Visitar URL original
Fistula occlusion with an internal sphincter flap versus ligation of intersphincteric fistula tract for complex anal fistula: a retrospective single-center cohort study | Surgical Endoscopy | Springer Nature Link Skip to main content
Springer Nature Link
Log in

Fistula occlusion with an internal sphincter flap versus ligation of intersphincteric fistula tract for complex anal fistula: a retrospective single-center cohort study

  • Published:
View saved research
Surgical Endoscopy Aims and scope Submit manuscript

Abstract

Background

Ligation of intersphincteric fistula tract (LIFT) is a widely adopted sphincter-preserving technique for anal fistulas. More recently, fistula occlusion with the internal sphincter flap (FOISF) is a novel sphincter‑preserving approach for complex fistulas that was developed and fully standardized at our institution in 2020, with its formal technique paper published in 2025. Comparative evidence of efficacy between FOISF and LIFT remains lacking. This study aimed to compare the healing rates of FOISF and LIFT.

Methods

This retrospective cohort study included patients with anal fistulas who underwent FOISF or LIFT at a tertiary care hospital between November 2020 and February 2023. The surgical procedure had been selected as part of routine clinical care based on fistula characteristics, patient-related factors, and the treating surgeon’s clinical judgment, rather than according to a study-specific allocation protocol. Data were collected through a review of electronic hospital records, including demographic characteristics, and fistula characteristics. Success rates, anal function, and follow-up data up to the last recorded visit were analyzed.

Results

A total of 69 patients (28 FOISF and 41 LIFT) were included with a median follow-up of 39 months (IQR 35–43). The primary healing rate was significantly higher in the FOISF group compared to the LIFT group (89.3% vs. 48.8%; P < 0.001). FOISF was associated with significantly improved healing rates versus LIFT on multivariate analysis (OR 23.27, 95% CI 4.35–204.34; P = 0.001). Kaplan–Meier analysis showed that FOISF was associated with significantly better treatment failure-free survival compared with LIFT (P < 0.001). Postoperative Wexner scores and anorectal manometry parameters did not differ significantly between groups, and no statistically detectable deterioration in continence was observed in either group.

Conclusions

In this small retrospective single-center cohort, FOISF was associated with a higher primary healing rate than LIFT, with no statistically detectable difference in measured continence outcomes.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Subscribe and save

Springer+
from $39.99 /Month
  • Starting from 10 chapters or articles per month
  • Access and download chapters and articles from more than 300k books and 2,500 journals
  • Cancel anytime
View plans

Buy Now

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5

Similar content being viewed by others

Explore related subjects

Discover the latest articles, books and news in related subjects, suggested using machine learning.

References

  1. Felt-Bersma RJF, Bartelsman JF (2009) Haemorrhoids, rectal prolapse, anal fissure, peri-anal fistulae and sexually transmitted diseases. Best Pract Res Clin Gastroenterol 23:575–592. https://doi.org/10.1016/j.bpg.2009.04.010

    Article  PubMed  Google Scholar 

  2. Bubbers E, Cologne K (2016) Management of complex anal fistulas. Clin Colon Rectal Surg 29:043–049. https://doi.org/10.1055/s-0035-1570392

    Article  Google Scholar 

  3. Barwood N, Clarke G, Levitt S, Levitt M (1997) Fistula-in-ano: a prospective study of 107 patients. ANZ J Surg 67:98–102. https://doi.org/10.1111/j.1445-2197.1997.tb01911.x

    Article  CAS  Google Scholar 

  4. Rojanasakul A, Pattanaarun J, Sahakitrungruang C, Tantiphlachiva K (2007) Total anal sphincter saving technique for fistula-in-ano; the ligation of intersphincteric fistula tract. J Med Assoc Thai 90:581–586

    PubMed  Google Scholar 

  5. Emile SH, Elfeki H, Shalaby M, Sakr A (2018) A systematic review and meta-analysis of the efficacy and safety of video-assisted anal fistula treatment (VAAFT). Surg Endosc 32:2084–2093. https://doi.org/10.1007/s00464-017-5905-2

    Article  PubMed  Google Scholar 

  6. Elfeki H, Shalaby M, Emile SH, Sakr A, Mikael M, Lundby L (2020) A systematic review and meta-analysis of the safety and efficacy of fistula laser closure. Tech Coloproctol 24:265–274. https://doi.org/10.1007/s10151-020-02165-1

