Surgical Techniques

Ranee Thakar, MD, MRCOG Dr. Thakar is Consultant ObGyn and Urogynecology Subspecial- ist at Mayday University Hospital in Croydon, United Kingdom. Abdul H. Sultan, MD, FRCOG Dr. Sultan is Consultant ObGyn at Mayday University Hospital in Croydon, United Kingdom. To repair a laceration involving The authors report no financial the external sphincter and anal relationships relevant to this article. epithelium, retrieve the sphincter's torn ends using tissue forceps and reapproximate them using interrupted Vicryl 3-0 sutures.

Obstetric anal sphincter injury: 7 critical questions about care In this Article y Is endoanal US When and how you manage an injury determines the helpful? patient’s quality of life. Here are 7 issues to consider. Page 58 CASE Large baby, extensive tear To minimize the risk of undiagnosed y Repair technique OASIS, a digital anorectal examination for internal and A 28-year-old primigravida undergoes a for- is warranted—before any suturing—in external sphincters ceps delivery with a midline episiotomy for every woman who delivers vaginally. Page 62 failure to progress in the second stage of la- This practice can help you avoid miss- bor. At birth, the infant weighs 4 kg (8.8 lb), ing isolated tears, such as “buttonhole” y How to code for and the episiotomy extends to the anal verge. of the rectal mucosa, which can occur obstetric anal The resident who delivered the child is uncer- even when the anal sphincter remains tain whether the anal sphincter is involved in intact (FIGURE 1), or a third- or fourth- sphincter injury the injury and asks a consultant to examine degree tear that can sometimes be present Page 66 the perineum. behind apparently intact perineal skin What should this examination entail? (FIGURE 2).1 OASIS = Clinical training of physicians and negligence? The obstetrician is rarely culpable when midwives also needs to improve. Did a jury find an OB guilty in a

a third- or fourth-degree obstetric anal Every labor room should have Martens

malpractice case that involved sphincter injury (OASIS) occurs—but a protocol for management of anal vacuum extraction? Read

2 Kimberly there is little excuse for letting one go un- sphincter injury ; this article describes "Medical Verdicts" on page 70

56 OBG M a n a g e m e n t • February 2008 focusing on seven critical questions. figure 1 Only a physician formally trained in Buttonhole tear primary anal sphincter repair (or under supervision) should repair OASIS.

1. When (and how) should the torn perineum be examined? The first requisite is informed consent EAS for vaginal and rectal examination immediately after delivery. Also vital are adequate exposure of the perineum, good lighting, and, if necessary, sufficient analgesia to prevent pain-related restriction of the evaluation. It may be advisable to place the patient in the lithotomy posi- A buttonhole tear of the rectal mucosa (arrow) with an intact external anal sphincter (EAS) demonstrated during a tion to improve exposure. digital rectal examination. SOURCE: Sultan AH3 (used with After visual examination of the permission). perineum, part the labia and examine the vagina to establish the full extent of the figure 2 tear. Always identify the apex of the vagi- Injury obscured nal laceration. by intact skin Next, perform a rectal examination to exclude injury to the anorectal mucosa A and anal sphincter.3

Palpation is necessary to confirm OASIS fast track Insert the index finger into the anal canal A rectal examination and the thumb into the vagina and perform a pill-rolling motion to palpate the with digital palpation anal sphincter. If this technique is incon- is always necessary clusive, ask the woman to contract her to determine anal sphincter with your fingers still in the extent of injury place. When the sphincter is disrupted, you feel a distinct gap anteriorly. If the B perineal skin is intact, there may be an absence of puckering on the perianal skin over any underlying defect that may not be evident under regional or general anesthesia. Because the external anal sphincter (EAS) is in a state of tonic contraction, the sphincter ends will retract when it is disrupted. These ends need to be grasped and retrieved at the time of repair. Also identify the internal anal sphincter (IAS). It is a circular smooth muscle (A) Intact perineum on visual examination. (B) Anal sphincter FIGURE 3, ( page 58) that is paler in ap- trauma detected after rectal examination. SOURCE: Sultan pearance (similar to the flesh of raw fish) AH, Kettle C1 (used with permission).

