http://informahealthcare.com/jmf ISSN: 1476-7058 (print), 1476-4954 (electronic) J Matern Fetal Neonatal Med, 2014; 27(15): 1584–1588 ! 2014 Informa UK Ltd. DOI: 10.3109/14767058.2013.870551
ORIGINAL ARTICLE
Cervical cerclage and type of suture material: a survey of UK consultants’ practice F. Israfil-Bayli1, P. Toozs-Hobson1, C. Lees2, M. Slack3, J. Daniels4, A. Vince4, and K. M. K. Ismail5 1
Birmingham Women’s Hospital NHS Foundation Trust, Edgbaston, Birmingham, UK, 2Department of Fetal Medicine, Imperial College Healthcare NHS Trust, London, UK, 3Department of Urogynaecology, Addenbrooke’s Hospital, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK, 4Birmingham Clinical Trials Unit, Robert Aitken Institute, University of Birmingham, Edgbaston, Birmingham, UK, and 5 Department of Obstetrics and Gynaecology, School of Clinical & Experimental Medicine, College of Medical & Dental Sciences, University of Birmingham, Edgbaston, Birmingham, UK Abstract
Keywords
Objective: The main aim of the survey was to explore current practices with regards to cervical cerclage procedures amongst UK consultants with particular emphasis on the type of suture material used. Methods: An electronic survey of UK consultant members and fellows of the Royal College of Obstetricians and Gynaecologists and who previously agreed to be contacted for survey purposes. Results: There were 261 respondents to the survey and 88% routinely performed cerclage. The majority performed the procedure between 12 and 16 weeks’ gestation (88.7%; n ¼ 180/203), following the McDonald technique (83.4%; n ¼ 166/199) and using a braided suture material (86.6%; n ¼ 175/202). Although only 27 of the 202 responders (13.4%) used a monofilament suture for cerclage (75%; n ¼ 149/201) of clinicians stated that they were not sure what is the best suture material to be used. Conclusion: There is considerable variation in practice amongst Consultant obstetricians with regards to cervical cerclage. Although most respondents use the traditional braided suture material, a significant proportion of them were not sure what is the best suture material to use. The ‘‘gestation at delivery’’ rate was judged to be the most important outcome for a future study.
Cervical incompetence, monofilament/non-braided sutures, multifilament/braided sutures, preterm birth
Introduction Cervical incompetence (CI) is one of the causes of prematurity and mid-trimester pregnancy loss, and cervical cerclage is the traditional method of management [1]. The mechanism of action of cerclage is not fully understood; however, it is suggested that the cervical suture provides mechanical support to the cervix, which helps to retain the cervical mucus plug and hence reduce the risk of ascending infection, pregnancy loss and early birth [2]. It is estimated that CI affects 1% of pregnancies [3], with half of these women requiring a planned cerclage procedure based on history or clinical indicators. Therefore it is estimated that approximately 3750 women have this procedure in the UK per annum. The effectiveness of cervical cerclage, compared to no intervention, has been assessed in several randomized Address for correspondence: Dr F. Israfil-Bayli, Research Fellow, Birmingham Women’s Hospital NHS Foundation Trust, Mindelsohn Way, Edgbaston, Birmingham, B15 2T, UK. Tel: +44(0)121 6274707. Fax: +44(0)121 6272667. E-mail: [email protected]; drbayli@ yahoo.co.uk
History Received 25 August 2013 Accepted 26 November 2013 Published online 23 December 2013
controlled trials (RCTs). Pooled data from these studies failed to demonstrate a significant impact of this procedure on improving neonatal outcomes [4]. Other RCTs have addressed the issue of timing of cerclage, the indication for the procedure, the surgical technique used and the number of sutures placed [5–7]. However, none of these studies controlled for the material of the suture used with regards to whether it is monofilament or braided. The impact of the type of suture material on the outcome of a surgical intervention should not be underestimated. Indeed, for perineal trauma, changing the type of suture materials has unmasked the effectiveness of a procedure which was previously unrecognized. Absorbable synthetic suture material for perineal repair following childbirth appears to decrease women’s experience of short-term pain when compared with catgut suture material [8]. Several suture materials have been used to perform the cervical cerclage including Mersilene 5 mm tape [9–11], Mersilene silk [12], metal wire, human fascia lata [13], Prolene [14] and Nylon [7,15–18]. The most commonly used suture material is the Mersilene tape because of its perceived strength and ease of removal. However, some clinicians
Cervical cerclage, survey of practice
DOI: 10.3109/14767058.2013.870551
1585
respondents (88.7%; n ¼ 180/203) reported performing the procedures between 12 and 16 weeks’ gestation. Of 200 respondents, 50 reported that they have a cerclage guideline in their unit. Most of the practitioners follow criteria suggested for cerclage insertion by the RCOG [1]. There were 202 respondents to the question relating to indications for performing cerclage. Consultants were given the option to choose more than one indication. The commonest indications chosen were history of two or more previous mid-trimester losses or preterm births, previous cerclage and cervical length of 525 mm by 152, 147 and 110 consultants, respectively. Of 202 respondents, 156 Consultants do 20 cerclage procedures annually, 39 between 20 and 40, four between 40 and 60 and only three perform more than 60 cerclages per annum, respectively. The majority of respondents (83.4%; n ¼ 166/199) reported using the McDonald procedure when performing a cerclage while the rest (16.6%; n ¼ 33/199) use the procedure described by Shirodkar. With regards to type of suture used, the majority routinely use multifilament sutures (86.6%; n ¼ 175/202) and only (16.6%; n ¼ 33/202) monofilament. There were several comments accompanying responses on those questions:
are concerned that braided non-absorbable material can increase the risk of infection. This issue is, potentially, of particular relevance to cerclage where infection is sometimes associated with miscarriage and preterm birth [19]. Currently there is no guidance with regards to type of suture material to be used for cervical cerclage and hence, depends on the surgeonsns are concThe main aim of this survey was to review current practice amongst UK based consultants with regards to planned cervical cerclage with particular emphasis on the type of suture material used for the procedure.
