A novel extraoral ultrasound-guided approach for mandibular nerve block in Rahmani sheep

BMC Vet Res. 2024 Feb 24;20(1):74. doi: 10.1186/s12917-024-03924-0.

Abstract

Background: Regional anesthesia is the favored choice in ruminant animals compared to general anesthesia, primarily due to its high safety margin and reduced demand for cost-intensive equipment in addition to its field applicability. Ultrasound-guided nerve block has gained significant attention in the field of veterinary medicine. This study utilized twenty-seven sheep of the native Rahmani breed to both demonstrate and evaluate the effectiveness of the ultrasound guided inferior alveolar nerve block technique.

Methods: The research comprised three phases: Phase 1 involved an anatomical examination of mandibles and sheep heads to locate the mandibular foramen and delineate the mandibular nerve course. Phase 2 included ultrasound-guided injection of methylene blue dye at specific sites along the mandibular nerve in cadaveric sheep heads. In Phase 3, clinical implementation of ultrasound-guided inferior alveolar nerve blocks was conducted in 27 live sheep, assessing efficacy, onset, and duration.

Results: Vertical extraoral ultrasound-guided nerve block was achieved successfully in 25 sheep (98%). A preliminary cadaveric study showed good distribution of the injectate at the mandibular nerve site. The mean onset time was 138 ± 18 s, and the mean duration time was 54 ± 4.1 min. Prominent analgesia of the ipsilateral mandible, medial surface of the cheek, and lateral border of the tongue was observed.

Conclusions: Ultrasound-guided mandibular nerve block holds promise as a technique for providing effective and safe anesthesia in sheep undergoing mandibular procedures.

Keywords: Extraoral; Mandibular nerve; Nerve block; Sheep; Ultrasound guided.

MeSH terms

  • Animals
  • Cadaver
  • Mandibular Nerve
  • Nerve Block* / veterinary
  • Sheep / surgery
  • Sheep Diseases*
  • Ultrasonography
  • Ultrasonography, Interventional / veterinary