Staged hybrid sphincter-preserving surgery with Video-Assisted Anal Fistula Treatment (VAAFT) and Ligation of Intersphincteric Fistula Tract (LIFT) for complex horseshoe trans-sphincteric anal fistula: A case report

Staged hybrid sphincter-preserving surgery with Video-Assisted Anal Fistula Treatment (VAAFT) and Ligation of Intersphincteric Fistula Tract (LIFT) for complex horseshoe trans-sphincteric anal fistula: A case report | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Case Report Staged hybrid sphincter-preserving surgery with Video-Assisted Anal Fistula Treatment (VAAFT) and Ligation of Intersphincteric Fistula Tract (LIFT) for complex horseshoe trans-sphincteric anal fistula: A case report Ting-Ho Chen, Shu-Huan Huang This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-9161050/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Background Horseshoe trans-sphincteric anal fistula is a complex variant of cryptoglandular fistula characterized by circumferential lateral extension within the deep postanal space and significant sphincter traversal, leading to a high risk of recurrence. Optimal surgical management remains challenging because procedures focusing solely on internal opening ligation or tract clearance may inadequately address this dual-mechanism anatomy. Case presentation We report a 29-year-old woman with recurrent perianal abscesses and persistent purulent discharge for two years. Pelvic magnetic resonance imaging demonstrated a horseshoe trans-sphincteric fistula with bilateral posterior extensions across the deep postanal space. An anatomy-driven staged surgical strategy was performed. On the left side, limited fistulectomy with seton drainage was initially conducted for infection control, followed by ligation of the intersphincteric fistula tract (LIFT) during the second-stage operation. On the right side, video-assisted anal fistula treatment (VAAFT) was used for endoscopic tract visualization and clearance, with a second VAAFT session performed to enhance cumulative tract sterilization. Postoperative recovery was uneventful, and satisfactory wound healing without recurrence or continence impairment was observed at 3-month follow-up. Conclusion Side-specific staged sequencing that aligns operative techniques with tract depth and sphincter involvement may represent a rational strategy for managing complex horseshoe trans-sphincteric fistulas while preserving sphincter function. Anal fistula Horseshoe fistula Hybrid surgery LIFT VAAFT Figures Figure 1 Figure 2 Background Horseshoe trans-sphincteric anal fistula represents one of the most complex forms of cryptoglandular fistula. According to the classification system described by Parks et al., anal fistulas are categorized into intersphincteric, trans-sphincteric, suprasphincteric, and extrasphincteric types, with trans-sphincteric fistulas representing a common but anatomically challenging subtype. Horseshoe variants are characterized by circumferential extension—typically posterior—into the deep postanal space [ 1 ]. This configuration frequently results in bilateral tracts, multiple external openings, and a higher recurrence rate than simple fistulas. According to the American Society of Colon and Rectal Surgeons (ASCRS) clinical practice guidelines, trans-sphincteric fistulas involving more than 30% of the external sphincter, as well as horseshoe fistulas, are classified as complex due to their anatomical characteristics and increased risk of postoperative incontinence and treatment failure [ 2 ]. Sphincter preservation is therefore a central principle in management. Guideline-recommended procedures for complex trans-sphincteric fistulas include ligation of the intersphincteric fistula tract (LIFT), endorectal advancement flap, selective use of cutting seton, and staged drainage with seton placement [ 2 ]. The LIFT procedure, first described by Rojanasakul, has gained widespread acceptance as a sphincter-preserving technique that targets the intersphincteric portion of the fistula tract [ 3 ]. LIFT demonstrates overall healing rates of approximately 70–80%; however, recurrence rates of approximately 20–25% have been reported in contemporary series, though horseshoe anatomy is recognized as a risk factor for recurrence [ 4 , 5 ]. Advancement flap procedures achieve primary healing rates of 66% to 87%, but technical difficulty in posterior horseshoe configurations and the risk of minor continence disturbance remain concerns [ 2 ]. Fistulotomy is generally avoided in complex or high trans-sphincteric fistulas because postoperative incontinence rates may range from 10% to 40% [ 2 ]. Minimally invasive techniques such as video-assisted anal fistula treatment (VAAFT) have been introduced to improve tract visualization and preserve sphincter integrity, with short-term success rates reported between 70% and 85% [ 6 , 7 ]. However, long-term follow-up studies suggest recurrence may increase over time, particularly in anatomically complex cases [ 8 ]. Consequently, no single sphincter-preserving technique has demonstrated consistent superiority in horseshoe trans-sphincteric fistulas [ 7 , 9 ], and staged or combined approaches are often required