Methods A questionnaire was designed in conjunction with the Birmingham Clinical Trials Unit (BCTU) and piloted amongst an independent group of Consultants. The list of names of UK-based practicing consultants, who are either the members or fellows registered with the Royal College of Obstetricians and Gynaecologists (RCOG) and who have agreed to be contacted for any survey purposes, was obtained following review of the survey questions by the RCOG. Consultants identified as pure gynecological oncologists were excluded at the outset. We intended to exclude consultants who did not have an obstetrics workload as part of their job plan; however, this was not feasible because such information was not readily available in the RCOG register. An electronic survey was sent using the Survey MonkeyÕ platform (Table 1). The survey was accessible between February and April 2012. A reminder was sent by email six weeks after initial launch. We did not collect any identifiable data on respondents.
The type of cerclage I put in depends on the length of the cervix at the time of insertion – if cervix is a good length then McDonald, if not then I dissect the bladder off like the beginning of a vaginal hysterectomy and go as high as I can. We insert very few elective sutures, most on women who have been referred to a specialist Pre-term labour clinic due to identification of risk factors and are identified with signs of cervical shortening between 16–20 weeks. Truly elective cerclage tends to be performed on women who have had this in previous pregnancies and wish to have this repeated rather than monitor the cervix for signs of incompetence. Technique is important to get high with the posterior bites so that weight of the pregnancy is not transmitted to the suture. Performing a Shirodkar needs a wider tape or heavier duty Nylon, but how many people can perform a true Shirodkar any more, will this be a biased trial anyway . . . . I see no place for a Shirodkar style suture. If there is not enough infra-vaginal cervix to insert a high cervical suture, then an abdominal is required, hence the bladder is not touched Choose my method of suture according to history and clinical findings
Results A total of 1334 members and fellows were sent an internet link to the survey via the email addresses listed in the RCOG database. Of these, 261 (19.5%) Consultants completed the survey on-line. The denominator for each question varied depending on the number of people responding to that particular question (Table 1). Current practice with elective cervical cerclage Practitioners were asked whether they ever perform planned cervical cerclage to prevent mid-trimester loss or preterm labour. The majority of the respondents (88%; n ¼ 227/258) inserted cervical suture electively as a part of their routine obstetrical practice. Reasons given for not performing cerclage procedures included not being involved in providing care for women at risk of mid-trimester loss or preterm labour 7% (n ¼ 18/258) or would not offer cerclage as a treatment option in 5% (n ¼ 13/258). Most of the Table 1. Number of responses for each proposed primary outcome by rank. Answer options
1
2
3
4
5
6
7
8
Total response count
Pregnancy loss 524 weeks Gestation at delivery Live birthrate Preterm birth rate 534 weeks Take home baby rate
66 54 21 27 66
29 42 43 36 31
15 41 27 45 24
18 15 35 30 18
29 14 19 21 9
6 6 13 7 9
1 6 9 3 7
11 1 7 3 8
175 179 174 172 172
1586
F. Israfil-Bayli et al.
It is a traditional practice to use Mersilene in our unit. PDS is used in our unit by some Obstetricians for rescue cerclage.
Multifilament versus monofilament is an important research question Of 201 Consultants, 94 considered question of type of suture material used in cerclage comparing multifilament versus monofilament suture an important research question, further (27.9%; n ¼ 56/201) was not sure and wanted to receive more information. Comments added by Consultants to this section of the questionnaire: I was not aware that McDonald can be done using monofilament sutures. If McDonald is done using monofilament sutures, it would be interesting to share information with Obstetricians who have the widest experience I have seen quite a number of the Nylon sutures cut through the tissues. Success is all to do with identifying the correct patients, placement of the sutures appropriately and timing of insertion. Mersilene seems to work fine and we don’t have urogynae type complications due to short duration of use. Infection may be a factor and would make us change practice. SROM? I have come across several women with embedded monofilament material from previous cervical suture? PDS inserted abroad – I have never seen anyone use other than Mersilene in UK. I think there may be a concern that finer suture may cut through more easily. I chose my method of suture according to history and clinical findings. I think choice of suture is an interesting area of research rather than important. Much more important is the mechanism by which sutures work or not. Another important question is whether a purse string is appropriate or performing a Shirodkar needs a wider tape or heavier duty Nylon, but how many people can perform a true Shirodkar any more.
