Distribution of injectates in the thoracic paravertebral space of the dog and cat: A cadaveric study

Background: Thoracic paravertebral block (TPVB) entails injecting a local anesthetic inside the thoracic space (TPVS). Loss of resistance to air injection (air-LOR) was first technique described in humans locate TPVS. To date, no study has investigated spread any substance after into TPVS using air-LOR nor cranial and caudal limits space.
 Aim: identify boundaries TPVS, determine whether is reliable for identification examine relationship between volume injectate its spread.
 Methods: After preliminary phase, thorax five cat dog cadavers accessed eviscerated. probing, polyurethane foam injected, borders were recorded maximum spread. Different volumes mixture new methylene blue ioversol injected localization with Tuohy needle fourteen six cadavers. Lateral radiographs vertebral column used document positioning, pattern extension. The these subjects then eviscerated observe record mixture.
 Results: Injecting dye localized by an technique, resulted multi-segmental often bilateral subpleural staining paravertebral, intercostal, dorsal mediastinal structures lateral most showed mixed cloud-like linear pattern, which could be predictor longitudinal dye. at level revealed anatomical communication cervical, axillar, lumbar regions.
 Conclusion: results axillary regions clinical interest brachial plexus intercostal nerve blocks setting.