BJOG Exchange
DOI: 10.1111/1471-0528.12582 www.bjog.org
Cerclage or cervical occlusion— what’s the difference?
Sir, Cervical occlusion, introduced by Saling et al. in 1981, involves removal of the epithelium lining before circular stitching of the cervical canal followed by a double row of stitches, which close the outer os uteri completely. According to a newly published multicenter randomised controlled study any beneficial effect of a cervical occlusion is arbitrary. Brix et al.1 report that cervical occlusion in addition to cervical cerclage did not improve pregnancy outcome compared with cervical cerclage alone. It is important to note the description of the operative procedure as ‘a simpler, less traumatic technique whereby the external cervical os is occluded using a continuous suture at the time that the cerclage is applied’ (p.614).1 This simpler, less traumatic procedure is problematic because the mechanism of cervical occlusion is a complete closure of the cervical canal, so preventing ascension by microorganisms. A cerclage may improve the function of the cervical plug but probably does not prevent ascending infections because it only tightens but does not close the cervical canal. Misclassification of the procedures cerclage and cervical occlusion is apparently not a new phenomenon. Saling et al. emphasise at their homepage the difference between the techniques: ‘Not everything that is called “cervix occlusion” is actually a cervix occlusion according to Saling!’ The portio can only grow completely together if the
superficial epithelium is removed before stitching. If this is not done, then it is not a cervix occlusion according to Saling, but in effect a kind of cerclage.’2 So let us call a spade a spade: In the present study by Brix et al. ‘cervical closure’ was actually an extra cervical stitch at the external os; and not surprisingly the effect of this additional cervical stitch is similar to the effect of two stitches versus one stitch for transvaginal cerclage—no effect.3 Whereas we question the surgical procedure used in the study, we do agree with Brix et al.’s final recommendation, namely that another large randomised controlled trial is needed to test the effect of cervical occlusion. &
References 1 Brix N, Secher NJ, McCormack CD, Helmig RB, Hein M, Weber T, et al. Randomised trial of cervical cerclage, with and without occlusion, for the prevention of preterm birth in women suspected for cervical insufficiency. BJOG 2013;120:613–20. 2 For Professionals—Early Total Cervix Occlusion. [www.saling-institut.de/eng/04infoph/04tmv. html#Saling1981]. Accessed 28 January 2014. 3 Giraldo-isaza MA, Fried GP, Hegarty SE, Suescum-diaz MA, Cohen AW, Berghella V. Comparison of 2 stitches vs 1 stitch for transvaginal cervical cerclage for preterm birth prevention. YMOB Elsevier Inc.; AJOG 2013;208:209.e1–209.e9.
K Sneidera & J Langhoff-Roosb a
Centre of Clinical Research, Vendsyssel Hospital/Clinical Institute, Aalborg University, Aalborg; bDepartment of Obstetrics, Juliane Marie Centre, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
Accepted 24 October 2013. DOI: 10.1111/1471-0528.12582
ª 2014 Royal College of Obstetricians and Gynaecologists
Authors’ reply Sir, We thank Drs Sneider and Langhoff-Roos for their Letter to the Editor1 and are grateful for the opportunity to clarify a number of points from our paper.2 They point out that our technique for cervical occlusion does not protect the cervix against ascending infection because our less traumatic procedure does not involve complete occlusion of the external cervical os, like the technique developed by Saling et al.3 Furthermore, they point out the confusing terminology of cervical occlusion. Cervical occlusion developed by Saling et al. involves surgical removal of the superficial epithelial lining of the cervical canal in a similar fashion to conisation followed by two circular sutures, with subsequent scar tissue formation, resulting in a completely occluded cervix.3 In our trial, we used a new less traumatic procedure, where the anterior and posterior cervical lips were simply stitched together to close the external os and protect the cervical mucus plug.2 The cervical mucus plug may act as an effective mechanical and immunological barrier, owing to its rich content of antimicrobial peptides, immunoglobulins and phagocytes.4 Hence, our less traumatic cervical occlusion may retain the cervical mucus plug in the cervical canal, or, in the situation where the plug has already started to dissipate, it may allow the re-accumulation of the plug.5 A positive effect of cervical cerclage (take-home baby rate) with the less traumatic cervical occlusion has been shown in unpublished data from McCormack (see ref. 5) and in two