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figure 3 the sonographic defect was not clinically Grade 3b tear visible despite exploration of the anal sphincter.5 as a result of this unnecessary exploration based on endoanal US, 20% of these women developed severe fecal incontinence. Therefore, we believe that OASIS is best detected clinically immediately after delivery, provided the physician performs a careful examination with palpation of the anal sphincter.6 In such a scenario, endoanal US is of limited value.

Grade 3b tear with an intact internal anal sphincter (IAS). 3. How is obstetric The external sphincter (EAS) is being grasped with Allis anal sphincter trauma forceps. Note the difference in appearance of the paler IAS and darker EAS. SOURCE: Sultan AH, Kettle C1 (used with classified? permission). To standardize the classification of perineal trauma, Sultan proposed the follow- than the striated EAS (similar to raw red ing system, which has been adopted by meat).4 Under normal circumstances, the the Royal College of Obstetricians and distal end of the IAS lies a few millime- Gynaecologists and internationally7–9: ters proximal to the distal end of the EAS First degree: Laceration of the vaginal (FIGURE 4, page 61). However, if the EAS epithelium or perineal skin only is relaxed due to regional or general an- Second degree: Involvement of the peri- esthesia, the distal end of the IAS will ap- neal muscles, but not the anal sphincter pear to be at a lower level. If the IAS or Third degree: Disruption of the anal anal epithelium is torn, the EAS is, invari- sphincter muscles (FIGURE 4, page 61): fast track ably, torn, too. • 3a: Less than 50% thickness of the Obstetric anal General or regional (spinal, epidural, external sphincter is torn caudal) anesthesia provides analgesia • 3b: More than 50% thickness of the sphincter injury and muscle relaxation and enables proper external sphincter is torn is best detected evaluation of the full extent of the injury. • 3c: Internal sphincter is also torn clinically Fourth degree: A third-degree anal tear immediately after with disruption of the anal epithelium 2. Is endoanal US helpful (FIGURE 4). delivery to detect OASIS? If there is any ambiguity about grad- Endoanal ultrasonography (US) to iden- ing of the injury, the higher grade should tify OASIS requires specific expertise, be selected. For example, if there is un- particularly in the immediate postpartum certainty between grades 3a and 3b, the period, when the anal canal is lax (espe- injury should be classified as Grade 3b. cially after an epidural). Ultimately, however, the diagnosis rests on clinical assessment and a rectal examination because, 4. Is an operating room even if a defect is seen on US, it has to be necessary? clinically apparent to be repaired. OASIS should be repaired in the oper- In a study by Faltin and colleagues, ating theater, where there is access to in which routine postpartum endoanal good lighting, appropriate equipment, US was used as the gold standard for and aseptic conditions. In our unit, we diagnosis of OASIS, five of 21 women have a specially prepared instrument had unnecessary intervention because tray containing:

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58 OBG M a n a g e m e n t • February 2008 Surgical Techniques CONTINUED figure 4 Classification of anal sphincter injury

First- and second-degree injuries are described on page 58.

Rectum

Internal sphincter Grades 3a 3b Grade 4 3c External sphincter

Anus

• a Weislander self-retaining retractor Fourth-degree tear • 4 Allis tissue forceps Repair torn anal epithelium with inter- • McIndoe scissors rupted Vicryl 3-0 sutures, with the knots • tooth forceps tied in the anal lumen. Proponents of this • 4 artery forceps widely described technique argue that fast track • stitch scissors it reduces the quantity of foreign body Repair torn anal • a needle holder. (knots) within the tissue and lowers the In addition, deep retractors (e.g., risk of infection. Concern about a foreign epithelium with Deavers) are useful when there are asso- body probably applies to the use of cat- interrupted ciated paravaginal tears. gut, which dissolves by proteolysis, rath- Vicryl 3-0 sutures, er than to newer synthetic material such with the knots tied as Vicryl or Dexon (polyglycolic acid), 5. What surgical technique which dissolves by hydrolysis. in the anal lumen is recommended? Subcuticular repair of anal epithelium Buttonhole injury using a transvaginal approach has also This type of injury can occur in the rec- been described and could be equally ef- tum without disrupting the anal sphincter fective if the terminal knots are secure.10 or perineum. It is best repaired transvagi- nally using interrupted Vicryl (polyglac- Sphincter muscles tin) sutures. Repair these muscles using 3-0 polydioxa- To minimize the risk of persistent rec- none (PDS) dyed sutures. Compared with tovaginal fistula, interpose a second layer braided sutures, monofilament sutures of tissue between the rectum and vagina by are believed to lessen the risk of infec- approximating the rectovaginal fascia. A tion, although a randomized controlled colostomy is rarely indicated unless a large trial revealed no difference in suture- tear extends above the pelvic floor or there related morbidity between Vicryl and is gross fecal contamination of the wound. PDS at 6 weeks postpartum.11 Complete