to optimize healing while maintaining continence [ 4 , 5 ]. Case presentation A 29-year-old woman presented with recurrent perianal abscesses for two years, accompanied by persistent anal pain and purulent discharge. She had undergone multiple incisions and drainage procedures without a durable resolution. There was no personal or family history of inflammatory bowel disease. Physical examination revealed two posterior external openings in the perianal region (Fig. 1 A). Pelvic magnetic resonance imaging demonstrated a horseshoe trans-sphincteric fistula extending across the deep postanal space with bilateral tracts (Fig. 1 B). Colonoscopy and computed tomography enterography were performed to exclude Crohn’s disease. Under general anesthesia, a staged operative management plan was developed based on the fistula's anatomical characteristics. During the first-stage operation, endoscopic exploration identified a posterior internal opening with bilateral extensions. The right-sided tract was circumferentially extensive but relatively superficial; therefore, video-assisted anal fistula treatment (VAAFT) was performed to allow direct visualization and thorough endoscopic debridement of the tract and its lateral extensions (Fig. 2 A, B). On the left side, where the tract demonstrated intersphincteric involvement with deeper sphincter traversal, a limited low-level fistulectomy was first performed to excise the superficial distal component and reduce the peripheral tract burden. Given the significant inflammatory activity, a draining seton was placed to ensure adequate sepsis control and allow tract stabilization before definitive intersphincteric management. The procedure was completed uneventfully with minimal blood loss (Fig. 2 C). After interval infection control and tract maturation, the patient underwent the second-stage operation one month after the primary surgery. Endoscopic reassessment confirmed resolution of active purulence. On the left side, the seton was removed and ligation of the intersphincteric fistula tract (LIFT) was performed through the intersphincteric plane to securely ligate and divide the tract at the level of the internal opening while preserving external sphincter integrity (Fig. 2 D). On the right side, recognizing the recurrence risk associated with single-session VAAFT in complex horseshoe anatomy, a second VAAFT session was intentionally performed to achieve additional endoscopic clearance of residual lateral extensions while minimizing further tissue trauma (Fig. 2 E). The external sphincter was preserved throughout the procedure (Fig. 2 F). The postoperative course was uneventful. At the three-month follow-up visit, satisfactory wound healing was observed, with no clinical evidence of recurrence or impairment of continence. Discussion Horseshoe trans-sphincteric fistulas are particularly prone to treatment failure because their anatomy presents two concurrent technical challenges: circumferential lateral extension within the deep postanal space and significant sphincter traversal. Durable healing requires both eradication of secondary tracts and secure control of the internal opening. Failure to address either component predisposes to recurrence [ 2 ]. Sphincter-preserving strategies such as LIFT have gained widespread adoption because they provide definitive intersphincteric ligation while preserving external sphincter integrity [ 2 ]. However, recurrence rates remain substantial in complex diseases, particularly in horseshoe configurations [ 4 , 5 ]. Although LIFT effectively controls the internal opening, it does not directly address circumferential lateral extensions beyond the intersphincteric plane. Residual branches may therefore persist despite technically adequate ligation. Conversely, VAAFT enhances direct endoscopic visualization and allows targeted debridement of secondary branches [ 6 ]. Short-term pooled success rates appear favorable [ 7 ], yet long-term data demonstrate increasing recurrence in complex fistulas, especially in horseshoe anatomy [ 8 ]. These findings indicate that while tract visualization and clearance may be optimized, durable internal opening closure may be inconsistent when VAAFT is applied alone. The lack of consistent superiority among sphincter-preserving techniques in complex fistula has been reinforced by network meta-analysis [ 9 ]. Hybrid approaches have therefore emerged to combine visualization and definitive ligation. Strategies such as VALIFT integrate endoscopic mapping with intersphincteric ligation [ 10 ]; hybrid VAAFT with seton tie has been proposed to achieve staged internal opening control under visualization [ 11 ]; and VAAFT combined with fistula plug has been applied in horseshoe disease to augment closure after tract clearance [ 12 ]. Despite these innovations, recurrence in anatomically asymmetric horseshoe configurations remains a persistent challenge. The underlying issue is anatomical mismatch: procedures prioritizing internal opening ligation may under-address circumferential spread, whereas procedures emphasizing tract clearance may inadequately secure the internal source of contamination. Single-modality treatment, therefore, risks