title: The level of termination of the dural sac by MRI and its clinical relevance in caudal epidural block in adults.
abstract: BACKGROUND
  Caudal epidural block (CEB) is a reliable and effective technique commonly used in pain practice. Having accurate knowledge of sacral anatomy and its anatomical variations is very important for avoiding complications, especially as may occur during dural puncture. This study was undertaken to delineate the anatomical features of the sacrococcygeal region relevant to dural sac (DS) puncture.
  
  
  METHODS
  We reviewed magnetic resonance (MRI) images of 1,000 adult patients to determine of the level of termination of the DS, the distance between the upper margin of the sacrococcygeal membrane and the DS, and the presence of incidental dural cystic lesions. Each sacral vertebra was divided into three equal portions (upper, middle, and lower thirds), was defined as a separate region.
  
  
  RESULTS
  The level (26.7% of all patients) of termination of the DS was most commonly the upper one-third of S2. The DS terminated below the 3rd sacral vertebra in 0.1% of all patients. No posterior sacral meningocele was seen, but 13 (1.3% of all patients) had a sacral Tarlov cyst. In three of 13 patients (23%), the Tarlov cysts terminated below 3rd sacral vertebra level (0.3% of all patients).
  
  
  CONCLUSIONS
  Knowledge of the level of termination of the DS, the distance between the upper margin of the sacrococcygeal membrane and the DS, and the presence of Tarlov cysts on MRI images of before CEB is very important and might decrease the risk of dural puncture.
authors.affiliation: Department of Anesthesiology, KSU School of Medicine, Kahramanmaras, Turkey.
authors.forename: N
authors.initials: N
authors.lastname: Senoglu
authors.forename: M
authors.initials: M
authors.lastname: Senoglu
authors.forename: F
authors.initials: F
authors.lastname: Ozkan
authors.forename: C
authors.initials: C
authors.lastname: Kesilmez
authors.forename: B
authors.initials: B
authors.lastname: Kızıldag
authors.forename: M
authors.initials: M
authors.lastname: Celik
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000704:Analysis of Variance; D000763:Anesthesia, Caudal / Q000379:methods*; D015331:Cohort Studies; D017352:Echo-Planar Imaging / Q000379:methods*; D004824:Epidural Space / Q000033:anatomy & histology; D005260:Female; D006801:Humans; D017116:Low Back Pain / Q000175:diagnosis / Q000628:therapy*; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D009407:Nerve Block / Q000379:methods; D059408:Pain Management / Q000379:methods; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012445:Sacrococcygeal Region; D012447:Sacrum / Q000033:anatomy & histology; D012585:Sciatica / Q000175:diagnosis / Q000628:therapy*; D055815:Young Adult