{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,1]],"date-time":"2026-02-01T20:20:54Z","timestamp":1769977254283,"version":"3.49.0"},"reference-count":15,"publisher":"BMJ","issue":"4","content-domain":{"domain":["bmj.com"],"crossmark-restriction":true},"short-container-title":["Reg Anesth Pain Med"],"accepted":{"date-parts":[[2020,1,9]]},"published-print":{"date-parts":[[2020,4]]},"abstract":"\n Background and objectives<\/jats:title>\n We assume that intrafascicular spread of a solution can only occur if a large enough portion of the distal needle orifice is placed inside the fascicle. Our aim is to present and evaluate a mathematical model that can calculate the theoretical vulnerability of fascicles, analyzing the degree of occupancy of the needle orifice in fascicular tissue by performing simulations of multiple positions that a needle orifice can take inside a cross-sectional nerve area.<\/jats:p>\n <\/jats:sec>\n \n Methods<\/jats:title>\n We superimposed microscopic images of two routinely used nerve block needles (22-gauge, 15\u00b0 needle and 22-gauge, 30\u00b0 needle) over the microscopic images of cross-sections of four nerve types photographed at the same magnification. Fascicular tissue that was overlapped between 80% and 100% by a needle orifice was considered at risk to possible intrafascicular injection. The effect of three angular approaches was evaluated.<\/jats:p>\n <\/jats:sec>\n \n Results<\/jats:title>\n There were statistical differences between the vulnerability of fascicular tissue depending on nerve type, the bevel angle of the needle and the angle approach. Fascicular vulnerability was greater in nerve roots of the brachial plexus after using a 22-gauge 30\u00b0 needle, as was choosing a 45\u00b0 angle approach to the longitudinal axis of the nerve.<\/jats:p>\n <\/jats:sec>\n \n Conclusions<\/jats:title>\n Our results suggest that clinicians may want to consider needle insertion angle and bevel type as they perform peripheral nerve blocks. Furthermore, researchers may want to consider this mathematical model when estimating vulnerabilities of various nerves, needle types and angles of approach of needles to nerves.<\/jats:p>\n <\/jats:sec>","DOI":"10.1136\/rapm-2019-100784","type":"journal-article","created":{"date-parts":[[2020,1,28]],"date-time":"2020-01-28T05:04:27Z","timestamp":1580187867000},"page":"306-310","update-policy":"https:\/\/doi.org\/10.1136\/crossmarkpolicy","source":"Crossref","is-referenced-by-count":2,"title":["Vulnerability of different nerves to intrafascicular injection by different needle types and at different approach angles: a mathematical model"],"prefix":"10.1136","volume":"45","author":[{"given":"Margarita","family":"Sanrom\u00e1n-Junquera","sequence":"first","affiliation":[{"name":"Cardiac Arrhythmia Heart Failure (CAHF) Division, Abbott Medical Espa\u00f1a SA, Madrid, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Andre","family":"Boezaart","sequence":"additional","affiliation":[{"name":"The Alon P Winnie Research Institute, Gainesville, Florida, USA and Still Bay, Still Bay, South Africa"},{"name":"Division of Acute and Perioperative Pain Medicine, Department of Anesthesiology and Department of Orthopaedic Surgery, University of Florida College of Medicine, Gainesville, Florida, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yury","family":"Zasimovich","sequence":"additional","affiliation":[{"name":"Division of Acute and Perioperative Pain Medicine, Department of Anesthesiology, University of Florida College of Medicine, Gainesville, Florida, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Olga C","family":"Nin","sequence":"additional","affiliation":[{"name":"Division of Acute and Perioperative Pain Medicine, Department of Anesthesiology, University of Florida College of Medicine, Gainesville, Florida, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Xavier","family":"Sala-Blanch","sequence":"additional","affiliation":[{"name":"Human Anatomy and Embryology Unit, Faculty of Medicine, Universitat de Barcelona and Department of Anesthesiology Hospital Clinic, Barcelona, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jose","family":"De Andres","sequence":"additional","affiliation":[{"name":"Department of Anesthesiology, Critical Care and Pain Management General University Hospital, School of Medicine, University of Valencia, Valencia, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Miguel A","family":"Reina","sequence":"additional","affiliation":[{"name":"CEU San Pablo University School of Medicine and Department of Anesthesiology, Madrid-Montepr\u00edncipe University Hospital, Madrid, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"239","published-online":{"date-parts":[[2020,1,27]]},"reference":[{"key":"2025101111355428000_45.4.306.1","doi-asserted-by":"publisher","DOI":"10.1097\/AAP.0000000000000125"},{"key":"2025101111355428000_45.4.306.2","doi-asserted-by":"crossref","first-page":"221","DOI":"10.1097\/ALN.0000000000002352","article-title":"Intraneural