addressing only one component of a dual-mechanism problem. In the present case, operative management was deliberately staged and anatomy-driven. On the left side, the tract involved the intersphincteric plane with meaningful sphincter traversal. A limited low-level fistulectomy was first performed to excise the superficial distal component and reduce peripheral tract burden. This was followed by seton drainage to control sepsis and allow tract stabilization. Definitive LIFT was subsequently undertaken to secure intersphincteric ligation while preserving external sphincter integrity [ 3 – 5 ]. This layered sequence addressed superficial disease through excision, controlled active inflammation through staged drainage, and definitively eliminated the internal opening through sphincter-preserving ligation. Conversely, the right-sided tract was circumferentially extensive but relatively superficial, with limited sphincter involvement. VAAFT was therefore selected to maximize endoscopic tract visualization and clearance while minimizing wound burden [ 6 , 7 ]. Recognizing the recurrence risk associated with single-session VAAFT in complex anatomy [ 8 ], the interval created by the staged left-sided procedure was intentionally used to perform a second VAAFT session on the right. Rather than representing procedural failure, this repetition functioned as cumulative tract sterilization, targeting residual lateral extensions that commonly contribute to recurrence in horseshoe configurations. Taken together, this side-specific and temporally sequenced approach reflects a strategic alignment of technique with tract depth and sphincter involvement. Superficial disease was excised, deep sphincter-crossing disease was ligated, and circumferential extensions were progressively cleared under endoscopic guidance. By integrating excision, staged drainage, ligation, and repeat endoscopic clearance within a structured timeline, the operative plan sought to mitigate both principal mechanisms of recurrence inherent to horseshoe trans-sphincteric fistula. Reports describing side-specific staged hybrid strategies tailored to asymmetric horseshoe trans-sphincteric fistula anatomy remain limited in the literature. This case suggests that aligning operative techniques with tract depth and sphincter involvement may help achieve effective tract eradication while preserving sphincter function. However, the present report is limited by the single-case design and relatively short follow-up. Further studies with larger cohorts and longer follow-up are needed to determine the reproducibility and long-term outcomes of this anatomy-driven approach. Conclusion Horseshoe trans-sphincteric fistula represents a dual-mechanism condition requiring both eradication of circumferential lateral extensions and durable control of the internal opening. Single-modality treatment may be insufficient to address this anatomical asymmetry. In this case, side-specific and staged sequencing aligned with operative technique, tract depth, and sphincter involvement, integrating excision, drainage, ligation, and repeat endoscopic clearance within a structured timeline. This anatomy-driven strategy may provide a rational framework for reducing recurrence risk while preserving sphincter function in complex horseshoe diseases. Abbreviations VAAFT Video-assisted anal fistula treatment LIFT Ligation of the intersphincteric fistula tract Declarations Ethics approval and consent to participate This study was approved by the Institutional Review Board of Chang Gung Memorial Hospital. The requirement for informed consent to participate was waived due to the retrospective nature of this case report. Consent for publication Written informed consent was obtained from the patient for publication of this case report and any accompanying images. Competing interests The authors declare that they have no competing interests. Funding This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors. Author Contribution THC collected the clinical data and drafted the manuscript. SHH performed the surgical procedures, supervised the study, and revised the manuscript. All authors read and approved the final manuscript. Acknowledgement The authors would like to thank the patient for consenting to share her clinical information for educational and scientific purposes. Data Availability All data relevant to this case report are included in this published article. Further information can be obtained from the corresponding author upon reasonable request. References Parks AG, Gordon PH, Hardcastle JD. A classification of fistula-in-ano. Br J Surg. 1976;63(1):1–12. Gaertner WB, Burgess PL, Davids JS, Lightner AL, Shogan BD, Sun MY, 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):964–85. Rojanasakul A. LIFT procedure: a simplified technique for fistula-in-ano. Tech Coloproctol. 2009;13(3):237–40. Sirikurnpiboon S. The risk factors for failure and recurrence of LIFT procedure for fistula in ano. Turk J Surg. 2023;39(1):27–33. Fogle SE, Donahue CA, Beresneva O, Kuhnen AH, Kleiman DA, Breen EM, et al. Horseshoe Fistulae in the Age of LIFT. J Gastrointest Surg. 2022;26(5):1077–83. Meinero P, Mori L. Video-assisted anal fistula treatment (VAAFT): a novel sphincter-saving procedure for treating complex anal fistulas. Tech Coloproctol. 