Empiric transarterial embolization in angiographically negative lower gastrointestinal bleeding using vessel tracking and 3D navigation tools: report of 2 patients

Empiric transarterial embolization in angiographically negative lower gastrointestinal bleeding using vessel tracking and 3D navigation tools: report of 2 patients | 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 Empiric transarterial embolization in angiographically negative lower gastrointestinal bleeding using vessel tracking and 3D navigation tools: report of 2 patients Laurens Hermie, Luc Defreyne This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-2523648/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 20 Apr, 2023 Read the published version in CVIR Endovascular → Version 1 posted 3 You are reading this latest preprint version Abstract Background: Recently, an empiric Cone-beam Computed Tomography (CBCT)-guided transarterial embolization (TAE) technique has been investigated for lower gastrointestinal bleeding (LGIB). Although this empirical strategy reduced the rate of rebleeding in hemodynamically unstable patients compared to a ‘wait and see’ strategy, the specified technique is challenging and time-consuming. Case presentation: We present two methods to perform a prompt empiric TAE in LGIB when catheter angiography is negative. Based on the pre-procedural Computed Tomography Angiography bleeding site and using vessel detection and navigation software tools that are integrated in contemporary angiosuites, the culprit bleeding artery could be targeted with only one selective intraprocedural CBCT acquisition. Conclusion: The proposed techniques is promising to reduce procedure time and facilitate the implementation of empiric CBCT-guided TAE in clinical practice when angiography is negative. Gastrointestinal hemorrhage Lower gastrointestinal tract Embolization therapeutic Cone-beam computed tomography Arterial intervention Figures Figure 1 Figure 2 Introduction Empiric transarterial embolization (TAE) is a well-known strategy in interventional radiology (IR). In upper gastrointestinal bleeding, when primary endoscopic hemostasis has failed, endoscopy-directed empiric TAE of the left gastric or gastroduodenal artery is recommended if angiography is negative [ 1 , 2 ]. For lower gastrointestinal bleeding (LGIB), the anatomy of the mesenteric arteries is not amenable for such a deliberate non-targeted TAE. Recently, however, a super-selective empiric TAE technique has been investigated for LGIB when catheter angiography is negative. Here, guided by the positive pre-procedural Computed Tomography Angiography (CTA) the suspected culprit bleeding vessel was tracked down using repetitive intra-procedural Cone-beam Computed Tomography (CBCT) angiograms [ 3 ]. In hemodynamically unstable LGIB, this empiric TAE strategy reduced the rebleeding rate significantly compared to a conservative “wait-and-see” management. Though, the specified technique is challenging and time-consuming, which raises some reluctance for its application in clinical practice. In this report we present two methods to perform an empiric TAE in LGIB more easily using guidance tools that are integrated in contemporary angiosuites and that many of us already use for other intra-arterial treatments [ 4 ]. Patient 1 A 76y old female patient with a hemodynamically unstable LGIB and a positive CTA, was referred to our IR department for emergent TAE after initial hemodynamic resuscitation. Despite persistent red blood per anum (RBPA) and vasopressor requirements upon arrival, subsequent inferior mesenteric Digital Subtraction Angiography (DSA) and CBCT angiography (Artis Q Angiography System; Siemens Healthineers) failed to demonstrate active bleeding. Because of HD instability and risk of bleeding recurrence, an empirical TAE (illustrated in Fig. 1 ) was pursued. Therefore, based on the pre-procedural CTA contrast extravasation, the suspected bleeding diverticula was exactly defined on the inferior mesenteric CBCT angiogram. This we did by comparing the CTA multiplanar reconstruction (MRP) images with equivalent MPR images of the volumetric inferior mesenteric CBCT dataset. Then, the suspected bleeding vas rectum (closest to the identified bleeding site) could be manually designating as target in the 4D workplace. After also indicating the catheter tip as the starting position, the vessel detection software (syngo Embolization Guidance, Siemens Healthineers) semi-automatically identified the vascular pathway between the selected points. By virtually displaying the segmented 3D roadmap on fluoroscopy, a 2.7F microcatheter