Skip to main content

Anal Sphincteroplasty

Anal sphincteroplasty is a surgical repair of a disrupted anal sphincter, most commonly performed for fecal incontinence (FI) due to obstetric anal sphincter injury (OASIS). Within reconstructive practice, it is encountered in the fistula world in three settings: as a simultaneous component of ERAF + sphincteroplasty for low RVF with anterior sphincter defect, as the sphincter-reconstruction step of episioproctotomy, and as a staged procedure for residual fecal incontinence after fistula closure. Short-term improvement is reported in up to 85% of patients, but the dominant long-term issue is progressive deterioration, with only 10–14% maintaining sustained improvement at 5 years.[1]

For fecal-incontinence-pathway context (sacral neuromodulation, biofeedback, PTNS, bulking agents, slings), the broader incontinence procedures live under Incontinence Procedures.

Indications​

SettingNotes
OASIS-related FIPrimary indication — 3rd or 4th degree perineal tear, either acute primary repair at delivery or delayed (secondary) repair[1][2]
Other traumatic sphincter injuryIatrogenic post-anorectal surgery, perineal trauma[3]
Component of RVF + sphincter-defect repairERAF + sphincteroplasty (raises healing 41% → > 80%); built-in to episioproctotomy[1]
Residual FI after fistula closureStaged sphincteroplasty 3–6 mo after fistula healing confirmed

Position in algorithm: ACG recommends sphincteroplasty when FI persists despite adequate management of coexisting bowel disturbance, or when medical / non-invasive therapies and SNS have failed or are not recommended.[3]

Preoperative Evaluation​

ModalityRole
Anorectal manometryResting and squeeze pressures; interpret for age and sex[3]
Endoanal ultrasoundCriterion standard for sphincter anatomy and defect identification (ASCRS conditional, very low certainty) — defect size does not necessarily correlate with FI severity[1]
MRIBetter than EAUS for distinguishing EAS tear from scar and identifying external sphincter atrophy; consider when EAUS unavailable or normal in a symptomatic patient[3]
PNTMLNot routinely recommended (ASCRS)[1]
Continence scoringWexner / Cleveland Clinic Incontinence Score or St. Mark's score documented preoperatively for objective comparison[1]

Surgical Technique​

Overlapping anterior sphincteroplasty (delayed / secondary repair)​

The standard for established sphincter injuries.

  1. Position: prone jackknife or lithotomy.
  2. Incision: curvilinear perineal incision over the perineal body (posterior fourchette).[4][5]
  3. Dissection: scarred sphincter remnant dissected back to healthy muscle on either side through the ischiorectal fat. Transect — do not excise — the scar; use it as part of the overlapping repair to restore an intact muscle ring.[5]
  4. Overlap: one EAS end brought over the other and sutured with mattress sutures through the fascial sheath (not just muscle).[5][6]
  5. IAS repair: if identified, repair separately with 3-0 monofilament polydioxanone — not universally practiced.[6][7]
  6. Levatorplasty: anterior plication of levator ani lengthens the restored anal canal — done in 75% of patients in one large series; some surgeons avoid it for dyspareunia concern; objective benefit unproven.[5][8]
  7. Closure: perineal-body reconstruction and skin closure.
  8. No diverting stoma: RCT data show no benefit and increased morbidity from diversion.[5]

Suture material: 3-0 polyglactin, 3-0 polydioxanone, or 2-0 polyglactin (expert opinion).[6]

End-to-end repair (acute / primary repair)​

Direct approximation and suturing of torn EAS ends — typically used at the time of delivery for acute OASIS. Overlap repair should not be used for grade 3a and partial-thickness 3b injuries, as it requires full-thickness disruption with 1–1.5 cm of torn muscle on either end.[6]

End-to-end vs overlap​

Meta-analysis of 6 RCTs (n = 588 women, grade 3c or greater laceration): no differences at 12 months in perineal pain, dyspareunia, or flatal incontinence.[6] ACOG: similar outcomes up to 36 mo postoperatively.[2]