2011;15(4):417–22. Tian Z, Li YL, Nan SJ, Xiu WC, Wang YQ. Video-assisted anal fistula treatment for complex anorectal fistulas in adults: a systematic review and meta-analysis. Tech Coloproctol. 2022;26(10):783–95. La Torre M, Goglia M, Micarelli A, Fiori E, D'Andrea V, Grossi U, et al. Long term results of video-assisted anal fistula treatment for complex anal fistula: another shattered dream? Colorectal Dis. 2023;25(10):2017–23. Bhat S, Xu W, Varghese C, Dubey N, Wells CI, Harmston C, et al. Efficacy of different surgical treatments for management of anal fistula: a network meta-analysis. Tech Coloproctol. 2023;27(10):827–45. Romaniszyn M, Walega PJ. Are two better than one? VALIFT: video-assisted ligation of the intersphincteric fistula tract-a combination of two minimally invasive techniques for treatment of transsphincteric perianal fistulas. Tech Coloproctol. 2019;23(3):273–6. Mittal T, Ahuja A, Dey A, Malik VK, Manglik S, Nahata TB. Hybrid Video-Assisted Fistula Treatment With Seton Tie for Management of Fistula-in-Ano: Results of a Novel Technique. Dis Colon Rectum. 2026;69(2):218–25. Zhang Y, Li F, Zhao T, Cao F, Zheng Y, Li A. Video-assisted anal fistula treatment combined with anal fistula plug for treatment of horseshoe anal fistula. J Int Med Res. 2021;49(1):300060520980525. Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-9161050","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Case Report","associatedPublications":[],"authors":[{"id":613997575,"identity":"13641f10-09ec-41b2-b3fd-f7619e7a5fab","order_by":0,"name":"Ting-Ho Chen","email":"","orcid":"","institution":"Chang Gung University","correspondingAuthor":false,"prefix":"","firstName":"Ting-Ho","middleName":"","lastName":"Chen","suffix":""},{"id":613997576,"identity":"8380e7ff-5c42-415c-aabf-367e9750045b","order_by":1,"name":"Shu-Huan Huang","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAy0lEQVRIiWNgGAWjYFACxsYHEhU2QAYP0VqYDxtYnElDaCFCJ1uaRGXLYRK06M4+YyZxs+G8vHzY2QMMH/fUMthLJODXYnYux9hy5o7bhhtv5yUwznh2nIGHoJYzPIa3Jc/cTjCcnWPAzHPgGAOPNGEtBtJ/286RpIUtSUKy7UCCvDRYSw0xWoCBLHEm2XADUMvBGQcO8PDcf0BICzgq7eTlZ+cYPvhwoE6OvecAfi1wYABUCESHiU8DDPINYKqOeB2jYBSMglEwYgAAGWVE9+/kjVAAAAAASUVORK5CYII=","orcid":"","institution":"Chang Gung Memorial Hospital","correspondingAuthor":true,"prefix":"","firstName":"Shu-Huan","middleName":"","lastName":"Huang","suffix":""}],"badges":[],"createdAt":"2026-03-18 15:24:10","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-9161050/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-9161050/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":106091912,"identity":"06e27337-fe0f-4eb6-86f8-7738382d9877","added_by":"auto","created_at":"2026-04-03 11:16:50","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":925659,"visible":true,"origin":"","legend":"\u003cp\u003e(A) Preoperative clinical appearance of the perianal region. The red dashed line marks the expected course of the fistula tract.\u003cbr\u003e\n(B) Axial T2-weighted magnetic resonance imaging demonstrating a horseshoe trans-sphincteric anal fistula.\u003c/p\u003e","description":"","filename":"floatimage1.png","url":"https://assets-eu.researchsquare.com/files/rs-9161050/v1/7b1d7faa81e4c7fe720219a8.png"},{"id":106094294,"identity":"5c6dec66-bafd-4637-b9e9-6a69cfac61d6","added_by":"auto","created_at":"2026-04-03 11:42:04","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":2608759,"visible":true,"origin":"","legend":"\u003cp\u003e(A, B) Intraoperative findings during the first surgical course: right-sided video-assisted anal fistula treatment (VAAFT) and left-sided seton placement combined with fistulectomy.\u003cbr\u003e\n(C) Postoperative wound condition after the first surgical course.\u003cbr\u003e\n(D, E) Intraoperative findings during the second surgical course: right-sided VAAFT and left-sided ligation of the intersphincteric fistula tract (LIFT) procedure.\u003cbr\u003e\n(F) Postoperative wound condition after the second surgical course.\u003c/p\u003e","description":"","filename":"floatimage2.png","url":"https://assets-eu.researchsquare.com/files/rs-9161050/v1/bb1b6ad92349a20f2add155d.png"},{"id":108438782,"identity":"363ead8d-5ff6-4cbf-981a-0cbe58c4bcde","added_by":"auto","created_at":"2026-05-04 16:10:29","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":5744986,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-9161050/v1/60197569-45eb-489b-96a6-a650e0878158.