How to repair an anal sphincter injury after vaginal delivery: results of a randomised controlled trial

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1 DOI: /j x Intrapartum care How to repair an anal sphincter injury after vaginal delivery: results of a randomised controlled trial Abimbola Williams, a Elisabeth J Adams, a Douglas G Tincello, b Zarko Alfirevic, c Stephen A Walkinshaw, a David H Richmond a a Departments of Urogynaecology and Fetal and Maternal Medicine, Liverpool Womens Hospital, UK b Reproductive Science Section, CSMM, University of Leicester, UK c University Department of Obstetrics and Gynaecology, Liverpool Womens Hospital, UK Correspondence: Dr A Williams, Departments of Urogynaecology and Fetal and Maternal Medicine, Liverpool Womens Hospital, UK. Accepted 5 October Objective To compare two surgical techniques and two types of suture material for anal sphincter repair after childbirth-related injury. Design Factorial randomised controlled trial. Setting Tertiary referral maternity unit. Population Women with an anal sphincter injury sustained during childbirth. Method Women were randomised into four groups: overlap repair with polyglactin (Vicryl); end-to-end repair with polyglactin (Vicryl); overlap repair with polydioxanone (PDS); and end-to-end repair with PDS. All repairs were completed as a primary procedure by staff trained in both methods. physiology at three months. Quality of life scores at 3 and 12 months. Results One hundred and fifty women (1.5% of deliveries) were eligible and 112 (75%) were randomised. One hundred and three (92%) attended follow up visit at 6 weeks, 89 (80%) at 3 months, 79 (71%) at 6 months and 60 (54%) at 12 months. At six weeks, there was no difference in suture-related morbidity between groups (P = 0.11) and 70% patients were completely asymptomatic. Incidence of bowel symptoms and quality of life disturbances were low, with no differences between the four groups. Conclusion Obstetric anal sphincter repair carried out by appropriately trained staff is associated with low morbidity, irrespective of the suture material and repair method used. Main outcome measures Suture-related morbidity at six weeks. Bowel symptoms at 3, 6 and 12 months. Anorectal Please cite this paper as: Williams A, Adams E, Tincello D, Alfirevic Z, Walkinshaw S, Richmond D. How to repair an anal sphincter injury after vaginal delivery: results of a randomised controlled trial. BJOG 2006; 113: Introduction Anal sphincter injuries complicate % of vaginal deliveries 1 4 and result in significant short and long term morbidity. Faecal incontinence, faecal urgency, dyspareunia and perineal pain have been reported in 30 50% of women 1,2,5 9 who sustain such tears and symptoms may persist for several years after primary repair. 2,3,10 Traditionally, anal sphincter tears have been repaired at the time of injury by trainee obstetricians using the technique of end to end approximation of the torn anal sphincter. Recently, a retrospective cohort study by Sultan et al. 11 suggested better outcomes using the overlap technique but the only published randomised controlled trial 12 comparing overlap with end to end approximation found no significant differences in outcome. The type of suture material used may also be important. Compared with braided sutures such as polyglactin (Vicryl), monofilament materials such as polydioxanone (PDS), polypropelene (Prolene) or nylon have a longer half-life and are less likely to harbour micro-organisms. 13 However, they may predispose to stitch abscess or cause discomfort when the ends of the suture impinge on the perineal skin (suture migration). There are no studies comparing different suture materials for repair of torn anal sphincter muscles in the obstetric setting. Adequate primary repair is thought to be central to the prevention of long term morbidity, 11 but recent Royal College of Obstetrician and Gynaecologist (RCOG) ª RCOG 2006 BJOG An International Journal of Obstetrics and Gynaecology 201