Primary outcome that can change practice To identify the most important outcome to be considered for future cerclage-related studies, we asked consultants to grade a list of possible outcomes on an 8-point Likert scale where 1 (most important) and 8 (least important). The most highly rated outcome was gestation at delivery, followed by ‘‘take home baby’’ rate followed by pregnancy loss before 24 weeks and preterm birth before 34 weeks of gestation and live birth rate (Table 2). Views expressed by some responders with regards to relevance of outcomes included: To me, the woman’s main desire is to take a baby home. I feel that should govern our practice. Would be interested in your multi versus mono filament question! Take home baby rate has been considered in some metaanalysis and has to be the most important factor – but also consider take well home baby rate. We sometimes manage
J Matern Fetal Neonatal Med, 2014; 27(15): 1584–1588
Table 2. Questions and possible answer options included in the electronic survey. Q1. Do you ever perform elective cerclage to prevent midterm pregnancy loss and preterm birth? 1. No I never perform elective cerclage as I do not see women at risk 2. No, I never perform elective cerclage even though I see woman at risk 3. Yes, I perform elective cerclage Q2. I perform cerclage on the basis of 1. History of 2 or more midtrimester losses or preterm deliveries 528 weeks 2. Cervical sutures in previous pregnancies 3. History of cervical surgery (e.g. large cone excision) 4. Risk of shortened cervix (525 mm) 5. Other (please specify) Q3. Which approach do you predominantly use? 1. Transvaginal cerclage (McDonald) 2. High transvaginal cerclage (Shirodkar) Q4. Do you use Multifilament (e.g. Mersilene) or Monofilament (e.g. Nylon) sutures for elective cervical cerclage? 1. Multifilament 2. Monofilament Q5. At what gestation do you usually/prefer to insert your elective cervical sutures? 1. Pre-pregnancy 2. 511 weeks 3. 12–16 weeks 4. 416 weeks 5. Other (please specify) Q6. Do you have a guideline for insertion of cerclage in your 1. Yes 2. No Q7. How many elective cerclages do you estimate are done annually in your Unit? 1. 0–20 2. 20–40 3. 40–60 4. 460 Q8. Do you consider multifilament vs. monofilament an important research question? 1. Yes 2. No 3. Not sure. Please send me more information Q9. In your opinion, what is the outcome that will change your practice (rank the importance from 1 (most) - 8 (least)? 1. Pregnancy loss before 24 weeks 2. Gestation at birth 3. Live birth rate 4. Preterm birth before 34 weeks 5. Take home baby rate Comments Q10. Do you have any more comments?
to get a woman to 24 weeks but the baby has severe problems. You MUST measure the cost of transferring a 20 week loss to a 25 week premature birth (to the child, woman, family and economic). What’s the point of pregnancy but to produce healthy children? Other measures hide the cost of taking home a very damaged baby.
Discussion In this study we reviewed current practice with regards to planned cervical cerclage amongst a cohort of UK Consultant Obstetricians. The information gathered from this survey demonstrated a major variation in practice with regards to
Cervical cerclage, survey of practice
DOI: 10.3109/14767058.2013.870551
different aspects of the procedure, in particular, to the type of suture material used, the degree of equipoise amongst senior obstetricians in the UK with regards to the best suture material for cervical cerclage and the keenness of a significant number of clinicians to participate in a study designed to answer this question. The main objective of any survey is to obtain information to investigate whether existing facts, hypothesis, opinion or attitude should be challenged. There are different types of surveys (postal, on-line, street, in-home personal, telephone) [20]. We opted to send the survey electronically because it is cost effective, faster to conduct and reassures the responders about the anonymity of their responses compared to postal or phone surveys [21]. Our response rate of 19.5% is comparable with the average response rate of 20% for RCOG facilitated surveys. There were a few obstacles which possibly prevented from obtaining higher response rate. First of all some clinicians did not perceive themselves as experts in the subject matter, the email address was not regularly accessed by the user or clinicians opting not to participate because of a lack of time, although, all consultants approached have previously indicated to the RCOG their approval to be included in surveys. Nevertheless, there is no reason to believe the sample of consultants who responded is not representative of the views of consultant obstetricians in the UK. The main aim of our survey was to review practice amongst Consultant obstetricians in the UK with regards to cerclage procedures, particularly the issue of suture material used. It is suggested that the preference of some surgeons for braided sutures stems from the perceived strength of the suture material and the ease of its removal. In contrast, advocates of non-braided sutures base their preference on the reduced likelihood of infection with monofilament sutures and the ease of their insertion. None of these claims is substantiated by evidence in the context of cerclage; however, this degree of variability in practice was demonstrated in our survey. Although the majority of respondents reported performing elective cerclage using Mersilene tape, 75% of them indicated they were not sure about the best suture material to use. Significantly, braided non-absorbable, multifilament tape has been abandoned in urogynecology and ophthalmology because of high risk of complications such as erosions and infections [22,23]. It is interesting to note that most clinicians perform fewer than 20 cerclage operations per year. As cerclage is a relatively infrequently performed operation it is informative to consider this technique in the context of other operative procedures. The NICE recommends that primary urinary stress incontinence operations should only be undertaken by surgeons who have an annual workload of at least 20 cases [24] and the RCOG recommends maintaining competence in amniocentesis by carrying out at least 30 invasive procedures per annum [25]. Surgical familiarity with the technique is likely to be related to outcome and if set against the benchmark for urogynecological and fetal medicine procedures, most practitioners are performing fewer cerclages than one might consider to be appropriate for a procedure of intermediate technical complexity.
1587
The other important outcome of our survey is an issue of patient selection for planned cerclage procedures. A lack of consistency in the indication for cerclage has been attributed previously to the variation in reported success rates of cervical cerclage. According to our survey, the majority of practitioners would select women at risk who had a cervical cerclage in the past or had a history of two or more mid-trimester losses or preterm deliveries, and offer them elective cerclage. Our data also suggests that nowadays more practitioners would offer cerclage on the basis of previous cervical surgery/treatment, most likely in a view of emerging evidence showing that women who had large or repeated cervical loop biopsies are at an increased risk of preterm labor [26]. For them cerclage could be one of the important possible treatment options. Usually history-indicated cervical cerclage is inserted in first trimester, at around 12–14 weeks, and removed at 37th week of gestation [4]. Ultrasound-indicated cerclages tend to be performed later in pregnancy, according to the RCOG before 24 weeks of gestation. In our survey, the majority (88.7%) would consider inserting planned cerclage between 12 and 16 weeks of gestation following the RCOG guideline or personal preference, as only quarter had a hospital guideline to be followed. An important outcome of the survey was to identify that the research question is of significant interest to the current obstetric professional community. Three quarters of respondents consider the important question and chose ‘‘gestation at delivery’’ as the best primary outcome for a future RCT on the question of multifilament versus monofilament suture material in planned cervical cerclage.