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Staged hybrid sphincter-preserving surgery with Video-Assisted Anal Fistula Treatment (VAAFT) and Ligation of Intersphincteric Fistula Tract (LIFT) for complex horseshoe trans-sphincteric anal fistula: A case report","fulltext":[{"header":"Background","content":"\u003cp\u003eHorseshoe trans-sphincteric anal fistula represents one of the most complex forms of cryptoglandular fistula. According to the classification system described by Parks et al., anal fistulas are categorized into intersphincteric, trans-sphincteric, suprasphincteric, and extrasphincteric types, with trans-sphincteric fistulas representing a common but anatomically challenging subtype. Horseshoe variants are characterized by circumferential extension\u0026mdash;typically posterior\u0026mdash;into the deep postanal space [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eThis configuration frequently results in bilateral tracts, multiple external openings, and a higher recurrence rate than simple fistulas. According to the American Society of Colon and Rectal Surgeons (ASCRS) clinical practice guidelines, trans-sphincteric fistulas involving more than 30% of the external sphincter, as well as horseshoe fistulas, are classified as complex due to their anatomical characteristics and increased risk of postoperative incontinence and treatment failure [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eSphincter preservation is therefore a central principle in management. Guideline-recommended procedures for complex trans-sphincteric fistulas include ligation of the intersphincteric fistula tract (LIFT), endorectal advancement flap, selective use of cutting seton, and staged drainage with seton placement [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. The LIFT procedure, first described by Rojanasakul, has gained widespread acceptance as a sphincter-preserving technique that targets the intersphincteric portion of the fistula tract [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eLIFT demonstrates overall healing rates of approximately 70\u0026ndash;80%; however, recurrence rates of approximately 20\u0026ndash;25% have been reported in contemporary series, though horseshoe anatomy is recognized as a risk factor for recurrence [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. Advancement flap procedures achieve primary healing rates of 66% to 87%, but technical difficulty in posterior horseshoe configurations and the risk of minor continence disturbance remain concerns [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. Fistulotomy is generally avoided in complex or high trans-sphincteric fistulas because postoperative incontinence rates may range from 10% to 40% [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eMinimally invasive techniques such as video-assisted anal fistula treatment (VAAFT) have been introduced to improve tract visualization and preserve sphincter integrity, with short-term success rates reported between 70% and 85% [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. However, long-term follow-up studies suggest recurrence may increase over time, particularly in anatomically complex cases [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. Consequently, no single sphincter-preserving technique has demonstrated consistent superiority in horseshoe trans-sphincteric fistulas [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e], and staged or combined approaches are often required to optimize healing while maintaining continence [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e].\u003c/p\u003e"},{"header":"Case presentation","content":"\u003cp\u003eA 29-year-old woman presented with recurrent perianal abscesses for two years, accompanied by persistent anal pain and purulent discharge. She had undergone multiple incisions and drainage procedures without a durable resolution. There was no personal or family history of inflammatory bowel disease.\u003c/p\u003e \u003cp\u003ePhysical examination revealed two posterior external openings in the perianal region (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eA). Pelvic magnetic resonance imaging demonstrated a horseshoe trans-sphincteric fistula extending across the deep postanal space with bilateral tracts (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eB). Colonoscopy and computed tomography enterography were performed to exclude Crohn\u0026rsquo;s disease.\u003c/p\u003e \u003cp\u003eUnder general anesthesia, a staged operative management plan was developed based on the fistula's anatomical characteristics. During the first-stage operation, endoscopic exploration identified a posterior internal opening with bilateral extensions. The right-sided tract was circumferentially extensive but relatively superficial; therefore, video-assisted anal fistula treatment (VAAFT) was performed to allow direct visualization and thorough endoscopic debridement of the tract and its lateral extensions (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003eA, B).\u003c/p\u003e \u003cp\u003eOn the left side, where the tract demonstrated intersphincteric involvement with deeper sphincter traversal, a limited low-level fistulectomy was first performed to excise the superficial distal component and reduce the peripheral tract burden. Given the significant inflammatory activity, a draining seton was placed to ensure adequate sepsis control and allow tract stabilization before definitive intersphincteric management. The procedure was completed uneventfully with minimal blood loss (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003eC).