Anatomical Compartment Involvement Predicts the Need for Rectal Resection in Deep Infiltrating Endometriosis: A Compartment-Based Analysis from Standardised Intraoperative Mapping at a High-Volume Tertiary Centre

Anatomical Compartment Involvement Predicts the Need for Rectal Resection in Deep Infiltrating Endometriosis: A Compartment-Based Analysis from Standardised Intraoperative Mapping at a High-Volume Tertiary Centre | 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 Research Article Anatomical Compartment Involvement Predicts the Need for Rectal Resection in Deep Infiltrating Endometriosis: A Compartment-Based Analysis from Standardised Intraoperative Mapping at a High-Volume Tertiary Centre Hungling Kwok, Yun Liu, Hongye Jiang, Hairong Zhang, Tian Li, and 1 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-9285792/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 5 You are reading this latest preprint version Abstract Purpose To quantify how anatomical compartment involvement—derived from standardised intraoperative mapping at 29 pelvic sites—predicts the need for segmental rectal resection in deep infiltrating endometriosis (DIE). We also characterise the causal pathway from compartment pattern through rectal resection to surgical outcomes. Patients and Methods: We conducted a retrospective cohort study of 398 women who underwent surgery for DIE with ovarian endometrioma at a high-volume tertiary centre (June 2008–June 2016) where all lesions were recorded on a fixed 29-site intraoperative form. Twenty-nine sites were mapped to five anatomical compartments: posterior, central/uterine, adnexal, lateral/parametrial, and anterior. The primary outcome was rectal resection (yes/no). Multivariable logistic regression with bootstrap internal validation assessed the ability of compartment pattern (with age and rASRM stage) to predict rectal resection; model discrimination was compared by area under the receiver-operating characteristic curve (AUC). Secondary outcomes (blood loss, operating time, length of stay [LOS]) were analysed with generalised linear models. Causal mediation analysis (bootstrap, 1 000 replicates) quantified the indirect effect of compartment involvement on LOS transmitted through rectal resection. Results Of 398 patients, 93 (23.4%) underwent segmental rectal resection. Posterior compartment involvement was present in 212 patients (53.3%) and was strongly associated with rectal resection (adjusted OR 4.28, 95% CI 1.87–10.8, p < 0.001). The primary logistic model (five compartments + age + rASRM stage) achieved an AUC of 0.819 (95% CI 0.765–0.873), with a bootstrap-corrected AUC of 0.804; Hosmer–Lemeshow goodness-of-fit p = 0.576. In the surgical-outcomes analysis, rectal resection independently increased blood loss by 42% (rate ratio 1.42, 95% CI 1.14–1.78, p = 0.003), prolonged operating time (exponentiated coefficient 1.36, 95% CI 1.24–1.50, p < 0.001), and lengthened LOS by 46% (rate ratio 1.46, 95% CI 1.27–1.69, p < 0.001). Causal mediation analysis showed that posterior compartment involvement increased LOS by a total of 5.3 days (95% CI 3.6–7.2), of which 2.1 days (95% CI 1.3–3.3; 40% of total effect) were mediated through rectal resection. Conclusion Compartment-based analysis of standardised intraoperative mapping identifies posterior compartment involvement as the dominant driver of rectal resection in DIE, with an AUC near 0.82. Rectal resection in turn mediates approximately 40% of the total effect of posterior involvement on hospital stay. These anatomically derived predictors translate directly to preoperative imaging targets, supporting compartment-based risk stratification and multidisciplinary operative planning. deep infiltrating endometriosis anatomical compartment rectal resection prediction model surgical outcomes mediation analysis intraoperative mapping Full Text Additional Declarations No competing interests reported. Supplementary Files SupplementaryFigureLegends.docx DIESupplementarytable.xlsx Cite Share Download PDF Status: Under Review Version 1 posted Reviewers invited by journal 05 Apr, 2026 Editor invited by journal 03 Apr, 2026 Editor assigned by journal 01 Apr, 2026 Submission checks completed at journal 01 Apr, 2026 First submitted to journal 31 Mar, 2026 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-9285792","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":617762489,"identity":"f3a2bcd3-f92e-4a14-9461-2579d738f32f","order_by":0,"name":"Hungling Kwok","email":"","orcid":"","institution":"The Seventh Affiliated Hospital of Sun Yat-sen University","correspondingAuthor":false,"prefix":"","firstName":"Hungling","middleName":"","lastName":"Kwok","suffix":""},{"id":617762490,"identity":"7c7ea9e1-e573-42b8-98b0-654e35b6dbff","order_by":1,"name":"Yun Liu","email":"","orcid":"","institution":"The Seventh Affiliated Hospital of Sun 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at a High-Volume Tertiary Centre\u003c/p\u003e","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":true,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":true,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"bmc-womens-health","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"bmwh","sideBox":"Learn more about [BMC Women's Health](http://bmcwomenshealth.