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figure 5 There is some evidence that repair of End-to-end repair an isolated IAS defect benefits patients with established anal incontinence. External anal sphincter. Because the EAS is normally under tonic contraction, it E tends to retract when torn. Therefore, repair requires identification and grasping of the torn ends using Allis tissue forceps I (FIGURE 6). When the EAS is only partially torn (Grade 3a and some cases of Grade 3b), A perform an end-to end repair using 2 or 3 mattress sutures, similar to repair of IAS injury, instead of hemostatic “figure of Internal anal sphincter (I) repair using mattress sutures, eight” sutures. demonstrated on the latex Sultan model, used for training (www.perineum.net) (E, external sphincter; A, anal epithelium). For a full-thickness tear (some cases SOURCE: Sultan AH, Thakar R2 (used with permission). of Grade 3b or 3c, or Grade 4), overlapping repair may be preferable in ex- figure 6 perienced hands. The EAS may need to Locating the external be mobilized by dissecting it free of the anal sphincter ischioanal fat laterally using a pair of McIndoe scissors. The torn ends of the EAS can then be overlapped in “double- breasted” fashion (FIGURE 7) using PDS 3-0 sutures. Proper overlap is possible only when the full length of the torn ends is identified. FAT E Overlapping the ends of the sphinc- fast track ter allows for greater surface area of C Repair the internal contact between muscle. In contrast, end-to-end repair can be performed and external anal without identifying the full length of the sphincters EAS and may give rise to incomplete ap- separately The external sphincter (E), grasped with Allis forceps, position. Fernando and colleagues dem- is surrounded by the capsule (C) and lies medial to the ischioanal fat. SOURCE: Sultan AH, Thakar R2 (used with onstrated that, in experienced hands, permission). early primary overlap repair carries a lower risk of fecal urgency and anal absorption of PDS takes longer than incontinence than does immediate pri- with Vicryl, with 50% tensile strength mary end-to-end repair.12,13 lasting more than 3 months, compared with 3 weeks for Vicryl.11 To minimize Perineal muscles suture migration, cut suture ends short After repair of the sphincter, suture the and ensure that they are covered by the perineal muscles to reconstruct the peri- overlying superficial perineal muscles. neal body and provide support to the Internal anal sphincter. Repair the IAS repaired anal sphincter. A short, deficient separately from the EAS. Grasp the ends perineum would leave the anal sphincter of the torn muscle using allis forceps more vulnerable to trauma during a sub- and perform an end-to-end repair with sequent vaginal delivery. interrupted or mattress 3-0 PDS sutures Next, suture the vaginal skin and ap- (FIGURE 5). Overlapping repair can be proximate the perineal skin using Vicryl technically difficult. Rapide 2-0 subcuticular suture.

62 OBG M a n a g e m e n t • February 2008 Examine, and document, the repair figure 7 Perform a rectal and vaginal examination Overlapping sphincter repair to confirm adequate repair and ensure that no other tears have been missed— and that all tampons or swabs have been removed. Make detailed notes of the findings and repair. A pro forma pictorial repre- sentation of the tears proves very useful E when notes are reviewed following com- plications or during audit or litigation. I E A