Conclusion This survey demonstrated the degree of variability in current practice with regards to indications, technique and suture materials used for cerclage. The majority of respondents were in equipoise with regards to the best suture material to be used and a significant number considered that an RCT addressing this issue is needed.
Declaration of interest The authors report no declarations of interest. C. C. Lees is supported by the National Institute Research (NIHR) Biomedical Research Centre based at Imperial College Healthcare NHS Trust and Imperial College London. The views expressed are those of the author(s) and not necessarily those of the NHS, the NIHR or the Department of Health.
References 1. Shennan AH, To MS. Green-top guideline No 60: cervical cerclage. London: RCOG; 2011. 2. Secher NJ, McCormack CD, Weber T, et al. Cervical occlusion in women with cervical insufficiency: protocol for a randomised, controlled trial with cerclage, with and without cervical occlusion. BJOG 2007;114:649–e6. doi: 10.1111/j.1471-0528.2007.01250.x. 3. McDonald IA. Cervical cerclage. Clin Obstetr Gynaecol 1980;7: 461–79. 4. Alfirevic Z, Stampalija T, Roberts D, Jorgensen AL. Cervical stitch (cerclage) for preventing preterm birth in singleton pregnancy. Cochrane Database Syst Rev 2012;4:CD008991.
1588
F. Israfil-Bayli et al.
5. Hume H, Rebarber A, Saltzman DH, et al. Ultrasound-indicated cerclage: Shirodkar vs. McDonald. J Matern Fetal Neonatal Med 2012;25:2690–2. 6. Woensdregt K, Norwitz ER, Cackovic M, et al. Effect of 2 stitches versus 1 stitch on the prevention of preterm birth in women with singleton pregnancies undergoing cervical cerclage. Am J Obstet Gynecol 2008;198:396.e1–e7. 7. Althuisius SM, Dekker GA, Hummel P, et al. Final results of the Cervical Incompetence Prevention Randomized Cerclage Trial (CIPRACT): therapeutic cerclage with bed rest versus bed rest alone. Am J Obstet Gynecol 2001;185:1106–12. 8. Kettle C, Dowswell T, Ismail KM. Absorbable suture materials for primary repair of episiotomy and second degree tears. Cochrane Database Syst Rev 2010;6:CD000006. 9. Owen J, Hankins G, Iams JD, et al. Multicenter randomized trial of cerclage for preterm birth prevention in high-risk women with shortened midtrimester cervical length. Am J Obstet Gynecol 2009; 201:375.el–e8. 10. MRC/RCOG Working Party on Cervical Cerclage. Final report of the Medical Research Council/Royal College of Obstetricians and Gynaecologists multicentre randomised trial of cervical cerclage. BJOG 1993;100:516–23. 11. Ezechi OC, Kalu BK, Nwokoro CA. Prophylactic cerclage for the prevention of preterm birth. Int J Gynaecol Obstet 2004;85: 283–4. 12. McDonald IA. Suture of the cervix for inevitable miscarriage. J Obstet Gynaecol Br Emp 1957;64:346–50. 13. Shirodkar VN. A new method of operative treatment for habitual abortions in the second trimester of pregnancy. Antiseptic 1955;52: 299. 14. Rust OA, Atlas RO, Reed J, et al. Revisiting the short cervix detected by transvaginal ultrasound in the second trimester: why cerclage therapy may not help. Am J Obstet Gynecol 2001;185: 1098–105.
J Matern Fetal Neonatal Med, 2014; 27(15): 1584–1588
15. Pereira L, Levy C, Lewis D, et al. Effect of suture material on the outcome of emergent cerclage. Obstet Gynecol 2011;103:35S. 16. Bernard L, Pereira L, Berghella V, et al. Effect of suture material on outcome of cerclage in women with dilated cervix in the 2nd trimester: results from the expectant management compared to physical exam-indicated cerclage (EM-PEC) international cohort study. Am J Obstet Gynecol 2006;195:103S. 17. Abdelhak YE, Sheen JJ, Kuczynski E, Bianco A. Comparison of delayed absorbable suture v nonabsorbable suture for treatment of incompetent cervix. J Perinat Med 1999;27:250–2. 18. Berghella V, Szychowski JM, Owen J, et al. Suture type and ultrasound-indicated cerclage efficacy. Vaginal Ultrasound Trial Consortium. J Matern Fetal Neonatal Med 2012;25:2287–90. 19. Israfil-Bayli F, Toozs-Hobson P, Lees C, et al. Pregnancy outcome after elective cervical cerclage in relation to type of suture material used. Medical Hypotheses 2013;81:119–21. 20. Sheehan KB. E-mail survey response rates: a review. J ComputerMed Commun 2001;6. doi: 10.1111/j.1083-6101.2001.tb00117.x. 21. Bachmann D, Elfrink J, Vazzana G. E-mail and snail mail face off in rematch. Market Res 1999;11:11–15. 22. Slack M, Sandhu JS, Staskin DR, Grant RC. In vivo comparison of suburethral sling materials. International Urogynecol J 2006;17: 106–10. 23. Mehta P, Patel P, Olver JM. Functional results and complications of mersilene mesh for use for frontalis suspension in ptosis surgery. Br J Opthalmol 2004;88:361–4. 24. NICE guideline: Urinary Incontinence CG171. Available from: http://guidance.nice.org.uk/CG171 [last accessed Oct 2013]. 25. Alfirevic Z, Walkinshaw SA, Kilby MD. Green-top guideline No 8: amniocentesis and chorionic villus sampling. London: RCOG; 2010. 26. Poon L, Savvas M, Zamblera D, et al. Large loop excision of transformation zone and cervical length in the prediction of spontaneous preterm delivery. BJOG 2012;119:692–8.