\u003c/p\u003e \u003cp\u003eAfter interval infection control and tract maturation, the patient underwent the second-stage operation one month after the primary surgery. Endoscopic reassessment confirmed resolution of active purulence. On the left side, the seton was removed and ligation of the intersphincteric fistula tract (LIFT) was performed through the intersphincteric plane to securely ligate and divide the tract at the level of the internal opening while preserving external sphincter integrity (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003eD).\u003c/p\u003e \u003cp\u003eOn the right side, recognizing the recurrence risk associated with single-session VAAFT in complex horseshoe anatomy, a second VAAFT session was intentionally performed to achieve additional endoscopic clearance of residual lateral extensions while minimizing further tissue trauma (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003eE). The external sphincter was preserved throughout the procedure (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003eF).\u003c/p\u003e \u003cp\u003eThe postoperative course was uneventful. At the three-month follow-up visit, satisfactory wound healing was observed, with no clinical evidence of recurrence or impairment of continence.\u003c/p\u003e "},{"header":"Discussion","content":"\u003cp\u003eHorseshoe trans-sphincteric fistulas are particularly prone to treatment failure because their anatomy presents two concurrent technical challenges: circumferential lateral extension within the deep postanal space and significant sphincter traversal. Durable healing requires both eradication of secondary tracts and secure control of the internal opening. Failure to address either component predisposes to recurrence [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eSphincter-preserving strategies such as LIFT have gained widespread adoption because they provide definitive intersphincteric ligation while preserving external sphincter integrity [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. However, recurrence rates remain substantial in complex diseases, particularly in horseshoe configurations [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. Although LIFT effectively controls the internal opening, it does not directly address circumferential lateral extensions beyond the intersphincteric plane. Residual branches may therefore persist despite technically adequate ligation.\u003c/p\u003e \u003cp\u003eConversely, VAAFT enhances direct endoscopic visualization and allows targeted debridement of secondary branches [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. Short-term pooled success rates appear favorable [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e], yet long-term data demonstrate increasing recurrence in complex fistulas, especially in horseshoe anatomy [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. These findings indicate that while tract visualization and clearance may be optimized, durable internal opening closure may be inconsistent when VAAFT is applied alone.\u003c/p\u003e \u003cp\u003eThe lack of consistent superiority among sphincter-preserving techniques in complex fistula has been reinforced by network meta-analysis [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. Hybrid approaches have therefore emerged to combine visualization and definitive ligation. Strategies such as VALIFT integrate endoscopic mapping with intersphincteric ligation [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]; hybrid VAAFT with seton tie has been proposed to achieve staged internal opening control under visualization [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]; and VAAFT combined with fistula plug has been applied in horseshoe disease to augment closure after tract clearance [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. Despite these innovations, recurrence in anatomically asymmetric horseshoe configurations remains a persistent challenge.\u003c/p\u003e \u003cp\u003eThe underlying issue is anatomical mismatch: procedures prioritizing internal opening ligation may under-address circumferential spread, whereas procedures emphasizing tract clearance may inadequately secure the internal source of contamination. Single-modality treatment, therefore, risks addressing only one component of a dual-mechanism problem.\u003c/p\u003e \u003cp\u003eIn the present case, operative management was deliberately staged and anatomy-driven. On the left side, the tract involved the intersphincteric plane with meaningful sphincter traversal. A limited low-level fistulectomy was first performed to excise the superficial distal component and reduce peripheral tract burden. This was followed by seton drainage to control sepsis and allow tract stabilization. Definitive LIFT was subsequently undertaken to secure intersphincteric ligation while preserving external sphincter integrity [\u003cspan additionalcitationids=\"CR4\" citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. This layered sequence addressed superficial disease through excision, controlled active inflammation through staged drainage, and definitively eliminated the internal opening through sphincter-preserving ligation.