6. What does postoperative care entail? Repair of a fourth degree tear (demonstrated on the Sultan Prophylactic antibiotics are common model) using the overlap repair technique on the external No randomized trials have substanti- sphincter (E). The anal epithelium (A) and the internal sphincter (I) have also been repaired. SOURCE: Sultan AH, Thakar ated the benefits of intraoperative and R2 (used with permission). postoperative antibiotics after repair of OASIS. nevertheless, these drugs are 91% of women continued to complain commonly prescribed, especially after of severe perineal pain 7 days after fourth-degree tears, because infection OASIS.15 and wound breakdown could jeopar- In a systematic review, Hedayati dize the repair and lead to incontinence and associates found rectal analgesia, or fistula.10,14 such as diclofenac sodium, to be ef- We prescribe intravenous broad- fective at reducing pain from perineal spectrum antibiotics such as cefuroxime trauma within the first 24 hours after and metronidazole intraoperatively and birth; they also found that women used continue the drugs orally for 5 days. less additional analgesia within the first fast track 48 hours after birth.16 Diclofenac is al- Avoid codeine-based Bladder catheterization most completely bound to protein, so is recommended excretion in breast milk is negligible.17 analgesia because Severe perineal discomfort, especially In women who have undergone re- it can cause after instrumental delivery, is a known pair of a fourth-degree tear, administer constipation and cause of urinary retention. Moreover, af- oral diclofenac; suppositories may be lead to excessive ter administration of regional anesthesia, uncomfortable, and there is a theoretical it can take up to 12 hours before bladder risk of poor healing associated with local straining and sensation returns. anti-inflammatory agents. disruption of We recommend insertion of a Foley Avoid codeine-based preparations be- the repair catheter for approximately 24 hours, cause they may cause constipation and unless medical staff can ensure that lead to excessive straining and disruption spontaneous voiding occurs at least ev- of the repair. ery 3 to 4 hours without bladder over- distension. Recommend a stool softener It is vital that constipation be avoided as Pain may persist after severe injury the patient heals; passage of constipated The degree of pain following perineal stool or fecal impaction can disrupt the trauma is related to the extent of the repair. We prescribe a stool softener (lact- injury. OASIS is frequently associated ulose, 15 mL twice daily) for 10 to 14 with other more extensive injuries days and have encountered no problem such as paravaginal tears. In one study, with bowel evacuation.18 CONTINUED

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figure 8 to the delivery. We also recommend pel- Defect visible on US vic floor and anal sphincter exercises as soon as her discomfort resolves.

Perform a comprehensive follow-up exam All women who sustain OASIS should be assessed by a senior obstetrician 6 to 8 weeks after delivery. In our practice, these women are seen in a dedicated perineal clinic.20 The clinic provides a supportive environment and increases the patient’s confidence in the team.21 At the clinic, each woman com- pletes the same symptom questionnaire Endoanal sonogram showing a defect in the external anal that she was given before hospital dis- sphincter between 11 o'clock and 1 o’clock (between the yellow arrows) (S, subepithelium; E, external anal sphincter). charge. She then undergoes a genital SOURCE: Sultan AH, Thakar R2 (used with permission). examination in which the physician checks the degree of scarring, residual We recommend that the patient granulation tissue, and tenderness; telephone a health-care provider 24 ensures that the patient understands to 48 hours after hospital discharge to the circumstances surrounding the de- confirm that bowel evacuation has oc- livery and injury; and addresses any curred. If it hasn’t, we add mineral oil, concerns. all women then undergo magnesium hydroxide, or another oral anal manometry and endoanal US bowel stimulant to the stool softener (FIGURE 8). each patient is encouraged and bulking agent. to continue pelvic floor exercises. If she Mahoney and colleagues conducted a has minimal sphincter contractility, she fast track randomized trial (n = 105) of constipat- may need electrical stimulation. Any woman who ing versus laxative regimens and found If a dedicated perineal clinic is un- the latter to be associated with earlier and available, the patient should be given sustains anal less painful first bowel motion and earlier clear instructions, preferably in writing, sphincter injury hospital discharge.19 Nineteen percent of before leaving the hospital. During the should be examined women following the constipating regi- 6 weeks immediately after delivery, she by a senior men had troublesome constipation (two should be instructed to look for signs required hospitalization for fecal impac- of infection or wound dehiscence and obstetrician 6 to 8 tion), compared with 5% of women re- to telephone the physician to report weeks after delivery ceiving a laxative. There were no signifi- any increase in pain or swelling, rectal cant differences in continence scores, anal bleeding, or purulent discharge. Any in- manometry, and endoanal US findings. continence of stool or flatus also should be reported. Give the patient adequate information Before the patient is discharged from 7. Is vaginal delivery the hospital, we give her a booklet that advisable after OASIS? describes the implications of OASIS and No randomized trials have determined the explains when and where to seek help if most appropriate mode of delivery after a symptoms of infection or incontinence third- or fourth-degree tear. We base our develop. All women also complete a vali- counseling of the patient on a completed dated bowel-health and quality-of-life symptom questionnaire and findings from questionnaire regarding conditions prior manometry and endoanal US (FIGURE 8).

