Geometry of the fusiform excision for skin lesions

Geometry of the fusiform excision for skin lesions | 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article Geometry of the fusiform excision for skin lesions Roman Rouzier, Gregoire Rocher This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-55440/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 Objective The fusiform excision technique is commonly used by surgeons to remove round skin lesions to minimize "dog-ears" at the ends of the incision. We propose a geometric analysis to easily design the fusiform incision and consequently standardize the surgical procedure. Background The classic ellipse is formed by tracing 2 arcs of a circle on the skin. The arcs, which are symmetrical with respect to the midline axis separating them, intersect at their ends to form a convex shape and classically result in a 1:3 width-length ratio between the short and long axes of the ellipse. Methods Using basic geometry rules, namely Pythagorean theorem and the ratios of the angles of right triangles, we first calculated the ratio between the radius of the lesion and the radius of the arcs of the circle of the fusiform incision and then the distance between the center of the lesion and the intersection between the line perpendicular to the axis of the fusiform excision and the tangent to the arcs of the circle. Results The ratio between the radius of the lesion and the radius of the arcs of the circle of the fusiform incision is 5 and the distance between the center of the lesion and the intersection between the vertical axis and the tangent is 2.25 for a fusiform incision with a width-length ratio of 1:3. We then generalized the formulas. Conclusions Our approach provides an introduction to the geometry of dermatologic surgery to students in order to standardize the surgical procedure. Surgery General Surgery geometry rules namely Pythagorean theorem Figures Figure 1 Full Text 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. 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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-55440","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research article","associatedPublications":[],"authors":[{"id":1672386,"identity":"a832fc9c-275e-4f0f-926a-8c2958472dfd","order_by":0,"name":"Roman Rouzier","email":"","orcid":"","institution":"Ensemble hospitalier de l'Institut Curie / Department of surgery","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Roman","middleName":"","lastName":"Rouzier","suffix":""},{"id":1672387,"identity":"cee8fd27-be7d-41cc-9726-545383f112d5","order_by":1,"name":"Gregoire Rocher","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAABA0lEQVRIiWNgGAWjYNACAwjFDMRyIMaBB6RoMQZrSSDWMpCWxAYQC58W+ejDh198KLgnxyB9+ODngop76fPDDj8E2mInp9uAXYvhubQ0yxkGxcYMfGnJ0jPOFOduvJ1mANSSbGx2AIeWHh4zYx6DhMQGHh4zZt62hNyNsxNAWg4kbsOphf8bSEs9RMu/hHTD2ekf8GqR5+FhfgzUksAA1tKQkCAvnYPfFgMeNjPGGQYJhm08bMnSPMcSDDdI5xQcSDDA7Rf5HubHHz78SZDn52E++JmnJkFefnb65g8fKuzkcGkxOMDAJgFisCGJMMAjF6stDQzMH9BFRsEoGAWjYBSgAAD6w1cxyBh4NQAAAABJRU5ErkJggg==","orcid":"https://orcid.org/0000-0003-4728-914X","institution":"Institute Curie","correspondingAuthor":true,"submittingAuthor":false,"prefix":"","firstName":"Gregoire","middleName":"","lastName":"Rocher","suffix":""}],"badges":[],"createdAt":"2020-08-07 11:01:29","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-55440/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-55440/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":2063480,"identity":"37a0819c-2651-43b8-a187-092d9403213b","added_by":"auto","created_at":"2020-08-25 11:08:06","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":516933,"visible":true,"origin":"","legend":"Geometric approach to fusiform incision. \nThe grey disc (circle C1, center A) represents the lesion; B is the right extremity of the fusiform incision, C is the top of the lesion, O is the center of the circle C2, defining the superior limit of the fusiform incision (arc-of-circle of C2) and I is the intersection of the AC straight line and the tangent of circle C2 at B. r = AC is the radius of the lesion (Circle C1). R is the radius of circle C2, h is the distance between B and C, t is the distance between B and I, h’ is the distance between C and I. We also define several angles that are used in the