Copyright of Journal of Maternal-Fetal & Neonatal Medicine is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use.
ORIGINAL ARTICLE
Cervical cerclage and type of suture material: a survey of UK consultants’ practice F. Israfil-Bayli1, P. Toozs-Hobson1, C. Lees2, M. Slack3, J. Daniels4, A. Vince4, and K. M. K. Ismail5 1
Birmingham Women’s Hospital NHS Foundation Trust, Edgbaston, Birmingham, UK, 2Department of Fetal Medicine, Imperial College Healthcare NHS Trust, London, UK, 3Department of Urogynaecology, Addenbrooke’s Hospital, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK, 4Birmingham Clinical Trials Unit, Robert Aitken Institute, University of Birmingham, Edgbaston, Birmingham, UK, and 5 Department of Obstetrics and Gynaecology, School of Clinical & Experimental Medicine, College of Medical & Dental Sciences, University of Birmingham, Edgbaston, Birmingham, UK Abstract
Keywords
Objective: The main aim of the survey was to explore current practices with regards to cervical cerclage procedures amongst UK consultants with particular emphasis on the type of suture material used. Methods: An electronic survey of UK consultant members and fellows of the Royal College of Obstetricians and Gynaecologists and who previously agreed to be contacted for survey purposes. Results: There were 261 respondents to the survey and 88% routinely performed cerclage. The majority performed the procedure between 12 and 16 weeks’ gestation (88.7%; n ¼ 180/203), following the McDonald technique (83.4%; n ¼ 166/199) and using a braided suture material (86.6%; n ¼ 175/202). Although only 27 of the 202 responders (13.4%) used a monofilament suture for cerclage (75%; n ¼ 149/201) of clinicians stated that they were not sure what is the best suture material to be used. Conclusion: There is considerable variation in practice amongst Consultant obstetricians with regards to cervical cerclage. Although most respondents use the traditional braided suture material, a significant proportion of them were not sure what is the best suture material to use. The ‘‘gestation at delivery’’ rate was judged to be the most important outcome for a future study.
Cervical incompetence, monofilament/non-braided sutures, multifilament/braided sutures, preterm birth
Introduction Cervical incompetence (CI) is one of the causes of prematurity and mid-trimester pregnancy loss, and cervical cerclage is the traditional method of management [1]. The mechanism of action of cerclage is not fully understood; however, it is suggested that the cervical suture provides mechanical support to the cervix, which helps to retain the cervical mucus plug and hence reduce the risk of ascending infection, pregnancy loss and early birth [2]. It is estimated that CI affects 1% of pregnancies [3], with half of these women requiring a planned cerclage procedure based on history or clinical indicators. Therefore it is estimated that approximately 3750 women have this procedure in the UK per annum. The effectiveness of cervical cerclage, compared to no intervention, has been assessed in several randomized Address for correspondence: Dr F. Israfil-Bayli, Research Fellow, Birmingham Women’s Hospital NHS Foundation Trust, Mindelsohn Way, Edgbaston, Birmingham, B15 2T, UK. Tel: +44(0)121 6274707. Fax: +44(0)121 6272667. E-mail: [email protected]; drbayli@ yahoo.co.uk
History Received 25 August 2013 Accepted 26 November 2013 Published online 23 December 2013
controlled trials (RCTs). Pooled data from these studies failed to demonstrate a significant impact of this procedure on improving neonatal outcomes [4]. Other RCTs have addressed the issue of timing of cerclage, the indication for the procedure, the surgical technique used and the number of sutures placed [5–7]. However, none of these studies controlled for the material of the suture used with regards to whether it is monofilament or braided. The impact of the type of suture material on the outcome of a surgical intervention should not be underestimated. Indeed, for perineal trauma, changing the type of suture materials has unmasked the effectiveness of a procedure which was previously unrecognized. Absorbable synthetic suture material for perineal repair following childbirth appears to decrease women’s experience of short-term pain when compared with catgut suture material [8]. Several suture materials have been used to perform the cervical cerclage including Mersilene 5 mm tape [9–11], Mersilene silk [12], metal wire, human fascia lata [13], Prolene [14] and Nylon [7,15–18]. The most commonly used suture material is the Mersilene tape because of its perceived strength and ease of removal. However, some clinicians
Cervical cerclage, survey of practice
DOI: 10.3109/14767058.2013.870551
1585
respondents (88.7%; n ¼ 180/203) reported performing the procedures between 12 and 16 weeks’ gestation. Of 200 respondents, 50 reported that they have a cerclage guideline in their unit. Most of the practitioners follow criteria suggested for cerclage insertion by the RCOG [1]. There were 202 respondents to the question relating to indications for performing cerclage. Consultants were given the option to choose more than one indication. The commonest indications chosen were history of two or more previous mid-trimester losses or preterm births, previous cerclage and cervical length of 525 mm by 152, 147 and 110 consultants, respectively. Of 202 respondents, 156 Consultants do 20 cerclage procedures annually, 39 between 20 and 40, four between 40 and 60 and only three perform more than 60 cerclages per annum, respectively. The majority of respondents (83.4%; n ¼ 166/199) reported using the McDonald procedure when performing a cerclage while the rest (16.6%; n ¼ 33/199) use the procedure described by Shirodkar. With regards to type of suture used, the majority routinely use multifilament sutures (86.6%; n ¼ 175/202) and only (16.6%; n ¼ 33/202) monofilament. There were several comments accompanying responses on those questions:
are concerned that braided non-absorbable material can increase the risk of infection. This issue is, potentially, of particular relevance to cerclage where infection is sometimes associated with miscarriage and preterm birth [19]. Currently there is no guidance with regards to type of suture material to be used for cervical cerclage and hence, depends on the surgeonsns are concThe main aim of this survey was to review current practice amongst UK based consultants with regards to planned cervical cerclage with particular emphasis on the type of suture material used for the procedure.