injection: is the jury still out?","volume":"129","author":"Vlassakov","year":"2018","journal-title":"Anesthesiology"},{"key":"2025101111355428000_45.4.306.3","doi-asserted-by":"crossref","first-page":"1050","DOI":"10.1002\/ca.23253","article-title":"A novel marker for identifying and studying the membranes, barriers, and compartments surrounding peripheral nerves microscopically","volume":"31","author":"Reina","year":"2018","journal-title":"Clin Anat"},{"key":"2025101111355428000_45.4.306.4","doi-asserted-by":"crossref","first-page":"1007","DOI":"10.1097\/ALN.0000000000002647","article-title":"Deliberate intraneural injections: extrafascicular and intraperineurium, but no endoneural spread","volume":"130","author":"Reina","year":"2019","journal-title":"Anesthesiology"},{"key":"2025101111355428000_45.4.306.5","unstructured":"Pitas L . Digital image processing algorithms and applications. Hoboken, NJ: Wiley-Interscience, 2008: 1\u2013360."},{"key":"2025101111355428000_45.4.306.6","unstructured":"Hollander M , Wolfe DA , Chicken E . Nonparametric statistical methods (Wiley series in probability and statistics book 751). 3rd ed. Hoboken, NJ: Wiley & Sons, Inc, 2013: 1\u2013845."},{"key":"2025101111355428000_45.4.306.7","doi-asserted-by":"publisher","DOI":"10.1097\/AAP.0000000000000863"},{"key":"2025101111355428000_45.4.306.8","doi-asserted-by":"publisher","DOI":"10.1097\/AAP.0000000000000772"},{"key":"2025101111355428000_45.4.306.9","first-page":"91","volume-title":"Nerves and nerve injury: history, embryology, anatomy, imaging, and diagnostics","volume":"1","author":"Reina","year":"2015"},{"key":"2025101111355428000_45.4.306.10","doi-asserted-by":"crossref","first-page":"552","DOI":"10.1016\/j.redar.2013.06.006","article-title":"Electron microscopy of human peripheral nerves of clinical relevance to the practice of nerve blocks. A structural and ultrastructural review based on original experimental and laboratory data","volume":"60","author":"Reina","year":"2013","journal-title":"Rev Esp Anestesiol Reanim"},{"key":"2025101111355428000_45.4.306.11","unstructured":"Reina MA , Fern\u00e1ndez P , Mach\u00e9s F , et al . Microanatomy of the sacral plexus and nerves of the lower extremity. In: Karmakar MK , ed. Musculoskeletal ultrasound for regional anesthesia and pain medicine. 2nd ed. Hong Kong: The Chinese University of Hong Kong, 2016: 139\u201358."},{"key":"2025101111355428000_45.4.306.12","unstructured":"Reina MA , Fern\u00e1ndez P , Mach\u00e9s F , et al . Microanatomy of the brachial plexus and nerves of the upper extremity. In: Karmakar MK , ed. Musculoskeletal ultrasound for regional anesthesia and pain medicine. 2nd ed. Hong Kong: The Chinese University of Hong Kong, 2016: 81\u201396."},{"key":"2025101111355428000_45.4.306.13","doi-asserted-by":"crossref","first-page":"1295","DOI":"10.1007\/s12630-015-0468-y","article-title":"Histological confirmation of needle tip position during ultrasound-guided interscalene block: a randomized comparison between the intraplexus and the periplexus approach","volume":"62","author":"Szerb","year":"2015","journal-title":"Can J Anaesth"},{"key":"2025101111355428000_45.4.306.14","doi-asserted-by":"crossref","first-page":"776","DOI":"10.1016\/j.bja.2019.01.006","article-title":"Incidence of sub-perineural injection using a targeted intracluster supraclavicular ultrasound-guided approach in cadavers","volume":"122","author":"Retter","year":"2019","journal-title":"Br J Anaesth"},{"key":"2025101111355428000_45.4.306.15","doi-asserted-by":"crossref","first-page":"424","DOI":"10.1002\/ca.23028","article-title":"3D reconstruction of peripheral nerves from optical projection tomography images: a method for studying fascicular interconnections and intraneural plexuses","volume":"31","author":"Prats-Galino","year":"2018","journal-title":"Clin Anat"}],"container-title":["Regional Anesthesia & Pain Medicine"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/syndication.highwire.org\/content\/doi\/10.1136\/rapm-2019-100784","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T18:36:04Z","timestamp":1760207764000},"score":1,"resource":{"primary":{"URL":"https:\/\/rapm.bmj.com\/lookup\/doi\/10.1136\/rapm-2019-100784"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2020,1,27]]},"references-count":15,"journal-issue":{"issue":"4","published-online":{"date-parts":[[2020,3,19]]},"published-print":{"date-parts":[[2020,4]]}},"alternative-id":["10.1136\/rapm-2019-100784"],"URL":"https:\/\/doi.org\/10.1136\/rapm-2019-100784","relation":{},"ISSN":["1098-7339","1532-8651"],"issn-type":[{"value":"1098-7339","type":"print"},{"value":"1532-8651","type":"electronic"}],"subject":[],"published":{"date-parts":[[2020,1,27]]}}}