Outcomes​

TimeframeContinenceKey findings
Short-term (≤ 12 mo)Up to 85% improvement60–88% achieve excellent / good outcome[1][2][3]
Medium-term (3–5 yr)~50%Continence averages 50% at 40–60 mo; 28% continent at 40 mo in one study[1][4]
Long-term (5–10 yr)10–14% sustained improvementHalf of women report FI symptoms at 5–10 yr[2][5]
> 10 yrFurther deteriorationAt median 18 yr, only 45% reported better outcome; scores return near baseline[2]

Despite objective deterioration, 74% of patients remain satisfied at long-term follow-up.[2] Cerdán Santacruz 2022 — single-center multimodal approach (sphincteroplasty + selective levatorplasty / IAS repair / biofeedback / PTNS / SNS): 93.3% good or excellent satisfaction at median 10 yr.[8]

Complications​

Overall surgical complication rate 5–27%:[2]

  • Wound infection — most common, 6–35%[2][9]
  • Fecal impaction
  • Wound hematoma
  • UTI
  • Dyspareunia
  • Defecatory dysfunction (incomplete evacuation, straining, manual disimpaction)[2]

Jain 2023 audit (n = 239 OASIS): structural failure on EAUS in 41.8%; only 20% of structural failures were symptomatic at mean 23 mo. No modifiable variable (location, operator hierarchy, repair type, suture material) significantly reduced secondary-failure risk.[11]

Prognostic Factors​

Technical and patient factors are not clearly established:[9]

  • Age, sex, extent of sphincter injury
  • Etiology and duration of FI
  • Pudendal neuropathy
  • Surgical technique (end-to-end vs overlap)

Some signals:

  • Pudendal neuropathy — patients may not improve[10]
  • > 10 years of symptoms before repair — worse outcomes[10]
  • The multifactorial nature of post-OASIS FI (mechanical disruption + neuropathy + pelvic-floor dysfunction + altered rectal sensation) likely explains the high long-term failure rate[1]

Sphincteroplasty vs Sacral Neuromodulation (SNM)​

The role of sphincteroplasty has been increasingly challenged:

  • ASCRS 2023 recommends SNM as a first-line surgical option for incontinent patients with or without sphincter defects (conditional, low certainty).[1]
  • Emile 2025 meta-analysis (n = 779): SNM yields better continence improvement than sphincteroplasty (OR 1.68, P = 0.006) with similar complication rates.[12]
  • Rodrigues 2017 (matched 13 vs 13): SNM significantly reduced Wexner (15.9 → 8.4, P = 0.003) while sphincteroplasty did not (16.9 → 12.9, P = 0.078).[13]
  • SNM is effective even with sphincter defects up to 120°.[1]
  • US sphincteroplasty volume decreased 7-fold between 2009–2015, reflecting the shift to SNM.[1]
  • Less SNM benefit when there is prior sphincteroplasty, EAS defect > 120°, or low resting anal pressure.[12]

Repeat Sphincteroplasty​

ASCRS 2023 — repeat sphincteroplasty after a failed overlapping sphincteroplasty should generally be avoided (conditional, very low certainty):[1]

  • Retrospective n = 56 repeat sphincteroplasty: mean Wexner 16.5 → 11.9 (P < 0.001 short-term). At 74 mo: only 28.6% reported a good result; 21.4% required further procedures; 5.4% required colostomy.[1]
  • Consider only when a specific failure cause is identified (e.g., recurrent sphincter injury from repeat vaginal delivery).[1]
  • Confirm muscle wrap on follow-up US; persisting defects can undergo repeat repair after 6–12 mo. Biofeedback is effective salvage for suboptimal result.[5]

Management Algorithm (FI with Sphincter Defect)​

  1. Conservative — diet, fiber, antidiarrheals (first-line)[1]
  2. Biofeedback[1]
  3. Sphincteroplasty — best for recent / acute sphincter injury or postpartum FI recognized shortly after delivery[3][9]
  4. Sacral neuromodulation — first-line surgical option for FI with or without sphincter defects, particularly delayed presentation or failed sphincteroplasty[1]
  5. Other — PTNS, injectable bulking agents (not routinely recommended), or colostomy as last resort[1]

Place in the RVF Repair Atlas​

  • Concurrent with ERAF + sphincteroplasty for low / mid RVF with anterior sphincter defect — raises healing from 41% to > 80%.[1]
  • Built into Episioproctotomy as Step 7 — overlapping reconstruction of the anterior sphincter after intentional division and layered RVF repair.
  • Staged after fistula closure — defer 3–6 months for residual FI; counsel re: long-term deterioration and the SNM alternative.