    Article  CAS  PubMed  Google Scholar 

  7. Emile SH, Elfeki H, Thabet W, Sakr A, Magdy A, El-Hamed TMA, Omar W, Khafagy W (2017) Predictive factors for recurrence of high transsphincteric anal fistula after placement of seton. J Surg Res 213:261–268. https://doi.org/10.1016/j.jss.2017.02.053

    Article  PubMed  Google Scholar 

  8. Aguilar PS, Plasencia G, Hardy TG, Hartmann RF, Stewart WR (1985) Mucosal advancement in the treatment of anal fistula. Dis Colon Rectum 28:496–498. https://doi.org/10.1007/BF02554093

    Article  CAS  PubMed  Google Scholar 

  9. Kontovounisios C, Tekkis P, Tan E, Rasheed S, Darzi A, Wexner SD (2016) Adoption and success rates of perineal procedures for fistula-in-ano: a systematic review. Colorectal Dis 18:441–458. https://doi.org/10.1111/codi.13330

    Article  CAS  PubMed  Google Scholar 

  10. Hong KD, Kang S, Kalaskar S, Wexner SD (2014) Ligation of intersphincteric fistula tract (LIFT) to treat anal fistula: systematic review and meta-analysis. Tech Coloproctol 18:685–691. https://doi.org/10.1007/s10151-014-1183-3

    Article  CAS  PubMed  Google Scholar 

  11. Malakorn S, Sammour T, Khomvilai S, Chowchankit I, Gunarasa S, Kanjanasilp P, Thiptanakij C, Rojanasakul A (2017) Ligation of intersphincteric fistula tract for fistula in ano: lessons learned from a decade of experience. Dis Colon Rectum 60:1065–1070. https://doi.org/10.1097/DCR.0000000000000880

    Article  PubMed  Google Scholar 

  12. Emile SH, Khan SM, Adejumo A, Koroye O (2020) Ligation of intersphincteric fistula tract (LIFT) in treatment of anal fistula: an updated systematic review, meta-analysis, and meta-regression of the predictors of failure. Surgery 167:484–492. https://doi.org/10.1016/j.surg.2019.09.012

    Article  PubMed  Google Scholar 

  13. Sirikurnpiboon S (2023) The risk factors for failure and recurrence of LIFT procedure for fistula in ano. Turk J Surg 39:27–33. https://doi.org/10.47717/turkjsurg.2023.5807

    Article  PubMed  PubMed Central  Google Scholar 

  14. Tan K-K, Tan IJ, Lim FS, Koh DC, Tsang CB (2011) The anatomy of failures following the ligation of intersphincteric tract technique for anal fistula: a review of 93 patients over 4 years. Dis Colon Rectum 54:1368–1372. https://doi.org/10.1097/DCR.0b013e31822bb55e

    Article  PubMed  Google Scholar 

  15. Huang D, Wang N, Li Y, Ren D, Yang Y, Wei K, Li Y, Liu Z (2025) Preliminary results of a novel sphincter-sparing technique-fistula occlusion with the internal sphincter flap (FOISF)-for high complex anal fistulas. Gastroenterol Rep (Oxf) 13:goaf006. https://doi.org/10.1093/gastro/goaf006

    Article  PubMed  PubMed Central  Google Scholar 

  16. Gaertner WB, Burgess PL, Davids JS, Lightner AL, Shogan BD, Sun MY, Steele SR, Paquette IM, Feingold DL (2022) 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 65:964–985. https://doi.org/10.1097/DCR.0000000000002473

    Article  PubMed  Google Scholar 

  17. Parks AG, Gordon PH, Hardcastle JD (1976) A classification of fistula-in-ano. Br J Surg 63:1–12. https://doi.org/10.1002/bjs.1800630102

    Article  CAS  PubMed  Google Scholar 

  18. Landrock GM (1936) Ischio-rectal abscess: a stage in the development of “horseshoe” fistula. Am J Dig Dis Nutr 3:122–123. https://doi.org/10.1007/BF02999075

    Article  Google Scholar 

  19. Rojanasakul A (2009) LIFT procedure: a simplified technique for fistula-in-ano. Tech Coloproctol 13:237–240. https://doi.org/10.1007/s10151-009-0522-2

    Article  CAS  PubMed  Google Scholar 

  20. Zwiep TM, Gilbert R, Boushey RP, Schmid S, Moloo H, Raiche I, Williams L, Musselman RP (2020) Comparison of ligation of the intersphincteric fistula tract and BioLIFT for the treatment of transsphincteric anal fistula: a retrospective analysis. Dis Colon Rectum 63:365–370. https://doi.org/10.1097/DCR.0000000000001573

