Obstetric anal sphincter injury: How to avoid, how to repair: A literature review

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Applied Evidence

Obstetric anal sphincter injury: How to avoid, how to repair: A literature review

J Fam Pract. 2006 March;55(3):193-200

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References

1. Mellgren A, Jensen LL, Zetterstrom JP, Wong WD, Hofmeister JH, Lowry AC. Long-term cost of fecal incontinence secondary to obstetric injuries. Dis Colon Rectum 1999;42:857-865.

2. Sultan AH, Kamm MA, Hudson CN, Thomas JM, Bartram CI. Anal-sphincter disruption during vaginal delivery. N Engl J Med 1993;329:1905-1911.

3. Royal College of Obstetricians and Gynaecologists. Methods and Materials used in Perineal Repair. Guideline No. 23. London: RCOG Press; 2004.

4. Fitzpatrick M, Behan M, O’Connell PR, O’Herlihy C. A randomized clinical trial comparing primary overlap with approximation repair of third-degree obstetric tears. Am J Obstet Gynecol 2000;183:1220-1224.

5. Simhan HN, Krohn MA, Heine RP. Obstetric rectal injury: risk factors and the role of physician experience. J Matern Fetal Neonatal Med 2004;16:271-274.

6. Handa VL, Danielsen BH, Gilbert WM. Obstetric anal sphincter lacerations. Obstet Gynecol 2001;98:225-230.

7. Oberwalder M, Connor J, Wexner SD. Meta-analysis to determine the incidence of obstetric anal sphincter damage. Br J Surg 2003;90:1333-1337.

8. Oberwalder M, Dinnewitzer A, Baig MK, et al. The association between late-onset fecal incontinence and obstetric anal sphincter defects. Arch Surg 2004;139:429-432.

9. Andrews V, Sultan AH, Thakar R, Jones PW. Occult anal sphincter injuries-myth or reality? BJOG 2006;113:195-200.

10. Sultan AH, Nugent K. Pathophysiology and nonsurgical treatment of anal incontinence. BJOG 2004;111 (Suppl 1):84-90.

11. Schafer A, Enck P, Furst G, et al. Anatomy of the anal sphincters. Dis Colon Rectum 1994;37:777-781.

12. Mahony R, Daly L, Behan M, Kirwan C, O’Herlihy C, O’Connell R. Internal Anal Sphincter injury predicts continence outcome following obstetric sphincter trauma. AJOG 2004;191:6s1-s89.

13. Bartram CL, Frudringer A. Handbook of Anal Endosonography. Petersfield, UK: Wrightson Biomedical Publishing; 1997.

14. Sultan AH, Kamm MA, Hudson CN. Pudendal nerve damage during labor: prospective study before and after childbirth. BJOG 1994;101:22-28.

15. Snooks SJ, Henry MM, Swash M. Fecal incontinence due to external anal sphincter division in childbirth is associated with damage to the innervation of the pelvic floor musculature: a double pathology. BJOG 1985;92:824-828.

16. Donnelly V, Fynes M, Campbell D, Johnson H, O’Connell PR, O’Herlihy C. Obstetric events leading to anal sphincter damage. Obstet Gynecol 1998;92:955-961.

17. Fitzpatrick M, Behan M, O’Connell PR, O’Herlihy C. Randomized clinical trial to assess anal sphincter function following forceps or vacuum assisted vaginal delivery. BJOG 2003;110:424-429.

18. Deering SH, Carlson N, Stitely M, Allaire AD, Satin AJ. Perineal body length and lacerations at delivery. J Reproductive Medicine 2004;49:306-310.

19. Goldberg J, Hyslop T, Tolosa JE, Sultana C. Racial Differences in severe Perineal lacerations after vaginal delivery. Am J Obstet Gynecol 2003;188:1063-1067.

20. Robinson JN, Norwitz ER, Cohen AP, McElrath TF, Lieberman ES. Epidural analgesia and third- or fourth-degree lacerations in nulliparas. Obstet Gynecol 1999;94:259-262.

21. Carroll TG, Engelken M, Mosier MC, Nazir N. Epidural analgesia and severe perineal laceration in a community-based obstetric practice. J Am Board Fam Prac 2003;16:1-6.

22. Riskin-Mashiah S, O’Brian Smith E, Wilkins IA. Risk factors for severe perineal tear: can we do better? Am J Perinatol 2002;19:225-234.

23. Bodner-Adler B, Bodner K, Kaider A, et al. Risk factors for third-degree perineal tears in vaginal deliveries with an analysis of episiotomy types. J Reprod Med 2001;46:752-756.

24. Eason E, Labrecque M, Marcoux S, Mondor M. Anal incontinence after childbirth. CMAJ 2002;166:326-330.

25. Eason E, Labrecque M, Wells G, Feldman P. Preventing perineal trauma during childbirth: a systematic review. Obstet Gynecol 2000;95:464-471.