Methods A questionnaire was designed in conjunction with the Birmingham Clinical Trials Unit (BCTU) and piloted amongst an independent group of Consultants. The list of names of UK-based practicing consultants, who are either the members or fellows registered with the Royal College of Obstetricians and Gynaecologists (RCOG) and who have agreed to be contacted for any survey purposes, was obtained following review of the survey questions by the RCOG. Consultants identified as pure gynecological oncologists were excluded at the outset. We intended to exclude consultants who did not have an obstetrics workload as part of their job plan; however, this was not feasible because such information was not readily available in the RCOG register. An electronic survey was sent using the Survey MonkeyÕ platform (Table 1). The survey was accessible between February and April 2012. A reminder was sent by email six weeks after initial launch. We did not collect any identifiable data on respondents.
The type of cerclage I put in depends on the length of the cervix at the time of insertion – if cervix is a good length then McDonald, if not then I dissect the bladder off like the beginning of a vaginal hysterectomy and go as high as I can. We insert very few elective sutures, most on women who have been referred to a specialist Pre-term labour clinic due to identification of risk factors and are identified with signs of cervical shortening between 16–20 weeks. Truly elective cerclage tends to be performed on women who have had this in previous pregnancies and wish to have this repeated rather than monitor the cervix for signs of incompetence. Technique is important to get high with the posterior bites so that weight of the pregnancy is not transmitted to the suture. Performing a Shirodkar needs a wider tape or heavier duty Nylon, but how many people can perform a true Shirodkar any more, will this be a biased trial anyway . . . . I see no place for a Shirodkar style suture. If there is not enough infra-vaginal cervix to insert a high cervical suture, then an abdominal is required, hence the bladder is not touched Choose my method of suture according to history and clinical findings
Results A total of 1334 members and fellows were sent an internet link to the survey via the email addresses listed in the RCOG database. Of these, 261 (19.5%) Consultants completed the survey on-line. The denominator for each question varied depending on the number of people responding to that particular question (Table 1). Current practice with elective cervical cerclage Practitioners were asked whether they ever perform planned cervical cerclage to prevent mid-trimester loss or preterm labour. The majority of the respondents (88%; n ¼ 227/258) inserted cervical suture electively as a part of their routine obstetrical practice. Reasons given for not performing cerclage procedures included not being involved in providing care for women at risk of mid-trimester loss or preterm labour 7% (n ¼ 18/258) or would not offer cerclage as a treatment option in 5% (n ¼ 13/258). Most of the Table 1. Number of responses for each proposed primary outcome by rank. Answer options
1
2
3
4
5
6
7
8
Total response count
Pregnancy loss 524 weeks Gestation at delivery Live birthrate Preterm birth rate 534 weeks Take home baby rate
66 54 21 27 66
29 42 43 36 31
15 41 27 45 24
18 15 35 30 18
29 14 19 21 9
6 6 13 7 9
1 6 9 3 7
11 1 7 3 8
175 179 174 172 172
1586
F. Israfil-Bayli et al.
It is a traditional practice to use Mersilene in our unit. PDS is used in our unit by some Obstetricians for rescue cerclage.
Multifilament versus monofilament is an important research question Of 201 Consultants, 94 considered question of type of suture material used in cerclage comparing multifilament versus monofilament suture an important research question, further (27.9%; n ¼ 56/201) was not sure and wanted to receive more information. Comments added by Consultants to this section of the questionnaire: I was not aware that McDonald can be done using monofilament sutures. If McDonald is done using monofilament sutures, it would be interesting to share information with Obstetricians who have the widest experience I have seen quite a number of the Nylon sutures cut through the tissues. Success is all to do with identifying the correct patients, placement of the sutures appropriately and timing of insertion. Mersilene seems to work fine and we don’t have urogynae type complications due to short duration of use. Infection may be a factor and would make us change practice. SROM? I have come across several women with embedded monofilament material from previous cervical suture? PDS inserted abroad – I have never seen anyone use other than Mersilene in UK. I think there may be a concern that finer suture may cut through more easily. I chose my method of suture according to history and clinical findings. I think choice of suture is an interesting area of research rather than important. Much more important is the mechanism by which sutures work or not. Another important question is whether a purse string is appropriate or performing a Shirodkar needs a wider tape or heavier duty Nylon, but how many people can perform a true Shirodkar any more.
