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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 fistula reconstruction, it is used 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 can be substantial, but benefit often declines. ASCRS cites some series with as few as 10–14% maintaining improvement after five years; this is not a pooled estimate for all repairs.[1]

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

Indications​

SettingNotes
Established OASI-related FIConsider delayed repair of a clinically relevant sphincter defect after appropriate nonoperative treatment; distinguish this from immediate repair of an acute birth injury.[1][2]
Other traumatic sphincter injuryIatrogenic post-anorectal surgery, perineal trauma[3]
Component of RVF + sphincter-defect repairSelected obstetric RVF with a documented defect may require sphincter reconstruction; observational healing comparisons do not establish the effect of adding repair.[15]
Residual FI after fistula closureReassess bowel function and sphincter anatomy after healing; timing is individualized rather than a mandatory 3–6-month wait.

Position in the pathway: address stool consistency and other reversible causes first. For persistent bothersome FI, discuss repair and SNM according to the defect, presentation and patient preference; a prior failed sphincteroplasty is not required before SNM.[1][3]

Preoperative Evaluation​

ModalityRole
Anorectal manometrySelectively characterize pressures, sensation and coordination when results will inform management; it does not reliably predict who benefits from repair or SNM.[1]
Endoanal ultrasoundUseful for defining a repairable sphincter defect (ASCRS conditional, very low certainty) — defect size does not necessarily correlate with FI severity[1]
MRIConsider alternative or dynamic imaging for selected patients when EAUS is unavailable or does not explain symptoms; MRI is not mandatory for every repair.[1]
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)​

An option for selected established sphincter defects; discuss the durability limitations and neuromodulation alternative below.

Overlapping external anal sphincter repairOriginal schematic · v2026-09-11 · Clinical review pending

Anterior perineal view of a schematic delayed external-sphincter overlap repair. The drawing assumes an intact internal sphincter; a coexisting IAS defect requires separate assessment and repair. Tissue mobilization and scar preservation depend on the actual defect. The image does not establish a preferred primary OASI repair or predict continence.[7]

A reported delayed-repair approach includes the following principles:[7]

  1. Expose the anterior defect through the perineum and distinguish anal mucosa, IAS, EAS and vaginal tissues.
  2. Mobilize enough viable sphincter for a tension-free repair while protecting the anterolateral neurovascular supply.
  3. Assess scar selectively. Traditional overlap techniques retain scar as a suture anchor; Ong's variant excised excess nonfunctional scar and sutured mobilized muscle. Neither “always preserve” nor “always excise” is an established universal rule.
  4. Identify an associated IAS defect and plan separate end-to-end repair when feasible. Reconstruct the EAS using the selected technique and restore the deficient perineal body.
  5. Provide wound and stool-management follow-up. Diversion is individualized for fistula, contamination, major reconstruction or patient needs, rather than routine for every delayed sphincteroplasty.

Absorbable polydioxanone or polyglactin sutures and several configurations have been used. The cited technique report does not establish one superior caliber or stitch. Avoid treating acute OASI recommendations as proof of superiority for a delayed repair.[6][7] Selective levator plication was common in the Cerdán series, but its independent continence benefit and effect on dyspareunia were not established.[8]

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

The July 2026 IUGA OASI guideline recommends end-to-end repair for partial-thickness EAS injuries (3a and partial 3b). Full-thickness EAS tears may be repaired end-to-end or by overlap when the full length is free. Identify and repair a torn IAS separately, end-to-end; do not overlap the IAS.[14]

End-to-end vs overlap​

The primary-repair trials include heterogeneous tear grades and follow-up. They do not establish equivalent long-term outcomes for delayed reconstruction; small-study advantages for particular endpoints should not be generalized to every repair.[6][14]

Dehiscence after primary OASI repair​

IUGA 2026 supports specialist assessment and selected early secondary repair, with counseling about infection, repeat dehiscence and fistula (Grade C). This differs from late reconstruction of a healed chronic defect. Avoid early secondary repair with obvious active infection; optimal timing and continence outcomes relative to later repair remain uncertain.[14]

Outcomes​

Outcome definitions differ: complete continence, score improvement and satisfaction are not interchangeable.[4][5]