26. Cargill YM, MacKinnon CJ, Arsensault MY, et al. Clinical Practice Obstetrics Committee. Guidelines for operative vaginal birth. J Obstet Gynaecol Can 2004;26:747-761.

27. Carroli G, Belizan J. Episiotomy for vaginal birth. Cochrane Database System Rev 1999;(3):CD000081.-

28. Schlomer G, Gross M, Meyer G. Effectiveness of liberal vs. conservative episiotomy in vaginal delivery with reference to preventing urinary and fecal incontinence: a systematic review [in German]. Wien Med Wochenschr 2003;153:269-275.

29. Klein MC, Gauthier RJ, Jorgensen SH, et al. Does episiotomy prevent perineal trauma and pelvic floor relaxation? Online J Curr Clin Trials 1992;Doc No 10.

30. Signorello LB, Harlow BL, Chekos AK, Repke JT. Midline episiotomy and anal incontinence: retrospective cohort study. BMJ 2000;320:86-90.

31. Shiono P, Klebanoff MA, Carey JC. Midline episiotomies: more harm than good? Obstet Gynecol 1990;75:765-770.

32. Coats PM, Chan KK, Wilkins M, Beard RJ. A comparison between midline and mediolateral episiotomies. BJOG 1980;87:408-412.

33. Poen AC, Felt-Bersma RJ, Dekker GA, Deville W, Cuesta MA, Meuwissen SG. Third degree obstetric perineal tears: risk factors and the preventive role of mediolateral episiotomy. Br J Obstet Gynaecol 1997;104:563-566.

34. Eogan M, O’Connell R, O’Herlihy C. Does the angle of episiotomy affect the incidence of anal sphincter injury? BJOG 2006;113:190-194.

35. Cook TA, Keane D, Mortensen NJ. Is there a role for the colorectal team in the management of acute severe third-degree vaginal tears? Colorectal Dis 1999;1:263-266.

36. Leeman L, Spearman M, Rogers R. Repair of obstetric perineal lacerations. Am Fam Physician 2003;68:1585-1590.

37. Fernando RJ, Sultan AH, Radley S, Jones PW, Johanson RB. Management of obstetric anal sphincter injury: a systematic review & national practice survey. BMC Health Serv Res 2002;2:9.-

38. Sultan AH, Kamm MA, Hudson CN. Obstetric perineal trauma: an audit of training. J Obstet Gynaecol 1995;15:19-23.

39. Sultan AH, Monga AK, Kumar D, Stanton SL. Primary repair of obstetric anal sphincter rupture using the overlap technique. BJOG 1999;106:318-23.

40. Royal College of Obstetricians and Gynaecologists. Management of third- and fourth-degree perineal tears following vaginal delivery. Guideline No. 29. London: RCOG Press; 2001.

41. Fitzpatrick M, Behan M, O’Connell PR, O’Herlihy C. A randomised clinical trial comparing primary overlap with approximation repair of third degree tears. Am J Obstet Gynecol 2000;183:1220-1224.

42. Kairaluoma MV, Raivio P, Aarnio MT, Kellokumpo IH. Immediate repair of obstetric anal sphincter rupture: medium-term outcome of the overlap technique. Dis Colon Rectum 2004;47:1358-1363.

43. Mahony R, Behan M, O’Herlihy C, O’Connell PR. Randomized, clinical trial of bowel confinement vs. laxative use after primary repair of a third-degree obstetric anal sphincter tear. Dis Colon Rectum 2004;47:12-17.

44. Liabsuetrakul T, Choobun T, Peeyananjarassri K, Islam M. Antibiotic prophylaxis for operative vaginal delivery (Cochrane review). In: The Cochrane Library, Issue 2, 2004.

45. Fitzpatrick M, O’Herlihy C. Postpartum anal sphincter dysfunction. Current Obstet Gynaecol 1999;9:210-215.

46. Mahony R, O’Brien C, O’Herlihy C. Evaluation of obstetric anal sphincter injury. Reviews in Gynaecological Practice 2001;1:114-121.

47. Jorge M, Wexner S. Etiology and management of fecal incontinence. Dis Colon Rectum 1993;36:77-97.

48. Fynes M, Donnelly V, Behan M, O’Connell PR, O’Herlihy C. Effect of second vaginal delivery on anorectal physiology and faecal continence: a prospective study. Lancet 1999;354:983-986.

49. Harkin R, Fitzpatrick M, O’Connell PR, O’Herlihy C. Anal sphincter disruption at vaginal deliver: is recurrence predictable? Eur J Obstet Gynaecol 2003;109:149-152.