1173
BJOG Exchange
smaller retrospective studies (please see refs 11 and 12 in our paper2). We believed that this effect was mainly due to the protective effects of the mucus plug.4 We thank Drs Sneider and Langhoff-Roos for the possiblity to clarify this important point. Sneider and Langhoff-Roos mention that the occlusion technique developed by Saling is ‘complete’, in contrast to our technique, as the external os is completely occluded due to formation of scar tissue in the cervical canal. We agree; our cervical occlusion does not completely occlude the cervical canal, but rather supports the mucus plug, and does to a lesser extent occlude the external os. The procedure developed by Saling et al. could be speculated to leave more scar tissue after delivery compared with our technique. Theoretically, this might decrease the fertility in subsequent pregnancy attempts. Furthermore, the efficacy of Saling’s technique has never been confirmed in randomised trials. As Sneider and Langhoff-Roos point out, this method would be relevant to evaluate in a large randomised trial. Finally, we agree that the terminology concerning cervical occlusion is very confusing; it would be ideal to have a two different terms for the two different techniques. &
References 1 Sneider K, Langhoff-Roos J. Cerclage or cervical occlusion—what’s the difference? BJOG 2014;121. 2 Brix N, Secher NJ, McCormack CD, Helmig RB, Hein M, Weber T, et al. Randomised trial of cervical cerclage, with and without occlusion, for the prevention of preterm birth in women suspected for cervical insufficiency. BJOG 2013;120:613–20. 3 For professionals—early total cervix occlusion [Internet] [www.saling-institut.de/eng/04infoph/ 04tmv.html#Saling1981]. Accessed 2 November 2013. 4 Hein M. The immunology of the cervical mucus plug. PhD thesis. Faculty of Health Sciences, SUN-TRYK, University of Aarhus, Denmark, 2002. 5 Secher NJ, McCormack CD, Weber T, Hein M, Helmig RB. Cervical occlusion in women with
1174
cervical insufficiency: protocol for a randomised, controlled trial with cerclage, with and without cervical occlusion. BJOG 2007;114:649.
N Brix,a NJ Secher,b,c & TB Henriksena a
Department of Paediatrics, Aarhus University Hospital, Skejby, Denmark; bDepartments of Obstetrics and Gynaecology, Copenhagen University Hospital, Rigshospitalet, Denmark; c Department of Obstetrics and Gynaecology, Aarhus University Hospital, Skejby, Denmark Accepted 5 November 2013. DOI: 10.1111/1471-0528.12583
How well can pelvic floor muscles with major defects contract? A cross- sectional comparative study six weeks post partum using transperineal 3D/4D ultrasound and manometer
Sir, I read with interest the article by Hilde et al.1 on the function of pelvic floor muscles 6 weeks after delivery. The mothers included in this study were primarily recruited from a cohort study that entailed the assessment of nulliparous pregnant women’s awareness and practice of antenatal pelvic floor muscle training, showing that 89% were aware of this training and 35% performed it at least once a week, and included thorough instructions by a specialist physiotherapist.2 This cohort therefore represents a group of women with a good level of awareness and instruction to practise antenatal pelvic floor muscle exercises. The study excluded those who sustained grade 3b, 3c and 4 perineal tear. Obstetric anal sphincter injuries have their highest incidence amongst primigravidas3 and may well be associated with levator avulsion injuries. First time mothers who had emergency caesarean section, who may have reached full cervical dilatation and may even have had an attempted instrumental delivery, were also excluded from the study. These patients may, although less likely, have had levator avulsion injury. All these factors may make the findings of the
study, including the ability to contract pelvic floor muscles in the presence of levator avulsion injury, an under-estimation of the actual impact of levator avulsion injury on pelvic floor muscle function. The lack of prior power calculation may explain the lack of a significant difference in vaginal resting pressure. It is customary to provide the mean and standard deviation as the mean SD. The use of parametric tests to describe and compare continuous data indicates a normal distribution, which was not confirmed in the article. &
