Article Text

Download PDFPDF
Transversus Abdominis Plane Block: A Cadaveric and Radiological Evaluation
  1. John G. McDonnell, M.B., F.C.A.R.C.S.I.,
  2. Brian D. O'Donnell, M.B., F.C.A.R.C.S.I.,
  3. Thomas Farrell, M.B., M.A., Ph.D.,
  4. Niall Gough, M.B., F.F.R.R.C.S.I.,
  5. David Tuite, M.B., F.F.R.R.C.S.I.,
  6. Camillus Power, M.D., F.C.A.R.C.S.I. and
  7. John G. Laffey, M.D., M.A., B.Sc., F.C.A.R.C.S.I.
  1. Department of Anaesthesia and Intensive Care Medicine, Galway University Hospitals, Tallaght, Dublin, Ireland
  2. Centre for Pain Research, National University of Ireland, Galway, Tallaght, Dublin, Ireland
  3. Department of Anaesthesia and Intensive Care Medicine, Adelaide and Meath Hospitals, Tallaght, Dublin, Ireland
  4. Department of Anatomy, Royal College of Surgeons in Ireland, Dublin, Ireland
  5. Department of Radiology, Galway University Hospitals, Tallaght, Dublin, Ireland
  6. Department of Radiology, AMNCH, Tallaght, Dublin, Ireland.


Background and Objectives: The abdominal wall is a significant source of pain after abdominal surgery. Anterior abdominal wall analgesia may assist in improving postoperative analgesia. We have recently described a novel approach to block the abdominal wall neural afferents via the bilateral lumbar triangles of Petit, which we have termed a transversus abdominis plane block. The clinical efficacy of the transversus abdominis plane block has recently been demonstrated in a randomized controlled clinical trial of adults undergoing abdominal surgery.

Methods: After institutional review board approval, anatomic studies were conducted to determine the deposition and spread of methylene blue injected into the transversus abdominis plane via the triangles of Petit. Computerized tomographic and magnetic resonance imaging studies were then conducted in volunteers to ascertain the deposition and time course of spread of solution within the transversus abdominis fascial plane in vivo.

Results: Cadaveric studies demonstrated that the injection of methylene blue via the triangle of Petit using the “double pop” technique results in reliable deposition into the transversus abdominis plane. In volunteers, the injection of local anesthetic and contrast produced a reliable sensory block, and demonstrated deposition throughout the transversus abdominis plane. The sensory block produced by lidocaine 0.5% extended from T7 to L1, and receded over 4 to 6 hours, and this finding was supported by magnetic resonance imaging studies that showed a gradual reduction in contrast in the transversus abdominis plane over time.

Conclusions: These findings define the anatomic characteristics of the transversus abdominis plane block, and underline the clinical potential of this novel block.

  • Anatomy
  • Triangle of Petit anatomy
  • Transversus abdominis plane analgesia
  • Postoperative regional analgesia
  • Neural plexus blockade

Statistics from

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.


  • This study was funded from Departmental resources.

    Dr. McDonnell and Dr. O'Donnell contributed equally to this article.

    The data in this article were presented in part at American Society of Anesthesiologists Annual Meeting, San Francisco, CA, August 16, 2004; the Delaney Medal Competition, College of Anaesthetists, Royal College of Surgeons in Ireland, Dublin, Ireland, March 2, 2006; and the Annual European Society of Regional Anaesthesia Congress, Monte Carlo, September 9, 2006.

    Reprints are not available.