SourceFindings and limitations
ASCRS 2023 synthesisHistorical short-term good/excellent results reached 85% in some series, but definitions varied and benefit often deteriorated. The cited 10–14% five-year sustained-improvement estimates are at the low end of individual reports.[1]
Haug 2021Twenty of 33 operated women were followed at median 5, 102 and 220 months. Median scores changed from 11.5 before surgery to 5.5, 10 and 12; 45% reported a better outcome at the last assessment. Attrition and small size limit generalization.[10]
Cerdán Santacruz 2022Retrospective 120-patient series, median follow-up ten years; 42 received additional treatment. Overall 93.3% rated the outcome good/excellent. This is satisfaction after a multimodal pathway, not a 93.3% cure rate from sphincteroplasty alone.[8]

The 2013 Cochrane review found only nine small trials involving 264 patients across surgical comparisons; it could not establish clinically important differences between techniques. It is an evidence limitation, not proof that all repairs are equivalent.[4]

Complications​

Counsel about wound infection or breakdown, persistent/recurrent FI, pain or dyspareunia and evacuation difficulty. Published complication percentages depend on the operation and population; acute obstetric repair and delayed reconstruction should not be pooled into one risk range.[2][7]

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 investigated repair variable was significantly associated with structural failure in this observational cohort; that does not prove technique or operator factors are irrelevant.[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:

  • Haug found no score improvement in five patients with neuropathy and five with more than ten years of symptoms. These small subgroups are counseling signals, not validated exclusion criteria; ASCRS does not recommend routine PNTML testing to select patients.[10][1]
  • 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 (online 2025; 2026 issue) pooled ten studies with 779 patients. SNM was associated with greater continence improvement than repair (OR 1.68, P = 0.006), but the authors judged the comparison insufficient for firm conclusions. No significant complication difference does not establish equivalent safety.[12]
  • Rodrigues compared 13 matched patients per group retrospectively. Scores improved within the SNM group, but the between-group improvement comparison was not statistically significant (P = 0.06); comparing the two within-group P values would overstate superiority.[13]
  • Successful SNM has been reported with sphincter defects up to 120°.[1]
  • US sphincteroplasty volume decreased 7-fold between 2009–2015; this utilization trend does not establish comparative effectiveness.[1]
  • Previous repair, defects over 120° and low resting pressure were associated with less SNM improvement in the newer synthesis; they are not absolute exclusions or substitutes for a test phase.[12]

See Fecal Incontinence for the newer sham-controlled SUBSoNIC trial and its substantial recruitment/attrition limitations.

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]
  • Reassess symptoms, bowel consistency, anatomy and other causes of FI. A residual ultrasound defect alone is not an automatic indication for another operation.[1]

Treatment Selection for Established FI​

Begin with individualized bowel management, then consider pelvic-floor rehabilitation/biofeedback. If symptoms remain unacceptable, discuss SNM or selected sphincter reconstruction rather than requiring repair before SNM. ASCRS supports SNM as a first surgical option with or without a defect; colostomy is an option when other treatments fail or the patient does not wish to pursue them. Anal bulking injections are not routinely recommended.[1] Older device algorithms should not be treated as a mandatory current sequence.[9]

Place in the RVF Repair Atlas​

  • Concurrent with ERAF + sphincteroplasty for selected low RVF with a defect. ASCRS cites 52 obstetric patients undergoing 62 procedures: healing was 11/27 after ERAF and 28/35 after sphincteroplasty with or without levatorplasty. This was not randomized evidence that adding sphincteroplasty doubles healing.[15]
  • Built into Episioproctotomy — reconstruction of the disrupted anterior sphincter accompanies layered fistula repair.
  • Residual FI after fistula closure — reassess the healed anatomy and all contributors to incontinence, then individualize timing and discuss durability and SNM.

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
  • Additional treatment may help residual symptoms; uncontrolled multimodal series do not establish the best sequence
  • 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. 2026;50(1):48–57. Published online November 22, 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

14. Sultan AH, Okeahialam NA, De Leeuw J, et al. IUGA International Guidelines on Obstetric Anal Sphincter Injuries. Int Urogynecol J. 2026;37:2223–2280. Published July 10, 2026. doi:10.1007/s00192-026-06642-3. PMID: 42429937.

15. Gaertner WB, Burgess PL, Davids JS, et al. The American Society of Colon and Rectal Surgeons clinical practice guidelines for the management of anorectal abscess, fistula-in-ano, and rectovaginal fistula. Dis Colon Rectum. 2022;65(8):964–985. doi:10.1097/DCR.0000000000002473.