\u003c/p\u003e \u003cp\u003eConversely, the right-sided tract was circumferentially extensive but relatively superficial, with limited sphincter involvement. VAAFT was therefore selected to maximize endoscopic tract visualization and clearance while minimizing wound burden [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. Recognizing the recurrence risk associated with single-session VAAFT in complex anatomy [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e], the interval created by the staged left-sided procedure was intentionally used to perform a second VAAFT session on the right. Rather than representing procedural failure, this repetition functioned as cumulative tract sterilization, targeting residual lateral extensions that commonly contribute to recurrence in horseshoe configurations.\u003c/p\u003e \u003cp\u003eTaken together, this side-specific and temporally sequenced approach reflects a strategic alignment of technique with tract depth and sphincter involvement. Superficial disease was excised, deep sphincter-crossing disease was ligated, and circumferential extensions were progressively cleared under endoscopic guidance. By integrating excision, staged drainage, ligation, and repeat endoscopic clearance within a structured timeline, the operative plan sought to mitigate both principal mechanisms of recurrence inherent to horseshoe trans-sphincteric fistula.\u003c/p\u003e \u003cp\u003eReports describing side-specific staged hybrid strategies tailored to asymmetric horseshoe trans-sphincteric fistula anatomy remain limited in the literature. This case suggests that aligning operative techniques with tract depth and sphincter involvement may help achieve effective tract eradication while preserving sphincter function.\u003c/p\u003e \u003cp\u003eHowever, the present report is limited by the single-case design and relatively short follow-up. Further studies with larger cohorts and longer follow-up are needed to determine the reproducibility and long-term outcomes of this anatomy-driven approach.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eHorseshoe trans-sphincteric fistula represents a dual-mechanism condition requiring both eradication of circumferential lateral extensions and durable control of the internal opening. Single-modality treatment may be insufficient to address this anatomical asymmetry. In this case, side-specific and staged sequencing aligned with operative technique, tract depth, and sphincter involvement, integrating excision, drainage, ligation, and repeat endoscopic clearance within a structured timeline. This anatomy-driven strategy may provide a rational framework for reducing recurrence risk while preserving sphincter function in complex horseshoe diseases.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cdiv class=\"DefinitionList\"\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eVAAFT\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eVideo-assisted anal fistula treatment\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eLIFT\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eLigation of the intersphincteric fistula tract\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003c/div\u003e"},{"header":"Declarations","content":" \u003cp\u003e \u003cstrong\u003eEthics approval and consent to participate\u003c/strong\u003e \u003cp\u003eThis study was approved by the Institutional Review Board of Chang Gung Memorial Hospital. The requirement for informed consent to participate was waived due to the retrospective nature of this case report.\u003c/p\u003e \u003c/p\u003e \u003cp\u003e \u003cstrong\u003eConsent for publication\u003c/strong\u003e \u003cp\u003eWritten informed consent was obtained from the patient for publication of this case report and any accompanying images.\u003c/p\u003e \u003c/p\u003e\u003cp\u003e \u003ch2\u003eCompeting interests\u003c/h2\u003e \u003cp\u003eThe authors declare that they have no competing interests.\u003c/p\u003e \u003c/p\u003e\u003ch2\u003eFunding\u003c/h2\u003e \u003cp\u003eThis research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.\u003c/p\u003e\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eTHC collected the clinical data and drafted the manuscript. SHH performed the surgical procedures, supervised the study, and revised the manuscript. All authors read and approved the final manuscript.\u003c/p\u003e\u003ch2\u003eAcknowledgement\u003c/h2\u003e\u003cp\u003eThe authors would like to thank the patient for consenting to share her clinical information for educational and scientific purposes.\u003c/p\u003e\u003ch2\u003eData Availability\u003c/h2\u003e\u003cp\u003eAll data relevant to this case report are included in this published article. Further information can be obtained from the corresponding author upon reasonable request.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eParks AG, Gordon PH, Hardcastle JD. A classification of fistula-in-ano. Br J Surg. 1976;63(1):1\u0026ndash;12.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eGaertner WB, Burgess PL, Davids JS, Lightner AL, Shogan BD, Sun MY, 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\u0026ndash;85.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRojanasakul A. LIFT procedure: a simplified technique for fistula-in-ano. Tech Coloproctol. 2009;13(3):237\u0026ndash;40.