{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,9]],"date-time":"2026-09-09T22:27:50Z","timestamp":1788992870960,"version":"build-2803163510"},"reference-count":22,"publisher":"Ovid Technologies (Wolters Kluwer Health)","issue":"6","license":[{"start":{"date-parts":[[2021,3,8]],"date-time":"2021-03-08T00:00:00Z","timestamp":1615161600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/academic.oup.com\/journals\/pages\/open_access\/funder_policies\/chorus\/standard_publication_model"}],"content-domain":{"domain":["lww.com","ovid.com"],"crossmark-restriction":true},"short-container-title":["Operative Surg.","ONSURG"],"published-print":{"date-parts":[[2021,5]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:sec>\n                    <jats:title>BACKGROUND<\/jats:title>\n                    <jats:p>Microvascular decompression (MVD) is the most effective treatment option for hemifacial spasm (HFS). However, deeply located forms of compression would require proper identification to allow for adequate decompression.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>OBJECTIVE<\/jats:title>\n                    <jats:p>To describe the usefulness of endoscopic visualization in one of the most challenging compression patterns in HFS, where the posterior inferior cerebellar artery (PICA) loop is severely indenting the brain stem at the proximal root exit zone of facial nerve along the pontomedullary sulcus.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>METHODS<\/jats:title>\n                    <jats:p>Radiological and operative data were checked for all patients in whom severe indentation of the brainstem by PICA at pontomedullary sulcus was recorded and endoscope-assisted MVD was performed. Clinical correlation and outcome were analyzed.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>RESULTS<\/jats:title>\n                    <jats:p>A total of 58 patients with HFS were identified with radiological and surgical evidence proving brainstem indentation at the VII transitional zone. In 31 patients, PICA was the offending vessel to the facial nerve. In 3 patients, the PICA loop was mobilized under visualization of a 45\u00b0 endoscope. A total of 31 patients had a mean follow-up duration of 52.1 mo. The mean duration between start of complaints and surgery was 7.2 yr. In the last follow-up, all patients had remarkable spasm improvement. A total of 5 patients had more than 90% disappearance of spasms and 26 patients experienced spasm-free outcome.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>CONCLUSION<\/jats:title>\n                    <jats:p>Although severe indentation of brain stem implies morphological damage, outcome after MVD is excellent. A 45\u00b0 endoscope is extremely helpful to identify compression down at the pontomedullary sulcus. Deeply located compression site can easily be missed with microscopic inspection alone.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1093\/ons\/opab008","type":"journal-article","created":{"date-parts":[[2021,3,11]],"date-time":"2021-03-11T02:49:12Z","timestamp":1615430952000},"page":"E399-E405","update-policy":"https:\/\/doi.org\/10.1097\/lww.0000000000001000","source":"Crossref","is-referenced-by-count":6,"title":["Outcome of Endoscope-Assisted Microvascular Decompression in Patients With Hemifacial Spasm Caused by Severe Indentation of the Brain Stem at the Pontomedullary Sulcus by the Posterior Inferior Cerebellar Artery"],"prefix":"10.1227","volume":"20","author":[{"given":"Ehab","family":"El Refaee","sequence":"first","affiliation":[{"name":"Department of Neurosurgery, University Medicine Greifswald, Greifswald, Germany"},{"name":"Department of Neurosurgery, Cairo University, Giza, Egypt"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Steffen","family":"Fleck","sequence":"additional","affiliation":[{"name":"Department of Neurosurgery, University Medicine Greifswald, Greifswald, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Marc","family":"Matthes","sequence":"additional","affiliation":[{"name":"Department of Neurosurgery, University Medicine Greifswald, Greifswald, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sascha","family":"Marx","sequence":"additional","affiliation":[{"name":"Department of Neurosurgery, University Medicine Greifswald, Greifswald, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Joerg","family":"Baldauf","sequence":"additional","affiliation":[{"name":"Department of Neurosurgery, University Medicine Greifswald, Greifswald, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Henry W S","family":"Schroeder","sequence":"additional","affiliation":[{"name":"Department of Neurosurgery, University Medicine Greifswald, Greifswald, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"276","published-online":{"date-parts":[[2021,6]]},"reference":[{"issue":"3","key":"bib1-20251027","doi-asserted-by":"crossref","first-page":"416","DOI":"10.3171\/JNS\/2008\/109\/9\/0416","article-title":"Neurovascular compression findings in hemifacial spasm","volume":"109","author":"Campos-Benitez","year":"2008","journal-title":"J Neurosurg"},{"issue":"1","key":"bib2-20251027","doi-asserted-by":"crossref","first-page":"121","DOI":"10.3171\/jns.2003.99.1.0121","article-title":"Microscopic measurement of the facial nerve root exit zone from central glial myelin to peripheral Schwann cell myelin","volume":"99","author":"Tomii","year":"2003","journal-title":"J Neurosurg"},{"issue":"2","key":"bib3-20251027","doi-asserted-by":"crossref","first-page":"94","DOI":"10.1016\/j.neuchi.2018.01.004","article-title":"The conflicting vessels in hemifacial spasm: literature review and anatomical-surgical implications","volume":"64","author":"Mercier","year":"2018","journal-title":"Neurochirurgie"},{"issue":"2","key":"bib4-20251027","doi-asserted-by":"crossref","first-page":"184","DOI":"10.1179\/1743132814Y.0000000424","article-title":"The mechanism of hemifacial spasm: a new understanding of the offending artery","volume":"37","author":"Dou","year":"2015","journal-title":"Neurol Res"},{"issue":"3","key":"bib5-20251027","doi-asserted-by":"crossref","first-page":"325","DOI":"10.1007\/s10143-010-0254-9","article-title":"Microvascular decompression for treating hemifacial spasm: lessons learned from a prospective study of 1,174 operations","volume":"33","author":"Hyun","year":"2010","journal-title":"Neurosurg Rev"},{"issue":"10","key":"bib6-20251027","doi-asserted-by":"crossref","first-page":"1019","DOI":"10.1007\/s00701-005-0583-6","article-title":"Microvascular decompression for primary hemifacial spasm. 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