could be accurately navigated into the targeted vas rectum. Super-selective contrast injection did eventually show extravasation. After TAE of the targeted vas rectum using N-butyl cyanoacrylate (NBCA) glue, the patient had a clinically reassuring course with no recurrent bleeding or ischemic complications. Patient 2 38y old female patient with history of a lateral pancreaticojejunostomy after pancreatic trauma was admitted because of recurrent RBPA and one-time hematemesis. Initial upper gastrointestinal endoscopy and CTA could not identify an active bleeding focus. However, because of progressive hemodynamic instability, the patient was transferred the following day to our tertiary referral hospital. A new CTA now did reveal an active bleeding proximally in the Roux-en Y jejunal loop and the patient was immediately transferred to the angiosuite. Nevertheless, superior mesenteric DSA and CBCT failed to identify a bleeding focus. Regarding inaccessibility for endoscopy, empiric TAE (illustrated in Fig. 2 ) was considered the most appropriate strategy to prevent rebleeding. Using the CTA bleeding focus, the targeted jejunal bowel segment could be identified on comparable superior mesenteric CBCT MPR images. Then, the mucosal enhancement in the depicted jejunal bowel segment (as close as possible to the expected bleeding site) was highlighted as region of interest (ROI). Here, automatic vessel tree detection software (syngo Embolization Guidance, Siemens Healthineers) identified the arterial supply to the ROI. After visual review and affirmation of the vessel tree segmentation, a 2.0F microcatheter was advanced along the 3D roadmap to the target site. Then, a super-selective CBCT acquisition confirmed correct catheter placement trough the mucosal enhancement overlapping the previously decided ROI. Eventually, after additional manual contrast injection in the engaged artery revealed an extravasation anyway, the vascular supply was super-selectively embolized with NBCA glue. The patient recovered well after the procedure and no recurrent bleeding or complications occurred. Discussion Recent guidelines emphasize the importance of CTA and TAE in the management of active or HD unstable LGIB [ 5 – 7 ]. While a negative CTA usually precludes immediate intervention, a positive CTA is considered as an indication for emergency catheter angiography [ 8 ]. Then, if extravasation is demonstrated on angiography, targeted TAE can be undertaken with a high technical success rate [ 3 , 9 ]. However, in as many as half of the patients, the bleeding is not identified on angiography and thus no TAE is performed [ 3 , 10 ]. While guidelines already erroneously referred to an empirical strategy in LGIB, we demonstrated in both presented patients how one can still attempt a TAE in this unfavorable situation with high risk of rebleeding [ 6 ], In essence, after determination of the CTA bleeding site within the inferior or superior mesenteric vasculature, using modern vessel tracking and navigation tools one can target the suspected vessel tree with only a single selective CBCT acquisition. In contrast, an average of 4.0 CBCTs were required to perform a TAE in the original empiric CBCT-guided technique [ 3 ]. Although embolization in both patients was not strictly empirical, the extravasation appeared only after targeting the suspected vas rectum based on prior positive CTA. Therefore, empiric TAE would have been identically even without the appearance of extravasation. Conversely, it ultimately confirms the effectiveness of this empiric approach. Even if the vessel tracking software would identify multiple arterial supply to the ROI, this does not preclude an empirical embolization. To overcome ischemic complications, TAE of up to 3 vasa recta has been shown to be acceptable [ 9 ]. Nevertheless, it is imperative that the delineation of the ROI is performed precisely, and that adjacent non-targeted bowl segments are withhold from the designated area. Therefore, after engaging the targeted vasculature, an additional super-selective CBCT angiogram is still recommended to demonstrate precise overlap of the mucosal enhancement with the pre-procedural CTA the bleeding site. Conclusion The use of vessel detection and navigation software could be promising to reduce procedure time and facilitate the implementation of empirical TAE in clinical practice. However, safety and efficacy of this approach should be verified on a larger scale. Abbreviations CBCT = cone-beam computed tomography, CTA = computed tomography angiography, IR = interventional radiology, TAE = transarterial embolization, LGIB = lower gastrointestinal bleeding, MPR = multiplanar reconstruction, NBCA = N-butyl cyanoacrylate (NBCA), ROI = region of interest. Declarations Ethical Approval and Consent to participate: All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. For this type of study, formal consent is not required. Consent for publication: Informed consent was obtained from all individual participants included in the study. Availability of data and materials: Data sharing is not applicable to this article as no datasets were generated or analyzed during the current study. Competing interests: The authors declare that they have no competing interests. Funding: The authors have no funding to declare. Authors' contributions: Conceptualization (LH), Validation (LH, LD), Investigation (LH), Resources (LH), Visualisation (LH), Supervision (LH, LD) Acknowledgements: Not applicable References Loffroy R, Guillen K, Chevallier O (2021) Empiric Versus Targeted Transarterial Embolization for Upper Gastrointestinal Bleeding: No Need for Randomized Controlled Trial. AJR Am J Roentgenol 217(4):1015 Yu Q et al (2021) Empiric Transcatheter Embolization for Acute Arterial Upper Gastrointestinal Bleeding: A Meta-Analysis. AJR Am J Roentgenol 216(4):880–893 Hermie L et al (2021) Empiric cone-beam CT-guided embolization in acute lower gastrointestinal bleeding. Eur Radiol 31(4):2161–2172 Carrafiello G et al (2016) Usefulness of Cone-Beam Computed Tomography and Automatic Vessel Detection Software in Emergency Transarterial Embolization. Cardiovasc Intervent Radiol 39(4):530–537 Triantafyllou K et al (2021) Diagnosis and management of acute lower gastrointestinal bleeding: European Society of Gastrointestinal Endoscopy (ESGE) Guideline. Endoscopy 53(8):850–868 Oakland K et al (2019) Diagnosis and management of acute lower gastrointestinal bleeding: guidelines from the British Society of Gastroenterology. Gut 68(5):776–789 Strate LL, Gralnek IM (2016) ACG Clinical Guideline: Management of Patients With Acute Lower Gastrointestinal Bleeding. Am J Gastroenterol 111(4):459–474 Chan V et al (2015) Outcome following a negative CT Angiogram for gastrointestinal hemorrhage. Cardiovasc Intervent Radiol 38(2):329–335 Kwon JH et al (2019) Transcatheter arterial embolisation for acute lower gastrointestinal haemorrhage: a single-centre study. Eur Radiol 29(1):57–67 Maleux G et al (2009) Long-term outcome of transcatheter embolotherapy for acute lower gastrointestinal hemorrhage. Am J Gastroenterol 104(8):2042–2046 Cite Share Download PDF Status: Published Journal Publication published 20 Apr, 2023 Read the published version in CVIR Endovascular → Version 1 posted Reviewers agreed at journal 24 Feb, 2023 Editor assigned by journal 21 Feb, 2023 First submitted to journal 17 Feb, 2023 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-2523648","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":178702460,"identity":"d2114328-37cf-44d8-a4e0-eec6109fd6d5","order_by":0,"name":"Laurens Hermie","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAABBklEQVRIiWNgGAWjYBACAzjjAJBIYLCB8Q8QrSUNpoFYLQwMh4nQwn7G7MPHHXUMBsd7n254UHE+cX7/4mOPPzDckcOphSfHeObMM4cZ7M8cN7uRcOZ2YuOMZ+lAK58Z43ZYjjEzb9sBBoMbaWw3EttuJzZLnDGTOMBwOLEBlxb+N8bMf9uADrv/DKjl37nENonz30Ba6nFqkQDawtjGDLSFDail4UBiD38PG0hLAk6HSTwrZuxtO8xjcAbosIRjycYzJNjMJM4YPDPEZYt9f/Jmhp9tdXIGx4+x3fxRYyc7v//wM4mKijvyuGyBAR4EUwLkJANcCrEC/gMkKR8Fo2AUjILhDwDMgmDDW4k/UQAAAABJRU5ErkJggg==","orcid":"","institution":"University Hospital Ghent: Universitair Ziekenhuis Gent","correspondingAuthor":true,"submittingAuthor":false,"prefix":"","firstName":"Laurens","middleName":"","lastName":"Hermie","suffix":""},{"id":178702461,"identity":"4174fbed-6bfb-4908-a3c8-801e08f916c5","order_by":1,"name":"Luc Defreyne","email":"","orcid":"","institution":"University Hospital Ghent: Universitair Ziekenhuis Gent","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Luc","middleName":"","lastName":"Defreyne","suffix":""}],"badges":[],"createdAt":"2023-01-28 12:22:56","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-2523648/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-2523648/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1186/s42155-023-00372-z","type":"published","date":"2023-04-20T20:31:40+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":33588329,"identity":"a6e111f0-166d-461f-91e2-47d83e5b7a55","added_by":"auto","created_at":"2023-02-28 23:15:32","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":6555884,"visible":true,"origin":"","legend":"\u003cp\u003eEmpiric TAE approach in patient 1 (A) Pre-procedural arterial-phase CTA MPR images demonstrates an extravasation