References 1 Hilde G, Stær-Jensen J, Siafarikas F, Gjestland K, €m Engh M, Bø K. How well can pelvic floor Ellstro muscles with major defects contract? A cross-sectional comparative study 6 weeks after delivery using transperineal 3D/D ultrasound and manometer BJOG 2013;120:1423–1429. €m EM, Brækken 2 Hilde G, Stær-Jensen J, Ellstro IH, Bø K. Continence and pelvic floor status in nulliparous women at midterm pregnancy. Int Urogynecol J 2012;23:1257–1263. 3 McLeod NL, Gilmour DT, Joseph KS, Farrell SA, Luther ER. Trends in major risk factors for anal sphincter lacerations: a 10 year study. J Obstet Gynecol Can 2003;25:586–593.
SIMF Ismail Department of Obstetrics and Gynaecology, Royal Sussex County Hospital, Brighton, UK Accepted 30 October 2013. DOI: 10.1111/1471-0528.12595
Authors’ reply Sir, Thank you for your important comments on our article.1 The statement saying that this study sample represents a group with a good level of pelvic floor awareness is reasonable, as 139 of the 175 women were included from a cohort study that started mid-pregnancy.2 The reasoning is sound as the 139 women recruited from this cohort study had their initial teaching session on how to contract the pelvic floor muscles (PFM) at mid-pregnancy, whereas the 36 women recruited in
ª 2014 Royal College of Obstetricians and Gynaecologists
DOI: 10.1111/1471-0528.12582 www.bjog.org
Cerclage or cervical occlusion— what’s the difference?
Sir, Cervical occlusion, introduced by Saling et al. in 1981, involves removal of the epithelium lining before circular stitching of the cervical canal followed by a double row of stitches, which close the outer os uteri completely. According to a newly published multicenter randomised controlled study any beneficial effect of a cervical occlusion is arbitrary. Brix et al.1 report that cervical occlusion in addition to cervical cerclage did not improve pregnancy outcome compared with cervical cerclage alone. It is important to note the description of the operative procedure as ‘a simpler, less traumatic technique whereby the external cervical os is occluded using a continuous suture at the time that the cerclage is applied’ (p.614).1 This simpler, less traumatic procedure is problematic because the mechanism of cervical occlusion is a complete closure of the cervical canal, so preventing ascension by microorganisms. A cerclage may improve the function of the cervical plug but probably does not prevent ascending infections because it only tightens but does not close the cervical canal. Misclassification of the procedures cerclage and cervical occlusion is apparently not a new phenomenon. Saling et al. emphasise at their homepage the difference between the techniques: ‘Not everything that is called “cervix occlusion” is actually a cervix occlusion according to Saling!’ The portio can only grow completely together if the
superficial epithelium is removed before stitching. If this is not done, then it is not a cervix occlusion according to Saling, but in effect a kind of cerclage.’2 So let us call a spade a spade: In the present study by Brix et al. ‘cervical closure’ was actually an extra cervical stitch at the external os; and not surprisingly the effect of this additional cervical stitch is similar to the effect of two stitches versus one stitch for transvaginal cerclage—no effect.3 Whereas we question the surgical procedure used in the study, we do agree with Brix et al.’s final recommendation, namely that another large randomised controlled trial is needed to test the effect of cervical occlusion. &
References 1 Brix N, Secher NJ, McCormack CD, Helmig RB, Hein M, Weber T, et al. Randomised trial of cervical cerclage, with and without occlusion, for the prevention of preterm birth in women suspected for cervical insufficiency. BJOG 2013;120:613–20. 2 For Professionals—Early Total Cervix Occlusion. [www.saling-institut.de/eng/04infoph/04tmv. html#Saling1981]. Accessed 28 January 2014. 3 Giraldo-isaza MA, Fried GP, Hegarty SE, Suescum-diaz MA, Cohen AW, Berghella V. Comparison of 2 stitches vs 1 stitch for transvaginal cervical cerclage for preterm birth prevention. YMOB Elsevier Inc.; AJOG 2013;208:209.e1–209.e9.
