of Beth Israel Hospital. Patients being treated for biopsy-proven dysplasia by LETZ were invited to participate. None of the patients invited declined to participate. All patients had grade-II or grade-III CIN (high-grade squamous intraepithelial lesion, SIL). Patients with CIN I (low-grade SIL) were excluded and followed with colposcopy.
Ultrasound scanswere performed by two of the authors using a General Electric RT 3200 Advantage II with a vaginal probe of 6.5 MHz. Cervical length was measured in the sagittal plane by first visualizing the internal cervical OS,then manipulating the probe until the entire cervical canal was visualized. The external OS was identified by following the curve of the posterior lip of the portio vaginalis of the cervix to its intersection with the cervical canal. Cervical length was measuredin
H.A. Ricciotti et al. / Internationd Journal of Gynecology & Obstetrics 50 (1995) I75-I78
177
Table 1 Cervical measurements Before LETZ (cm)
After LETZ (cm)
Difference (cm)
Pathology (cm)
% Removed
3.2 2.8 3.5 4.8 3.0 2.5 2.6 3.7 2.7 3.1 3.7 2.7 3.9 2.7 2.9 3.3 3.4 4.1 3.5 2.6 2.6 5.2 2.8 2.4 3.5 2.1 2.3 2.7 5.0 3.2 f 0.9
2.5 2.1 3.0 3.4 2.8 1.9 1.8 3.0 2.0 2.3 3.3 2.5 3.1 2.1 2.6 2.5 2.7 3.7 3.2 2.2 1.3 4.5 1.0 2.1 2.9 1.6 1.6 2.1 4.2 2.6 zt 0.9
0.7 0.7 0.5 1.4 0.2 0.6 0.8 0.7 0.7 0.8 0.4 0.2 0.8 0.6 0.3 0.8 0.7 0.4 0.3 0.4 1.3 0.7 1.8 0.3 0.6 0.5 0.7 0.6 0.8 0.7 f 0.4
0.7 0.5 0.6 1.0 0.2 0.6 1.0 0.8 0.7 0.8 0.4 0.2 0.6 0.7 0.3 0.8 0.7 0.4 0.3 0.4 1.3 0.4 1.8 0.2 0.5 0.5 0.6 0.6 0.8 0.6 zt 0.3
22 25 14 29 7 24 31 19 26 26 11 7 21 22 10 24 21 10 9 15 50 13 64 13 17 24 30 22 18 22 f 12
centimeters as a straight line from the internal to the external OS(Fig. 1). Patients (n = 29) were examined just prior to LET2 by vaginal ultrasound to determine their cervical length. The ultrasound examination was repeated immediately (approximately 5 min) after LETZ, and the cervical length remeasured. The length of the pathologic specimen by ruler examination (prior to fixation) was recorded. The ultrasonographer was blinded to the result of the pathologic specimen measurement. Mean ( f S.D.) cervical length measurementsby ultrasound and mean (f SD.) ruler measurements of the pathologic specimenswere determined. Correlation between means was calculated as the correlation coefficient, r. The mean (f SD.)
percentage of cervical length removed was calculated.
3.Results Twenty-nine patients with high-grade SIL being treated by LETZ were examined between January 1994 and January 1995. Sonographic cervical length measurements, pathologic specimen measurementsand percentage of cervical length removed are reported in Table 1. Mean (f S.D.) cervical length measurements prior to LETZ were 3.2 * 0.9 cm, and 5 min after LETZ were 2.6 A 0.9 cm , with a mean difference of 0.7 f 0.4 cm. The mean measurement of the pathologic specimenwas 0.6 f 0.3 cm. There was
178
H.A. Riccioiti et al. /International
Journal of Gynecology & Obstetrics 50 (1995) 175-178
no cervical edema observed on the post-LETZ ultrasound. The correlation coefficient between the ultrasound measurementand the pathology specimen was t = 0.9 @ < 0.0001). Mean (f S.D.) cervical length was shortened by 22 f 12%. 4. Discussion The use of ultrasound to assessthe cervix is gaining popularity. Ultrasonography has been used to describe the cervix of patients at risk for cervical incompetence and premature delivery [8]. Norms for cervical length as measured by transvaginal sonography have been described and their accuracy validated [9]. Our data show that vaginal sonographic evaluation of the cervix offers an objective means of evaluating cervical changesfollowing surgical procedures.A significant percentageof cervical length (22%) is removed by LETZ. The amount of cervix removed is dependent on the operator and the size of the lesion, since extensive high-grade lesions may require a larger or deeper excision. Transvaginal sonography offers an excellent method of following thesepatients, who may be at risk for future pregnancy complications. Extrapolating from cervical cone data, one can postulate that LETZ may place some patients at similar risk for incompetent cervix as cervical conization. We suspectthat those patients who end up with a significantly shortened cervix due to cervical surgery may represent the subset of patients who go on to have pregnancy complications, but this remains to be proven. With the advent of vaginal sonography, those patients with shortened cervices from extensive surgery may be prospectively identified by transvaginal sonography and followed closely for pregnancy complications.
The indications for LETZ are not as clear as those for cervical conization, and in some cases LETZ may be overused. The consequencesof such overuseare unknown but potentially serious. Further studies are necessary to determine whether cervical length regenerates. In addition, future pregnancy outcomes need to be followed in order to determine whether a cervix shortened by LETZ places the patient at increased risk for adverse pregnancy outcome. References 111 Prendiville W. Large loop excision of the transformation
zone (LLETZ). A new method of managementfor women with cervical intraepithelial neoplasia. Br J Obstet Gynaecol 1989;96: 1054. 121 Kennedy S, Robinson J, Hallam N. LLETZ and infertility. Br J Obstet Gynaecol 1993; 100: 965. [31 Jones JM, Sweetnam P, Hibbard BM. The outcome of pregnancy after cone biopsy of the cervix: a case-control study. Br J Obstet Gynaecol 1979; 86: 913. 141 Kuoppala T, Saarikoski S. Pregnancy and delivery after cone biopsy of the cervix. Arch Gynecol 1986;237: 149. 151 Andersen JF, Nugenet CE, Wanty SD et al. Prediction of risk for preterm delivery by ultrasound measurement of cervical length. Am J Obstet Gynecol 1990; 163: 859. 161 Murakawa H, Utumi T, Hasegawa I, Tanaka K, Ruximori R. Evaluation of threatened preterm delivery by transvaginal ultrasonographic measurement of cervical length. Obstet Gynecol 1993; 82: 829. [71 JacksonGM, Ludmir J, Bader TJ. The accuracy of digital examination and ultrasound in the evaluation of cervical length. Obstet Gynecol 1992;79: 214. 181 Ludmir J. Sonographic detection of cervical incompetence. Clin Obstet Gynecol 1988; 31: 101. [91 JacksonGM, Ludmir J, Bader TJ. The accuracy of digital examination and ultrasound in the evaluation of cervical length. Obstet Gynecol 1992;79: 214.