2 Williams et al. guidelines were unable to make clear recommendations. 14 The aim of this study was to compare two repair techniques and two suture materials for anal sphincter repair. Participants and methods All women who sustained a third- or fourth-degree perineal tear were eligible to participate. The study was conducted from October 2000 to December 2002 at a tertiary obstetric unit with around 6000 deliveries per annum. Ethical approval was granted by the local research ethics committee. All women booking for antenatal care were given information sheets so that they could consider the study in advance of labour and delivery. Women who subsequently sustained a third- or fourth-degree tear were identified by the supervising medical or midwifery staff at the time. The diagnosis was confirmed by the senior trainee obstetrician on duty for labour ward who obtained written consent. A partial or complete disruption of the external anal sphincter without involvement of the anal or rectal mucosa was classified as a third-degree perineal tear, while tears involving the anal or rectal mucosa were classified as fourth degree. Randomisation was determined using sequentially numbered sealed opaque envelopes that contained a description of the repairmethodandsuturematerialtobeused.therandomisation sequence was generated using a table of random numbers in varied blocks of four and eight. Participants were randomised into four groups: end end or overlap repair of the torn anal sphincter and use of either braided polyglactin (coated Vicryl 2/0, Ethicon, UK) or PDS (3/0 Ethicon, UK). Polyglactin retains 50% of its strengths at three weeks and causes a minimal tissue reaction. PDS is a monofilament suture, which is absorbed slowly with minimal absorption until about 90 days and is widely used instead of non-absorbable suture materials because it does not cause chronic suture sinuses. 15,16 All repairs were performed by trainees or consultants who had been trained in both repair methods using pig sphincters at regular workshops that were provided by a colorectal surgeon and senior urogynaecology trainee. The repair was performed under full aseptic conditions in an obstetric theatre under regional or general anaesthesia. The torn ends of the external sphincter were identified but no attempt was made to separately identify the internal anal sphincter. For the overlap repair, approximately 2 cm of one end of the sphincter was laid over the other end in a double breast fashion where the full thickness of the anal sphincter fibres was disrupted. 11,17 In cases with only partial disruption of anal sphincter fibres, the intact anal sphincter fibres were left undisturbed and an overlap of the disrupted fibres was performed. The vaginal mucosa and perineal muscles were repaired using 2/0 Vicryl in a continuous non-locking fashion according to standard practice. The perineal skin was closed with subcuticular Vicryl 2/0. For the end-to-end repair, the edges of the torn sphincter were identified and repaired in apposition with three or four interrupted mattress sutures. The vaginal mucosa and perineal muscle and skin were repaired as described above. Patients received one dose of intravenous cefuroxime 1.5 g and metronidazole 500 mg in theatre followed by a seven-day course of oral cephalexin 500 mg and metronidazole 500 mg three times daily. All patients received lactulose 10 ml three times daily and one sachet of ispaghula husk (Fybogel) twice daily for 10 days. Follow up Follow up visits were arranged at 6 weeks and 3, 6 and 12 months after delivery. At the first visit, the perineum was examined for evidence of suture migration and patients completed a questionnaire to assess problems of perineal pain, dyspareunia and loss of libido. At three months, patients were asked to complete the St Mark s bowel symptom questionnaire, the St Mark s continence scoring system 18 and a validated quality of life questionnaire (Manchester Health Questionnaire; MHQ). 19 Objective assessment of anorectal function using endoanal ultrasound, anal manometry and pudendal nerve terminal latency tests was performed at this visit using previously validated methods Both the women and the clinicians performing these investigations were blinded to the treatment allocation. At six months, patients were sent the St Mark s bowel questionnaire by post with a reply paid envelope. Patients who did not return these after four weeks were sent a second mailing followed by a telephone reminder if they did not respond. At 12 months, the St Mark s bowel questionnaire and the MHQ were sent by post, and reminders were sent as above. Statistics The study was design to test the following hypotheses: 1. That absorbable sutures would reduce suture-related morbidity (defined as need for suture removal due to pain, migration or dyspareunia) from 30% to <1% compared with non-absorbable sutures. 2. That the overlapping technique would reduce suturerelated morbidity (defined as above) from 30% to <1% compared with end to end anastomoses. This size of treatment effect was based on an audit where such complications were essentially abolished. 24 Twenty-eight women per group would have 80% power to demonstrate such an effect assuming alpha 0.5, and a two-sided test of significance. It was assumed at the design stage that there was interaction between the techniques such that the different suture groups and different repair technique groups would have to be analysed separately. All data were entered into password-protected computer databases by specialist nurses who were not involved in the 202 ª RCOG 2006 BJOG An International Journal of Obstetrics and Gynaecology

3 A randomised controlled trial of how to repair an anal sphincter injury trial and transferred to SPSS V10 (SPSS, Chicago, Illinois) for analysis. Continuous data were analysed with the t test or Kruskal Wallis test. Categorical data were analysed using x 2 or Fisher s exact test. Results Of 10,266 women who delivered vaginally in the study period, 150 (1.5%) sustained third- or fourth-degree tears. The randomisation schedule of these women is shown in the CONSORT diagram (Fig. 1). Of these, 112 (75%) agreed to participate and were randomised (Table 1) and 103 (92%) women attended for 6-week follow up, 89 (80%) for anorectal studies at 3 months, 79 returned completed symptom questionnaires at 6 months and 60 at 12 months. At six weeks, there were no significant differences in the primary outcome of suture-related morbidity in all the subgroups. There were no differences in any secondary clinical outcomes by type of suture material (Tables 2 and 3) nor when the four groups were analysed separately (Table 4), apart from an excess of internal sphincter defects identified by ultrasound in the Vicryl end-to-end group. Despite repeated reminders, only 71% women returned the questionnaire at 6 months and 54% at 12 months. Among responders, the proportion of women who remain completely asymptomatic was 62% and 68%, respectively, with no significant differences in complications between the groups. There was a gradual increase in the number of sexually active women from 54% at 6 weeks to 98% at 12 months. Among symptomatic women, vaginal dryness and loss of libido were the most common complaint, while most other reported symptoms comprised of faecal urgency and flatus incontinence occurring less frequently than once a week. The number of women complaining of faecal incontinence (solids and liquids) defined as incontinence to solid or liquid stools in the preceding four weeks was less than 10%. We also compared the subgroup of women who had complete third- or fourth-degree tear with those with a partial third-degree tear and found no difference (data not shown). Discussion This study is the first randomised controlled trial comparing suture materials and the second to compare repair methods for obstetric anal sphincter injury. Our results showed that overall morbidity is not influenced by the repair method or suture material used. Figure 1. Consort flow diagram. ª RCOG 2006 BJOG An International Journal of Obstetrics and Gynaecology 203