64 OBG M a n a g e m e n t • February 2008 If vaginal delivery is contemplated, figure 9 these tests should be performed during How do you determine the mode the current pregnancy unless they were of delivery after OASIS? abnormal at an earlier date. FIGURE 9 is a simple flow diagram from our unit that illustrates management of subse- Pregnancy after obstetric quent delivery after OASIS. anal sphincter injury When determining the mode of delivery, thorough counseling and clear documentation of that counseling are ex- Symptomatic Asymptomatic tremely important.

Vaginal delivery is possible unless anal sphincter function is impaired Severe Borderline Intact Severe Borderline Intact One study found that when a large sonographic defect (more than one quad- rant) is present, or the squeeze-pressure ? ? Cesarean Vaginal Cesarean Vaginal Cesarean Cesarean increment (above resting pressure) is less delivery section delivery section section section than 20 mm Hg, the risk of impaired continence after a subsequent delivery Intact = no external anal sphincter defect and normal pressures increases dramatically.22 Borderline = external anal sphincter defect >1 hr and <2 hr (1 hr = 30°) and anal pressure increment of 20–40 mm Hg Based on these findings, we con- Severe = external anal sphincter defect >2 hr and anal pres- ducted a prospective study that found no sure increment below 20 mm Hg deterioration of sphincter function or increase in symptoms after vaginal delivery unless the patient had significant com- Threshold for C-section is lower promise of anal sphincter function before if additional risk factors are present the pregnancy.23 Therefore, we encourage If traumatic delivery is anticipated, as in asymptomatic women who have minimal the presence of one or more additional fast track compromise of anal sphincter function to risk factors (macrosomia, shoulder dys- There is undergo vaginal delivery. tocia, prolonged labor, difficult instrumental delivery), cesarean section may be no evidence that Routine episiotomy is not protective appropriate. routine episiotomy There is no evidence that routine epi- prevents recurrent siotomy prevents recurrent OASIS. If Consider emotional needs anal sphincter injury episiotomy is deemed to be necessary— Some women who have sustained OASIS e.g., for a thick inelastic or scarred may be scarred emotionally as well as perineum—mediolateral episiotomy is physically and may find it difficult to preferred. cope with the thought of another vaginal delivery. These women deserve sympathy, High likelihood of success psychological support, and consideration in some women of their request for cesarean section. Women who have minimal compromise of anal sphincter function should When cesarean is a good idea be counseled that they have an 88% (in Women who have a minor degree of in- centers practicing midline episiotomy) to continence (e.g., fecal urgency or flatus 95% (in centers practicing mediolateral incontinence) may be managed with episiotomy) chance of delivering with- dietary advice, constipating agents (lop- out sustaining another OASIS.24,25 this eramide or codeine phosphate), and should reassure them if they have mis- physiotherapy or biofeedback. these givings about vaginal delivery. women who have some degree of anal