Key Takeaways​

  • Good short-term results, progressive deterioration over time
  • Best for recent sphincter injury with early symptom onset (especially postpartum)
  • For patients decades after obstetric trauma, SNM may be more appropriate first-line surgical option
  • A multimodal approach (sphincteroplasty + biofeedback ± neuromodulation) optimizes long-term outcomes
  • Repeat sphincteroplasty should generally be avoided unless a specific correctable failure cause is identified

References​

1. Bordeianou LG, Thorsen AJ, Keller DS, et al. "The American Society of Colon and Rectal Surgeons clinical practice guidelines for the management of fecal incontinence." Dis Colon Rectum. 2023;66(5):647–661. doi:10.1097/DCR.0000000000002776

2. ACOG Committee on Practice Bulletins—Gynecology. "ACOG practice bulletin no. 210: fecal incontinence." Obstet Gynecol. 2019;133(4):e260–e273. doi:10.1097/AOG.0000000000003187

3. Wald A, Bharucha AE, Limketkai B, et al. "ACG clinical guidelines: management of benign anorectal disorders." Am J Gastroenterol. 2021;116(10):1987–2008. doi:10.14309/ajg.0000000000001507

4. Brown SR, Wadhawan H, Nelson RL. "Surgery for faecal incontinence in adults." Cochrane Database Syst Rev. 2013;(7):CD001757. doi:10.1002/14651858.CD001757.pub4

5. Madoff RD, Parker SC, Varma MG, Lowry AC. "Faecal incontinence in adults." Lancet. 2004;364(9434):621–632. doi:10.1016/S0140-6736(04)16856-6

6. ACOG Committee on Practice Bulletins—Obstetrics. "ACOG practice bulletin no. 198: prevention and management of obstetric lacerations at vaginal delivery." Obstet Gynecol. 2018;132(3):e87–e102. doi:10.1097/AOG.0000000000002841

7. Ong F, Phan-Thien KC. "How to do it: delayed sphincteroplasty for obstetric anal sphincter injury." ANZ J Surg. 2022;92(5):1208–1210. doi:10.1111/ans.17650

8. Cerdán Santacruz C, Cerdán Santacruz DM, Milla Collado L, Ruiz de León A, Cerdán Miguel J. "Multimodal management of fecal incontinence focused on sphincteroplasty: long-term outcomes from a single center case series." J Clin Med. 2022;11(13):3755. doi:10.3390/jcm11133755

9. Bharucha AE, Rao SSC, Shin AS. "Surgical interventions and the use of device-aided therapy for the treatment of fecal incontinence and defecatory disorders." Clin Gastroenterol Hepatol. 2017;15(12):1844–1854. doi:10.1016/j.cgh.2017.08.023

10. Haug HM, Carlsen E, Johannessen HO, Johnson E. "Short-, long-, and very long-term results of secondary anterior sphincteroplasty in 20 patients with obstetric injury." Int J Colorectal Dis. 2021;36(12):2775–2778. doi:10.1007/s00384-021-04026-1

11. Jain A, Lew C, Thungathruthi K, et al. "Incidence and risk factors for secondary failure after acute obstetric sphincter injury repair — an audit of 239 women." Colorectal Dis. 2023;25(1):95–101. doi:10.1111/codi.16313

12. Emile SH, Wignakumar A, Horesh N, et al. "Efficacy of sacral neuromodulation in treatment of fecal incontinence associated with anal sphincter defects: a systematic review and meta-analysis." World J Surg. 2025. doi:10.1002/wjs.70152

13. Rodrigues FG, Chadi SA, Cracco AJ, et al. "Faecal incontinence in patients with a sphincter defect: comparison of sphincteroplasty and sacral nerve stimulation." Colorectal Dis. 2017;19(5):456–461. doi:10.1111/codi.13510