in sigmoid diverticula (white arrow). (B) No extravasation on subsequent inferior mesenteric DSA (C) Volumetric inferior mesenteric CBCT dataset displayed as MRP images in the 4D workplace. Although again no bleeding could be demonstrated, this allowed to identify the culprit diverticula (white asterisk) based on prior CTA. Then, the adjacent vas rectum (white arrowhead), presumably responsible for diverticular arterial supply and LGIB, was pointed as target for vessel detection. After also designating the catheter tip as proximal starting point, the vessel trajectory to the defined target could be identified semi-automatically (black arrowhead). (D) 3D roadmap (black arrowhead) virtually displayed on fluoroscopy for real-time guidance. After engaging the targeted vas rectum with a microcatheter, super-selective contrast injection ultimately reveals an extravasation (black asterisk).\u003c/p\u003e","description":"","filename":"Figure1..png","url":"https://assets-eu.researchsquare.com/files/rs-2523648/v1/2646f6b5ffddbdd568f85446.png"},{"id":33588330,"identity":"4cc6fe56-44f1-49cd-ae01-b95dade125ba","added_by":"auto","created_at":"2023-02-28 23:15:32","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":6999092,"visible":true,"origin":"","legend":"\u003cp\u003eEmpiric TAE approach in patient 2 (A) Pre-procedural arterial-phase CTA displays a contrast extravasation proximally in the Roux-en Y jejunal loop (white arrow). (B) No bleeding focus on subsequent superior mesenteric DSA. (C) Superior mesenteric CBCT MPR images in the 4D workplace. Here, using prior CTA bleeding focus, mucosal enhancement in the suspected culprit jejunal bowel segment was highlighted as ROI (black arrowhead) for automatic vessel detection. The resulting 3D vessel segmentation (white arrowhead) was used for catheter navigation. (D) A CBCT acquisition with super-selective contrast injection in the engaged artery confirmed correct targeting trough the mucosal enhancement (white arrow) overlapping the previously decided ROI (intended bleeding site). (E) Contrast injection after selecting the targeted artery eventually showed an extravasation (black asterisk).\u003c/p\u003e","description":"","filename":"Figure2..png","url":"https://assets-eu.researchsquare.com/files/rs-2523648/v1/601fda270e1f0c2362ef3b76.png"},{"id":44725390,"identity":"e9955fa2-4f9d-4e01-a632-d0463d0fdaa7","added_by":"auto","created_at":"2023-10-16 20:40:53","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":2891389,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-2523648/v1/ea791b7c-5e81-4616-b737-da0abd1c6368.pdf"}],"financialInterests":"","formattedTitle":"Empiric transarterial embolization in angiographically negative lower gastrointestinal bleeding using vessel tracking and 3D navigation tools: report of 2 patients","fulltext":[{"header":"Introduction","content":"\u003cp\u003eEmpiric transarterial embolization (TAE) is a well-known strategy in interventional radiology (IR). In upper gastrointestinal bleeding, when primary endoscopic hemostasis has failed, endoscopy-directed empiric TAE of the left gastric or gastroduodenal artery is recommended if angiography is negative [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. For lower gastrointestinal bleeding (LGIB), the anatomy of the mesenteric arteries is not amenable for such a deliberate non-targeted TAE. Recently, however, a super-selective empiric TAE technique has been investigated for LGIB when catheter angiography is negative. Here, guided by the positive pre-procedural Computed Tomography Angiography (CTA) the suspected culprit bleeding vessel was tracked down using repetitive intra-procedural Cone-beam Computed Tomography (CBCT) angiograms [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. In hemodynamically unstable LGIB, this empiric TAE strategy reduced the rebleeding rate significantly compared to a conservative \u0026ldquo;wait-and-see\u0026rdquo; management. Though, the specified technique is challenging and time-consuming, which raises some reluctance for its application in clinical practice. In this report we present two methods to perform an empiric TAE in LGIB more easily using guidance tools that are integrated in contemporary angiosuites and that many of us already use for other intra-arterial treatments [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e].