4 Williams et al. Table 1. Status at randomisation Vicryl/end end PDS/end end Vicryl/overlap PDS/overlap Women Age (years)* 29 (5.51) 28 (5.49) 28 (6.34) 27 (6.00) Ethnic origin Caucasian Other Primipara Multipara Delivery mode (episiotomy) # Normal 24 (3) 18 (1) 20 (2) 20 (3) Instrumental 4 (2) 10 (9) 8 (7) 8 (7) Length of second stage Birthweight (g)* 3663 (555.6) 3633 (480.6) 3701 (514.7) 3687 (333.8) Sphincter tears Partial third degree Complete third degree Fourth degree Analgesia for repair General Spinal Epidural *Mean (SD). # Number of deliveries with episiotomy in brackets. The incidence of suture migration and dyspareunia was much lower than found in a previous audit within the same hospital where we detected a 30% suture migration rate. 24 It is likely that this difference was due to the change of suture material from Prolene (a non-absorbable suture) in the first audit to PDS (which is a long acting absorbable suture, associated with less morbidity) 11 in the trial. The incidence of perineal pain and dyspareunia at three months was in broad agreement with other published studies. Sultan et al. 11 reported no perineal pain after overlap repair although 13% complained of dyspareunia, while Fitzpatrick 25 found that 40% of women had perineal pain in the three months following delivery. The mean continence scores at three-month follow up were low in all the subgroups and only two women had a continence score of more than 10. Between a fifth and a quarter of women complained of faecal urgency, data that are comparable to those of Fitzpatrick et al. 12 The number of symptomatic women at three-month follow up may be explained by the increase in the number of sexually active women, as the majority of symptoms were of vaginal dryness, loss of libido and perineal pain/dyspareunia. There were also reports of flatus incontinence at this visit, although most patients described this as an infrequent occurrence. Occasional flatus incontinence was the most common complaint overall, but not bothersome enough to have an impact on quality of life. Sultan et al. 11 described a higher cure rate than in our study, with only 8% incidence of flatus incontinence in the overlap repair group, but this was a case series compared with historical controls. Other nonrandomised reports of symptoms after repair of third-degree tears confirm the proportion of women with continuing symptoms to be between 19% and 58%. 10,26 28 We found only slight differences in manometry but none with pudendal nerve motor latency between the groups, and the figures were similar to results reported by others. 2,11,12,28 More importantly, we demonstrated fewer ultrasound sphincter defects compared with the other published RCT 12 where 62% of women in the overlap group and 70% in the end-end group had defects. Smaller number of persistent defects is likely to be an effect of training such that many cases of partial sphincter disruption were identified, which previously may have been wrongly classified. 29 Our finding of more internal sphincter defects on ultrasound during follow up is likely to 204 ª RCOG 2006 BJOG An International Journal of Obstetrics and Gynaecology