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSirikurnpiboon S. The risk factors for failure and recurrence of LIFT procedure for fistula in ano. Turk J Surg. 2023;39(1):27\u0026ndash;33.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFogle SE, Donahue CA, Beresneva O, Kuhnen AH, Kleiman DA, Breen EM, et al. Horseshoe Fistulae in the Age of LIFT. J Gastrointest Surg. 2022;26(5):1077\u0026ndash;83.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMeinero P, Mori L. Video-assisted anal fistula treatment (VAAFT): a novel sphincter-saving procedure for treating complex anal fistulas. Tech Coloproctol. 2011;15(4):417\u0026ndash;22.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTian Z, Li YL, Nan SJ, Xiu WC, Wang YQ. Video-assisted anal fistula treatment for complex anorectal fistulas in adults: a systematic review and meta-analysis. Tech Coloproctol. 2022;26(10):783\u0026ndash;95.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLa Torre M, Goglia M, Micarelli A, Fiori E, D'Andrea V, Grossi U, et al. Long term results of video-assisted anal fistula treatment for complex anal fistula: another shattered dream? Colorectal Dis. 2023;25(10):2017\u0026ndash;23.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBhat S, Xu W, Varghese C, Dubey N, Wells CI, Harmston C, et al. Efficacy of different surgical treatments for management of anal fistula: a network meta-analysis. Tech Coloproctol. 2023;27(10):827\u0026ndash;45.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRomaniszyn M, Walega PJ. Are two better than one? VALIFT: video-assisted ligation of the intersphincteric fistula tract-a combination of two minimally invasive techniques for treatment of transsphincteric perianal fistulas. Tech Coloproctol. 2019;23(3):273\u0026ndash;6.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMittal T, Ahuja A, Dey A, Malik VK, Manglik S, Nahata TB. Hybrid Video-Assisted Fistula Treatment With Seton Tie for Management of Fistula-in-Ano: Results of a Novel Technique. Dis Colon Rectum. 2026;69(2):218\u0026ndash;25.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZhang Y, Li F, Zhao T, Cao F, Zheng Y, Li A. Video-assisted anal fistula treatment combined with anal fistula plug for treatment of horseshoe anal fistula. J Int Med Res. 2021;49(1):300060520980525.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Anal fistula, Horseshoe fistula, Hybrid surgery, LIFT, VAAFT","lastPublishedDoi":"10.21203/rs.3.rs-9161050/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-9161050/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e \u003cp\u003eHorseshoe trans-sphincteric anal fistula is a complex variant of cryptoglandular fistula characterized by circumferential lateral extension within the deep postanal space and significant sphincter traversal, leading to a high risk of recurrence. Optimal surgical management remains challenging because procedures focusing solely on internal opening ligation or tract clearance may inadequately address this dual-mechanism anatomy.\u003c/p\u003e\u003ch2\u003eCase presentation\u003c/h2\u003e \u003cp\u003eWe report a 29-year-old woman with recurrent perianal abscesses and persistent purulent discharge for two years. Pelvic magnetic resonance imaging demonstrated a horseshoe trans-sphincteric fistula with bilateral posterior extensions across the deep postanal space. An anatomy-driven staged surgical strategy was performed. On the left side, limited fistulectomy with seton drainage was initially conducted for infection control, followed by ligation of the intersphincteric fistula tract (LIFT) during the second-stage operation. On the right side, video-assisted anal fistula treatment (VAAFT) was used for endoscopic tract visualization and clearance, with a second VAAFT session performed to enhance cumulative tract sterilization. Postoperative recovery was uneventful, and satisfactory wound healing without recurrence or continence impairment was observed at 3-month follow-up.\u003c/p\u003e\u003ch2\u003eConclusion\u003c/h2\u003e \u003cp\u003eSide-specific staged sequencing that aligns operative techniques with tract depth and sphincter involvement may represent a rational strategy for managing complex horseshoe trans-sphincteric fistulas while preserving sphincter function.\u003c/p\u003e","manuscriptTitle":"Staged hybrid sphincter-preserving surgery with Video-Assisted Anal Fistula Treatment (VAAFT) and Ligation of Intersphincteric Fistula Tract (LIFT) for complex horseshoe trans-sphincteric anal fistula: A case report","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-04-03 11:16:47","doi":"10.21203/rs.3.rs-9161050/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"9984b6fd-2bb0-4e2c-b27d-03063363a394","owner":[],"postedDate":"April 3rd, 2026","published":true,"recentEditorialEvents":[{"type":"decision","content":"Rejected","date":"2026-05-04T15:58:50+00:00","index":"","fulltext":""}],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2026-05-04T16:09:20+00:00","versionOfRecord":[],"versionCreatedAt":"2026-04-03 11:16:47","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-9161050","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-9161050","identity":"rs-9161050","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}