Primary outcome that can change practice To identify the most important outcome to be considered for future cerclage-related studies, we asked consultants to grade a list of possible outcomes on an 8-point Likert scale where 1 (most important) and 8 (least important). The most highly rated outcome was gestation at delivery, followed by ‘‘take home baby’’ rate followed by pregnancy loss before 24 weeks and preterm birth before 34 weeks of gestation and live birth rate (Table 2). Views expressed by some responders with regards to relevance of outcomes included: To me, the woman’s main desire is to take a baby home. I feel that should govern our practice. Would be interested in your multi versus mono filament question! Take home baby rate has been considered in some metaanalysis and has to be the most important factor – but also consider take well home baby rate. We sometimes manage
J Matern Fetal Neonatal Med, 2014; 27(15): 1584–1588
Table 2. Questions and possible answer options included in the electronic survey. Q1. Do you ever perform elective cerclage to prevent midterm pregnancy loss and preterm birth? 1. No I never perform elective cerclage as I do not see women at risk 2. No, I never perform elective cerclage even though I see woman at risk 3. Yes, I perform elective cerclage Q2. I perform cerclage on the basis of 1. History of 2 or more midtrimester losses or preterm deliveries 528 weeks 2. Cervical sutures in previous pregnancies 3. History of cervical surgery (e.g. large cone excision) 4. Risk of shortened cervix (525 mm) 5. Other (please specify) Q3. Which approach do you predominantly use? 1. Transvaginal cerclage (McDonald) 2. High transvaginal cerclage (Shirodkar) Q4. Do you use Multifilament (e.g. Mersilene) or Monofilament (e.g. Nylon) sutures for elective cervical cerclage? 1. Multifilament 2. Monofilament Q5. At what gestation do you usually/prefer to insert your elective cervical sutures? 1. Pre-pregnancy 2. 511 weeks 3. 12–16 weeks 4. 416 weeks 5. Other (please specify) Q6. Do you have a guideline for insertion of cerclage in your 1. Yes 2. No Q7. How many elective cerclages do you estimate are done annually in your Unit? 1. 0–20 2. 20–40 3. 40–60 4. 460 Q8. Do you consider multifilament vs. monofilament an important research question? 1. Yes 2. No 3. Not sure. Please send me more information Q9. In your opinion, what is the outcome that will change your practice (rank the importance from 1 (most) - 8 (least)? 1. Pregnancy loss before 24 weeks 2. Gestation at birth 3. Live birth rate 4. Preterm birth before 34 weeks 5. Take home baby rate Comments Q10. Do you have any more comments?
to get a woman to 24 weeks but the baby has severe problems. You MUST measure the cost of transferring a 20 week loss to a 25 week premature birth (to the child, woman, family and economic). What’s the point of pregnancy but to produce healthy children? Other measures hide the cost of taking home a very damaged baby.
Discussion In this study we reviewed current practice with regards to planned cervical cerclage amongst a cohort of UK Consultant Obstetricians. The information gathered from this survey demonstrated a major variation in practice with regards to
Cervical cerclage, survey of practice
DOI: 10.3109/14767058.2013.870551
different aspects of the procedure, in particular, to the type of suture material used, the degree of equipoise amongst senior obstetricians in the UK with regards to the best suture material for cervical cerclage and the keenness of a significant number of clinicians to participate in a study designed to answer this question. The main objective of any survey is to obtain information to investigate whether existing facts, hypothesis, opinion or attitude should be challenged. There are different types of surveys (postal, on-line, street, in-home personal, telephone) [20]. We opted to send the survey electronically because it is cost effective, faster to conduct and reassures the responders about the anonymity of their responses compared to postal or phone surveys [21]. Our response rate of 19.5% is comparable with the average response rate of 20% for RCOG facilitated surveys. There were a few obstacles which possibly prevented from obtaining higher response rate. First of all some clinicians did not perceive themselves as experts in the subject matter, the email address was not regularly accessed by the user or clinicians opting not to participate because of a lack of time, although, all consultants approached have previously indicated to the RCOG their approval to be included in surveys. Nevertheless, there is no reason to believe the sample of consultants who responded is not representative of the views of consultant obstetricians in the UK. The main aim of our survey was to review practice amongst Consultant obstetricians in the UK with regards to cerclage procedures, particularly the issue of suture material used. It is suggested that the preference of some surgeons for braided sutures stems from the perceived strength of the suture material and the ease of its removal. In contrast, advocates of non-braided sutures base their preference on the reduced likelihood of infection with monofilament sutures and the ease of their insertion. None of these claims is substantiated by evidence in the context of cerclage; however, this degree of variability in practice was demonstrated in our survey. Although the majority of respondents reported performing elective cerclage using Mersilene tape, 75% of them indicated they were not sure about the best suture material to use. Significantly, braided non-absorbable, multifilament tape has been abandoned in urogynecology and ophthalmology because of high risk of complications such as erosions and infections [22,23]. It is interesting to note that most clinicians perform fewer than 20 cerclage operations per year. As cerclage is a relatively infrequently performed operation it is informative to consider this technique in the context of other operative procedures. The NICE recommends that primary urinary stress incontinence operations should only be undertaken by surgeons who have an annual workload of at least 20 cases [24] and the RCOG recommends maintaining competence in amniocentesis by carrying out at least 30 invasive procedures per annum [25]. Surgical familiarity with the technique is likely to be related to outcome and if set against the benchmark for urogynecological and fetal medicine procedures, most practitioners are performing fewer cerclages than one might consider to be appropriate for a procedure of intermediate technical complexity.
1587
The other important outcome of our survey is an issue of patient selection for planned cerclage procedures. A lack of consistency in the indication for cerclage has been attributed previously to the variation in reported success rates of cervical cerclage. According to our survey, the majority of practitioners would select women at risk who had a cervical cerclage in the past or had a history of two or more mid-trimester losses or preterm deliveries, and offer them elective cerclage. Our data also suggests that nowadays more practitioners would offer cerclage on the basis of previous cervical surgery/treatment, most likely in a view of emerging evidence showing that women who had large or repeated cervical loop biopsies are at an increased risk of preterm labor [26]. For them cerclage could be one of the important possible treatment options. Usually history-indicated cervical cerclage is inserted in first trimester, at around 12–14 weeks, and removed at 37th week of gestation [4]. Ultrasound-indicated cerclages tend to be performed later in pregnancy, according to the RCOG before 24 weeks of gestation. In our survey, the majority (88.7%) would consider inserting planned cerclage between 12 and 16 weeks of gestation following the RCOG guideline or personal preference, as only quarter had a hospital guideline to be followed. An important outcome of the survey was to identify that the research question is of significant interest to the current obstetric professional community. Three quarters of respondents consider the important question and chose ‘‘gestation at delivery’’ as the best primary outcome for a future RCT on the question of multifilament versus monofilament suture material in planned cervical cerclage.