    Article  PubMed  Google Scholar 

  21. Mei Z, Du P, Han Y, Qu Y, Tang H, Li Y, Gao H, Wang Q, Zheng D (2025) Risk factors for delayed wound healing after anal fistula surgery: protocol of a meta-analytic study. PLoS ONE 20:e0329030. https://doi.org/10.1371/journal.pone.0329030

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  22. Sainio P (1984) Fistula-in-ano in a defined population. Incidence and epidemiological aspects. Ann Chir Gynaecol 73:219–224

    CAS  PubMed  Google Scholar 

  23. Eisenhammer S (1985) Emergency fistulectomy of the acute primary anorectal cryptoglandular intermuscular abscess-fistula in ano. S Afr J Surg 23:1–7

    CAS  PubMed  Google Scholar 

  24. Garg P, Bhattacharya K, Yagnik VD, Mahak G (2024) Recent advances in the diagnosis and treatment of complex anal fistula. Ann Coloproctol 40:321–335. https://doi.org/10.3393/ac.2024.00325.0046

    Article  PubMed  PubMed Central  Google Scholar 

  25. Jayne DG, Scholefield J, Tolan D, Gray R, Senapati A, Hulme CT, Sutton AJ, Handley K, Hewitt CA, Kaur M, Magill L (2021) A multicenter randomized controlled trial comparing safety, efficacy, and cost-effectiveness of the Surgisis anal fistula plug versus surgeon’s preference for transsphincteric fistula-in-ano. Ann Surg 273:433–441. https://doi.org/10.1097/SLA.0000000000003981

    Article  PubMed  Google Scholar 

  26. Schlichtemeier S, Tou S (2018) Treatment for complex anal fistula, are we any wiser? Colorectal Dis 20:1067–1068. https://doi.org/10.1111/codi.14464

    Article  PubMed  Google Scholar 

  27. Garg P (2022) Comparison between recent sphincter-sparing procedures for complex anal fistulas-ligation of intersphincteric tract vs transanal opening of intersphincteric space. World J Gastrointest Surg 14:374–382. https://doi.org/10.4240/wjgs.v14.i5.374

    Article  PubMed  PubMed Central  Google Scholar 

  28. Rojanasakul A, Booning N, Huimin L, Pongpirul K, Sahakitrungruang C (2021) Intersphincteric exploration with ligation of intersphincteric fistula tract or attempted closure of internal opening for acute anorectal abscesses. Dis Colon Rectum 64:438–445. https://doi.org/10.1097/DCR.0000000000001867

    Article  PubMed  Google Scholar 

  29. Aboulian A, Kaji AH, Kumar RR (2011) Early result of ligation of the intersphincteric fistula tract for fistula-in-ano. Dis Colon Rectum 54:289–292. https://doi.org/10.1007/DCR.0b013e318203495d

    Article  PubMed  Google Scholar 

  30. Placer-Galán C, Enriquez-Navascués JM, Pastor-Bonel T, Aguirre-Allende I, Saralegui-Ansorena Y (2021) The use of seton as a bridge to definitive ligation of the intersphincteric fistula tract procedure for fistula-in-ano: a systematic review and meta-analysis. J Coloproctol 41:308–315. https://doi.org/10.1055/s-0041-1730039

    Article  Google Scholar 

  31. Zhang ZJ, Ali MS, Hegde R, Jugo RH, Zhang TA, Kurtzman SH (2025) Modified transanal opening of the intersphincteric space (TROPIS): a safe and effective procedure for transsphincteric fistula-in-ano in comparison with ligation of intersphincteric fistula tract (LIFT). Tech Coloproctol 29:153. https://doi.org/10.1007/s10151-025-03193-5

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  32. Zhang L, Zhan C, Li L, Shao W, Sun G, Chen Y, Chen G, Lang Y, Xiao Z, Xiao X (2025) Ligation of the intersphincteric fistula tract (LIFT) for high transsphincteric fistulas: a double-center retrospective study with long-term follow-up. Ann Coloproctol 41:77–83. https://doi.org/10.3393/ac.2024.00024.0003

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  33. Wallin UG, Mellgren AF, Madoff RD, Goldberg SM (2012) Does ligation of the intersphincteric fistula tract raise the bar in fistula surgery? Dis Colon Rectum 55:1173–1178. https://doi.org/10.1097/DCR.0b013e318266edf3

    Article  PubMed  Google Scholar 

  34. Lehmann J-P, Graf W (2013) Efficacy of LIFT for recurrent anal fistula. Colorectal Dis 15:592–595. https://doi.org/10.1111/codi.12104

    Article  PubMed  Google Scholar 

Download references

Funding

This work is supported by the Sixth Affiliated Hospital of Sun Yat-Sen University Clinical Research—“1010” Program [Grant Number 1010PY (2022)-40].