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/bmwh/default.aspx","title":"BMC Women's Health","twitterHandle":"","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"deep infiltrating endometriosis, anatomical compartment, rectal resection, prediction model, surgical outcomes, mediation analysis, intraoperative mapping","lastPublishedDoi":"10.21203/rs.3.rs-9285792/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-9285792/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003ePurpose\u003c/h2\u003e \u003cp\u003eTo quantify how anatomical compartment involvement\u0026mdash;derived from standardised intraoperative mapping at 29 pelvic sites\u0026mdash;predicts the need for segmental rectal resection in deep infiltrating endometriosis (DIE). We also characterise the causal pathway from compartment pattern through rectal resection to surgical outcomes.\u003c/p\u003e\u003ch2\u003ePatients and Methods:\u003c/h2\u003e \u003cp\u003eWe conducted a retrospective cohort study of 398 women who underwent surgery for DIE with ovarian endometrioma at a high-volume tertiary centre (June 2008\u0026ndash;June 2016) where all lesions were recorded on a fixed 29-site intraoperative form. Twenty-nine sites were mapped to five anatomical compartments: posterior, central/uterine, adnexal, lateral/parametrial, and anterior. The primary outcome was rectal resection (yes/no). Multivariable logistic regression with bootstrap internal validation assessed the ability of compartment pattern (with age and rASRM stage) to predict rectal resection; model discrimination was compared by area under the receiver-operating characteristic curve (AUC). Secondary outcomes (blood loss, operating time, length of stay [LOS]) were analysed with generalised linear models. Causal mediation analysis (bootstrap, 1 000 replicates) quantified the indirect effect of compartment involvement on LOS transmitted through rectal resection.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003eOf 398 patients, 93 (23.4%) underwent segmental rectal resection. Posterior compartment involvement was present in 212 patients (53.3%) and was strongly associated with rectal resection (adjusted OR 4.28, 95% CI 1.87\u0026ndash;10.8, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001). The primary logistic model (five compartments\u0026thinsp;+\u0026thinsp;age\u0026thinsp;+\u0026thinsp;rASRM stage) achieved an AUC of 0.819 (95% CI 0.765\u0026ndash;0.873), with a bootstrap-corrected AUC of 0.804; Hosmer\u0026ndash;Lemeshow goodness-of-fit \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.576. In the surgical-outcomes analysis, rectal resection independently increased blood loss by 42% (rate ratio 1.42, 95% CI 1.14\u0026ndash;1.78, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;=\u0026thinsp;0.003), prolonged operating time (exponentiated coefficient 1.36, 95% CI 1.24\u0026ndash;1.50, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001), and lengthened LOS by 46% (rate ratio 1.46, 95% CI 1.27\u0026ndash;1.69, \u003cem\u003ep\u003c/em\u003e\u0026thinsp;\u0026lt;\u0026thinsp;0.001). Causal mediation analysis showed that posterior compartment involvement increased LOS by a total of 5.3 days (95% CI 3.6\u0026ndash;7.2), of which 2.1 days (95% CI 1.3\u0026ndash;3.3; 40% of total effect) were mediated through rectal resection.\u003c/p\u003e\u003ch2\u003eConclusion\u003c/h2\u003e \u003cp\u003eCompartment-based analysis of standardised intraoperative mapping identifies posterior compartment involvement as the dominant driver of rectal resection in DIE, with an AUC near 0.82. Rectal resection in turn mediates approximately 40% of the total effect of posterior involvement on hospital stay. These anatomically derived predictors translate directly to preoperative imaging targets, supporting compartment-based risk stratification and multidisciplinary operative planning.\u003c/p\u003e","manuscriptTitle":"Anatomical Compartment Involvement Predicts the Need for Rectal Resection in Deep Infiltrating Endometriosis: A Compartment-Based Analysis from Standardised Intraoperative Mapping at a High-Volume Tertiary Centre","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-04-09 11:06:47","doi":"10.21203/rs.3.rs-9285792/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"reviewersInvited","content":"","date":"2026-04-05T10:22:06+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2026-04-03T12:36:30+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2026-04-01T06:07:17+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2026-04-01T06:07:06+00:00","index":"","fulltext":""},{"type":"submitted","content":"BMC Women's Health","date":"2026-04-01T02:52:04+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"bmc-womens-health","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"bmwh","sideBox":"Learn more about [BMC Women's Health](http://bmcwomenshealth.biomedcentral.com/)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/bmwh/default.aspx","title":"BMC Women's Health","twitterHandle":"","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"97afd1da-c21e-49b0-b237-d413741449bf","owner":[],"postedDate":"April 9th, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2026-04-09T11:06:47+00:00","versionOfRecord":[],"versionCreatedAt":"2026-04-09 11:06:47","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-9285792","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-9285792","identity":"rs-9285792","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}