title: Vertebral artery loops in surgical perspective.
abstract: Vertebral artery loop is a congenital or acquired anomaly. Vertebral artery loops are incidentally diagnosed during evaluation of neck problems and trauma. We aimed to present the incidence of VA loops using magnetic resonance angiography in consecutive patients and discuss epidemiological data including the gender, age, location, signs and symptoms, treatment approaches and outcomes of VA loops via analyzing literature.
  
  
  
  In the first leg of our two-legged study, consecutive patients were evaluated using magnetic resonance angiography to detect any medial loop of vertebral arteries. The study period was from October 2015 to March 2016. In the second leg, academic databases about medial loop of vertebral artery were screened. Case reports, case series, abstracts and references of relevant literature were searched manually to avoid any missing cases.
  
  
  
  We evaluated 239 consecutive patients using magnetic resonance angiography. Twenty-one patients were excluded from the study due to inadequate image acquisition, aplastic vertebral artery and/or concomitant vertebral artery stenosis. Medial loop of V2 vertebral artery was observed in 13 patients (5.9 %): 9 with left, 2 with right and 2 with bilateral medial V2 loop. Patients with medial V2 loop were significantly older than patients with straight vertebral arteries (70.30 vs. 62.36, p = 0.028). In the literature analysis, VA loops were more commonly observed at V2 segment (90.5 %). Vertebral artery loops were mostly diagnosed at the 5th and 6th decades of life predominantly in females. The most common signs and symptoms were radiculopathy and/or neck pain, and signs and symptoms of vertebrobasilar insufficiency.
  
  
  
  Concise pre-operative evaluation of the vertebral arteries is essential to avoid the injury of undiagnosed VA loops during surgery, which might result in catastrophic circumstances. Further evaluation of the vertebral arteries using MR angiography is required, especially in elder age, before cervical spine surgeries.
authors.affiliation: Department of Orthopedic Surgery-Spine Center, University of California at San Francisco, Medical Center, 500 Parnassus Avenue MU320 West, San Francisco, CA, 94143-0728, USA. muratsakireksi@gmail.com.
authors.forename: Murat Şakir
authors.initials: MŞ
authors.lastname: Ekşi
authors.affiliation: Department of Neurosurgery, Bahçeşehir University Medical School, Istanbul, Turkey.
authors.forename: Zafer Orkun
authors.initials: ZO
authors.lastname: Toktaş
authors.affiliation: Department of Neurosurgery, Bahçeşehir University Medical School, Istanbul, Turkey.
authors.forename: Baran
authors.initials: B
authors.lastname: Yılmaz
authors.affiliation: Department of Radiology, Bahçeşehir University Medical School, Istanbul, Turkey.
authors.forename: Mustafa Kemal
authors.initials: MK
authors.lastname: Demir
authors.affiliation: Department of Physical Medicine and Rehabilitation, Antalya Ataturk State Hospital, Antalya, Turkey.
authors.forename: Emel Ece
authors.initials: EE
authors.lastname: Özcan-Ekşi
authors.affiliation: Department of Neurosurgery, Bahçeşehir University Medical School, Istanbul, Turkey.
authors.forename: Ahmed B
authors.initials: AB
authors.lastname: Bayoumi
authors.affiliation: Department of Anesthesiology, Medical Park Göztepe Hospital, Istanbul, Turkey.
authors.forename: Yasin
authors.initials: Y
authors.lastname: Yener
authors.affiliation: Department of Neurosurgery, Bahçeşehir University Medical School, Istanbul, Turkey.
authors.forename: Akın
authors.initials: A
authors.lastname: Akakın
authors.affiliation: Department of Neurosurgery, Bahçeşehir University Medical School, Istanbul, Turkey.
authors.forename: Deniz
authors.initials: D
authors.lastname: Konya
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D002574:Cervical Vertebrae / Q000601:surgery*; D005260:Female; D006801:Humans; D015994:Incidence; D018810:Magnetic Resonance Angiography; D008297:Male; D019300:Medical Errors / Q000517:prevention & control; D008875:Middle Aged; D019547:Neck Pain / Q000209:etiology; D011843:Radiculopathy / Q000209:etiology; D012189:Retrospective Studies; D012737:Sex Factors; D054079:Vascular Malformations / Q000150:complications / Q000000981:diagnostic imaging / Q000453:epidemiology; D057772:Vascular System Injuries / Q000517:prevention & control*; D014711:Vertebral Artery / Q000002:abnormalities* / Q000000981:diagnostic imaging; D014715:Vertebrobasilar Insufficiency / Q000209:etiology; D055815:Young Adult
keywords: Loop; Neck pain; Radiculopathy; Tortuous anomaly; Vertebral artery