Conclusion This survey demonstrated the degree of variability in current practice with regards to indications, technique and suture materials used for cerclage. The majority of respondents were in equipoise with regards to the best suture material to be used and a significant number considered that an RCT addressing this issue is needed.
Declaration of interest The authors report no declarations of interest. C. C. Lees is supported by the National Institute Research (NIHR) Biomedical Research Centre based at Imperial College Healthcare NHS Trust and Imperial College London. The views expressed are those of the author(s) and not necessarily those of the NHS, the NIHR or the Department of Health.
References 1. Shennan AH, To MS. Green-top guideline No 60: cervical cerclage. London: RCOG; 2011. 2. Secher NJ, McCormack CD, Weber T, et al. Cervical occlusion in women with cervical insufficiency: protocol for a randomised, controlled trial with cerclage, with and without cervical occlusion. BJOG 2007;114:649–e6. doi: 10.1111/j.1471-0528.2007.01250.x. 3. McDonald IA. Cervical cerclage. Clin Obstetr Gynaecol 1980;7: 461–79. 4. Alfirevic Z, Stampalija T, Roberts D, Jorgensen AL. Cervical stitch (cerclage) for preventing preterm birth in singleton pregnancy. Cochrane Database Syst Rev 2012;4:CD008991.
1588
F. Israfil-Bayli et al.
5. Hume H, Rebarber A, Saltzman DH, et al. Ultrasound-indicated cerclage: Shirodkar vs. McDonald. J Matern Fetal Neonatal Med 2012;25:2690–2. 6. Woensdregt K, Norwitz ER, Cackovic M, et al. Effect of 2 stitches versus 1 stitch on the prevention of preterm birth in women with singleton pregnancies undergoing cervical cerclage. Am J Obstet Gynecol 2008;198:396.e1–e7. 7. Althuisius SM, Dekker GA, Hummel P, et al. Final results of the Cervical Incompetence Prevention Randomized Cerclage Trial (CIPRACT): therapeutic cerclage with bed rest versus bed rest alone. Am J Obstet Gynecol 2001;185:1106–12. 8. Kettle C, Dowswell T, Ismail KM. Absorbable suture materials for primary repair of episiotomy and second degree tears. Cochrane Database Syst Rev 2010;6:CD000006. 9. Owen J, Hankins G, Iams JD, et al. Multicenter randomized trial of cerclage for preterm birth prevention in high-risk women with shortened midtrimester cervical length. Am J Obstet Gynecol 2009; 201:375.el–e8. 10. MRC/RCOG Working Party on Cervical Cerclage. Final report of the Medical Research Council/Royal College of Obstetricians and Gynaecologists multicentre randomised trial of cervical cerclage. BJOG 1993;100:516–23. 11. Ezechi OC, Kalu BK, Nwokoro CA. Prophylactic cerclage for the prevention of preterm birth. Int J Gynaecol Obstet 2004;85: 283–4. 12. McDonald IA. Suture of the cervix for inevitable miscarriage. J Obstet Gynaecol Br Emp 1957;64:346–50. 13. Shirodkar VN. A new method of operative treatment for habitual abortions in the second trimester of pregnancy. Antiseptic 1955;52: 299. 14. Rust OA, Atlas RO, Reed J, et al. Revisiting the short cervix detected by transvaginal ultrasound in the second trimester: why cerclage therapy may not help. Am J Obstet Gynecol 2001;185: 1098–105.
J Matern Fetal Neonatal Med, 2014; 27(15): 1584–1588
15. Pereira L, Levy C, Lewis D, et al. Effect of suture material on the outcome of emergent cerclage. Obstet Gynecol 2011;103:35S. 16. Bernard L, Pereira L, Berghella V, et al. Effect of suture material on outcome of cerclage in women with dilated cervix in the 2nd trimester: results from the expectant management compared to physical exam-indicated cerclage (EM-PEC) international cohort study. Am J Obstet Gynecol 2006;195:103S. 17. Abdelhak YE, Sheen JJ, Kuczynski E, Bianco A. Comparison of delayed absorbable suture v nonabsorbable suture for treatment of incompetent cervix. J Perinat Med 1999;27:250–2. 18. Berghella V, Szychowski JM, Owen J, et al. Suture type and ultrasound-indicated cerclage efficacy. Vaginal Ultrasound Trial Consortium. J Matern Fetal Neonatal Med 2012;25:2287–90. 19. Israfil-Bayli F, Toozs-Hobson P, Lees C, et al. Pregnancy outcome after elective cervical cerclage in relation to type of suture material used. Medical Hypotheses 2013;81:119–21. 20. Sheehan KB. E-mail survey response rates: a review. J ComputerMed Commun 2001;6. doi: 10.1111/j.1083-6101.2001.tb00117.x. 21. Bachmann D, Elfrink J, Vazzana G. E-mail and snail mail face off in rematch. Market Res 1999;11:11–15. 22. Slack M, Sandhu JS, Staskin DR, Grant RC. In vivo comparison of suburethral sling materials. International Urogynecol J 2006;17: 106–10. 23. Mehta P, Patel P, Olver JM. Functional results and complications of mersilene mesh for use for frontalis suspension in ptosis surgery. Br J Opthalmol 2004;88:361–4. 24. NICE guideline: Urinary Incontinence CG171. Available from: http://guidance.nice.org.uk/CG171 [last accessed Oct 2013]. 25. Alfirevic Z, Walkinshaw SA, Kilby MD. Green-top guideline No 8: amniocentesis and chorionic villus sampling. London: RCOG; 2010. 26. Poon L, Savvas M, Zamblera D, et al. Large loop excision of transformation zone and cervical length in the prediction of spontaneous preterm delivery. BJOG 2012;119:692–8.
Copyright of Journal of Maternal-Fetal & Neonatal Medicine is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use.