50. Fitzpatrick M, O’Herlihy C. The effects of labour and delivery on the pelvic floor. Best Pract Res Clin Obstet Gynaecol 2001;15:63-79.

51. Wood J, Amos L, Rieger N. Third degree anal sphincter tears: risk factors and outcome. Aust N Z J Obstet Gynaecol 1998;38:414-417.

Observational data conflict as to whether mediolateral episiotomy contributes to, or protects against, obstetric anal sphincter injury—although the burden of evidence favors it as a risk factor that should be avoided when possible.^16,23,33 An angle of mediolateral incision cut closer to 45 degrees from the midline has been associated with less obstetric anal sphincter injury than incisions cut at closer angles to the midline.³⁴

Repairing sphincter injury

Detecting injury in labor

With any severe perineal laceration, closely inspect the external and, if exposed, internal anal sphincter and perform a rectal exam, particularly for women with numerous risk factors (although no good evidence supports the role of the rectal exam in diagnosing obstetric anal sphincter injury). Colorectal surgeons have advocated the use of a muscle stimulator to assist in identifying the ends of the external sphincter, but this has not become common practice.³⁵

Immediate vs delayed repair

It is standard practice to repair a damaged anal sphincter immediately or soon after delivery. However, given that a repair should be well done, and since a short delay does not appear to adversely affect healing, be prepared to wait for assistance for up to 24 hours rather than risk a suboptimal repair.³⁶

Better training is needed

Even among trained obstetricians and obgyn residents, 64% have reported no training or unsatisfactory training in management of obstetric anal sphincter injury; 94% of physicians felt inadequately prepared at the time of their first independent repair of the anal sphincter.^37,38 To improve your repair skills in a workshop setting, consult the following sources—www.aafp.org/also.xml in the US, or www.perineum.net in UK.

Analgesia and setting

Adequate analgesia is an essential element in a good repair. Complete relaxation of the anesthetized anal sphincter complex facilitates bringing torn ends of the sphincter together without tension.³⁹ Though theoretically this can be attained with local anesthetic infiltration, RCOG recommends that regional or general anesthesia be considered to provide complete analgesia.³⁷ It is further recommended that repair of the anal sphincter occur in an operating room, given the degree of contamination present in the labor room after delivery and the devastating effects of an infected repair (SOR: C).⁴⁰

FAST TRACK

Strong evidence shows that routine episiotomy should be abandoned; midline episiotomy is strongly linked with anal sphincter injury

Repair technique

There are 2 commonly used methods of external anal sphincter repair: one, the traditionally taught end-to-end approximation of the cut ends, and the other, overlapping the cut ends of the external sphincter and suturing through the overlapped portions (FIGURE 2).³⁶ Though an RCT from 2000 noted no significant difference in outcomes between these methods,⁴¹ other authors have suggested that an overlapping technique is preferred, and it remains the method most often used by colorectal surgeons in elective, secondary anal sphincter repairs.^36,39,42

A Cochrane review of which technique is better has been registered in the Clinical Trials Database. General agreement is that closure using interrupted sutures of a monofilament material, such as 2-0 polydioxanone sulfate (PDS), is the preferred closure method for the external sphincter (SOR: C).^36,40 It is recommended that a damaged internal sphincter be repaired with a running continuous suture of a material such as 2-0 polyglactin 910 (Vicryl) (SOR: C).³⁶

FIGURE 2
2 methods of anal sphincter repair

Two commonly used methods of external anal sphincter repair are end-to-end approximate of the cut ends (top), and overlapping the cut ends and suturing through the overlapped portions (bottom). (Adapted from Leeman et al, Am Fam Physician 2003.³³) ILLUSTRATION BY RICH LaROCCO

FAST TRACK

Immediately after repair, consider giving patients laxatives and broad-spectrum antibiotics, and possibly refer for physical therapy

Immediate post-repair management

Use a stool softener

It had long been thought that constipation following obstetric anal sphincter injury allowed the sphincter to heal more effectively. However, new evidence from RCTs shows that using a laxative instead of a constipating regimen is more helpful in the immediate postpartum phase.⁴³ Toward this end, use a stool softener, such as lactulose, for 3 to 10 days postpartum for women with obstetric anal sphincter injury.⁴⁰

Should you prescribe an antibiotic?

Given the devastating effects of post-repair infection, most authorities consider it prudent to prescribe a course of broad-spectrum antibiotics, possibly including metronidazole (SOR: C)^37,40 A Cochrane review is registered to further examine this issue. A separate Cochrane review of the use of antibiotics for instrument vaginal delivery concluded that quality data were insufficient to make any recommendations.⁴⁴

Refer for physical therapy

Some authorities consider an early referral to physical therapy for pelvic floor exercises helpful in the immediate post-partum for all patients with obstetric anal sphincter injury (SOR: C).⁴⁵