\u003c/p\u003e"},{"header":"Patient 1","content":"\u003cp\u003eA 76y old female patient with a hemodynamically unstable LGIB and a positive CTA, was referred to our IR department for emergent TAE after initial hemodynamic resuscitation. Despite persistent red blood per anum (RBPA) and vasopressor requirements upon arrival, subsequent inferior mesenteric Digital Subtraction Angiography (DSA) and CBCT angiography (Artis Q Angiography System; Siemens Healthineers) failed to demonstrate active bleeding. Because of HD instability and risk of bleeding recurrence, an empirical TAE (illustrated in Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e) was pursued. Therefore, based on the pre-procedural CTA contrast extravasation, the suspected bleeding diverticula was exactly defined on the inferior mesenteric CBCT angiogram. This we did by comparing the CTA multiplanar reconstruction (MRP) images with equivalent MPR images of the volumetric inferior mesenteric CBCT dataset. Then, the suspected bleeding vas rectum (closest to the identified bleeding site) could be manually designating as target in the 4D workplace. After also indicating the catheter tip as the starting position, the vessel detection software (syngo Embolization Guidance, Siemens Healthineers) semi-automatically identified the vascular pathway between the selected points. By virtually displaying the segmented 3D roadmap on fluoroscopy, a 2.7F microcatheter could be accurately navigated into the targeted vas rectum. Super-selective contrast injection did eventually show extravasation. After TAE of the targeted vas rectum using N-butyl cyanoacrylate (NBCA) glue, the patient had a clinically reassuring course with no recurrent bleeding or ischemic complications.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e"},{"header":"Patient 2","content":"\u003cp\u003e38y old female patient with history of a lateral pancreaticojejunostomy after pancreatic trauma was admitted because of recurrent RBPA and one-time hematemesis. Initial upper gastrointestinal endoscopy and CTA could not identify an active bleeding focus. However, because of progressive hemodynamic instability, the patient was transferred the following day to our tertiary referral hospital. A new CTA now did reveal an active bleeding proximally in the Roux-en Y jejunal loop and the patient was immediately transferred to the angiosuite. Nevertheless, superior mesenteric DSA and CBCT failed to identify a bleeding focus. Regarding inaccessibility for endoscopy, empiric TAE (illustrated in Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e) was considered the most appropriate strategy to prevent rebleeding. Using the CTA bleeding focus, the targeted jejunal bowel segment could be identified on comparable superior mesenteric CBCT MPR images. Then, the mucosal enhancement in the depicted jejunal bowel segment (as close as possible to the expected bleeding site) was highlighted as region of interest (ROI). Here, automatic vessel tree detection software (syngo Embolization Guidance, Siemens Healthineers) identified the arterial supply to the ROI. After visual review and affirmation of the vessel tree segmentation, a 2.0F microcatheter was advanced along the 3D roadmap to the target site. Then, a super-selective CBCT acquisition confirmed correct catheter placement trough the mucosal enhancement overlapping the previously decided ROI. Eventually, after additional manual contrast injection in the engaged artery revealed an extravasation anyway, the vascular supply was super-selectively embolized with NBCA glue. The patient recovered well after the procedure and no recurrent bleeding or complications occurred.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eRecent guidelines emphasize the importance of CTA and TAE in the management of active or HD unstable LGIB [\u003cspan additionalcitationids=\"CR6\" citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. While a negative CTA usually precludes immediate intervention, a positive CTA is considered as an indication for emergency catheter angiography [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. Then, if extravasation is demonstrated on angiography, targeted TAE can be undertaken with a high technical success rate [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e, \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. However, in as many as half of the patients, the bleeding is not identified on angiography and thus no TAE is performed [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e, \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. While guidelines already erroneously referred to an empirical strategy in LGIB, we demonstrated in both presented patients how one can still attempt a TAE in this unfavorable situation with high risk of rebleeding [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e], In essence, after determination of the CTA