5 A randomised controlled trial of how to repair an anal sphincter injury Table 2. Outcome compared by suture material. Vicryl PDS RR (CI) P 6-week follow up (women) Suture-related morbidity at 6 weeks # ( ) month follow up (women) Continence score at 3 months 0 (0 14) 0 (0 10) Qol score at 3 months 25 (0 425) 7.5 (0 350) 0.19 Defects on anal endosonography Internal sphincter ( ) 0.01 External sphincter ( ) 0.09 Anal manometry Resting pressure 43 (10 84) 48 (18 91) 0.25 Increment squeeze pressure 23 (5 70) 30 (6 82) 0.02 Pudendal nerve motor latency Right 1.85 ( ) 1.91 ( ) 0.24 Left 1.92 ( ) 1.95 ( ) 0.57 Median (range). Fisher s exact test. Kruskal Wallis test. # Both suture migration and/or dyspareunia. Qol = Quality of life have occurred by chance, because no attempts were made to repair the internal sphincter separately during the study. The occurrence of fewer ultrasound defects in patients with similar functional outcomes to those reported in the other studies also suggests that functional assessment utilising questionnaires alone is the most important tool to be used in the follow up of women who have suffered anal sphincter injuries. Therefore, we would recommend functional assessments of continence, Table 3. Outcome compared by technique End end Overlap RR (CI) P Number at 6-week follow up Suture-related morbidity at 6 weeks # ( ) 0.19 Number at 3-month follow up Suture-related morbidity at 3 months # ( ) 0.06 Continence score at 3 months 0 (0 14) 0 (0 14) Qol score at 3 months 25 (0 425) 17.5 (0 198) 0.45 Defects on anal endosonography Internal sphincter (0.4 10) 0.24 External sphincter (0.6 3.) 0.15 Anal manometry Resting pressure 44 (10 91) 47 (17 90) 0.63 Increment squeeze pressure 30 (5 70) 29 (6 82) 0.62 Pudendal nerve motor latency Right 1.87 ( ) 1.90 ( ) 0.67 Left 1.95 ( ) 1.93 ( ) 0.93 Median (range). Fisher s exact test. Kruskal Wallis test. # Both suture migration and/or dyspareunia. Qol = Quality of life ª RCOG 2006 BJOG An International Journal of Obstetrics and Gynaecology 205

6 Williams et al. Table 4. Outcome data by randomisation group Follow up interval Vicryl end end PDS end end Vicryl overlap PDS overlap P 6 weeks Number Suture-related morbidity # months Number Suture-related morbidity # Continence score 1 (0 14) 0 (0 10) 0 (0 14) 0 (0 7) 0.81 Score MHQ Qol score 25 (0 425) 25 (0 350) 25 (0 198) 0 (0 95) 0.20 Defects on anal endosonography Internal sphincter External sphincter Anal manometry Resting pressure 43.5 (10 84) 45.0 (18 91) 41.5 (17 78) 51.5 (21 90) 0.89 Increment squeeze pressure 25.0 (5 70) 30.0 (10 45) 22.0 (10 50) 30.0 (6 62) 0.44 Pudendal nerve motor latency Right Left # Both suture migration and/or dyspareunia. Median (range). Fisher s exact test. Kruskal-Wallis test. Qol = Quality of life without the use of ultrasound or manometry. These tests should be reserved for the few women with significant symptoms where secondary repair may be considered. We accept that the main weakness of our study is relatively high loss to follow up, but other studies in this area have also had similar problems. 24,30 The reasons are likely to include reluctance to attend reviews in the absence of symptoms or difficulty attending due to the pressure of caring for a new baby. However, given the low complication rates at three months and referral pattern in our region, we are confident that women who failed to return questionnaires at 6 and 12 months did not have clinically important morbidity. The main strength of our trial was the detail of the repair procedure. All repairs were performed or directly supervised by senior trainee obstetricians or consultants, which was not usual practice in most obstetric units in the UK at the time the trial began. All staff had attended practical workshops involving the dissection and repair of animal anal sphincters. Notwithstanding the Hawthorne effect, 31 we believe that the improved clinical outcomes we have seen were a direct result of appropriate training of staff. This appears to be the major influence upon success rather than any differences in suture material or technique. In conclusion, anal sphincter repair performed by appropriately trained staff has low long term morbidity, which is not dependent on the method of sphincter repair or suture material used. We recommend formal training of all medical staff working on labour wards to ensure accurate diagnosis and proper identification of injury. j References 1 Walsh CJ, Mooney EF, Upton GJ, Motson RW. Incidence of third-degree perineal tears in labour and outcome after primary repair. Br J Surg 1996;83(2): Sultan AH, Kamm MA, Hudson CN, Bartram CI. Third degree obstetric anal sphincter tears: risk factors and outcome of primary repair. BMJ 1994;308: Zetterstrom J, Mellgren A, Jensen LL, et al. Effect of delivery on anal sphincter morphology and function. Dis Colon Rectum 1999;42(10): Fenner DE, Genberg B, Brahma P, Marek L, DeLancey JOL. Fecal and urinary incontinence after vaginal delivery with anal sphincter disruption in an obstetrics unit in the United States. Am J Obstet Gynecol 2003;189(6): Samuelsson E, Ladfors L, Wennerholm UB, Gareberg B, Nyberg K, Hagberg H. Anal sphincter tears: prospective study of obstetric risk factors. BJOG 2000;107(7): Fornell EK, Berg G, Hallbook O, Matthiesen LS, Sjodahl R. Clinical consequences of anal sphincter rupture during vaginal delivery. JAm Coll Surg 1996;183(6): Crawford LA, Quint EH, Pearl ML, Delancey JO. Incontinence following rupture of the anal sphincter during delivery. Obstet Gynecol 1993; 82(4 Pt 1): ª RCOG 2006 BJOG An International Journal of Obstetrics and Gynaecology

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