Author information

Author notes

  1. Yuanji Fu and Yiping Li have contributed equally and share co-first authorship.

Authors and Affiliations

  1. Department of General Surgery (Coloproctology), The Sixth Affiliated Hospital, Sun Yat-Sen University, Yuancun Er Heng Road 26, Guangzhou, 510655, China

    Yuanji Fu, Yiping Li, Dandan Huang, Xingyang Wan, Heng Zhang, Donglin Ren, Hongcheng Lin & Zhimin Liu

  2. Guangdong Provincial Key Laboratory of Colorectal and Pelvic Floor Diseases, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510655, China

    Yuanji Fu, Yiping Li, Dandan Huang, Xingyang Wan, Heng Zhang, Donglin Ren, Hongcheng Lin & Zhimin Liu

  3. Biomedical Innovation Center, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, 510655, China

    Yuanji Fu, Yiping Li, Dandan Huang, Xingyang Wan, Heng Zhang, Donglin Ren, Hongcheng Lin & Zhimin Liu

  4. Université Paris Cité, INSERM, CNRS, Institut Necker Enfants Malades, 75015, Paris, France

    Yuanji Fu

Authors
  1. Yuanji Fu
    View author publications

    Search author on:PubMed Google Scholar

  2. Yiping Li
    View author publications

    Search author on:PubMed Google Scholar

  3. Dandan Huang
    View author publications

    Search author on:PubMed Google Scholar

  4. Xingyang Wan
    View author publications

    Search author on:PubMed Google Scholar

  5. Heng Zhang
    View author publications

    Search author on:PubMed Google Scholar

  6. Donglin Ren
    View author publications

    Search author on:PubMed Google Scholar

  7. Hongcheng Lin
    View author publications

    Search author on:PubMed Google Scholar

  8. Zhimin Liu
    View author publications

    Search author on:PubMed Google Scholar

Contributions

Z.L., H.L, and D.R. served as the principal investigators responsible for the study plan; Y.F. and Y.L. participated in drafting the manuscript and analyzed the data; D.H., X.W., and H.Z. collected the data and revised the draft; Z.L. and H.L. were responsible for finalizing the manuscript. All authors have read and approved the final version of the manuscript.

Corresponding authors

Correspondence to Hongcheng Lin or Zhimin Liu.

Ethics declarations

Disclosures

Yuanji Fu, Yiping Li, Dandan Huang, Xingyang Wan, Heng Zhang, Donglin Ren, Hongcheng Lin, and Zhimin Liu have no conflicts of interest or financial ties to disclose.

Additional information

Publisher's Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Supplementary Information

Below is the link to the electronic supplementary material.

Supplementary file1 (DOCX 13 kb) (download DOCX )

Supplementary file2 (DOCX 14 kb) (download DOCX )

464_2026_13520_MOESM3_ESM.tif (download TIF )

Supplement FIGURE 1. Assessment of transsphincteric fistula parameters on coronal axial T1-weighted LAVA MRI. (A, B) Transsphincteric tract length was measured as the distance along the fistula from the IO to the external border of the EAS, as seen in the oblique tract (A) and straight tract (B). (C, D) Transsphincteric tract width was measured as the maximal diameter of the fistula tract within the EAS, as shown in the oblique tract (C) and straight tract (D) (TIFF 658 kb)

Rights and permissions

Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Fu, Y., Li, Y., Huang, D. et al. Fistula occlusion with an internal sphincter flap versus ligation of intersphincteric fistula tract for complex anal fistula: a retrospective single-center cohort study. Surg Endosc (2026). https://doi.org/10.1007/s00464-026-13520-y

Download citation

  • Received:

  • Accepted:

  • Published:

  • Version of record:

  • DOI: https://doi.org/10.1007/s00464-026-13520-y

Keywords

Profiles

  1. Zhimin Liu View author profile