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
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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
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