title: Extraforaminal needle tip position reduces risk of intravascular injection in CT-fluoroscopic lumbar transforaminal epidural steroid injections.
abstract: BACKGROUND
  Lumbar transforaminal epidural steroid injection is a common and effective tool for managing lumbar radicular pain, although accidental intravascular injection can rarely result in paralysis. The purpose of this study is to determine the safest needle tip position for computed tomography (CT)-guided lumbar transforaminal epidural steroid injections as determined by incidence of intravascular injection.
  
  
  METHODS
  Three radiologists, in consensus, reviewed procedural imaging for consecutive CT-fluoroscopic lumbar transforaminal epidural steroid injections performed during a 16-month period. Intravascular injections were identified and categorized by needle tip position, vessel type injected, intravascular injection volume and procedural phase containing the intravascular injection. Pearson chi-square and logistic regression testing were used to assess differences between groups, as appropriate.
  
  
  RESULTS
  Intravascular injections occurred in 9% (52/606) of injections. The intravascular injection rate was significantly lower (P<0.001) for extraforaminal needle position (0%, 0/109) compared to junctional (8%, 27/319) and foraminal (14%, 25/178) needle tip positions. Of the intravascular injections, 4% (2/52) were likely arterial, 35% (18/52) were likely venous, and 62% (32/52) were indeterminate for vessel type injected. 46% (24/52) of intravascular injections were large volume, 33% (17/52) were small volume, and 21% (11/52) were trace volume. 56% (29/52) of intravascular injections occurred with the contrast trial dose, 29% (15/52) with the steroid/analgesic cocktail, and 15% (8/52) with both.
  
  
  CONCLUSIONS
  An extraforaminal needle position for CT-fluoroscopic lumbar transforaminal epidural steroid injections decreases the risk of intravascular injection and therefore may be safer than other needle tip positions.
authors.affiliation: Department of Radiology, University of Pittsburgh Medical Center, Pittsburgh, PA, USA.
authors.forename: Robinson K
authors.initials: RK
authors.lastname: Yu
authors.affiliation: Department of Radiology, University of Pittsburgh Medical Center, Pittsburgh, PA, USA.
authors.forename: Gerritt M
authors.initials: GM
authors.lastname: Lagemann
authors.affiliation: Department of Radiology, University of Pittsburgh Medical Center, Pittsburgh, PA, USA.
authors.forename: Anish
authors.initials: A
authors.lastname: Ghodadra
authors.affiliation: Department of Radiology, University of Pittsburgh Medical Center, Pittsburgh, PA, USA.
authors.forename: Vikas
authors.initials: V
authors.lastname: Agarwal
keywords: Transforaminal epidural steroid injection (TFESI); nerve root block (NRB)