K Sneidera & J Langhoff-Roosb a
Centre of Clinical Research, Vendsyssel Hospital/Clinical Institute, Aalborg University, Aalborg; bDepartment of Obstetrics, Juliane Marie Centre, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark
Accepted 24 October 2013. DOI: 10.1111/1471-0528.12582
ª 2014 Royal College of Obstetricians and Gynaecologists
Authors’ reply Sir, We thank Drs Sneider and Langhoff-Roos for their Letter to the Editor1 and are grateful for the opportunity to clarify a number of points from our paper.2 They point out that our technique for cervical occlusion does not protect the cervix against ascending infection because our less traumatic procedure does not involve complete occlusion of the external cervical os, like the technique developed by Saling et al.3 Furthermore, they point out the confusing terminology of cervical occlusion. Cervical occlusion developed by Saling et al. involves surgical removal of the superficial epithelial lining of the cervical canal in a similar fashion to conisation followed by two circular sutures, with subsequent scar tissue formation, resulting in a completely occluded cervix.3 In our trial, we used a new less traumatic procedure, where the anterior and posterior cervical lips were simply stitched together to close the external os and protect the cervical mucus plug.2 The cervical mucus plug may act as an effective mechanical and immunological barrier, owing to its rich content of antimicrobial peptides, immunoglobulins and phagocytes.4 Hence, our less traumatic cervical occlusion may retain the cervical mucus plug in the cervical canal, or, in the situation where the plug has already started to dissipate, it may allow the re-accumulation of the plug.5 A positive effect of cervical cerclage (take-home baby rate) with the less traumatic cervical occlusion has been shown in unpublished data from McCormack (see ref. 5) and in two
1173
BJOG Exchange
smaller retrospective studies (please see refs 11 and 12 in our paper2). We believed that this effect was mainly due to the protective effects of the mucus plug.4 We thank Drs Sneider and Langhoff-Roos for the possiblity to clarify this important point. Sneider and Langhoff-Roos mention that the occlusion technique developed by Saling is ‘complete’, in contrast to our technique, as the external os is completely occluded due to formation of scar tissue in the cervical canal. We agree; our cervical occlusion does not completely occlude the cervical canal, but rather supports the mucus plug, and does to a lesser extent occlude the external os. The procedure developed by Saling et al. could be speculated to leave more scar tissue after delivery compared with our technique. Theoretically, this might decrease the fertility in subsequent pregnancy attempts. Furthermore, the efficacy of Saling’s technique has never been confirmed in randomised trials. As Sneider and Langhoff-Roos point out, this method would be relevant to evaluate in a large randomised trial. Finally, we agree that the terminology concerning cervical occlusion is very confusing; it would be ideal to have a two different terms for the two different techniques. &
References 1 Sneider K, Langhoff-Roos J. Cerclage or cervical occlusion—what’s the difference? BJOG 2014;121. 2 Brix N, Secher NJ, McCormack CD, Helmig RB, Hein M, Weber T, et al. Randomised trial of cervical cerclage, with and without occlusion, for the prevention of preterm birth in women suspected for cervical insufficiency. BJOG 2013;120:613–20. 3 For professionals—early total cervix occlusion [Internet] [www.saling-institut.de/eng/04infoph/ 04tmv.html#Saling1981]. Accessed 2 November 2013. 4 Hein M. The immunology of the cervical mucus plug. PhD thesis. Faculty of Health Sciences, SUN-TRYK, University of Aarhus, Denmark, 2002. 5 Secher NJ, McCormack CD, Weber T, Hein M, Helmig RB. Cervical occlusion in women with
1174
cervical insufficiency: protocol for a randomised, controlled trial with cerclage, with and without cervical occlusion. BJOG 2007;114:649.