bleeding site within the inferior or superior mesenteric vasculature, using modern vessel tracking and navigation tools one can target the suspected vessel tree with only a single selective CBCT acquisition. In contrast, an average of 4.0 CBCTs were required to perform a TAE in the original empiric CBCT-guided technique [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. Although embolization in both patients was not strictly empirical, the extravasation appeared only after targeting the suspected vas rectum based on prior positive CTA. Therefore, empiric TAE would have been identically even without the appearance of extravasation. Conversely, it ultimately confirms the effectiveness of this empiric approach. Even if the vessel tracking software would identify multiple arterial supply to the ROI, this does not preclude an empirical embolization. To overcome ischemic complications, TAE of up to 3 vasa recta has been shown to be acceptable [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. Nevertheless, it is imperative that the delineation of the ROI is performed precisely, and that adjacent non-targeted bowl segments are withhold from the designated area. Therefore, after engaging the targeted vasculature, an additional super-selective CBCT angiogram is still recommended to demonstrate precise overlap of the mucosal enhancement with the pre-procedural CTA the bleeding site.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eThe use of vessel detection and navigation software could be promising to reduce procedure time and facilitate the implementation of empirical TAE in clinical practice. However, safety and efficacy of this approach should be verified on a larger scale.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cp\u003eCBCT = cone-beam computed tomography, CTA = computed tomography angiography, IR = interventional radiology, TAE = transarterial embolization, LGIB = lower gastrointestinal bleeding, MPR = multiplanar reconstruction, NBCA = N-butyl cyanoacrylate (NBCA), ROI = region of interest.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cem\u003eEthical Approval and Consent to participate:\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eAll procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. For this type of study, formal consent is not required.\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eConsent for publication:\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eInformed consent was obtained from all individual participants included in the study.\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eAvailability of data and materials:\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eData sharing is not applicable to this article as no datasets were generated or analyzed during the current study.\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eCompeting interests:\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare that they have no competing interests.\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eFunding:\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eThe authors have no funding to declare.\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eAuthors\u0026apos; contributions:\u003c/em\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eConceptualization (LH), Validation (LH, LD), Investigation (LH), Resources (LH), Visualisation (LH), Supervision (LH, LD)\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eAcknowledgements:\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eLoffroy R, Guillen K, Chevallier O (2021) Empiric Versus Targeted Transarterial Embolization for Upper Gastrointestinal Bleeding: No Need for Randomized Controlled Trial. AJR Am J Roentgenol 217(4):1015\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eYu Q et al (2021) Empiric Transcatheter Embolization for Acute Arterial Upper Gastrointestinal Bleeding: A Meta-Analysis. AJR Am J Roentgenol 216(4):880\u0026ndash;893\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHermie L et al (2021) Empiric cone-beam CT-guided embolization in acute lower gastrointestinal bleeding. Eur Radiol 31(4):2161\u0026ndash;2172\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCarrafiello G et al (2016) Usefulness of Cone-Beam Computed Tomography and Automatic Vessel Detection Software in Emergency Transarterial Embolization. Cardiovasc Intervent Radiol 39(4):530\u0026ndash;537\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTriantafyllou K et al (2021) Diagnosis and management of acute lower gastrointestinal bleeding: European Society of Gastrointestinal Endoscopy (ESGE) Guideline. Endoscopy 