formulas","description":"","filename":"Figure1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-55440/v1/Figure1.jpg"},{"id":13525885,"identity":"80099ab0-b36d-42b4-b0c8-34f5ca980549","added_by":"auto","created_at":"2021-09-17 00:50:14","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":415394,"visible":true,"origin":"","legend":"","description":"","filename":"FusiformfinalRouzieretal.pdf","url":"https://assets-eu.researchsquare.com/files/rs-55440/v1_covered.pdf"},{"id":2063482,"identity":"a66170b1-13e4-4712-abff-ef5ef91d90c1","added_by":"auto","created_at":"2020-08-25 11:08:10","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":815615,"visible":true,"origin":"","legend":"","description":"","filename":"FusiformfinalRouzieretal.pdf","url":"https://assets-eu.researchsquare.com/files/rs-55440/v1_stamped.pdf"},{"id":2063481,"identity":"fd164a5b-aa63-4ba8-9868-94c93823cfa7","added_by":"auto","created_at":"2020-08-25 11:08:06","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":773139,"visible":true,"origin":"","legend":"","description":"","filename":"FusiformfinalRouzieretal.pdf","url":"https://assets-eu.researchsquare.com/files/rs-55440/v1/FusiformfinalRouzieretal.pdf"}],"financialInterests":"","formattedTitle":"Geometry of the fusiform excision for skin lesions","fulltext":[{"header":"Full Text","content":"\u003cp\u003eThis preprint is available for \u003ca href='/article/rs-55440/latest.pdf' target='_blank'\u003edownload as a PDF\u003c/a\u003e.\u003c/p\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":true,"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":"geometry rules, namely Pythagorean theorem ","lastPublishedDoi":"10.21203/rs.3.rs-55440/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-55440/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eObjective\u003c/h2\u003e \u003cp\u003eThe fusiform excision technique is commonly used by surgeons to remove round skin lesions to minimize \"dog-ears\" at the ends of the incision. We propose a geometric analysis to easily design the fusiform incision and consequently standardize the surgical procedure.\u003c/p\u003e\u003ch2\u003eBackground\u003c/h2\u003e \u003cp\u003eThe classic ellipse is formed by tracing 2 arcs of a circle on the skin. The arcs, which are symmetrical with respect to the midline axis separating them, intersect at their ends to form a convex shape and classically result in a 1:3 width-length ratio between the short and long axes of the ellipse.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e \u003cp\u003eUsing basic geometry rules, namely Pythagorean theorem and the ratios of the angles of right triangles, we first calculated the ratio between the radius of the lesion and the radius of the arcs of the circle of the fusiform incision and then the distance between the center of the lesion and the intersection between the line perpendicular to the axis of the fusiform excision and the tangent to the arcs of the circle.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003eThe ratio between the radius of the lesion and the radius of the arcs of the circle of the fusiform incision is 5 and the distance between the center of the lesion and the intersection between the vertical axis and the tangent is 2.25 for a fusiform incision with a width-length ratio of 1:3. We then generalized the formulas.\u003c/p\u003e\u003ch2\u003eConclusions\u003c/h2\u003e \u003cp\u003eOur approach provides an introduction to the geometry of dermatologic surgery to students in order to standardize the surgical procedure.\u003c/p\u003e","manuscriptTitle":"Geometry of the fusiform excision for skin lesions","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2020-08-25 11:08:05","doi":"10.21203/rs.3.rs-55440/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":"5aa55151-364b-485c-af54-bb67583920e3","owner":[],"postedDate":"August 25th, 2020","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[{"id":356434,"name":"Surgery"},{"id":356435,"name":"General Surgery"}],"tags":[],"updatedAt":"2020-10-03T18:34:07+00:00","versionOfRecord":[],"versionCreatedAt":"2020-08-25 11:08:05","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-55440","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-55440","identity":"rs-55440","version":["v1"]},"buildId":"rHA-KDH7Qsr4HCuvH75dn","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}