Ultrasound-guided thoracic paravertebral block: cadaveric study in foxes (Vulpes vulpes)

Published:March 22, 2017DOI:



      To describe an ultrasound-guided thoracic paravertebral block in canidae.

      Study design

      Prospective, experimental, cadaveric study.


      Twelve thawed fox cadavers.


      A 15 MHz linear transducer was used to visualize the paravertebral space at the level of the fifth thoracic vertebrae. Iohexol (300 mg mL−1) at 0.2 mL kg−1 was injected into the right and left paravertebral spaces under ultrasound guidance using a Tuohy needle. The needle was advanced in a lateral to medial direction using an in-plane technique. Injections were performed by two operators, each performing 12 injections in six fox cadavers. A thoracic computed tomography was then performed and evaluated by a single operator. The following features were recorded: paravertebral contrast location (yes/no), length of contrast column (number of intercostal spaces), location of contrast relative to the fifth thoracic vertebrae (cranial/caudal/mixed), epidural contrast contamination (yes/no), pleural contrast contamination (yes/no) and mediastinal contrast contamination (yes/no).


      All injections resulted in paravertebral contrast distribution (24/24). The mean length of the contrast column was five intercostal spaces. Contrast spread was caudal to the injection site in 54% (7/24), cranial in 29% (4/24) and mixed in 17% (3/24). Pleural contamination was observed in 50% (12/24) of injections; 42% (10/24) and 4% (1/24) of the injections resulted in mediastinal and epidural contamination, respectively.

      Conclusions and clinical relevance

      Injection of the paravertebral space in canidae is possible using the technique described. Possible complications include epidural, pleural and mediastinal contamination. To establish clinical efficacy and safety of this technique, further studies are required.


      To read this article in full you will need to make a payment

      Purchase one-time access:

      Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online access
      One-time access price info
      • For academic or personal research use, select 'Academic and Personal'
      • For corporate R&D use, select 'Corporate R&D Professionals'


      Subscribe to Veterinary Anaesthesia and Analgesia
      Already a print subscriber? Claim online access
      Already an online subscriber? Sign in
      Institutional Access: Sign in to ScienceDirect


        • Cowie B.
        • McGlade D.
        • Ivanusic J.
        • et al.
        Ultrasound-guided thoracic paravertebral blockade: a cadaveric study.
        Anesth Analg. 2010; 110: 1735-1739
        • Karmakar M.K.
        • Ho A.M.
        Thoracic & lumbar paravertebral block.
        in: Hadzic A. Textbook of Regional Anaesthesia and Acute Pain Management. McGraw-Hill Medical, USA2007: 583-597
        • Komatsu T.
        • Sowa T.
        • Kino A.
        • et al.
        The importance of pleural integrity for effective and safe thoracic paravertebral block: a retrospective comparative study on postoperative pain control by paravertebral block.
        Interact Cardiovasc Thorac Surg. 2015; 20: 296-299
        • Krediet A.C.
        • Moayeri N.
        • van Geffen G.
        • et al.
        Different approaches to ultrasound-guided thoracic paravertebral block.
        Anesthesiology. 2015; 123: 459-474
        • Marhofer D.
        • Marhofer P.
        • Kettner S.C.
        • et al.
        Magnetic resonance imaging analysis of the spread of local anesthetic solution after ultrasound-guided lateral thoracic paravertebral blockade: a volunteer study.
        Anesthesiology. 2013; 118: 1106-1112
        • Naja M.Z.
        • Ziade M.F.
        • Rajab M.E.
        • et al.
        Varying anatomical injection points within the thoracic paravertebral space: effect on spread of solution and nerve blockade.
        Anaesthesia. 2004; 59: 459-463
        • Portela D.A.
        • Otero P.E.
        • Sclocco M.
        • et al.
        Anatomical and radiological study of the thoracic paravertebral space in dogs: iohexol distribution pattern and use of the nerve stimulator.
        Vet Anaesth Analg. 2012; 39: 398-408
        • Purcell-Jones G.
        • Pither C.E.
        • Justins D.M.
        Paravertebral somatic nerve block: a clinical, radiographic, and computed tomographic study in chronic pain patients.
        Anesth Analg. 1989; 68: 32-39
        • Specchi S.
        • D’Anjou M.A.
        • Carmel E.N.
        • et al.
        Computed tomographic characteristics of collateral venous pathways in dogs with caudal vena cava obstruction.
        Vet Radiol Ultrasound. 2014; 55: 531-538