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Women who have undergone a previ- Coding for obstetric anal ous successful secondary sphincter repair sphincter injury for fecal incontinence should be delivered by cesarean delivery.9 Q. What is the proper code for reporting an anal sphincter injury incurred in pregnancy? Not all women fit neatly into one category A. That depends—on when the tear occurred, whether the patient is currently pregnant, and whether there were There are going to be women who do additional lacerations of the perineum. not entirely fit any of the categories described—such as those who have isolated ICD-9-CM offers four codes in this setting. Choose one, as follows: internal sphincter defects or irritable bowel syndrome. Management of these women • If you note an anal tear at the time of, or after, delivery but should be individualized, with the mode there is no perineal laceration, report 664.6x. This code takes a fifth digit: 1“ ,” for the patient who has just delivered, or “4,” of delivery determined by mutual agree- if you are treating the tear after she has been discharged. ment after taking into account symptoms and clinical and other findings. • If the tear is noted in addition to a third-degree perineal tear, If there are no facilities for anal ma- report 664.2x instead; fifth-digit choices for this code are also “1” and “4.” nometry and US, the physician should base management on symptoms and • If the patient had an anal tear before delivery, from a prior clinical evaluation. Asymptomatic wom- pregnancy, code 654.8x [congenital or acquired abnormality of the vulva]. en who do not have clinical evidence of sphincter compromise during anal • Last, if you are treating the patient for an old anal tear and tone assessment may be allowed to un- she is not pregnant at the moment, report 569.43 and add dergo vaginal delivery. All women who any additional codes that have resulted from the tear, such as fecal incontinence (787.6). are symptomatic should be referred to a center with facilities for anorectal assess- —Melanie Witt, RN, CPC-OGS, MA ment to establish the ideal management and mode of delivery. fast track sphincter compromise but whose symp- Cesarean delivery toms are controlled should be counseled Pay attention to modifiable that cesarean delivery is recommended risk factors is recommended (FIGURE 9, page 65). In the case described at the beginning of for women who Women who have sustained a pre- this article, two risk factors could have have some degree vious third- or fourth-degree tear with been modified to minimize the patient’s of anal sphincter subsequent severe incontinence should risk of OASIS—namely, midline episi- be offered secondary sphincter repair by otomy and forceps delivery. In a quasi- compromise, even if a colorectal surgeon or urogynecologist randomized study by Coats, involving their symptoms are with expertise in secondary sphincter 407 nulliparous women, which com- controlled repair. All subsequent deliveries by these pared mediolateral and midline episi- women should be by cesarean section. otomy (when episiotomy was necessary), Some women with fecal incontinence tears into or through the anal sphincter may choose to complete their family be- occurred in 12% of women undergoing fore embarking on anal sphincter surgery. midline episiotomy and 2% of those un- It remains unclear whether these women dergoing mediolateral episiotomy.26 should be allowed a vaginal delivery, but If operative vaginal delivery is re- it is likely that most damage has already quired, vacuum extraction is preferred. occurred and that the risk of further in- In a meta-analysis of randomized stud- jury is minimal and possibly insignificant. ies, Thakar and Eason found that fewer The benefit of cesarean delivery, if any, women have anal sphincter trauma with should be weighed against its risks for all vacuum delivery than with forceps.27 One subsequent pregnancies. anal sphincter tear is avoided for every

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18 women delivered by vacuum extrac- 14. Fernando RJ, Sultan AH, Radley S, Jones PW, Johan- tion instead of forceps. a randomized son RB. Management of obstetric anal sphincter injury: a systematic review and national practice survey. trial conducted in the United Kingdom BMC Health Serv Res. 2002;2:9. involving mediolateral episiotomy found 15. MacArthur AJ, MacArthur C. Incidence, severity, and severe vaginal laceration in 17% of for- determinants of perineal pain after vaginal delivery: ceps deliveries and 11% of vacuum de- a prospective cohort study. Am J Obstet Gynecol. 2004;191:1199–1204. liveries.28 A randomized controlled trial 16. Hedayati H, Parsons J, Crowther CA. Rectal analgesia in Canada involving midline episiotomy for pain from perineal trauma following childbirth. Co- found third- or fourth-degree tears in chrane Database Syst Rev. 2003;(3):CD003931. 29% of forceps deliveries, versus 12% of 17. Kettle C, Hills RK, Jones P, Darby L, Gray R, Johanson vacuum deliveries.29 n R. Continuous versus interrupted perineal repair with standard or rapidly absorbed sutures after spontane- References ous vaginal birth: a randomised controlled trial. Lan- cet. 2002;359:2217–2223. 1. Sultan AH, Kettle C. Diagnosis of perineal trauma. In: 18. Sultan AH, Monga AK, Kumar D, Stanton SL. Pri- Sultan AH, Thakar R, Fenner DE, eds. Perineal and Anal mary repair of obstetric anal sphincter rupture us- Sphincter Trauma. London: Springer; 2007:13–19. ing the overlap technique. Br J Obstet Gynaecol. 2. Sultan AH, Thakar R. Third and fourth degree tears. 1999;106:318–323. In: Sultan AH, Thakar R, Fenner DE, eds. Perineal 19. Mahony R, Behan M, O’Herlihy C, O’Connell PR. Ran- and Anal Sphincter Trauma. London: Springer; domized, clinical trial of bowel confinement vs. laxative 2007:33–51. use after primary repair of a third-degree obstetric anal 3. Sultan AH. 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