title: Three-dimensional computed tomography for difficult thoracic epidural needle placement.
abstract: BACKGROUND
  Thoracic epidural anesthesia is often used as a postoperative analgesic technique in thoracic surgery. However, the structure of the overlapping spinous processes, resulting in interlaminar space occlusion, often makes thoracic epidural needle placement difficult. With the development of multi-detector row spiral computed tomography (CT), three-dimensional (3D) thoracic images can be readily obtained, providing potentially useful clinical information. Therefore, we conducted this study to evaluate the correlation between difficult thoracic epidural needle placement and anatomical findings obtained by 3DCT image processing techniques.
  
  
  METHODS
  Seventy-eight patients were studied. The number of new skin puncture attempts required for successful catheter insertion into the epidural space and the time spent during the procedure were recorded for each patient. The patients were defined as a first-level success when the needle placement was successful at the spinal level initially attempted. The others were defined as a first-level failure. The number of occluded mid-thoracic interlaminar spaces and the existence of mid-thoracic supraspinous and interspinous ligament ossification on the 3DCT images were also evaluated.
  
  
  RESULTS
  The percentage of first-level success was 84.6%. The number of occluded mid-thoracic interlaminar spaces was significantly greater in the first-level failure than in the first-level success (P < 0.001). The incidence of ossification of the mid-thoracic supraspinous ligament was significantly more frequent in first-level failure than in the first-level success (P = 0.001). The number of attempts and the time spent during the procedure significantly correlated to the number of occluded mid-thoracic interlaminar spaces (P < 0.001).
  
  
  CONCLUSIONS
  Preoperative 3DCT imaging may be useful in predicting difficult thoracic epidural needle placement.
authors.affiliation: Department of Anesthesiology, Nagasaki University School of Medicine, 1-7-1 Sakamoto, Nagasaki-City, Nagasaki 852-8501, Japan. hiroaki_muramura@yahoo.co.jp
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Murata
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Sakai
authors.forename: Shinichi
authors.initials: S
authors.lastname: Goto
authors.forename: Koji
authors.initials: K
authors.lastname: Sumikawa
mesh_terms: D000368:Aged; D000767:Anesthesia, Epidural / Q000295:instrumentation* / Q000379:methods*; D004824:Epidural Space / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009339:Needles; D014057:Tomography, X-Ray Computed / Q000379:methods*