A cadaver study comparing two approaches for performing maxillary nerve block in dogs
Article first published online: 27 SEP 2012
© 2012 The Authors. Veterinary Anaesthesia and Analgesia. © 2012 Association of Veterinary Anaesthetists and the American College of Veterinary Anesthesiologists
Veterinary Anaesthesia and Analgesia
Volume 40, Issue 2, pages 212–219, March 2013
How to Cite
Viscasillas, J., Seymour, C. J. and Brodbelt, D. C. (2013), A cadaver study comparing two approaches for performing maxillary nerve block in dogs. Veterinary Anaesthesia and Analgesia, 40: 212–219. doi: 10.1111/j.1467-2995.2012.00781.x
- Issue published online: 13 FEB 2013
- Article first published online: 27 SEP 2012
- Received 21 January 2012; accepted 20 April 2012.
- infraorbital approach;
- local anaesthesia;
- maxillary nerve
Objective To compare the success by inexperienced anaesthetists of using a modified infraorbital approach to the maxillary nerve with the traditional percutaneous approach.
Study design Prospective, randomized, blinded controlled study.
Animals Heads from 37 euthanized Beagle and Beagle cross dogs.
Methods Four anaesthetists were recruited to perform two different approaches to block the maxillary nerve of the cadavers. The infraorbital (I) approach advanced an intravenous catheter along the infraorbital canal. Earlier measurements from scans of similar heads were used to assess suitable catheter size. The percutaneous (P) approach introduced a needle percutaneously just below the ventral border of the zygomatic arch. The side of the head where the technique was to be performed was randomized. A total volume of 0.5 mL methylene blue was injected in each approach. After completion of injections, head dissections were performed by an investigator unaware of the approach used and staining of the maxillary and pterygopalatine nerves was evaluated. Chi squared analysis examined the relationship between the methods (p < 0.05). Complications related to the techniques, such as intravascular/intraneural injection and location of the dye, were evaluated macroscopically.
Results Maxillary nerve staining >6 mm was found in 64.9% (I) versus 21.6% (P) attempts; staining <6 mm was found in 27% (I) versus 21.6% (P); and no nerve staining 8.1% (I) versus 56.8% (M). Pterygopalatine nerve staining was found in 70% (I) versus 21% (P). The infraorbital approach demonstrated significantly higher maxillary and pterygopalatine nerve staining compared to the percutaneous approach (p = 0.001 for both nerves). No evidence of intravascular/intraneural injections was found.
Conclusion and clinical relevance The infraorbital approach was more successful than the percutaneous approach when performed by inexperienced anaesthetists. No macroscopic complications were observed.