53(8):850\u0026ndash;868\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eOakland K et al (2019) Diagnosis and management of acute lower gastrointestinal bleeding: guidelines from the British Society of Gastroenterology. Gut 68(5):776\u0026ndash;789\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eStrate LL, Gralnek IM (2016) ACG Clinical Guideline: Management of Patients With Acute Lower Gastrointestinal Bleeding. Am J Gastroenterol 111(4):459\u0026ndash;474\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eChan V et al (2015) Outcome following a negative CT Angiogram for gastrointestinal hemorrhage. Cardiovasc Intervent Radiol 38(2):329\u0026ndash;335\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKwon JH et al (2019) Transcatheter arterial embolisation for acute lower gastrointestinal haemorrhage: a single-centre study. Eur Radiol 29(1):57\u0026ndash;67\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMaleux G et al (2009) Long-term outcome of transcatheter embolotherapy for acute lower gastrointestinal hemorrhage. Am J Gastroenterol 104(8):2042\u0026ndash;2046\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"cvir-endovascular","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"cire","sideBox":"Learn more about [CVIR Endovascular](https://www.springer.com/journal/42155)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/cire/default.aspx","title":"CVIR Endovascular","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"Gastrointestinal hemorrhage, Lower gastrointestinal tract, Embolization, therapeutic, Cone-beam computed tomography, Arterial intervention ","lastPublishedDoi":"10.21203/rs.3.rs-2523648/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-2523648/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eBackground: Recently, an empiric Cone-beam Computed Tomography (CBCT)-guided transarterial embolization (TAE) technique has been investigated for lower gastrointestinal bleeding (LGIB). Although this empirical strategy reduced the rate of rebleeding in hemodynamically unstable patients compared to a ‘wait and see’ strategy, the specified technique is challenging and time-consuming.\u003c/p\u003e\n\u003cp\u003eCase presentation: We present two methods to perform a prompt empiric TAE in LGIB when catheter angiography is negative. Based on the pre-procedural Computed Tomography Angiography bleeding site and using vessel detection and navigation software tools that are integrated in contemporary angiosuites, the culprit bleeding artery could be targeted with only one selective intraprocedural CBCT acquisition.\u003c/p\u003e\n\u003cp\u003eConclusion: The proposed techniques is promising to reduce procedure time and facilitate the implementation of empiric CBCT-guided TAE in clinical practice when angiography is negative.\u003c/p\u003e","manuscriptTitle":"Empiric transarterial embolization in angiographically negative lower gastrointestinal bleeding using vessel tracking and 3D navigation tools: report of 2 patients","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2023-02-28 23:15:27","doi":"10.21203/rs.3.rs-2523648/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"reviewerAgreed","content":"","date":"2023-02-24T13:40:57+00:00","index":0,"fulltext":""},{"type":"editorAssigned","content":"","date":"2023-02-21T05:45:33+00:00","index":"","fulltext":""},{"type":"submitted","content":"CVIR Endovascular","date":"2023-02-17T05:00:43+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"cvir-endovascular","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"cire","sideBox":"Learn more about [CVIR Endovascular](https://www.springer.com/journal/42155)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/cire/default.aspx","title":"CVIR Endovascular","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"52308d07-4202-4b25-82eb-1ff7f4bcb736","owner":[],"postedDate":"February 28th, 2023","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2023-10-16T20:36:15+00:00","versionOfRecord":{"articleIdentity":"rs-2523648","link":"https://doi.org/10.1186/s42155-023-00372-z","journal":{"identity":"cvir-endovascular","isVorOnly":false,"title":"CVIR Endovascular"},"publishedOn":"2023-04-20 20:31:40","publishedOnDateReadable":"April 20th, 2023"},"versionCreatedAt":"2023-02-28 23:15:27","video":"","vorDoi":"10.1186/s42155-023-00372-z","vorDoiUrl":"https://doi.org/10.1186/s42155-023-00372-z","workflowStages":[]},"version":"v1","identity":"rs-2523648","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-2523648","identity":"rs-2523648","version":["v1"]},"buildId":"7rjqhiLT3MXkJMwkYKINL","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}