N Brix,a NJ Secher,b,c & TB Henriksena a
Department of Paediatrics, Aarhus University Hospital, Skejby, Denmark; bDepartments of Obstetrics and Gynaecology, Copenhagen University Hospital, Rigshospitalet, Denmark; c Department of Obstetrics and Gynaecology, Aarhus University Hospital, Skejby, Denmark Accepted 5 November 2013. DOI: 10.1111/1471-0528.12583
How well can pelvic floor muscles with major defects contract? A cross- sectional comparative study six weeks post partum using transperineal 3D/4D ultrasound and manometer
Sir, I read with interest the article by Hilde et al.1 on the function of pelvic floor muscles 6 weeks after delivery. The mothers included in this study were primarily recruited from a cohort study that entailed the assessment of nulliparous pregnant women’s awareness and practice of antenatal pelvic floor muscle training, showing that 89% were aware of this training and 35% performed it at least once a week, and included thorough instructions by a specialist physiotherapist.2 This cohort therefore represents a group of women with a good level of awareness and instruction to practise antenatal pelvic floor muscle exercises. The study excluded those who sustained grade 3b, 3c and 4 perineal tear. Obstetric anal sphincter injuries have their highest incidence amongst primigravidas3 and may well be associated with levator avulsion injuries. First time mothers who had emergency caesarean section, who may have reached full cervical dilatation and may even have had an attempted instrumental delivery, were also excluded from the study. These patients may, although less likely, have had levator avulsion injury. All these factors may make the findings of the
study, including the ability to contract pelvic floor muscles in the presence of levator avulsion injury, an under-estimation of the actual impact of levator avulsion injury on pelvic floor muscle function. The lack of prior power calculation may explain the lack of a significant difference in vaginal resting pressure. It is customary to provide the mean and standard deviation as the mean SD. The use of parametric tests to describe and compare continuous data indicates a normal distribution, which was not confirmed in the article. &
References 1 Hilde G, Stær-Jensen J, Siafarikas F, Gjestland K, €m Engh M, Bø K. How well can pelvic floor Ellstro muscles with major defects contract? A cross-sectional comparative study 6 weeks after delivery using transperineal 3D/D ultrasound and manometer BJOG 2013;120:1423–1429. €m EM, Brækken 2 Hilde G, Stær-Jensen J, Ellstro IH, Bø K. Continence and pelvic floor status in nulliparous women at midterm pregnancy. Int Urogynecol J 2012;23:1257–1263. 3 McLeod NL, Gilmour DT, Joseph KS, Farrell SA, Luther ER. Trends in major risk factors for anal sphincter lacerations: a 10 year study. J Obstet Gynecol Can 2003;25:586–593.
SIMF Ismail Department of Obstetrics and Gynaecology, Royal Sussex County Hospital, Brighton, UK Accepted 30 October 2013. DOI: 10.1111/1471-0528.12595
Authors’ reply Sir, Thank you for your important comments on our article.1 The statement saying that this study sample represents a group with a good level of pelvic floor awareness is reasonable, as 139 of the 175 women were included from a cohort study that started mid-pregnancy.2 The reasoning is sound as the 139 women recruited from this cohort study had their initial teaching session on how to contract the pelvic floor muscles (PFM) at mid-pregnancy, whereas the 36 women recruited in
ª 2014 Royal College of Obstetricians and Gynaecologists
